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How Much Paint Do I Need?

Estimate paint gallons from wall area, coats, and coverage before starting a room or home project.

5 min read

Start with paintable area

Measure the wall area you plan to paint. For a room, add the area of each wall. You can subtract large windows and doors for a tighter estimate.

Account for coats

Two coats are common for many repainting projects, especially when changing colors. One coat may be enough for touch-ups or similar colors in good condition.

Check coverage per gallon

Paint coverage varies by product, surface texture, color, and application. Many paints list a coverage range on the label, such as 300 to 400 square feet per gallon.

Round up carefully

Paint is usually bought in whole containers. Rounding up helps avoid color mismatch or stopping mid-project, but avoid buying far more than you can use.

Planning checklist

Before you make the final plan

  • Measure the real surfaces you plan to paint, including walls, trim, doors, and repaired areas separately.
  • Check product coverage, dry time, sheen, primer needs, and surface preparation before buying.
  • Plan supplies such as tape, rollers, brushes, trays, drop cloths, sanding blocks, and cleanup materials.
  • Use calculator results as a planning baseline, then compare with the label on the exact paint you choose.

Related calculators

Turn this guide into numbers.

Next step

Use the estimate before you buy materials.

Turn this guide into a quick planning number, then compare the result with local prices, supplier notes, and your real site conditions.