No, over-the-range microwaves vary in height and depth, though most standard models are designed to fit a 30-inch wide cabinet opening.
You find yourself in the kitchen aisle or browsing online, tape measure in hand, wondering if a simple swap works. Replacing an appliance feels like it should be straightforward. You buy a unit, mount it, and cook dinner. Yet, the reality of over-the-range (OTR) microwaves often complicates this plan. Sizing standards exist, but they are not absolute laws.
Most homeowners assume a new unit fits exactly where the old one sat. This assumption leads to frustration during installation. While width remains consistent across most brands, other dimensions shift significantly. Manufacturers change designs to accommodate larger fans, new sensor technology, or modern aesthetics. A unit that is too tall might block your view of the back burners. A unit that is too deep might stick out awkwardly past your cabinetry.
Understanding the nuances of these dimensions prevents return hassles. You must account for cabinet depth, door swing clearance, and the critical vertical gap above your range. This guide breaks down exactly where sizes match and where they deviate.
Are All Over Range Microwaves The Same Size? (The Core Facts)
The short answer is no, but with a caveat. The width is the only dimension you can rely on to be consistent. Virtually every standard over-the-range microwave fits a 30-inch wide opening. This aligns with standard stove widths. If you have a 30-inch range, you likely have a 30-inch cabinet opening above it.
Height and depth tell a different story. Older microwaves were often shorter and shallower. Modern units tend to offer larger capacities, which translates to taller and deeper exterior frames. A standard height used to be around 15 inches. Today, many models exceed 17 inches. This 2-inch difference impacts your cooking space drastically. If your cabinets are mounted low, a taller microwave reduces the clearance above your pots and pans.
Depth varies based on the handle design and venting system. Some sleek models sit flush with standard 12-inch cabinets, while others protrude significantly. Protrusion is not just aesthetic; it affects airflow and how the door hinges operate. If a deeper unit sits next to a deeper pantry cabinet, the door might bind against the wall when you try to open it.
Standard Width Requirements Explained
Industry standards dictate width to make appliance replacement manageable. The cutout width for these units is usually 30 inches. The actual appliance width is slightly less, typically around 29 7/8 inches. This small gap allows the unit to slide between cabinets without scraping the finish.
Exceptions exist in custom kitchens or older homes. You might encounter a 36-inch opening. In these cases, the microwave itself is usually still the standard width, but the manufacturer uses side filler panels to close the gap. True 36-inch wide microwaves are rare in today’s market. If you are replacing a wide unit, you will likely buy a standard 30-inch model and a separate filler kit.
| Microwave Type | Typical Width | Typical Height |
|---|---|---|
| Standard OTR | 29.8″ – 30″ | 16″ – 17.5″ |
| Low Profile OTR | 29.8″ – 30″ | 10″ – 11″ |
| Large Capacity OTR | 29.8″ – 30″ | 17.5″ – 18.5″ |
| Compact Models | 23″ – 24″ (Rare) | 13″ – 15″ |
| Commercial Style | 29.8″ – 30″ | 18″ + |
| Wide Configuration | 36″ (With Fillers) | 16″ – 17″ |
| Smart Screen Models | 29.8″ – 30″ | 17″ – 17.75″ |
Over Range Microwave Size Variations
Designers create these size variations to solve specific kitchen problems. The introduction of low-profile microwaves addressed the issue of low-hanging cabinets. Many older kitchens were built with range hoods in mind, not microwaves. Range hoods are thin. When homeowners switched to microwaves, they lost vertical cooking space. Low-profile models reclaim that space by compressing the motor and electronics into a shorter, wider footprint.
Capacity drives size changes in the other direction. Families wanting to cook a whole turkey or heat large casserole dishes need interior volume. Increasing cubic footage forces the exterior dimensions to grow. A 2.1 cubic foot model will almost always be taller than a 1.6 cubic foot model. You trade vertical clearance for interior cooking space.
Venting mechanisms also play a role. Microwaves that vent externally often require specific duct alignment. While the blower motor is usually adjustable, the housing for these powerful fans adds bulk to the top or back of the unit. Recirculating models that filter air back into the kitchen often have bulky front grilles to push the air out, adding to the perceived depth.
