Old Built-In Microwave Died — Can't Find One That Fits. Now What?
We hear this story a lot. Your built-in microwave dies, you go to replace it, and nothing fits.
Here's why: there are no standard microwave dimensions or trim kit dimensions. There are common trim kit widths — 27" and 30" are the most popular — but the height is not standardized - ranging from 15" to 20" typically. And that's where things get tricky.
Why Finding an Exact Match Is So Hard
A built-in microwave trim kit has two main components:
- The base — this is what the microwave sits in. It centers the microwave in the cabinet opening.
- The face frame — the decorative trim that covers the gap between the microwave and the surrounding cabinetry.
For a replacement to drop right in, the microwave dimensions, the base dimensions, and the face frame dimensions all have to line up with your existing opening. That's a lot of variables. And the older your microwave is, the harder it's going to be to find an exact match.
Step 1: Try to Find an Exact Match
It's worth the effort to search. One site I'd recommend is AJ Madison — they have solid search functionality with filters for size and features, which helps narrow things down.
You can also use AI tools like ChatGPT, Gemini or Claude. Give them your specific opening dimensions and microwave specs and see if they can find a model that fits. It's not a guarantee, but it can save you hours of scrolling through spec sheets.
If you find something that works, that's usually the most straightforward path.
Step 2: If You Can't Find a Match — Or Don't Want To
There are two common reasons people move away from a direct replacement:
- They simply can't find a built-in microwave that fits their opening.
- They don't want to spend the money on a true built-in model or they can't find one with the features they want.
That being said, you still have options.
Option A: Buy a built-in microwave and skip the manufacturer's trim kit. If you find a built-in model you like but its trim kit won't fit your opening, you can forgo the factory trim kit and use a custom microwave trim kit instead. Our kits are made to your exact dimensions, so the opening size doesn't matter — we build the trim to fit.
Option B: Go with a countertop microwave and a custom trim kit. This is a popular route. You pick whatever countertop model has the features you want — often at a lower price point — and pair it with a custom microwave trim kit to make it look built-in. Same clean, finished look without being locked into a specific built-in model.
A Note About Appliance Stores
A few things to consider — and this comes from talking with hundreds of customers. A lot of times, appliance stores aren't terribly knowledgeable about trim kits and built-in appliances. Especially the big box stores.
We've talked with customers who have had the appliance store out to their house three or four times, each visit promising the next microwave is going to fit. It turns into a hassle. Multiple trips, multiple returns, and no closer to a solution.
Our custom kits solve that problem. They include the custom risers that raise the microwave up and center it in the opening, plus the decorative face frame that covers the gap. Everything is built to your measurements, so it usually fits right the first time. No guesswork.
Installation
Our microwave trim kits are DIY-friendly. If you're reasonably handy, you can install the microwave and the trim kit yourself. If not, a handyman can knock it out — it doesn't require a specialized contractor.
If you want to see more examples of how to solve this problem, browse installed examples in our Gallery.
