MICROWAVE TRIM KIT SIZING GUIDE: FIND THE RIGHT FIT

A microwave trim kit lets you install a compatible microwave within a cabinet or wall cutout for a built-in look. It frames the microwave, helps secure it in place and helps create a seamless, integrated appearance in your kitchen.

For added practical benefit, a trim kit can help free up valuable space on your countertop while helping support proper airflow and a secure installation. Since the cabinet opening is fixed and each kit fits specific microwave models, measure first and check your model to avoid ordering the wrong kit.

Read on to learn more about common kit sizes, how to find the right match, how to measure and more.

HOW DO YOU KNOW WHAT SIZE TRIM KIT YOU NEED?

The microwave trim kit size you need depends mainly on your cabinet opening and your countertop microwave's exterior width. Most kits are built for 27- or 30-inch openings, but that doesn’t mean your microwave measurements need to match.

Standard and large countertop microwaves are usually about 21-25 inches wide. It's the trim kit's frame, not the microwave itself, that brings the finished width up to 27-30 inches.

27-INCH VS. 30-INCH TRIM KITS

Two common microwave trim kit widths are 27 and 30 inches, and the right one generally lines up with your compatible microwave's capacity as well as your cabinet's cutout width. A 27-inch kit is typically built around a smaller-capacity model, while a 30-inch kit pairs with a larger-capacity microwave.

Here's how the two standard trim kit sizes typically compare*:

Common Trim Kit Widths	Typical Microwave Capacity	Best For
27 inches	About 1.5 cu. ft.	Compact to standard countertop microwaves
30 inches	About 2.2 cu. ft.	Large-capacity countertop microwaves

*Trim kit sizes and compatibility vary by brand. See your microwave owner’s manual for more information.

Capacity alone doesn’t guarantee a match so always double-check your model’s specs before you order to make sure it’s compatible, since trim kits are built to fit specific models, dimensions and venting needs.

MATCHING A KIT TO YOUR MICROWAVE MODEL

A microwave trim kit is model-specific, so the safest way to match one is to start with your microwave's model number, not just its size. Not all microwaves are designed to be built in, so it's also worth getting familiar with the manufacturer's guidelines before you shop. Look for recommended trim kit models in your user manual and compare the microwave's size to the kit to help make sure your model is compatible.

Whether you’re looking to create a built-in aesthetic for a large Maytag^® countertop microwave or frame a built-in low profile model, Maytag brand offers a variety of microwave trim kits for the job.

SHOP MAYTAG^® MICROWAVE TRIM KITS

HOW TO MEASURE YOUR CABINET OPENING

Before you buy a trim kit, get familiar with your kitchen’s layout and the way it may impact the installation location, and measure the dimensions of your cabinet opening. Measure the height, width and depth of the installation area to help confirm the trim kit and microwave will fit well.

Keep these factors in mind as you check your cabinet opening:

Measure the width, height and depth of the opening at the top, middle and bottom, since cabinets may not be perfectly square.
Use the smallest measurement at each point to help ensure a proper fit.
Measure your microwave's own width, height and depth so you can compare it against both the cabinet opening and the trim kit's spec sheet.
Consider nearby appliances, cabinet doors or other features that may obstruct the install.
Evaluate whether your cabinet's structure and strength can support the combined weight of the microwave and the trim kit.

VENTILATION AND OUTLET CLEARANCE

Beyond width, height and depth, plan for proper ventilation clearance, outlet access and sufficient clearance for the microwave’s door swing. Before installation day, be sure to:

Verify if any rear clearance is required by your specific model prior to installation.
Check clearance near walls or cabinetry so doors can open fully. Standard countertop microwaves often measure about 24 to 29 inches deep with the microwave door open.
Ensure you have access to a grounded, accessible outlet inside the cabinet. Microwaves typically aren’t designed to run through extension cords.
Confirm that airflow won't be blocked by surrounding cabinetry or appliances.

COUNTERTOP VS. BUILT-IN: WHEN A TRIM KIT MAKES SENSE

A trim kit isn't required for a true built-in microwave, since those models are typically designed to fit into cabinetry on their own. However, if you're using a countertop microwave in a built-in space, a microwave trim kit can give you a sleek, built-in look and help make sure the microwave vents properly.

FREQUENTLY ASKED QUESTIONS

Still have questions about trim kits? Find quick answers below about compatibility, measuring, cabinet sizing and installation.

No. Trim kits are made for freestanding microwaves you want to install into a cabinet or wall opening, and not every kit works with every model. Built-in microwaves generally don't need one, so check your manual and the kit's specs before buying.

A 27-inch microwave trim kit is generally built for a countertop microwave with around 1.5 cubic feet of capacity, but it can vary by model. Check your specific model's user manual to confirm it's listed as compatible with a 27-inch kit before you buy. If it is, you also need to check the specs on the specific kit you like, to be sure it’s compatible with your model.

For a 30-inch cabinet opening, look for a countertop microwave paired with a 30-inch trim kit, generally built around a larger-capacity model of about 2.2 cubic feet. Confirm that the exact cutout measurements match your cabinet and that the kit is compatible with your microwave model before ordering.

Yes. Built-in microwave cabinet size options generally align with standard cabinet widths, including 24, 27 and 30 inches. A 24-inch option can be a good fit for a smaller kitchen or a narrower cabinet run.

Generally, no. A trim kit isn't required for installing a true built-in microwave, since those models are typically designed to fit into cabinetry on their own. Trim kits are mainly for installing a countertop microwave in a built-in space.

It's generally not recommended. A compatible kit can include detailed instructions, labeled hardware and user-friendly designs uniquely engineered for your microwave’s dimensions, venting requirements and more.

Pricing can vary by brand, finish and what's included. Some trim kits—like select models from Maytag brand—include a full hardware set complete with rails, a bottom duct, a frame, screws and mounting hardware. As you shop, make sure you compare trim kits with the same included equipment to get a more accurate picture of total cost.