Paint · 6 min read

How to Estimate Paint for a Room

Wall area, coats, coverage rates, and practical buying tips — plus a visual paint calculator to see liters and cans.

Use with our Paint Calculator.

Paint estimates hinge on surface area, how many coats you plan, and the coverage printed on the can (m² per liter or sq ft per gallon). Textured or porous walls need more product than smooth primed drywall.

Simple estimation formula

Paint volume

Liters ≈ (wall area × number of coats) ÷ coverage per liter

Bedroom 4 m × 2.5 m, 2 coats, 10 m²/L

Area = 10 m². Total painted area = 20 m². Liters = 20 ÷ 10 = 2 L — often one large can plus touch-up reserve.

Surface preparation checklist

  • ✓Clean walls of dust and grease
  • ✓Fill nail holes and sand smooth
  • ✓Apply primer on patched or new areas
  • ✓Mask trim, ceilings, and floors

How many coats?

  • New drywall: primer + 2 finish coats
  • Repaint similar color: often 2 coats
  • Dark over light: may need 3 coats or tinted primer
  • Exterior: manufacturer minimum coats for warranty

Paint types and coverage

TypeTypical coverageBest useVOC level
Latex interior10–12 m²/LBedrooms, living areasLow
Acrylic exterior8–10 m²/LSiding, trimMedium to low
Oil-based12–15 m²/LMetal, high-trafficHigher
Specialty (textured)6–8 m²/LDecorative finishesVaries

Application workflow

  1. 1

    Measure and calculate

    Use the paint calculator to get exact liters and can count.

  2. 2

    Surface prep

    Clean, prime, and mask as needed.

  3. 3

    Mix batches

    Stir multiple cans for consistent color.

  4. 4

    Apply coats

    Follow manufacturer drying time between coats.

Open paint calculator

Enter wall size, coats, and coverage — see liters, cans, and live fill animation.

Open calculator →

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