Paint Calculator
Calculate how much paint you need for your room
A paint calculator estimates how much paint you need from the wall perimeter, wall height, number of coats, doors, and windows.
Calculator Inputs
Sum of all wall widths
Standard door size subtraction
Standard window size subtraction
Results
Enter values above to see your results
How It Works
We calculate the total wall area, subtract typical areas for doors and windows, and multiply by the number of coats. Standard coverage is 350 sq ft per gallon (or ~9-10 sqm per liter).
Worked example
Feet and gallons
40 ft= Given8 ft= Given2= Given1= 20 sq ft1= 15 sq ft40 × 8= 320 sq ft20 + 15= 35 sq ft320 − 35= 285 sq ft285 × 2= 570 sq ft570 / 350= 1.63 gallonsRounded up to the nearest tenth (1.7); heading prints whole gallons= 2 gallonsTips & Best Practices
- •Always buy a little extra for touch-ups.
- •Textured walls may require 10-20% more paint.
- •Darker colors covering lighter ones may need 3 coats.
Frequently Asked Questions
How much does a gallon of paint cover?
A standard gallon of paint covers approximately 350 to 400 square feet with one coat.
Guides & Articles
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