Paint Calculator
How many gallons to buy from square footage, coats, and coverage per gallon. Click any i for detail.
Paint takeoff
Paintable area (sq ft)
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Area
Walls/ceilings minus big openings, or a rough room total. |
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|---|---|
Coats
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Coats
Two coats is typical over a similar color; primer is extra. |
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Coverage (sq ft/gal)
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Coverage
Can label is often 250–400 sq ft per gallon per coat. |
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Waste (%)
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Waste
Cutting in, texture, and dark-to-light color changes use more. |
How to use this calculator
- Estimate wall/ceiling square footage.
- Enter coats and the coverage from your can.
- Add waste, then round up when buying.
- Treat primer as a separate takeoff.
Results explained
The headline rounds in 0.1 gal steps so you can see true need before store rounding to quarts/gallons.
Quick reference: paint
Typical coverage assumptions.
| Item | Detail |
|---|---|
| Flat/eggshell | Often ~350–400 sq ft/gal |
| Semi-gloss / trim | Often less, ~250–350 |
| Textured / new drywall | Uses more paint |
| Primer | Count as its own coat |
For labor dollars see interior/exterior painting cost calculators.
How the estimate is built
Gallons = (area × coats × (1 + waste%)) ÷ coverage.
Example scenario
400 sq ft × 2 coats ÷ 350 sq ft/gal × 1.10 waste ≈ 2.5 gallons (buy 3).
FAQ
Do I subtract doors and windows?
Yes for a tighter takeoff. A rough room total with extra waste also works.
One gallon short?
Always round up. Partial gallons are hard to match later.
Is this a painting quote?
No — quantity only. Labor and prep are separate.