BEFORE BUYING

SECTION 01 · USABLE AREA

1. Measure the area you want to paint

Multiply the width by the height of each wall and add the results. For a quick estimate, use the room's total wall area. For more precision, subtract large doors and windows.

WIDTH×HEIGHT=AREA IN SQ FT

Example: a 12 ft wide by 8 ft tall wall is 96 sq ft. If you are painting three identical walls, your working area is 288 sq ft.

Useful shortcut.

You don't need a perfect number to start. The calculator adds a 10% waste margin to cover absorption, touch-ups and small losses.

SECTION 02 · COATS

2. Decide how many coats you will apply

One coat can be enough for light touch-ups over a similar color. To change color, cover stains or get a uniform finish, two coats are the sensible reference. The calculator keeps it to one, two or three coats so the result stays clear.

Blue, white, black and clay pigment swatches with a metal ruler
REFERENCE PALETTE The wall type, the previous color and the paint you choose all change real-world coverage.

SECTION 03 · COVERAGE

3. Understand the math without a spreadsheet

We use a practical reference of 350 sq ft per gallon per coat — the mid-range of what BEHR and Glidden declare. First we multiply your area by the coats and add 10% waste. Then we divide by the coverage. The purchase rounds up to the nearest quart, because buying 1.1 gallons is not a practical US container.

350

CALCULATION REFERENCE

350 sq ft per gallon, per coat

An orientative value for interior latex over prepared walls. Always check the coverage stated by the brand and finish you plan to use.

Got your measurements?

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