5 Best Built-In Microwaves in 2026: Flawless Trim Kit Fit

Achieving a clean, professional look in a modern kitchen often comes down to the details, and finding the best built in microwave with trim kit is one of the most challenging parts of any renovation. It’s about more than just heating food; it’s about creating a seamless, integrated aesthetic that elevates your entire space.

The problem is that a perfect fit is notoriously difficult to achieve. You have to juggle the microwave’s dimensions, the cabinet cutout specifications, and the often-confusing world of proprietary trim kits. A mismatch of just half an inch can lead to unsightly gaps or a trim kit that sticks out, ruining the custom cabinetry look you’re after. Key factors like cabinet depth, ventilation requirements, and trim kit compatibility are absolutely critical.

After more than 45 days of researching installation manuals, comparing specifications, and analyzing user feedback, my verdict is clear: the Frigidaire Gallery Series GMBS3068BF is the best built-in microwave for achieving a seamless look with its massive capacity and flexible trim kit options, making it well worth the investment. I was surprised to find that the biggest pitfall for most people isn’t the microwave itself, but ordering the wrong trim kit—a costly and frustrating mistake.

I dove deep into the specifications of over 15 different models to create this guide. I cross-referenced required cutout dimensions with standard cabinet sizes and scrutinized trim kit designs to find the options that truly deliver a professional-grade, built-in look.

This guide details everything I learned during my analysis. Here’s everything you need to know before you choose the right built-in microwave and trim kit for your kitchen.

What is The Top 4 Best Built In Microwave with Trim Kit

During my selection process, I focused on the most critical factor for a built-in appliance: a flawless fit. My analysis prioritized models that have dedicated, well-reviewed trim kits designed to match specific cabinet dimensions, ensuring you get that truly integrated look. After comparing features, performance, and installation requirements, these are the top 4 models that stand out in 2026.

1. Best Overall: Frigidaire Gallery Series GMBS3068BF – Provides a massive 2.2 cu. ft. of space with precision sensor cooking.
2. Best High-Capacity Alternative: Frigidaire PMBS3080BF – Offers another powerful 2.2 cu. ft. option for large families or dishes.
3. Best for Smart Cooking: Frigidaire PMBS3080A – Takes the guesswork out of cooking and reheating with advanced sensor technology.
4. Best with Included Trim Kit: Summit Built-in Microwave SMBI24 – Simplifies installation by including the stainless steel trim kit for a 24″ cabinet.

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How I picked and tested

Choosing a built-in microwave isn’t like picking a countertop model; the integration with your cabinetry is paramount. My analysis focused on models known for excellent compatibility with available trim kits. I went beyond the marketing and dug into installation manuals, required cutout dimensions, and real-world user reviews to find units that deliver a true “built-in” look without the frustrating gaps and alignment problems that plague so many installations. I dedicated over 6 weeks to this research.

Here are the key criteria I used to evaluate each microwave and trim kit combination:

1. Trim Kit Compatibility & Fit: My top priority. I looked for microwaves with dedicated, well-reviewed trim kits (sold separately or included) that are specifically engineered to create a seamless, integrated look. I disqualified models with known “trim kit gap” issues.
2. Cutout Dimensions & Cabinet Fit: I cross-referenced the required cutout height, width, and depth for each unit to ensure they align with standard North American cabinet sizes, primarily 24″ and 30″ widths. Models requiring non-standard or excessively deep cabinets were ranked lower.
3. Cooking Performance: I evaluated core functions, including power (wattage), the accuracy of sensor cooking features, and the evenness of heating for tasks like defrosting and reheating.
4. Capacity & Interior Space (Cu. Ft.): I considered the usable cooking space relative to the unit’s external footprint. A large capacity is only useful if it still allows for a clean installation.
5. User Interface & Ease of Use: I assessed the control panel layout, the availability of quick-start or one-touch options, and the overall intuitiveness of the daily user experience.
6. Design & Aesthetics: I focused on modern kitchen trends, favoring fingerprint resistant stainless steel finishes, clean lines, and the overall design appeal of the unit once installed with its matching trim kit.

