Measuring for an appliance: dimensions, clearances and doorways

North American appliances are built to a fairly rigid set of sizes, which is what makes swapping one out possible at all. These are the figures to plan around:

A kitchen laid out in the last forty years almost certainly has a 30-inch range opening and a 24-inch dishwasher bay. Where things go wrong is the fridge alcove, which is built to whatever the original fridge was, and laundry rooms, which are built to whatever fit at the time.

Walls are not square and floors are not level. One measurement is a guess.

• Width: measure at the front, the middle, and the back of the opening. Use the smallest number.
• Height: measure at the left, centre, and right. Use the smallest number. Watch for a cabinet or bulkhead above a fridge.
• Depth: measure from the back wall to the front edge of the counter. Then check for anything in the way at the back — a water line, a gas shut-off, a plug, a duct. A receptacle sticking out steals two inches you thought you had.
• Check the floor. An older kitchen often has raised flooring laid up to the appliance but not under it, meaning the new unit sits higher than the old one did.

The unit's outside dimensions are not the space it needs. Appliances need room to breathe, vent, and open.

Walk the route the appliance will travel, from the truck to its final position, with a tape measure. Measure every one of these:

• The exterior door, measured inside the frame with the door open — and note whether the door itself or its hardware narrows the opening.
• Any turn in a hallway. A tight 90-degree turn is more restrictive than a straight doorway of the same width, because a tall appliance can't be angled through it.
• Stairs: tread depth, headroom, and the width at the landing. A turning landing is where most refrigerators get stuck.
• Interior door frames along the route.
• The height of the lowest obstruction — a light fixture, a low soffit, a door closer.

The working rule: you want the narrowest point on the path to be at least an inch wider than the appliance's smallest dimension, since a fridge or washer can be walked through on its side or narrow face. If it's close, refrigerator doors usually come off and buy back 3–4 inches, and a dryer's door can often be removed too. Tell whoever is delivering before the truck is loaded, not when it's in your driveway.

• Range: is the receptacle 240V (large, three or four slots) or is there a gas line? An electric range cannot be made to run on a standard outlet.
• Dryer: same question — 240V receptacle, or gas valve plus a standard outlet.
• Electric cord configuration: 3-prong and 4-prong are both common depending on the age of the wiring. The cord swaps cheaply; it just has to match.
• Washer: hot and cold taps plus a standpipe or laundry tub for the drain.
• Fridge with ice or water: a 1/4-inch water line. No line means either running one or accepting the dispenser won't work.
• Dishwasher: hot water supply, a drain connection, and power — often hard-wired rather than plugged in.

Take photos of every hookup and the appliance's model plate on your phone before you go shopping. It takes a minute and answers most of the questions anyone will ask you.