Paint Gallon Calculator

Quick estimate for your project. Free — no account.

Formula

Gallons = (wall area × coats) ÷ coverage per gallon. Wall area ≈ 2 × (length + width) × height − openings.

Worked example

{
  "length": 12,
  "width": 10,
  "height": 8,
  "coats": 2,
  "coverage": 350,
  "doors": 1,
  "windows": 2
}

Affiliate links, when shown, are labeled.

Source & last checked

https://www.epa.gov/indoor-air-quality-iaq

Last checked: 2026-09-25

FAQ
Is this exact?

No. Site conditions, waste, and product coverage vary. Buy a little extra.

Do you sell materials?

No. Optional affiliate links are labeled when present.

Can I embed this?

Yes — see the embed box below.

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