Which measurement units should I use?
Use one consistent length unit and enter coverage in the matching square unit per can, liter, or gallon.
Paint Calculator
Estimate paint quantity from wall area, coverage, coats, and excluded openings.
Calculations happen locally. We do not send your values to our server.
Example
A 5 by 4 room with 2.5-high walls has 45 square units of wall before subtracting doors and windows.
Calculation method
Wall area is two times length plus width, multiplied by height. Openings are subtracted, then coats are applied and divided by coverage.
Important notes
This planning estimate excludes ceilings, trim, waste, surface absorption, texture, application loss, and manufacturer-specific coverage differences.
Frequently asked questions
Should I subtract doors and windows?
Yes. Enter their combined area, or enter zero for a more conservative paint estimate.
Why might I need more paint than shown?
Rough surfaces, color changes, spills, application method, and leftover reserve can increase real usage.