No, while most over-the-range microwaves fit a standard 30-inch width, heights and depths vary significantly between models and brands.
You might assume swapping out an old microwave is a simple plug-and-play job. Many homeowners walk into an appliance store believing that every unit sits in the exact same footprint. That assumption often leads to installation headaches.
Standardization exists, but it has limits. Most kitchen cabinets leave a 30-inch opening, and appliance makers build for that gap. However, the similarities usually stop at the width. Height, depth, and door swing clearance differ wildly depending on the brand, capacity, and model year. Failing to measure these other angles can leave you with a unit that hangs too low over your stove or sticks out too far to open the cabinet doors next to it.
The Standard 30-Inch Width Rule
If you ask, “Are All Over The Range Microwaves The Same Dimensions?” regarding width, the answer is mostly yes. This is the one measurement you can rely on roughly 99% of the time. Builders and cabinet makers adhere to a strict 30-inch spacing between upper cabinets above the range.
Manufacturers design these microwaves to fit into that specific cavity. You will find that the actual physical width of the appliance is usually just under 30 inches—typically 29 7/8 inches. This slight reduction allows the unit to slide in without scraping the paint off your cabinetry.
Rare exceptions exist. Some older homes or custom kitchens might have 36-inch openings. In those cases, you usually buy a standard 30-inch microwave and purchase a “filler kit” (side panels) to close the gaps on the left and right. But for the vast majority of kitchens, width is the easy part.
Variable Dimensions: Height And Depth
Width gives you false confidence. The real trouble starts when you look at height and depth. These measurements affect how the appliance looks and, more importantly, how it functions safely above your heat source.
Height varies based on the internal capacity of the microwave. A larger cubic-foot model needs more room, and it takes that space by growing downward. If your upper cabinets are mounted lower than standard, a tall microwave might sit dangerously close to your burner flames.
Depth is another variable. Older units were shallower. Modern units often protrude further out from the cabinets. This extra depth helps the ventilation system capture steam from the front burners, but it can look bulky if your cabinets are shallow.
Common Microwave Size Variations
To help you visualize the differences, this table breaks down the typical ranges you will encounter when shopping. Note that capacity directly influences the external size.
| Dimension Type | Standard Measurement | Why It Varies |
|---|---|---|
| Width | 29 7/8 inches | Fits standard 30-inch cabinet openings. |
| Height | 15 to 18 inches | Depends on internal capacity (1.1 to 2.2 cu. ft.). |
| Depth (Closed) | 15 to 18 inches | Deeper units capture more steam/smoke. |
| Depth (Door Open) | 40 to 45 inches | Length of the door swing arc. |
| Cutout Width | 30 inches min | The actual space between cabinets. |
| Low Profile Height | 10.25 inches | Specialty models for tight spaces. |
| Clearance Below | 18 to 30 inches | Code requirements from stovetop to microwave. |
The Critical Importance Of Safety Clearance
Safety codes dictate specific distances between the cooktop and any combustible material or appliance above it. Most manufacturers require a minimum of 30 inches from the cooktop surface to the bottom of the upper cabinet (the wood part, not the microwave).
For the microwave itself, you typically need at least 13.5 to 16 inches of clearance between the microwave’s underside and the range surface. Some local codes push this to 18 inches. If you buy a tall model—say, 17 inches in height—and your cabinets are low, you might violate this safety zone.
Heat damage is a real risk. Plastic handles on the bottom of the microwave can melt if they sit too close to a large gas burner. Always check the specific install guide for your chosen model. You can verify installation requirements for brands like GE or Whirlpool to see their specific safety minimums.
Do Low Profile Microwaves Solve The Size Issue?
Low profile microwaves are a relatively recent innovation designed to fix height problems. These units offer the standard width (29 7/8 inches) but compress the height down to roughly 10 inches. They look sleek and offer massive clearance above the stove.
