Paint Calculator
Gallons and cost for kitchen/bath moisture-resistant paint.
Each door is deducted as 20 sq ft.
Each window is deducted as 15 sq ft.
How to use this calculator
Enter the room's length, width, and ceiling height in feet, then choose the number of coats. The calculator returns the gallons of paint you need, rounded up to the nearest half gallon, and an estimated cost. Measure the actual room rather than the outside of the house, and remember that the calculation covers walls only.
How this is calculated
The calculator works out total wall area from your room's perimeter and ceiling height, subtracts 20 square feet for each door and 15 for each window you enter, then divides by paint coverage. Kitchen and bathroom paints (moisture- and mildew-resistant formulas) tend to cover slightly less per gallon than standard interior paint, so the calculator uses 350 sq ft/gallon rather than the usual 400.
Example
A 12 by 10 foot kitchen with 9-foot ceilings has about 396 square feet of wall, or roughly 361 square feet to paint after deducting one door and one window. Two coats need about 2 gallons, which the calculator rounds up to 2.5 gallons. At $35–$65 per gallon that is roughly $88–$163. With a single coat, the same room needs about 1.5 gallons.
Why two coats
Two coats is standard for durability in high-moisture, high-traffic rooms like kitchens and bathrooms, especially over a different existing color. Use a primer first when going from a dark color to a light one or painting over bare or repaired drywall.
What isn't included
Ceilings, trim, doors, and primer are not part of this estimate. Add the ceiling separately by dividing its area by the paint coverage. Buy a little extra for touch-ups, and check the coverage printed on the can, since it varies by product.
Estimate only — ceilings are not included in this calculation.
Read the full guide
How Much Paint Do I Need for a Kitchen or Bathroom?