Materials & Projects

Paint Calculator

Enter the room length, width, and wall height instead of trying to figure out wall square footage yourself. You can subtract windows/doors and add ceiling or other extra area in advanced settings.

Last updated: May 2026

Unit system Switch between U.S. customary and metric units. Your choice is remembered on other calculators.

Room measurements

This estimates wall paint from room dimensions. Use advanced settings to subtract openings or add ceiling/extra area.

Visual guide

Which measurement goes where?

Room length, width, and wall height estimate wall area. Openings can be subtracted and ceiling/extra area can be added in advanced settings.

Room length

Room width

Wall height

Number of coats

coats

Advanced settings

Windows/doors to subtract

sq ft

Approximate total window and door area. Set to 0 if you do not want to subtract openings.

Ceiling / extra area to add

sq ft

Add ceiling area, closets, accent walls, or other surfaces if needed.

Paint coverage

sq ft/gal

Most cans list coverage on the label. 300–400 sq ft/gal is common.

Extra / touch-up allowance

Buying and sizing notes

For dark color changes, porous surfaces, textured walls, or bare drywall, plan extra paint or primer.
Keep a labeled leftover container for touch-ups.

How to use this estimate

What this includes

The required inputs shown on this page
common planning assumptions
optional advanced adjustments where provided

What it does not include

site-specific professional design
local code approval
manufacturer-specific requirements
installation quality

Common mistakes

Leaving a required input at the default when your situation is different
ignoring product labels or ratings
treating the estimate as an exact final answer

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