Are All Over The Range Microwaves The Same Dimensions regarding internal space? Definitely not. The trade-off with low profile units is the cavity height. You can fit a tall coffee mug or a casserole dish, but you might struggle with a large turkey or a tall blender pitcher. If you do a lot of tall-item cooking, measure your favorite cookware before committing to a slim unit.
Understanding Depth And Cabinet Protrusion
Depth causes more aesthetic issues than functional ones, but it still matters. Standard upper cabinets are usually 12 inches deep. Over-the-range microwaves are almost always deeper than this, typically around 15 to 16 inches. They are designed to stick out.
This protrusion serves a purpose. The ventilation fans are located on the bottom of the unit. For the fan to work, it needs to cover at least half of the front burners. If the microwave were flush with a 12-inch cabinet, the fan would only suck up air from the back burners, leaving the front of your kitchen filled with smoke.
However, newer “chef style” or high-capacity units can be up to 18 inches deep. In a small kitchen, a unit sticking out that far might feel oppressive or block your line of sight to the back of the stove.
Why Mounting Brackets Are Not Universal
A common misconception is that you can reuse the old wall bracket. You unscrew the old unit, and surely the new one will hook right onto the existing metal plate, right? This is rarely true.
Every manufacturer designs a unique mounting plate. Even within the same brand, the bracket design often changes between generations. The hooks on the bottom of the bracket must align perfectly with the slots on the back of the microwave.
When you ask, “Are All Over The Range Microwaves The Same Dimensions?”, you should also ask if the bolt holes are in the same place. They are not. Installing a new unit almost always involves removing the old bracket, finding new studs or using new toggle bolts, and drilling new holes in the upper cabinet for the top support screws.
Door Swing And Side Wall Clearance
If your range is located next to a wall or a deeper pantry cabinet, you have a “zero clearance” problem. The width of the microwave fits the hole, but the door needs room to swing open.
Many older microwaves had hinges that required an inch or two of clearance to the left. If a wall was there, the door wouldn’t open to 90 inches. Modern units often use zero-clearance hinges where the door rotates within the body’s width. However, thicker doors on premium models can still bind against a side wall.
Check the “spec sheet” for a diagram showing the door swing arc. If the spec sheet shows the door extending beyond the width of the unit when open, you need side clearance.
Internal Capacity Vs External Size
You might think a 2.2 cubic foot microwave is physically massive compared to a 1.6 cubic foot model. While usually true, engineering advancements have blurred these lines. Manufacturers have become better at thinning out the insulation and electronic components.
It is possible to find a 1.9 cubic foot model that takes up less external space than an older 1.5 cubic foot unit. Don’t judge the fit solely by the internal capacity number. Always look at the physical Height, Width, and Depth dimensions listed on the box.
Are All Over The Range Microwaves The Same Dimensions For Venting?
Venting options generally follow a standard, but the alignment varies. OTR microwaves typically offer three venting styles:
- Recirculating: Air is pulled through a charcoal filter and blown back into the room. (Requires no external duct).
- Vertical (Roof) Venting: The fan blows air upward through a rectangular damper.
- Horizontal (Wall) Venting: The fan blows air straight back through the wall.
The size of the damper (the rectangular exhaust port) is standard (usually 3.25″ x 10″), but its location on the top or back of the unit shifts. If you have existing ductwork rigid in the wall, a difference of half an inch in alignment can force you to cut sheet metal or modify your cabinets.
How To Measure Your Space Correctly
Don’t rely on the specs of your old unit. Measure the empty space. Here is a quick checklist to ensure accuracy:
- Measure Width at Top and Bottom: Cabinets can warp or bow. Measure the opening width at the front and the back. You need a consistent 30 inches.
- Measure Height from Range to Cabinet: Distance from the top of the stove to the bottom of the upper cabinet.
- Subtract Safety Buffer: Take that height measurement and subtract the height of the new microwave. Is the remaining number at least 13-15 inches?
- Check Depth: Measure from the wall to the front of the closed cabinet door. Compare this to the microwave depth to see how much it will protrude.
Replacing A Hood With A Microwave
Homeowners often want to replace a simple range hood with an OTR microwave to save counter space. This is where dimensions get tricky. Range hoods are much shorter than microwaves.
