5 Things to Measure Before You Design Any Cabinet

Getting the dimensions right before you sketch a single line saves hours of rework. Here are the five measurements most DIYers miss — and why they matter.

Every cabinet project starts with measurements. But most people only measure the obvious stuff — width, height, depth — and call it done. The problem is, cabinets live in real spaces with real constraints. A quarter-inch error in the wrong place can mean a door that won't open, a drawer that hits a pipe, or a countertop that doesn't sit flush.

1. Wall-to-Wall at Three Heights

Walls are rarely perfectly straight or plumb. Measure the width of your space at the floor, at counter height (36 inches), and at the top of the upper cabinets. Use the smallest measurement as your working width. This prevents you from building something that physically won't fit.

2. Floor Level and Slope

Place a 4-foot level on the floor where your cabinets will sit. Check front-to-back and side-to-side. Most floors have some slope — you need to know how much so you can shim the base cabinets level. Ignoring this leads to doors that swing open or closed on their own and countertops that pool water.

3. Obstruction Mapping

Before you design anything, map every obstruction in the space: electrical outlets, light switches, plumbing lines, HVAC vents, windows, and door swings. Mark their exact positions on your wall elevation drawing. These determine where you can and can't place cabinets, and they often force design changes that are much easier to handle on paper than in the middle of an install.

4. Ceiling Height Variations

Measure ceiling height at multiple points along the wall. Older homes especially can have significant variation. If you are running cabinets to the ceiling or adding crown molding, you need to know the high and low points. A scribe strip or filler piece can handle small differences, but you have to plan for it.

5. Appliance Dimensions (Not Just the Spec Sheet)

Spec sheets give you nominal dimensions, but real appliances have handles, hinges, and ventilation requirements that add inches. Measure the actual appliance — including the door swing, handle protrusion, and any required clearances noted in the installation manual. Design your cabinet openings around the real footprint, not the marketing dimensions.

Taking these five measurements adds maybe 30 minutes to your planning phase. Skipping them can cost you days of rework and wasted material. Measure twice, design once.