Over-the-range microwave mounting height is set by two measurements in the installation guide: how high the cabinet above sits from the floor, and how far that cabinet is from the cooking surface below. The guide treats them as requirements because the microwave hangs from the wall and cabinet over a hot cooktop, and it has to be both safely clear of the heat and solidly supported.
What the spec actually says
GE's over-the-range microwave installation instructions (publication 49-8699-3) give a set of linked figures:
- •Cabinet above, from the floor: The bottom edge of the cabinet that will be above the microwave must be at least 66 inches from the floor.
- •Cabinet above, from the cooktop: The bottom of that cabinet must be 30 inches or more from the cooking surface.
- •Width: A minimum of 30 inches between the cabinets.
- •Backsplash: The microwave's bottom should be at least 2 inches above the range backsplash.
- •Support: The microwave must be mounted to both the top cabinet and the wall, and connected to at least one wall stud. The wall needs 2-by-4 studs and drywall or plaster at least 3/8 inch thick. Island and peninsula installations aren't permitted.
- •Weight: The unit weighs 65 pounds, and the mounting must hold up to 115 pounds including up to 50 pounds of food and cookware.
- •Power: A separate 15- to 20-amp branch circuit with a single grounded outlet located in the cabinet above.
- •Venting: Outside through the top, outside through the back, or recirculating with a charcoal filter kit.
Other brands use similar figures, but check the guide that comes with your model.
Why manufacturers require it
- •Heat from below: The 30-inch cabinet-to-cooktop distance keeps the microwave's underside a safe distance from burners and pans.
- •The two heights together: The 66-inch floor figure and the 30-inch cooktop figure fix the space the microwave hangs in, so its bottom ends up well above the burners while the door and controls stay within reach.
- •Load: A loaded microwave hangs out over the cooktop. A stud and the cabinet above share that weight; drywall anchors alone don't.
- •Outlet in the cabinet: The cord runs up through the cabinet bottom, keeping it away from cooktop heat.
How to check your home against it
- Measure from the floor to the bottom of the cabinet above the range. It should be at least 66 inches.
- Measure from the cooking surface to the bottom of that cabinet. It should be at least 30 inches.
- Measure the opening width between the side cabinets. It should be at least 30 inches.
- Measure from the top of the range backsplash to where the microwave's bottom will sit, allowing the 2-inch gap.
- Use a stud finder on the wall behind the opening and mark at least one stud.
- Open the cabinet above and look for a grounded outlet. If there isn't one, plan for one.
- Decide on venting: if there's an existing duct through the wall or roof, note its location.
What happens when it's ignored
- •A microwave hung too low runs hot from the cooktop below and is hard to use safely.
- •One mounted without a stud can pull away from the wall under load.
- •An extension cord run from a countertop outlet is a hazard.
- •Grease and heat collect if the vent isn't connected or the filter kit isn't installed.
A range hood follows different height rules. See range hood mounting height.
When it needs a licensed pro
- •Adding the outlet in the upper cabinet, or a dedicated circuit for it, is work for a licensed electrician.
- •Cutting a new vent through an exterior wall or roof is a job for a contractor.
- •Raising or replacing the cabinet above to reach 66 inches is cabinet or carpentry work.
- •Never open the microwave's cabinet itself. Microwaves contain high-voltage parts that stay charged after unplugging.
Sources
- •GE: Over-the-range microwave installation instructions 49-8699-3 (66 inches from the floor; 30 inches above the cooking surface; 30-inch width; stud; weight; outlet; venting)
Quick check: Two numbers decide it: at least 66 inches from the floor to the cabinet above, and at least 30 inches from the cooktop to that cabinet.
If an over-the-range microwave stops heating or its fan or light fails, call TrueFix Long Island at (631) 985-3690 or visit our microwave repair page.