Microwave depth is measured front to back with the door closed, and most US models fall between 12 and 18 inches deep.
A cabinet that swallows a 12-inch compact model won’t hold a 16-inch over-the-range unit, and that gap is where most kitchen remodels stall. Measured depth decides whether a microwave slides into a shallow counter run, hangs flush over a cooktop, or bumps into the wall behind it.
What Does Microwave Depth Actually Measure?
Depth is the front-to-back distance of the unit with the door shut, and it is the number that decides fit — not the wider figure you get with the door swung open. Home Depot’s measuring guide is blunt about this: measure from front to back with the door closed, and for built-in or over-the-range units, measure the cabinet cutout depth instead of the appliance alone.
The confusion costs people money. That open figure matters for walkway clearance, but it is the closed number that has to match your shelf, cabinet, or cutout.
Three measurements travel together: width, height, and depth. A countertop microwave may list 12 to 16 inches deep, and Home Depot notes heights can start as low as 10 inches on compact models. Match all three before buying.
What 10, 12, 13, and 15 Inch Depths Mean For Your Kitchen
Each depth band points to a different installation, and knowing which one you’re shopping for narrows the field fast. The table below maps the common depths to the units that use them and what each one demands from your space.
| Depth (Door Closed) | Typical Unit | Fit Consideration |
|---|---|---|
| 10–12 inches | Compact countertop | Fits shallow counter runs; needs rear ventilation space |
| 12–13 inches | Countertop, flush built-in | Whirlpool cites about 12¾ inches for flush built-in designs |
| 13 inches | Shallow countertop or custom | Uncommon; sits at the shallow end of the 12–16 inch countertop band |
| 15–17 inches | Over-the-range body | Standard OTR sizing; body projects past a 12–13 inch cabinet face |
| 15–18 inches | Over-the-range, closed door | Whirlpool’s stated range for OTR units |
| 19–26 inches | OTR including door and handle | Projection figure, not the fit measurement |
A 12-inch-deep countertop model fits most shallow counters, but it still needs breathing room. Skip those and a snug fit turns into a heat problem.
Over-the-range units are a different animal. Their bodies typically run 15 to 17 inches deep, which means an OTR microwave will always project beyond a standard 12–13 inch wall cabinet. That projection is normal, not a defect — but it changes how the unit looks above your range.
How Depth Affects Fit and Safety
Fit problems cluster around three places: the cabinet face, the wall behind the unit, and the cooktop below an over-the-range model.
Cabinet depth is the sleeper issue. Standard wall cabinets run about 12 to 13 inches deep, so any OTR body deeper than that overhangs the cabinet line. If you’re working with shallow cabinets and want a tighter projection, a roundup of the best 11 inch deep microwave options covers models built to sit closer to the wall.
A few more points worth checking before you commit:
- Handle and door projection adds inches — one guide puts OTR depth including door and handle at 19 to 26 inches.
- Built-in and OTR cutouts need measuring separately from the appliance; the cabinet opening can limit installation even when the microwave looks like it fits.
- Shallow models sometimes need a kit. Whirlpool’s guide to microwave sizes is a solid reference for confirming these numbers.
Frequently Asked Questions
Do I measure depth with the door open or closed?
Closed. Depth is measured front to back with the door shut, and that is the figure that decides whether the unit fits your shelf, cabinet, or cutout. Open-door depth runs far larger — Whirlpool cites 42 to 45 inches — and it only matters for clearing walkways and adjacent walls after installation.
Will a 15-inch-deep microwave fit in a standard cabinet?
It will overhang. Standard wall cabinets are roughly 12 to 13 inches deep, so a 15-inch OTR body projects past the cabinet face. That is normal for over-the-range models, but it is worth confirming you’re comfortable with the look before buying.
How much clearance does a countertop microwave need?
These figures apply to countertop models specifically, and skipping them can trap heat around the appliance or leave it unstable on the counter.
References & Sources
- The Home Depot. “How to Measure Microwaves: Sizes & Tips” Supports closed-door measuring method and countertop clearance figures.
- Whirlpool. “A Guide to Microwave Sizes” Supports OTR depth ranges and the 12¾ inch flush built-in figure.
- Whirlpool. “Over-the-Range Microwave Buying Guide” Supports open-door depth, cooktop clearance, and sidewall clearance guidance.