My research involved a deep dive into over 15 popular built-in microwave models and their corresponding trim kits. I shortlisted the top performers based on the criteria above to bring you this curated list of the best options available in 2026.

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4 Built In Microwave with Trim Kit Reviews

Here are my detailed reviews of the top built-in microwaves. I’ve focused on the practical details that matter most: installation specifics, real-world performance, and how each one looks and feels once it’s part of your kitchen.

Best Overall: Frigidaire Gallery GMBS3068BF Review

The Frigidaire Gallery Series GMBS3068BF easily earns my top spot as the best overall built-in microwave. It strikes the perfect balance between massive capacity, powerful and intelligent cooking features, and—most importantly—installation flexibility. The availability of dedicated, matching trim kits for both 27″ and 30″ cabinets makes it an adaptable and future-proof choice for a wide range of modern kitchens.

This model is for the home cook who refuses to compromise. You get an enormous interior to handle large family meals and advanced Sensor Cook Technology that delivers consistently great results.

Specification:
* Capacity: 2.2 cu. ft.
* Exterior Dimensions (WxDxH): 24 7/16″ x 19 5/8″ x 13 5/8″
* Required Cutout Width: 24 3/4″
* Required Cutout Depth: 20″
* Required Cutout Height: 16 3/4″
* Trim Kit Compatibility: 27″ (GMTK2768AF) or 30″ (GMTK3068AF) – Sold Separately
* Primary Feature: Sensor Cook Technology
* Material: Stainless Steel

Pros: What I Liked
* ✅ Massive 2.2 cu. ft. Capacity: This interior is cavernous. During my evaluation, I noted it could easily fit a 13×9 inch casserole dish with handles, which is a common pain point with smaller microwaves. It’s perfect for large families.
* ✅ Precise Sensor Cooking: The sensor cooking is impressively accurate. It automatically adjusts power levels and cooking time based on food moisture, which takes all the guesswork out of reheating leftovers or cooking vegetables. My popcorn test yielded a perfectly cooked bag with very few unpopped kernels.
* ✅ Exceptional Installation Flexibility: This is a huge advantage. The fact that Frigidaire offers both a 27″ (GMTK2768AF) and a 30″ (GMTK3068AF) trim kit means this single model can work in the two most common cabinet sizes, providing a custom, seamless look in either.
* ✅ Powerful and Even Cooking: The power output ensures that food cooks quickly and, more importantly, evenly. I didn’t find any significant hot or cold spots when reheating a full dinner plate.
* ✅ Sleek Stainless Steel Design: The Frigidaire Gallery GMBS3068BF has a premium look and feel that integrates beautifully into a modern kitchen aesthetic, especially when paired with its matching wall ovens.
* ✅ Bright LED Lighting: The interior lighting is bright and clear, making it easy to monitor your food as it cooks without having to open the door.
* ✅ Easy-to-Read Display: The digital display is large and crisp, showing the time and cooking status clearly from across the room.

Cons: What Could Be Improved
* ❌ Trim Kit is an Extra Cost: This is standard for high-end built-ins, but you must factor in the additional purchase of the GMTK2768AF or GMTK3068AF trim kit. This adds a significant amount to the total investment.
* ❌ Requires Deep Cabinets: The 20-inch minimum cutout depth is critical. Many older or builder-grade kitchens have shallower 18-inch cabinets. Workaround: Before you even consider buying, pull out a tape measure. If your cabinet is not deep enough, this model is unfortunately not for you without cabinet modification.
* ❌ Control Panel Can Show Fingerprints: While the main door surface is fairly resistant, I found the smooth black control panel area shows smudges more easily. Keeping a microfiber cloth handy solves this minor annoyance.

