Rolling vs spraying interior paint — spraying buys about 45% more paint

What this diagram shows

Two side-by-side scenes compare rolling and spraying the same wall. A roller transfers nearly all of its paint onto the wall, so the calculator multiplies the bare gallons by 1.0 for material and 1.10 for waste, a total of 1.10 times. A sprayer atomizes the paint into a fan, and a large share never reaches the wall — overspray drifts off the edges and bounces back as fog — so the calculator multiplies the bare gallons by 1.33 for material and 1.20 for waste, a total of about 1.60 times. The result is that spraying the same wall with the same number of coats buys roughly 45 percent more paint than rolling. Spraying still wins on doors, trim, and cabinets for a fine, fast finish, but rolling a few walls buys less paint and needs no masking.