A standard countertop microwave is about 16–20 inches deep with the door closed; compact units run 12–16 inches and built-ins take up 20–25 inches.
Closed-door depth decides the fit against your wall or cabinet; open-door depth decides whether anyone can stand in front of it. Mixing them up is why a “standard” microwave gets returned. This covers real depths by type, where to measure, and the clearance most buyers forget.
How Deep Are Countertop Microwaves?
Countertop microwaves typically run 16–20 inches deep, the everyday US standard. Depth scales with size class, so a dorm unit and a family model don’t share a footprint.
KitchenAid puts countertop models at roughly 16–20 inches deep, 21–25 inches wide, and 12–15 inches high. Maytag groups “standard and large microwaves” into the same 16–20 inch depth band, with capacities from 0.8 to 2.1 cubic feet. Smaller countertop units drop to about 12–16 inches deep. Angi cites the same 16–20 inches for the common range.
Capacity and width climb together, and depth follows. For a shallow counter or shelf, our tested roundup of compact 10-inch-deep microwave picks covers units built for that tight footprint.
Does Microwave Depth Change By Type?
Yes — depth shifts by whether the unit is countertop, over-the-range, or built-in. Over-the-range models run shallower because they tuck under the cabinet; built-ins run deeper because they slide into a wall cutout.
KitchenAid puts over-the-range microwaves at about 15–18 inches deep, 30 inches wide, and 17 inches high. Built-ins are the deep end at 20–25 inches deep, 24, 27, or 30 inches wide, and 17–22 inches high. Larger countertop categories can also stretch into the 20–25 inch band.
| Microwave Type | Typical Closed-Door Depth | Typical Height And Width |
|---|---|---|
| Compact countertop | About 12–16 in | 10–12 in high, 15–19 in wide |
| Standard countertop | About 16–20 in | 12–15 in high, 21–25 in wide |
| Large countertop | Up to 20–25 in | 12–15 in high, 21–25 in wide |
| Over-the-range | About 15–18 in | About 17 in high, 30 in wide |
| Built-in | About 20–25 in | 17–22 in high, 24/27/30 in wide |
KitchenAid’s dimensions guide lays out each category side by side, and Maytag’s size breakdown matches the same bands, so these ranges hold across both brands.
Why Open-Door Depth Matters
Spec sheets list closed-door depth, but the door swings out on a hinge and adds large forward clearance. Both KitchenAid and Maytag flag this: open-door depth runs roughly 23–45 inches depending on type and door style — often double the closed-door figure.
A 20-inch-deep countertop model can need nearly three feet of clear floor to open fully. A wall, island, or refrigerator opposite the counter can block the door even when the microwave fits your counter depth perfectly. Angi notes the same: depth is measured front to back with the door closed, and door-open clearance is a separate check.
Measuring For A Microwave Fit
Depth, width, and door clearance each decide a different part of the fit. Grab a tape measure and run these checks before ordering.
- Measure counter or shelf depth from front edge to back wall — your max closed-door depth.
- Measure the open space width, then subtract breathing room for the unit and rear venting.
- Measure height clearance to whatever sits above — cabinet, shelf, or hood.
- Stand in front of the counter and measure forward to the nearest obstacle; it must clear the 23–45 inch open-door depth.
- For built-in or over-the-range, measure the cabinet cutout depth, not the appliance body. Angi and both brand guides agree this is the number installers care about most.
Mark the footprint with tape before buying — the fastest way to see whether the door will clear the space in front.
The Bottom Line
For a countertop microwave, plan on about 16–20 inches of closed-door depth, with compact units around 12–16 inches and built-ins at 20–25 inches. Over-the-range models run shallower at roughly 15–18 inches. Then check door-swing clearance separately — the number left off spec sheets and the one that turns a “fits perfectly” purchase into a return. Tape off the footprint, walk the open door in your head, and you’ll pick the right depth first try.
FAQs
Is every countertop microwave the same depth?
No. Depth tracks size class. Compact units sit around 12–16 inches, standard models near 16–20 inches, and larger countertop microwaves can reach 20–25 inches. Check a specific model’s closed-door depth rather than assuming a single “standard” number.
Should I measure depth with the door closed or open?
Measure available space against closed-door depth first — the spec-sheet number that decides whether the unit sits flush. Then check open-door depth separately, since it runs roughly 23–45 inches and decides whether the door can swing out without hitting anything.
Do built-in microwaves need a different measurement than countertop models?
Yes. For built-in or over-the-range installation, measure the cabinet cutout opening, not just the appliance body. Built-ins commonly run 20–25 inches deep, and the cutout must match so the unit sits flush and vents correctly.
References & Sources
- KitchenAid. “Microwave Dimensions.” Supplies depth, height, and width ranges by microwave type, plus the open-door depth caveat.
- Maytag. “Microwave Sizes.” Confirms the 16–20 inch standard and large microwave depth band, capacity range, and open-door depth note.
- Angi. “Standard Microwave Dimensions.” Provides measuring guidance, including measuring depth front-to-back with the door closed and using cutout depth for built-ins.
