How to measure your kitchen for new cabinets

Quick answer: Draw the room first, then measure every wall at three heights, in inches, to the nearest 1/8 in, taking each number from one corner. Add the windows, doors, ceiling and every pipe, outlet and vent, check the corners for square and the floor for level, and plan to the smallest number you find. Before anything is ordered, have the dealer or installer measure the room again.

What you need

• A 25 ft tape measure with a stiff blade, and a helper for long walls
• Graph paper, a pencil and a clipboard
• A 4 ft level, or a shorter level on a long straight board
• Painter's tape, to mark pipes and outlets as you find them
• Your phone, to photograph every wall and the inside of the sink cabinet

Step 1: Sketch the room before you measure

Draw the room freehand, large enough to write on. Show every wall, door, window and opening, and mark where the sink, range and refrigerator are today. Every number you take goes straight onto this drawing, next to the thing it measures.

Write everything in inches: 127 1/4 in, not 10 ft 7 1/4 in. Cabinet widths are listed in inches, so you never have to convert.

Step 2: Measure each wall at three heights

Walls are rarely straight and corners are rarely square, so one number per wall is not enough. Measure each wall from corner to corner:

1. Just above the baseboard, where the base cabinets and toe kick sit.
2. At counter height, about 36 in off the floor.
3. At wall cabinet height, about 60 in off the floor or higher.

Circle the smallest of the three: that is the space the cabinets have to fit. If the numbers differ, note by how much, because the plan has to leave room for the fillers and scribe molding that close those gaps.

Step 3: Locate windows and doors from the corner

Start the tape in the corner and read every point along the wall without moving it: the near edge of the window trim, the far edge, then the door trim. Running measurements like these keep small errors from piling up.

For each window, note the distance from the corner to each outside edge of the trim, and the height from the floor to the sill and to the top of the trim. For each door, note where the trim starts and stops and which way the door swings. No wall cabinet or tall cabinet can cover a window or its trim, and the sill height tells you whether the counter, the backsplash and the faucet fit below it.

Step 4: Measure up

Measure from the floor to the ceiling at several points along each wall and keep the lowest. For a soffit or bulkhead, record its height, how far it comes out from the wall and where it starts and stops. These numbers choose your wall cabinets: 30, 36 or 42 in cabinets hung at the usual 54 in reach 84, 90 or 96 in. Our guide to how high to hang upper cabinets shows what fits under each ceiling.

Step 5: Mark every utility

From the same corner, measure to the center of each of these, and note its height off the floor:

• the drain and the supply lines,
• the gas line, if there is one,
• every outlet and switch, including the large outlet for an electric range,
• heating and cooling registers, in the wall, the floor or the toe kick,
• the hood duct, if it leaves through the wall or the ceiling.

Almost any of these can move, but moving a drain, a gas line or a circuit is work for a licensed plumber or electrician, and it changes the budget. Knowing where they are now tells you what each layout really costs.

Step 6: Check the corners and the floor

To check a corner for square, use the 3-4-5 test. Mark 3 ft out along one wall and 4 ft along the other; the diagonal between the marks should be exactly 5 ft. Longer means the corner is more than 90 degrees, and shorter means it is tighter. On a long L or U, use 6, 8 and 10 ft.

For the floor, lay the level where the base cabinets will stand and find the high point. Base cabinets are set level from it and shimmed up everywhere else, so it sets the counter height and the line for the wall cabinets.

Step 7: Write down the appliances you will buy

Do not measure the old refrigerator unless you are keeping it. Get the installation guides for the models you plan to buy: the cutout size, the clearances the maker asks for and how far the doors swing. A dishwasher is usually 24 in wide and a standard range 30 in, but the maker's numbers always win.

What to write down

Mistakes that cost money

1. Measuring the room instead of the wall. A bulge in the plaster at counter height can take half an inch the floor measurement never shows.
2. Forgetting the trim. Window and door casing is often 2 to 4 in wide, and cabinets have to stop short of it.
3. Rounding up. Write the fraction, and if you must round, round down: a run that is 1/8 in too long does not go in.
4. Ignoring what opens. Drawers that meet in a corner and a refrigerator door against a wall both need room, and fillers, often 3 in wide, give it to them.

Turn the numbers into a plan

With the drawing done, you can try layouts. In the free OpalSketch 3D designer you can draw the room to your numbers, or start from an L, U, galley, one-wall or island layout and stretch it to fit, then place real cabinets at their real sizes. The plan notes point out where landing space, aisles or the work triangle fall short of the planning guidelines. For the sizes you will be fitting, see standard kitchen cabinet sizes, and to compare shapes, kitchen layouts compared.

If you measure for clients, the OpalSketch portal keeps each design with its project, and the client page is where your client sees it, approves the quote and sends you messages.

Questions people ask

Should I measure in inches or feet?

Inches. Cabinets are sold in inch widths, in 3 in steps, so 138 1/2 in is far easier to work with than 11 ft 6 1/2 in.

How accurate do my measurements need to be?

To the nearest 1/8 in for walls, windows and doors. Fillers absorb a little, but not a mistake of an inch.

Do I measure to the wall or to the baseboard?

To the wall. The baseboard comes off where the cabinets go, but note its thickness, because the end panels have to meet it where it stays.

Can I order cabinets from my own measurements?

You can plan and price from them. Before the order, the dealer or installer should measure again, after any walls are opened or moved, so the cabinets fit the room as it really is.