Measure first: sizing an accent wall and its paint

Almost every decision about an accent wall starts with one number: its area. Paint is sold by coverage, layouts are drawn to scale, and even a design idea that looks right in a photo has to be scaled to the wall you actually have. Getting that number right takes a tape measure, a pencil and a few minutes.

How do you measure the wall?

Sherwin-Williams describes the basic step simply: measure the length and width of the surface and multiply them to get the square footage⁴. For a wall, that means its width along the floor and its height from floor to ceiling, both in feet. Take the height in more than one spot, at each end and in the middle, because ceilings and floors are rarely perfectly level. Use the largest figure for buying and the smallest for any layout that has to fit.

What should you subtract?

Windows, doors and anything else that will not be painted. Behr notes that the more “unpaintable” features a wall has, such as windows and doors, the less paint it will need⁵. Measure each opening the same way, width times height, and subtract it from the wall’s total.

Arithmetic worked out for this guide.

How much paint does that take?

Sherwin-Williams says a gallon typically covers about 350 to 400 square feet, and that a quart covers about 100 square feet, which it calls enough for an accent wall project⁴. Behr gives a wider range of 250 to 400 square feet per gallon for one coat⁵. In our example, 111 square feet per coat is a little over one quart’s worth; two coats, 222 square feet, fit within a single gallon at either company’s figures. Behr adds that porous, rough, textured or previously unpainted surfaces, or a dramatic color change, may call for additional coats⁵, so a deep accent color over a pale wall deserves a margin.

What about trim?

If the plan includes painting trim in the accent color, Behr suggests measuring the total length of baseboard, casing and molding and, using an average trim width of six inches, multiplying that length by 0.5 foot to estimate its area⁵.

How does the number help with layout?

The same measurements turn into a scale drawing. At one square per two inches on graph paper, a 14-foot wall is 84 squares wide, which is enough to see how boards, battens or a color block will meet the corners and the window. Most layout problems show up on paper first, where they cost nothing to fix. Every wall is different, so any pricing has to start from the real room; Trim My Crib, the publisher of this guide, prices projects only after seeing them in person.

What else is worth writing down?

While the tape is out, note where outlets, switches, vents and the thermostat sit, measured from one corner and from the floor. Those few extra numbers feed straight into the planning checklist and make a scale drawing quick to produce.