Measure a room or enter direct wall area, subtract openings, and get gallons and whole-gallon purchasing quantity.
Use the room mode when you want a quick wall and ceiling estimate from room dimensions. Use direct-area mode when you already measured the wall area. In both cases, the calculator lets you subtract openings and account for coats.
Room wall area is 2 × (length + width) × height. Subtract doors and windows, optionally add the ceiling, then divide by coverage after applying coats.
A 12 × 10 room with 8 ft walls has 352 sq ft of gross walls. Subtract a 21 sq ft door and two 15 sq ft windows for 301 sq ft. Two coats at 350 sq ft per gallon need about 1.72 gallons, or 2 gallons to buy.
Keep some paint for touch-ups, but check whether primer is needed and whether the label coverage assumes one coat over a similar color. Trim and cabinets need separate measurements.
Surface texture, color change, primer, sheen, coats, ceiling coverage, and product label coverage can change the final amount.
This estimates paint quantity only. It does not choose primer, sheen, color, trim coverage, cabinets, or a painting method.
Use it when you already measured the paintable wall area or when the room shape is not well represented by four walls.
Yes. Enter their repeated area when you want the estimate to reflect the surfaces that will actually be painted.
No. Coverage varies by product and surface. Use the label and enter the number of coats you plan to apply.
Short, practical help for the next step in this project.