A standard range hood might be 5 to 7 inches tall. A standard microwave is 16 inches tall. If you simply swap them, the microwave will hang 10 inches lower than the hood did. In many older kitchens, this puts the bottom of the microwave dangerously close to the stockpot. You may need to cut down the cabinet above or install a Low Profile model to make this switch work.
Understanding OTR Microwave Size Variations
Since we know the answer to “Are All Over The Range Microwaves The Same Dimensions?” is a firm no regarding height, let’s look at how to choose based on these variations. The variation is not a flaw; it is a feature designed to fit different kitchen lifestyles.
Families who cook large meals need the height for stacking dishes. Apartment dwellers might prioritize a flush look. The variation allows you to customize the appliance to your cabinetry, not the other way around. Always prioritize the fit over the features. A microwave with 50 sensors is useless if it blocks your view of the back burner.
Troubleshooting Fit Issues
Even with careful measuring, you might run into snags during installation. Here are common dimension-related problems and how to solve them.
| Problem | Likely Cause | The Fix |
|---|---|---|
| Gap on sides | Opening is 36″ (wide) instead of 30″. | Install a microwave filler kit (side trim panels). |
| Door hits wall | Zero clearance needed next to deep wall. | Swap for a model with internal hinge clearance. |
| Unit tilts forward | Top cabinet is not deep enough for bolts. | Use wood spacer blocks inside the cabinet. |
| Too low to cook | Microwave is too tall for the space. | Return for a Low Profile model. |
| Vent misaligned | New unit exhaust port shifted. | Adjust ductwork or use flexible transition duct. |
| Backsplash block | Tile runs too high up the wall. | Remove top row of tile or mount bracket on shim. |
| Screw Alignment | Top cabinet holes don’t match. | Drill new holes; never force angular screws. |
Electrical Requirements And Cord Placement
Dimensions also apply to the power cord. The cord for an OTR microwave usually exits the top right of the unit (when facing it). You must drill a hole in the cabinet floor for the plug to pass through.
Because dimensions vary, the location of this cord hole changes. Do not drill the hole based on the old microwave. Use the paper template included in the box. If you drill blindly, you turn your cabinet floor into Swiss cheese. Check electrical safety standards or local building codes to ensure your dedicated outlet is properly rated for the new appliance’s amperage.
The Backsplash Conflict
A hidden dimension that trips up many DIYers is the wall space behind the unit. If you have a tile backsplash that runs all the way up to the bottom of your old microwave, a new unit might not fit.
If the new microwave is even a quarter-inch taller (meaning it hangs lower), it will hit the top of the tile before the mounting hooks engage. You effectively have two choices: remove a row of tile (messy and difficult) or buy a shorter microwave. Sometimes, you can mount the wall bracket on a piece of plywood (a shim) to push the microwave forward slightly, clearing the tile thickness, but this pushes the unit further out into the room.
Weight Considerations
Size often correlates with weight. A massive 2.2 cubic foot commercial-style microwave can weigh over 60 pounds. Older cabinets, especially particle board ones, might sag under this increased load.
While checking dimensions, check the integrity of the cabinet floor and the wall studs. The two top screws take about half the weight, while the wall bracket takes the rest. If your cabinet bottom looks thin or water-damaged, reinforce it before hanging a heavier, larger unit.
Final Sizing Checks Before Buying
Before you head to the checkout, take photos of your current setup. Capture the cabinet height, the backsplash, and the current clearance. When you look at the floor model, bring a tape measure. Store signage can be inaccurate.
Verify the “Height at Front” versus “Height at Back.” Some stylish microwaves slope downward. The back might fit your tile, but the front might hang too low. Precision here saves you the hassle of repacking a heavy appliance and driving it back to the store.
So, Are All Over The Range Microwaves The Same Dimensions? Only in width. For every other angle, assume nothing and measure everything. Your backsplash, cabinet hinges, and cooking clearance depend on getting those specific numbers right.