Paint Calculator

Gallons of paint needed for a room, with door and window deductions.

Quick answer: Free Paint Calculator online. Figure out exactly how many gallons of paint you need, accounting for doors, windows, and multiple coats.

Paint needed2.49 gallons
Paintable area872 sq ft
Quarts (round up)10
Coats2
NoteCoverage varies by paint brand (300–400 sq ft/gal). Add 10% for trim.

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Find exactly how many gallons of paint you need for any room, with deductions for doors and windows and support for multiple coats.

How it works

  1. Enter the dimensions of your room (length, width, ceiling height).
  2. Input the number of doors and windows to accurately deduct area.
  3. Set the required number of coats to see your exact gallon requirement.

Frequently asked questions

Why does my coverage differ from the label?

Label coverage assumes a smooth primed surface. Rough or unpainted walls absorb more — use 300 sq ft/gal as a conservative estimate.

Do I need primer?

For new drywall, very dark colors, or covering stains, yes. Primer is calculated separately and usually needs one coat.

How much extra should I buy?

Pick up one extra quart for touch-ups. Seal the lid tightly and store indoors — it lasts years.

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