Exterior Paint Quantity Calculator

Exterior coverage typically 250-300 ft²/gal — rougher surfaces, porous siding.

Inputs

Result

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How to use this calculator

  • Estimate house exterior surface (perimeter × height + gables).
  • Enter coats and coverage.
  • Buy rounded-up gallons.

About this calculator

Exterior paint coverage is lower than interior because siding is rougher and absorbs more. Use 250-300 ft²/gal for typical wood siding; lower for masonry. Higher waste factor (15%) reflects the larger surface and outdoor working conditions.

Frequently asked

How do I estimate house exterior area?+
Perimeter × wall height + gable triangles. A 2,000 ft² house typically has 1,500-2,500 ft² of paintable exterior.
Two coats outside?+
Almost always. Exterior weathering plus the rougher surface mean you really need that second coat for durability.
Different paint type?+
Use the manufacturer's coverage on the can. Acrylic latex usually 250-275; oil-based 200-250.
What about trim?+
Add separately: 1 quart per 100 LF of trim. Pre-prime bare wood for adhesion.
Should I prime?+
Bare wood, weathered surfaces, or extreme color changes: yes. Repainting same color on good substrate: usually no.

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