Height Clearance Safety Codes
Safety dictates specific clearance rules that limit your size choices. Generally, you need at least 66 inches from the floor to the bottom of the microwave cabinet. More practically, you need roughly 13.5 to 16 inches of space between the microwave bottom and the stovetop surface.
If you install a tall microwave in a space designed for a short range hood, you violate these safety buffers. The heat from high-BTU gas burners can damage the microwave electronics. Large stockpots become difficult to stir because the appliance hangs too low. You must measure your current vertical void before falling in love with a tall, high-capacity model.
Common Myths: Are All Over Range Microwaves The Same Size?
A prevalent myth is that all 30-inch microwaves mount on the same bracket. This is false. Wall plates differ between brands and even between generations of the same brand. You generally cannot reuse the old metal mounting bracket screwed into your wall. The new unit will have different hooks and toggle bolt locations.
Another myth suggests that “counter depth” applies to microwaves. While refrigerators have a strict counter-depth category, OTR microwaves do not follow a strict depth rule. Some handle designs protrude up to 18 inches from the wall, while others stay closer to 15 inches. If your stove is positioned in a galley kitchen or a tight island setup, those extra three inches of handle depth impinge on your walkway.
You also cannot assume the power cord location is identical. You might need to drill a new hole in the upper cabinet to pass the plug through. While not a size issue per se, this installation variance surprises many DIYers who expect a plug-and-play experience based on the standard width.
Measuring For The Perfect Fit
Accuracy requires more than measuring the old appliance. The old unit might have been installed incorrectly or undersized for the space. Measure the cabinet opening width at the top and bottom. Cabinets can warp or settle over time, creating a trapezoid shape that pinches the appliance.
Check the depth of the upper cabinet. Standard upper cabinets are 12 inches deep. Some modern cabinets are 13 or 14 inches deep. If your cabinets are deeper than standard, you need a microwave with a “zero clearance” door hinge or one that sits proud enough so the door can swing open. If the microwave face sits flush with deep cabinets, the door will hit the adjacent wood when you open it.
Measure the distance from the wall to the front of your stove. You want the microwave to cover the rear burners and part of the front burners for effective ventilation. However, you do not want it sticking out so far that you bump your head while tasting sauce on the front burner. A balance between coverage and ergonomics is necessary.
Understanding “Cutout” Vs. “Product” Dimensions
Product specs list “product dimensions” and “cutout dimensions.” For OTR microwaves, the cutout width is the space between the cabinets (usually 30 inches). The product width is slightly smaller. Never buy a unit with a product width of exactly 30 inches if your opening is exactly 30 inches; it will be too tight. You need that fraction of an inch for clearance.
Height measurements usually include the mounting plate. Some specs list the height of the front face only, ignoring the slight protrusion of the mounting tab at the back. Always read the detailed installation manual PDF before purchasing. These documents provide the granular measurements that simple product pages miss.
Low Profile Models For Tight Spaces
Low profile microwaves are a specific category designed to solve the height problem. These units pack standard power (usually 1000 watts) into a chassis that is only about 10 inches tall. They fit in the same 30-inch width but leave much more room above the stove.
These are the best choice if you are replacing a range hood with a microwave for the first time. Range hoods take up very little vertical space. A standard microwave is tall. If you swap a hood for a standard microwave without moving the cabinets, the microwave hangs dangerously low. The low profile model mimics the form factor of a hood while providing microwave utility.
The trade-off is interior height. You cannot fit a tall travel mug or a large whole bird in a low profile unit. They accommodate dinner plates and casserole dishes easily, but vertical items pose a challenge. You decide based on your cooking habits. If you reheat coffee in tall tumblers, verify the interior cavity height first.
Installation Hardware And Venting Space
The box includes hardware that affects the final fitted position. The toggle bolts that secure the top of the unit require space inside the upper cabinet. If your upper cabinet is full of permanent shelving or plumbing, installation becomes difficult. You might need to modify the cabinet shelving to allow room for the bolts and the power cord.
Venting options change the effective depth. If you vent externally through the roof or wall, you must rotate the internal blower motor. This procedure is standard, but some units require an adapter damper that adds height or depth to the connection point. Always check if the installation instructions list specific clearance zones for the damper.
