What this calculator does

Gallons of paint for a room from its size, the doors and windows, the number of coats and whether you paint the ceiling. Coverage is about 350 sq ft per gallon.

How to use it

1. Measure the room length, width and wall height.
2. Enter the doors and windows, which are subtracted from the wall area.
3. Pick the number of coats and whether the ceiling is painted.

Why it matters

Paint colour changes slightly from batch to batch. If you run out half way and open a new can, a visible line can appear. Buying about the right amount avoids that and avoids storing half empty cans. New drywall and dark colours need more coats.

Tips from the job site

• Prime new drywall and patched areas first.
• Buy all the paint at once and mix the cans together for an even colour.
• Choose a washable finish for kitchens, bathrooms and kids rooms.

These results are estimates. We measure on site before we quote, and we confirm local rules with your city.