An over-the-range microwave is a popular choice in small kitchens because it combines two appliances in one space: a microwave and a vent hood with a light. In a townhouse galley or an apartment kitchen with limited counter space, it can free up valuable room. But it only works if the space above your range fits it, both in measurements and in structure.
This walkthrough takes you through what to measure and check before buying.
What the installation guide controls
Every over-the-range microwave comes with an installation guide that sets out:
- •The minimum distance from the cooktop to the bottom of the microwave.
- •The minimum distance from the cooktop to the bottom of the cabinet above, which the microwave hangs from.
- •The width of the opening the microwave fits into.
- •How the unit mounts to the wall and cabinet.
- •Venting options: outside through the roof or wall, or recirculating back into the kitchen.
Those numbers vary by brand and model. Do not plan with a figure you read somewhere else; download the guide for the model you are considering from the manufacturer's website.
Step 1: Measure cooktop to cabinet
Measure from the cooktop surface, not the floor, to the underside of the cabinet above the range. Measure at both ends and the middle, because cabinets in older kitchens are not always level.
Compare that number to two figures from the installation guide:
- •The minimum cooktop-to-cabinet distance.
- •The microwave's own height.
The difference between the two tells you how much clearance there will be between the cooktop and the bottom of the microwave. If the gap is too small, the microwave's underside can overheat, and you will have trouble using tall pots on the back burners.
Step 2: Measure the width
Most over-the-range microwaves are made for a standard cabinet width over a standard range. Measure:
- •The width between the cabinets on either side, if any.
- •The width of the cabinet above.
If you have a narrower or wider range, or a cabinet that is not a standard width, check whether a filler kit or a different model works.
Step 3: Check the wall structure
An over-the-range microwave is heavy, and it hangs mostly from the wall, with bolts through the cabinet above for support. The installation guide will specify a mounting plate that attaches to wall studs or a solid surface, and toggle bolts or similar fasteners where studs are not available.
Depending on the age of the house, the wall behind the range might be:
- •Plaster over lath, which can crumble around fasteners.
- •Brick or block, common in older brick rows and some masonry walls, which needs masonry anchors.
- •Drywall over studs in a renovated kitchen.
Find the studs or determine the wall type before you buy. If the wall cannot hold the mounting plate as the guide requires, a hood may be the better choice.
Step 4: Check the cabinet above
The top of the microwave usually bolts through the bottom of the cabinet above. That cabinet needs:
- •A solid bottom panel that can take the bolts.
- •Enough space inside to reach the bolts during installation.
- •If venting through the cabinet to the roof or an outside wall, room for the duct.
Some older or custom cabinets have thin bottoms or decorative trim that gets in the way.
Step 5: Decide on venting
Over-the-range microwaves can usually be set up two ways:
- •Exhausting outside. Air is pulled up through the microwave and pushed into a duct that runs through the cabinet and out the roof or wall, or through the back of the microwave straight out the wall. This is the more effective option.
- •Recirculating. Air passes through a charcoal filter and blows back into the kitchen. Easier to install, but it does not remove heat or moisture.
If you have a gas range, consider exhausting outside. Our article on range hood duct problems explains why duct size and routing matter.
In condo buildings, venting to the outside may be restricted by building rules. Check with your management office.
Step 6: Check the outlet
Most over-the-range microwaves plug into an outlet inside the cabinet above. The installation guide will say whether a dedicated circuit is called for. If there is no outlet in the cabinet, or it is not grounded, an electrician needs to install one.
When a hood is the better choice
An over-the-range microwave is a compromise. It is generally less effective at clearing smoke and grease than a dedicated range hood. Consider a hood if:
- •You cook often on high heat, especially on a gas range.
- •Your cooktop-to-cabinet distance is too tight for a microwave.
- •The wall cannot support the microwave's weight.
- •You have a high-output or professional-style range. Many of those ranges' manuals say an over-the-range microwave should not be installed above them.
Our article on range hood mounting height covers how to choose and place a hood.
Quick reference
| What to check | Why it matters |
|---|---|
| Cooktop to cabinet distance | Heat and pot clearance |
| Opening width | Microwave must fit |
| Wall type and studs | Supports the mounting plate |
| Cabinet bottom | Supports top bolts |
| Venting route | Outside or recirculating |
| Outlet in cabinet | Power for the microwave |
| Range type | Some ranges are not compatible |
Signs an existing installation is a problem
- •The microwave's underside, controls or door get very hot during stovetop cooking.
- •The microwave sags or pulls away from the wall.
- •The vent fan runs constantly or automatically turns on during cooking. Many models do that on purpose to protect themselves from heat, but if it happens all the time, the gap may be too small.
- •Grease drips from the underside or the filters are saturated.
When to call a technician
If your over-the-range microwave is not heating, the turntable will not turn, the vent fan or light has stopped, or the control panel is not responding, a technician can find the fault. Microwaves contain high-voltage parts that hold a charge even when unplugged, so internal repairs are not a DIY job. See our microwave repair page, and book a visit online.