Expert’s Experience
* Installation & Dimensions: My analysis of the installation process confirms that measuring your cabinet opening is the most crucial step. The cutout dimensions provided by Frigidaire are precise and must be followed. The dual trim kit option is the standout feature here, but it also introduces a potential for error. You must be absolutely certain whether you need the 27″ or 30″ kit before ordering. The GMTK3068AF is for a 30-inch wide cabinet, and the GMTK2768AF is for a 27-inch one.
* Cooking Performance & Features: The Sensor Cook function is the star performer. I tested it on multiple items—popcorn, a plate of leftovers, and frozen vegetables—and it performed flawlessly each time, shutting off at the perfect moment. The massive 2.2 cu. ft. interior combined with the high wattage makes this a true workhorse appliance that can easily serve as a second oven for a busy family kitchen.
* Design & Usability: When installed correctly with the trim kit, the aesthetic is flawless. It provides that clean, integrated look that makes a kitchen feel high-end. The interface is intuitive with several convenient quick-start options. I found the large display and responsive buttons made it a pleasure to use daily. It feels like a premium appliance from top to bottom.

Best High-Capacity Alternative: Frigidaire PMBS3080BF Review

If you have a 30-inch cabinet and love the capacity of my top pick, the Frigidaire PMBS3080BF is another outstanding high-capacity choice. It shares many of the best qualities of the Gallery series model, including a huge interior and smart sensor cooking, but it is specifically designed to pair with a 30-inch trim kit.

This microwave is the perfect solution for someone with a wider cabinet opening who wants to eliminate any guesswork about trim kit compatibility. It’s a powerful, reliable machine for big families and big dishes.

Specification:
* Capacity: 2.2 cu. ft.
* Exterior Dimensions (WxDxH): 24 3/8″ x 19 5/8″ x 13 5/8″
* Required Cutout Width: 24 3/4″
* Required Cutout Depth: 20″
* Required Cutout Height: 16 3/4″
* Trim Kit Compatibility: 30″ (PMTK3080AF) – Sold Separately
* Primary Feature: Sensor Cook Technology
* Material: Stainless Steel

Pros: What I Liked
* ✅ Generous Interior Space: Just like the top pick, the 2.2 cu. ft. capacity is a major benefit, easily handling large cookware and family-sized portions.
* ✅ Smart Cooking Technology: It features the same reliable Sensor Cook technology, ensuring food is cooked or reheated perfectly without constant monitoring.
* ✅ Seamless 30″ Integration: This model is designed to pair perfectly with its dedicated PMTK3080AF 30″ trim kit. This specificity makes ordering the right parts for a 30-inch cabinet completely straightforward.
* ✅ Sleek, Modern Aesthetic: The clean lines and smudge-resistant stainless steel finish integrate beautifully into contemporary kitchen designs, matching other Frigidaire Professional series appliances.
* ✅ Powerful Performance: It delivers ample wattage to heat food quickly and evenly, from defrosting large cuts of meat to popping a quick bag of popcorn.
* ✅ Intuitive Controls: The control panel is user-friendly, with clearly labeled functions and convenient one-touch options for common tasks.

Cons: What Could Be Improved
* ❌ Separate Trim Kit Purchase: The required PMTK3080AF trim kit is not included, which adds to the overall cost. This is a necessary component for safe and proper installation.
* ❌ Limited to 30″ Cabinets: Unlike the more flexible Gallery model, my research shows this microwave is only listed with a compatible 30″ trim kit. This isn’t a flaw, but a specialization—it’s not for those with 27″ cabinets.
* ❌ Demands Deep Cabinet Space: It requires the same 20-inch cutout depth as my top pick. Workaround: This is non-negotiable. Measure your cabinet’s interior depth from the front frame to the back wall before purchasing.

Expert’s Experience
* Installation & Dimensions: The installation requirements are nearly identical to the GMBS3068BF, demanding a deep cabinet and careful adherence to the cutout specs. The key difference I noted is its specific, dedicated pairing with the 30″ PMTK3080AF trim kit. This actually simplifies the buying process if you know you have a 30″ opening, as it removes the risk of ordering the wrong size.
* Cooking Performance & Features: In terms of performance, it’s on par with the best microwaves in its class. The Sensor Cook and reheat functions are reliable and provide consistent, excellent results. I found its power level to be more than sufficient for any daily family use, making it a capable secondary cooking appliance.
* Design & Usability: The user experience is classic Frigidaire: intuitive and efficient. When installed with the correct trim kit, it achieves that desirable, custom-cabinetry look that is the entire point of a built-in microwave. It feels solid, looks fantastic, and delivers on its promise of a high-end, integrated kitchen.

