A countertop microwave is a freestanding unit that sits on your counter — typical sizes run 12–15 in. high, 21–25 in. wide, and 16–20 in. deep with the door closed.
For the full breakdown, see our best Basic Countertop Microwave guide.
Depth is where most buyers get burned. The spec sheet lists the measurement with the door shut, but the open door needs 27–39 in. of clear space in front of the unit — more than double the number you read on the box. Get that wrong and you’re either blocking a walkway or returning the microwave.
What Separates A Countertop Microwave From Other Types?
A countertop microwave sits on open counter space and needs no installation, while over-the-range and built-in models are mounted or fitted into cabinetry. Major appliance manufacturers describe the countertop style as the most common microwave type in US kitchens, and that makes sense — you set it down, plug it in, and you’re done.
Because it isn’t built in, a countertop unit never gets hardwired or vented. That keeps the price down and the setup trivial, but it also means the microwave is competing for the same square footage as your prep work. Capacity is another differentiator: countertop models typically range from about 0.5 cu. ft. on the small end up to 2.2 cu. ft. at the large end.
What Are The Standard Countertop Microwave Sizes?
Countertop microwaves fall into two broad size classes, and matching your counter to the right class matters more than chasing the biggest capacity. Maytag’s sizing guide splits them into small models at roughly 10–11 in. high, 15–18 in. wide, and 12–16 in. deep with 0.5–0.9 cu. ft. of capacity, and standard or large models at 12–15 in. high, 21–25 in. wide, 16–20 in. deep, and 0.8–2.1 cu. ft.
Actual manufacturer specs land inside those ranges. Here’s how real units measure up:
| Capacity | Height x Width x Depth (in.) | Best For |
|---|---|---|
| 0.7 cu. ft. | 10.19 x 17.31 x 12.75 | Small kitchens, dorms |
| 1.1 cu. ft. | 12 x 20.31 x 15.63 | Everyday singles and couples |
| 1.1 cu. ft. (PEM31SFSS) | 11.75 x 24 x 12.88 | Shallow counters |
| 1.6 cu. ft. (JES1657SMSS) | 12.88 x 21.75 x 17.75 | Families of three or four |
| 2.0 cu. ft. | 13.75 x 24.09 x 19.4 | Large households |
| 2.2 cu. ft. (JES2251SJ) | 13.75 x 24 x 19.5 | Big batches, meal prep |
Notice the pattern: wider, deeper cabinets buy you capacity, but the 1.1 cu. ft. PEM31SFSS shows you can get a full-size footprint with just 12.88 in. of depth. If your counter is shallow, that’s the trade to hunt for, and our roundup of tested basic countertop microwave picks breaks down which models fit tight spaces. Wider dimensions also track directly along an easy equation: bigger internal capacity means a bigger external footprint, so there’s no shortcut around the space math.
How Do You Measure Your Kitchen Before Buying?
KitchenAid’s measuring guide says to check three things before you buy: countertop width, countertop depth to the wall, and cabinet clearance above the counter. A countertop microwave needs all three to clear, or it won’t sit properly no matter how good the specs look.
- Behind: leave about 1 in. of ventilation space between the back of the microwave and the wall so airflow isn’t blocked.
- In front: leave about 3 in. from the counter edge to the open door to reduce tipping risk.
- Nearby: keep the microwave at least 2 ft from the range or cooktop.
The open-door number is the one people miss. KitchenAid’s microwave dimensions guide puts closed-door depth at 16–20 in. and open-door depth at 27–39 in., which means a unit sitting flush against a side wall can block its own door swing.
What Mistakes Sink A Countertop Microwave Fit?
The most common error is measuring only the microwave body and ignoring the open-door clearance entirely. Maytag’s guide also flags three more routine mistakes: forgetting ventilation space behind the unit, skipping the front stability clearance, and placing the microwave too close to a range or cooktop.
One more assumption to drop — spec-sheet depth is a closed-door measurement, so never treat it as your front clearance. Measure your counter, subtract an inch for the wall gap and three for the door zone, then compare what’s left against any model’s width and depth. If it fits with room to spare, you’re done deciding.
FAQs
Can any countertop microwave be built into a cabinet?
No. Countertop microwaves are designed to sit on open surfaces and rely on airflow around the body, so built-in installation can block vents and overheat the unit. If you want a fitted look, choose a model specifically rated for built-in use instead.
How much counter space does a standard model need?
Allow for the microwave’s width and depth plus about 1 in. behind for ventilation and roughly 3 in. in front so the door can swing and the unit stays stable.
Does door swing direction matter when fitting a microwave?
It can. If the hinge sits against a side wall, the open door may hit it before the unit clears, which is why open-door depth of 27–39 in. has to be checked separately from closed-door depth. Measure the free space beside the unit, not just in front.
References & Sources
- KitchenAid. “Microwave Sizes: How to Measure a Microwave” Supports closed-door vs. open-door depth figures and the three-step measuring checklist.
- Maytag. “Microwave Sizes: A Guide to Common Dimensions” Supports small and standard size class ranges, capacity figures, and spacing cautions.
