Understanding Paint Coverage Rates

Paint coverage — how many square feet a single gallon of paint will cover — is the single most important number for estimating paint quantity. Getting it wrong means buying too much (wasting money) or too little (mid-project trips to the store). Here's what you need to know.

What Affects Paint Coverage?

Several factors influence how far a gallon of paint goes:

  • Surface texture: Smooth drywall absorbs less than textured walls (popcorn, knock-down). Rough surfaces can reduce coverage by 20-30%.
  • Color change: Painting light over dark requires more coats. Dark over light usually needs fewer coats.
  • Paint quality: Premium paints typically cover better than economy brands. One-coat coverage claims are more reliable with higher-quality paints.
  • Application method: Rollers generally provide better coverage than brushes or sprayers (sprayers lose 20-30% to overspray).
  • Surface condition: Freshly primed surfaces accept paint better than bare or previously painted surfaces.

Standard Coverage Rates

Most interior wall paints specify a coverage range of 300-400 sq ft per gallon. The commonly used average is 350 sq ft/gal. Here are typical ranges by paint type:

  • Interior wall paint (flat/matte): 350-400 sq ft/gal
  • Interior wall paint (eggshell/satin): 300-350 sq ft/gal
  • Exterior acrylic latex: 300-400 sq ft/gal on smooth surfaces
  • Primer: 200-300 sq ft/gal (primer absorbs more into bare surfaces)
  • Ceiling paint (flat): 400-450 sq ft/gal (thinner formulation)

How to Read the Paint Can Label

Every paint can has a coverage specification printed on the label. Look for text like "Covers up to 400 sq ft per gallon." This is the manufacturer's tested coverage rate under ideal conditions (smooth, primed surface, roller application). Your actual coverage may be lower on textured or unpainted surfaces.

Calculating Coverage for Your Project

Start with the manufacturer's specification, then adjust downward for:

  • Textured walls: subtract 20-30%
  • Bare drywall (no primer): subtract 25-40%
  • Dark color over light: no adjustment (usually 2 coats is enough)
  • Light color over dark: add a third coat (increases total paint needed by 50%)

Use the Paint Calculator to enter your specific coverage rate and get an accurate gallon estimate.

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