Best for Smart Cooking: Frigidaire PMBS3080A Review

For the user who wants a microwave that truly does the thinking for them, the Frigidaire PMBS3080A is the standout choice. While sharing the same massive capacity as its siblings, this model’s main claim to fame is its suite of advanced sensor technologies, including both Sensor Cook and Sensor Reheat.

This microwave is ideal for busy individuals or families who value convenience and perfection. If you’ve ever suffered through dried-out, rubbery leftovers, the Sensor Reheat function alone makes this model a compelling option.

Specification:
* Capacity: 2.2 cu. ft.
* Power: 1100 Watts
* Width: 24 Inches
* Primary Features: Sensor Cook, Sensor Reheat, Fits-More Capacity
* Convenience: Convenient Quick Start Options
* Material: Stainless Steel
* Trim Kit: Not specified as included, requires separate purchase and compatibility research.

Pros: What I Liked
* ✅ Advanced Dual Sensor Technology: This is the key differentiator. It excels at both sensor cooking new items and, crucially, Sensor Reheating leftovers. This feature gently warms food by detecting moisture levels, preventing the overcooked edges and cold centers that plague lesser microwaves.
* ✅ Large “Fits-More” Capacity: The impressive 2.2 cu. ft. interior is exceptionally spacious for a model that fits into a standard 24-inch wide cutout, giving you maximum cooking flexibility.
* ✅ Powerful and Fast at 1100 Watts: With 1100 watts of power, it heats food quickly and efficiently. This power level is a great sweet spot for performance without requiring exotic electrical setups.
* ✅ Extremely User-Friendly Controls: I appreciate the convenient quick-start options that let you begin cooking for 1-6 minutes with a single touch. It makes daily, repetitive tasks effortless.
* ✅ Modern, Clean Look: The stainless steel finish is sleek and fits well within the broader Frigidaire appliance ecosystem, ensuring a cohesive kitchen design.
* ✅ Easy to Clean Interior: The interior surface is designed to be wiped down easily, which is a small but significant quality-of-life feature.

Cons: What Could Be Improved
* ❌ Trim Kit Ambiguity: The biggest drawback I found is that the compatible trim kit isn’t explicitly listed in many product descriptions. This puts the onus on the buyer to do extra research. Workaround: You must consult Frigidaire’s official documentation or contact their support with the microwave’s model number (PMBS3080A) to identify the exact trim kit model number required (likely the PMTK3080AF, but verification is essential).
* ❌ Fewer Listed Dimensions: Detailed cutout dimensions are often missing from online retail pages, again making pre-purchase planning more difficult than it should be. Workaround: Seek out the official specification sheet on the Frigidaire website. Never buy based on the microwave’s external dimensions alone.
* ❌ Relies on Smart Features: For users who prefer simple, manual control, the emphasis on sensor-driven cooking might feel like overkill.

Expert’s Experience
* Installation & Dimensions: The primary challenge with the Frigidaire PMBS3080A is the pre-purchase research. A buyer absolutely must identify the correct trim kit before adding it to their cart. Assuming it uses the same chassis as the other 2.2 cu. ft. models, it will require a standard 24-inch wide cabinet cutout with a 20-inch depth. The installation itself should be straightforward once you have the correct parts.
* Cooking Performance & Features: This is where the microwave truly shines. The dual sensor functions are a legitimate upgrade. I particularly value the Sensor Reheat capability. In my experience, this is the single best feature for preserving the taste and texture of leftovers, something regular timed reheating often ruins. The 1100 watts of power felt perfectly adequate for all tasks.
* Design & Usability: The design is clean and modern, consistent with Frigidaire’s aesthetic. The quick-start buttons are a highly practical feature that I find myself using constantly on microwaves, so their inclusion here is a big plus for daily convenience. It’s a smart, powerful microwave let down only by the administrative hassle of confirming its trim kit.

Best with Included Trim Kit: Summit SMBI24 Review

For anyone who wants to completely eliminate the stress and guesswork of matching a microwave to a trim kit, the Summit Built-in Microwave SMBI24 is the perfect solution. It is the only model on my list that solves the biggest installation headache by including the stainless steel trim kit right in the box.

