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Paint Coverage Calculator

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Doors & Windows

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How to Calculate Paint Coverage

Calculating the right amount of paint for your project prevents costly overbuying and frustrating mid-project store runs. One gallon of paint typically covers 350-400 square feet of smooth surface in one coat. However, several factors affect actual coverage.

Paint Coverage by Surface Type

Surface Type Coverage per Gallon Notes
Smooth Drywall 350-400 sq ft Best coverage rate
Textured Drywall 300-350 sq ft Knockdown, orange peel
Rough/Stucco 200-250 sq ft Porous surfaces absorb more
Brick/Masonry 150-200 sq ft Very porous, multiple coats needed
Wood (bare) 300-350 sq ft Prime first for best results

How Many Coats Do You Need?

  • 1 Coat: Touch-ups or same-color repainting with quality paint
  • 2 Coats: Standard for most color changes, provides uniform finish
  • 3+ Coats: Dark-to-light transitions, reds/yellows over different colors

Standard Deductions

When calculating paintable area, subtract openings:

  • Standard Door: 21 sq ft (3' x 7')
  • Standard Window: 15 sq ft (3' x 5' average)
  • Sliding Glass Door: 42 sq ft (6' x 7')
  • Fireplace: 20-30 sq ft (varies)

Tips for Accurate Paint Estimates

  • Always add 10% extra for waste, touch-ups, and mistakes
  • Buy an extra quart for future touch-ups
  • Dark colors typically require additional coats
  • New drywall may absorb more paint than expected
  • Primer reduces the number of topcoats needed
  • Calculate trim and ceiling paint separately

Paint Types and Their Uses

Finish Best For Durability
Flat/Matte Ceilings, low-traffic areas Low
Eggshell Living rooms, bedrooms Medium
Satin Kitchens, bathrooms, kids rooms Medium-High
Semi-Gloss Trim, doors, high-moisture areas High
Gloss Cabinets, furniture, accent trim Very High