Dishwasher cutout dimensions are the width, height and depth of the cabinet opening a built-in dishwasher slides into, measured from the floor to the underside of the countertop. They lead the installation guide because a dishwasher's leveling legs and mounting brackets only adjust within a set range, so the opening has to fall inside it.
What the spec actually says
Most built-in dishwashers sold in the U.S. are designed for an opening about 24 inches wide, but the exact numbers and tolerances vary:
- •GE GLD6500: GE's installation instructions say the rough cabinet opening must be at least 24 inches deep, 24 inches wide and approximately 34 1/2 inches high from the floor to the underside of the countertop. They also call for 28 3/8 inches clear in front for the door and, in a corner, 2 inches between the dishwasher and the adjacent cabinet or wall.
- •Bosch SHE53T56UC: The spec sheet lists a required cutout of 33 7/8 by 23 5/8 by 24 inches (height by width by depth) and tells you to consult the installation instructions before making the cutout.
- •Whirlpool-published undercounter dishwasher guide (W10702387): The guide says to measure the height of the opening from the underside of the countertop to the floor where the dishwasher will be installed, using the lowest point, and to compare it with the height range in its opening diagram. It notes that an ADA installation, 32 1/2 inches beneath a 34-inch countertop, can be done by adjusting the toe kick and leveling legs. The opening must be fully enclosed on both sides, the back and the top. The guide calls for 25 5/8 inches in front for the door and at least a 1/2-inch gap between the countertop and the top of the door.
Why manufacturers require it
- •Height: The leveling legs extend only so far. Too short an opening and the unit won't slide in. Too tall and the legs can't raise it to the countertop for mounting.
- •Width: Too tight and the tub rubs the cabinets or the door binds. Too wide and side brackets don't reach.
- •Depth: The unit needs room for the water line, drain hose and power connection behind or beneath it.
- •Enclosure: The dishwasher is secured to the countertop or adjacent cabinets. Whirlpool's guide gives screws through top brackets for wood countertops and side-mount brackets for granite or other surfaces that can't take screws.
- •Front clearance: The door opens down and out, and in a corner it needs side room so it doesn't hit a drawer pull or handle.
How to check your home against it
- Measure the width at the front and back of the opening, and at the top and bottom. Use the smallest number.
- Measure the height from the floor to the underside of the countertop at the front and the back. Use the lowest point, as Whirlpool's guide says.
- If new flooring will go in, subtract its thickness, including underlayment, from the height.
- Measure the depth from the front of the cabinets to the back wall, and note pipes or the outlet that stick out.
- Check the corner situation. If the opening meets a corner, measure to the nearest cabinet, wall or appliance on the door side.
- Note your countertop material, because it decides between top brackets and side-mount brackets.
- Compare every number with the guide for the model you plan to buy, not a generic chart.
What happens when it's ignored
- •The new unit doesn't fit, or fits only after the legs are fully retracted, leaving no room to level it.
- •An unsecured dishwasher can tip forward when the door is opened with loaded racks.
- •The door rubs adjacent cabinets or hits a handle in a corner.
- •Pinched hoses behind the unit cause drain or fill problems. The drain hose has its own height spec, explained in dishwasher high loop vs. air gap.
When it needs a licensed pro
- •If the outlet, water supply or drain has to move to fit the new unit, the plumbing parts are a plumber's job and the electrical parts are an electrician's.
- •Raising or lowering a countertop, or rebuilding the opening after a floor change, is work for a cabinet installer or contractor.
- •If a hardwired unit is being swapped for a cord-connected one, or the reverse, see dishwasher electrical requirements and have an electrician handle the connection.
Sources
- •GE: GLD6500 built-in dishwasher installation instructions (24 by 24 by about 34 1/2 inches; front and corner clearances)
- •Bosch: SHE53T56UC spec sheet (33 7/8 by 23 5/8 by 24 inches)
- •Whirlpool: Undercounter dishwasher installation instructions W10702387 (height measurement; ADA note; enclosure; front clearance; countertop gap and brackets)
Quick check: Measure the height at the back of the opening, not just the front. Floors and countertops are rarely perfectly parallel.
If the replacement won't sit level or drain right after the swap, have it checked before small problems turn into leaks. TrueFix Long Island takes those calls at (631) 985-3690, or you can book through our dishwasher repair page.