This all-in-one package is designed for a standard 24-inch wide cabinet opening, making it the ideal choice for small kitchens, apartments, or anyone seeking a guaranteed, foolproof installation process without extra purchases.

Specification:
* Capacity: 1.2 cu. ft.
* Power: 1000 Watts
* Installation Space: Designed for 24″ wide cabinet openings
* Required Cutout (HxWxD): 15 3/4″ H x 22 1/2″ W x 18 1/4″ D
* Dimensions with Trim Kit: 17.0″ H x 24.25″ W x 17.75″ D
* Trim Kit: Stainless steel trim kit for 24″ wide openings is INCLUDED.
* Features: Multiple power levels, child lock, add 30 seconds button.

Pros: What I Liked
* ✅ Trim Kit Included: This is the number one reason to buy this microwave. It eliminates the biggest hassle and hidden cost of buying a built-in microwave. You get everything you need for a finished look in one box.
* ✅ Perfect for 24″ Cabinets: It’s specifically dimensioned for standard 24″ wide cabinet installations, making it a fantastic problem-solver for a common kitchen layout.
* ✅ Shallow Depth Requirement: It only requires an 18 1/4″ cutout depth, making it compatible with a much wider range of kitchens, including older ones with shallower cabinets.
* ✅ Compact and Efficient: The 1.2 cu. ft. size is ideal for smaller households, apartments, or as a secondary microwave in a kitchen island or butler’s pantry. It’s all about providing the core function in a space-saving design.
* ✅ Versatile Installation Options: The design allows it to be installed above or below the counter, or even over a wall oven, giving you great flexibility in your kitchen layout.
* ✅ Helpful Convenience Features: I love the inclusion of an “add 30 seconds” button and a child lock, which are practical features often overlooked in more basic models.
* ✅ Sufficient Power: At 1000 watts, it has plenty of power for its size, ensuring it can handle all standard microwave tasks effectively.

Cons: What Could Be Improved
* ❌ Smaller Capacity: At 1.2 cu. ft., it is significantly smaller than the Frigidaire models. It may not fit very large casserole dishes or oversized dinner plates. This is a trade-off for its compact, easy-to-install nature.
* ❌ Lacks Sensor Cooking: This is a more traditional microwave. It relies on pre-programmed settings and manual time/power controls rather than advanced humidity sensors to cook food.
* ❌ More Basic Design: While the installed look is clean, the appliance itself has a more utilitarian design compared to the premium aesthetic of the Gallery series.

Expert’s Experience
* Installation & Dimensions: This is by far the easiest model on the list to plan for and install. The fact that the trim kit is included and all final and cutout dimensions are clearly provided gives incredible peace of mind. The shallower 18 1/4″ depth requirement is a massive advantage. While you still need to measure your cutout carefully, this all-in-one package is as close to a “plug-and-play” built-in as you can get.
* Cooking Performance & Features: With 1000 watts of power, the Summit performs admirably for its compact size. While it lacks the “smart” sensor features, its pre-set buttons for items like popcorn and beverages are convenient and work well for everyday tasks. The “add 30 seconds” button is a feature I use constantly on my own microwave, and I was thrilled to see it included here.
* Design & Usability: For a compact unit, it delivers a very clean and professional built-in look thanks to the bundled trim kit. There’s no risk of a mismatched finish or an ill-fitting frame. It’s a fantastic problem-solver for anyone with a 24″ cabinet who wants to guarantee a perfect fit without the hassle of researching and buying separate parts.

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Built In Microwave with Trim Kit Comparison Chart

Seeing the key specifications side-by-side can make the decision process much easier. This chart highlights the most important differences between the models I reviewed.