Recirculating installation (venting back into the room) usually requires installing a charcoal filter. Access to this filter is typically behind a grille on the top front. You need clearance to remove this grille for filter changes. If the cabinet above has a deep overhang or light rail, it might block access to the filter door.
Door Swing And Side Wall Issues
One of the most overlooked “size” issues is the door swing radius. If your stove is next to a wall or a refrigerator panel, a standard microwave door might not open 90 degrees. It will hit the wall. You cannot remove the food if the door only opens halfway.
Manufacturers solve this with “zero clearance” hinges on some models. These doors open within the width of the microwave body. They do not swing wide. If you have a tight side clearance, you must hunt for this feature. It is not standard on every model. Check the spec sheet for “door swing with handle” measurements.
The handle itself adds to this problem. Bar handles protrude further than pocket handles. In a tight corner, a pocket handle (recessed into the door) might save the inch you need to fully open the unit.
| Measurement Zone | Recommended Distance | Why It Matters |
|---|---|---|
| Stove to Microwave Bottom | 13″ Minimum (check codes) | Prevents heat damage to unit. |
| Floor to Microwave Top | 66″ Standard | Ensures ergonomic reach. |
| Cabinet Width Opening | 30″ Min | Required for standard units. |
| Upper Cabinet Depth | 12″ – 13″ Max | Ensures venting works properly. |
Capacity Vs. Exterior Dimensions
Do not assume that a higher cubic foot rating means a wider microwave. The width is capped at 30 inches. Manufacturers gain capacity by stretching the height and depth or by thinning the insulation walls. A 1.7 cubic foot model and a 2.1 cubic foot model often share the same 29 7/8 inch width.
The difference lies in the height. The 2.1 model hangs lower. If you have plenty of clearance above your stove, the larger capacity is a nice upgrade. If your space is tight, the smaller capacity unit is the safer bet. You rarely miss the extra 0.4 cubic feet, but you will definitely notice if you cannot put a large stockpot on your back burner because the microwave is in the way.
Interior measurements vary more than exterior ones. Some units have a bi-level cooking rack that lets you cook two dishes at once. This rack requires vertical interior space. If you plan to use this feature, prioritize a taller unit.
Smart Features And Size Creep
The latest generation of appliances includes large touchscreens and smart home hubs. These screens are often embedded in the door. To accommodate the electronics for a 20-inch touchscreen, the door assembly becomes thicker and heavier. This adds to the overall depth of the unit.
These “hub” microwaves often have slightly different mounting requirements due to the added weight on the front. The wall bracket must be hit perfectly into studs. While the width remains standard, the physical bulk of the door changes how the unit feels in the room. It dominates the space more than a basic model.
Verify that your cabinetry can visually support a heavy-looking appliance. A massive smart microwave looks out of place hanging from delicate, shallow vintage cabinets. The size is correct technically, but the visual fit is jarring.
Replacing Or Modifying Cabinetry
Sometimes the standard 30-inch microwave simply will not fit your existing layout. This happens often in custom homes built before the 1990s. You might find a 24-inch or 27-inch cabinet opening. In this scenario, you cannot force a standard OTR unit.
You have two choices. You can modify the cabinetry, which involves cutting wood and potentially ordering new doors. Or, you can look for the very rare compact OTR models. Compact models are scarce and expensive. Cabinet modification is often the cheaper long-term solution because it standardizes your kitchen for future replacements.
If your opening is too wide (36 inches or more), you are in a better position. You can buy a standard 30-inch microwave and a filler kit. These metal strips screw into the side of the microwave or the cabinet to cover the gap. They give the installation a built-in look without requiring custom carpentry.
Final Fitment Checklist
Before you click “buy” or load the cart, run through a quick mental checklist. Confirm the width of your opening is 30 inches. Measure the height from your stovetop to the bottom of the current cabinet. Subtract the height of the new microwave from that number. If the remaining result is less than 13 inches, you need a shorter microwave or a low profile model.
Check your backsplash. If you have thick tile that runs up the wall, it might interfere with the mounting bracket. You might need to remove a row of tile or shim the bracket to sit flush. These small details cause the most headaches during installation.
Lastly, check the swing. Stand in front of your stove and mimic opening the door. Look at what is to your left. If there is a wall, measure the distance. Compare this to the side clearance requirement in the manual. This step saves you from installing a brand new appliance that you cannot open.