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Primer Calculator — Estimate Primer Instantly

Calculate how much primer you need for any surface type. Get accurate gallon and quart estimates based on surface material and coverage rates.

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Enter your surface dimensions and click Calculate to see primer estimates.

Frequently Asked Questions

Primer coverage varies by surface type. Drywall covers about 300 sq ft per gallon, wood covers 250 sq ft per gallon, metal and masonry cover 200 sq ft per gallon, and previously painted surfaces cover 350 sq ft per gallon.
Use drywall primer for new drywall, wood primer for bare wood, metal primer for metal surfaces, masonry primer for brick and concrete, and general-purpose primer for previously painted surfaces in good condition.
Primer is essential when painting bare surfaces, covering dark colors, or painting over stains. It seals the surface, provides better adhesion, and ensures a uniform finish. For previously painted surfaces in good condition, you may not need primer.
One coat of primer is usually sufficient for most surfaces. Apply two coats when covering dark colors, painting over stains, or when the surface is highly porous like fresh drywall or unpainted wood.
Primer is not designed to be a final finish. It lacks the durability, UV protection, and washability of paint. Always apply at least two coats of paint over primer for a professional, long-lasting result.
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