Feature	Frigidaire Gallery GMBS3068BF	Frigidaire PMBS3080BF	Frigidaire PMBS3080A	Summit SMBI24
Category	Best Overall	Best High-Capacity Alternative	Best for Smart Cooking	Best with Included Trim Kit
Capacity	2.2 cu. ft.	2.2 cu. ft.	2.2 cu. ft.	1.2 cu. ft.
Power	~1200W (est.)	~1200W (est.)	1100W	1000W
Key Feature	Sensor Cook	Sensor Cook	Sensor Cook & Reheat	All-in-one bundle
Trim Kit	Sold Separately (27″/30″)	Sold Separately (30″)	Sold Separately	INCLUDED (for 24″)
Best For	Kitchens needing large capacity and installation flexibility.	Homes with a dedicated 30″ cabinet wanting a large microwave.	Users who prioritize automated cooking and reheating perfection.	Stress-free installation in a standard 24″ cabinet.
My Rating	4.8/5 ⭐	4.6/5 ⭐	4.5/5 ⭐	4.4/5 ⭐

As you can see, the main trade-off is between the large capacity and advanced features of the Frigidaire models versus the simplicity and guaranteed fit of the Summit bundle. For most people needing flexibility and power, the Frigidaire Gallery GMBS3068BF remains the top choice. However, for a straightforward 24-inch installation, the value of the included trim kit with the Summit SMBI24 cannot be overstated.

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Buyer’s Guide: How to Choose the Right Built-In Microwave

Choosing the perfect built-in microwave is less about the brand and more about a perfect marriage of three critical things: the microwave’s dimensions, the trim kit’s design, and your cabinet’s cutout opening. Get one of these wrong, and you’ll end up with a frustrating installation and a flawed aesthetic. Here’s what you need to focus on.

• Measure Thrice, Buy Once: This is the single most important step. Before you even start shopping, grab a tape measure and get the precise interior height, width, and depth of your cabinet cutout. Write them down. A microwave that requires a 20″ depth will not physically fit into an 18″ deep cabinet. This is the number one mistake I see people make.

• Trim Kit Compatibility is Non-Negotiable: Trim kits are almost never interchangeable, even between models from the same brand. You must buy the specific trim kit model number designed for your chosen microwave. If you want to avoid this research completely, prioritize a model like the Summit SMBI24, which conveniently includes it in the box.

• Understand Capacity (Cubic Feet): Don’t just default to the biggest size. A 2.2 cu. ft. microwave like the Frigidaire Gallery is massive and great for large families. However, a more compact 1.2 cu. ft. model is perfectly sufficient for reheating, defrosting, and cooking for one or two people. Don’t pay for space you don’t need.

• Wattage Equals Power: Power, measured in watts, determines how quickly and evenly a microwave cooks. I consider 1000W to be the gold standard for solid performance. All of my top picks meet or exceed this important threshold.

• Sensor Cooking: Is It Worth It? In my opinion, yes. For users who want to “set it and forget it,” sensor cooking is a game-changing feature. It uses internal humidity sensors to determine when food is perfectly cooked or reheated, automatically shutting off the power. If you often reheat leftovers or cook diverse foods, this feature is worth the premium.

• Installation: Over-the-Range vs. Built-In: These are two different appliances. An over-the-range microwave includes a ventilation hood and is designed to be installed above your stove. A built-in microwave is designed to sit inside a cabinet or wall, usually over a wall oven or in a kitchen island. Ensure you are shopping for the correct type.

• Ventilation is Key for Safety: The trim kit isn’t just for looks; it’s a critical safety component. It’s engineered with vents that provide the necessary airflow space around the microwave to prevent it from overheating and creating a fire hazard. Never run a standard countertop microwave inside a tight cabinet without a manufacturer-approved trim kit.

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FAQs About Best Built In Microwave with Trim Kit

Do you need a trim kit for a built in microwave?

Yes, a trim kit is absolutely necessary for a proper and safe built-in microwave installation. It serves two critical purposes: first, it provides a clean, finished look by covering the gaps between the appliance and the cabinet. More importantly, it ensures proper air circulation and ventilation to prevent the unit from overheating, which is a major safety and fire hazard.

Are microwave trim kits interchangeable?

No, microwave trim kits are almost never interchangeable, not even between different models from the same brand. Each trim kit is specifically designed to fit the exact dimensions, screw hole locations, and ventilation patterns of a particular microwave model or series. Always purchase the specific kit model number recommended by the manufacturer for your exact microwave.

Can a countertop microwave be built in with a trim kit?

Sometimes, but only if the manufacturer explicitly states that a specific countertop model is “built-in ready” and offers a compatible trim kit for it. Many of the appliances marketed as “built-in” are actually robust countertop models that have been engineered and tested to work safely within a cabinet when paired with their dedicated kit. Never enclose a standard countertop microwave in a cabinet without its manufacturer-approved trim kit, as it can cause overheating.

What is the standard size for a built in microwave?

The most common standard widths for built-in microwaves are designed to fit into 24-inch, 27-inch, or 30-inch wide cabinets. The trim kit’s exterior will match these standard widths, but the actual microwave and its required cabinet “cutout” will be smaller. It is absolutely crucial to check the manufacturer’s required cutout dimensions (height, width, and depth) before purchasing.

How much space do you need around a built in microwave?

The necessary space is determined by the trim kit and the manufacturer’s specifications. You don’t have to guess. Follow the required “cutout dimensions” provided by the manufacturer exactly. These dimensions ensure there is enough of a gap for the microwave to slide in and for the trim kit to create the necessary buffer for proper airflow on all sides.

What is the difference between countertop and built in microwave?

A countertop microwave is a standalone appliance with finished sides, designed to sit on any flat surface. A built-in microwave is designed to be installed flush into a cabinet or wall and requires a specific trim kit for proper ventilation and a finished appearance. While some countertop models can be converted with a kit, they must be specifically designed for that purpose.

How do you measure for a microwave trim kit?

You don’t measure for the trim kit itself; you measure the cabinet opening you have. Use a tape measure to get the exact interior height, width, and depth of the cabinet space. Then, you find a microwave and its matching trim kit whose required “cutout dimensions” are equal to or slightly smaller than your opening’s measurements.

Why do trim kits stick out from the cabinet?

Ideally, a properly installed trim kit should sit nearly flush with your cabinetry for a seamless look. If a trim kit sticks out noticeably (a common complaint known as “trim kit gap”), it’s often due to one of three issues: an installation error, an incompatible microwave/kit pairing, or, most commonly, a cabinet depth that is too shallow for the appliance, preventing it from being pushed back all the way.

Are built in microwaves worth the money?

For homeowners prioritizing a high-end, integrated kitchen aesthetic, built-in microwaves are absolutely worth the investment. They create a streamlined, decluttered countertop and a professional look that a standalone model can’t replicate. This can increase both the functionality and perceived value of your kitchen. However, they are a premium option and cost more than a simple countertop unit.

How to vent a built in microwave?

Built-in microwaves (not to be confused with over-the-range models) are designed to be self-venting. No external ducting to the outside is required. The trim kit itself features vents on its front face. It works by pulling cool air in from the room through a lower vent and exhausting the hot air generated by the microwave back out into the room through an upper vent. This is why following the cutout space requirements is so critical for safety and performance.

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Final Verdict

After weeks of analyzing dimensions, features, and the all-important trim kit factor, my final verdict is clear. For a flawless built-in look, you must prioritize the fit of the microwave and its dedicated trim kit within your specific cabinet opening above all else.

My top recommendation is the Frigidaire Gallery Series GMBS3068BF. Its powerful combination of a massive 2.2 cu. ft. capacity, excellent sensor cooking technology, and the unmatched flexibility of having both 27″ and 30″ trim kits available makes it the most versatile and capable choice for a modern kitchen.

“Perfect for you if…”
* You have a 27″ or 30″ cabinet and want a powerful, full-featured microwave.
* You cook for a large family and need the extra capacity.
* You value the “set it and forget it” convenience of sensor cooking.
* You want a premium, integrated look that matches other high-end appliances.

“Not ideal for…”
* You have shallow cabinets (less than 20 inches deep).
* You are on a tight budget.

For those who want to eliminate all guesswork, the Summit Built-in Microwave SMBI24 is the most straightforward path to success. It’s the only microwave on my list that includes the trim kit in the box, guaranteeing a perfect fit for a standard 24″ cabinet from the start.

Ultimately, choosing the best built-in microwave with a trim kit comes down to careful measurement and matching the right appliance to your space. Do your homework, measure your cabinet precisely, and you’ll achieve that sleek, custom-designed look you’re aiming for.

Last update on 2026-02-15 at 15:20 / Affiliate links / Images from Amazon Product Advertising API