PaintingPaint Calculator

Paint Calculator

Calculate exactly how much paint you need for your project. No waste, no guesswork.

Room Dimensions

Ready to calculate

Enter your room dimensions

Expert Review byHawkin, CCP, CEP

Paint Types & Coverage

Latex

350-400

sq ft/gal • Interior walls

Oil-Based

400-450

sq ft/gal • Trim & doors

Primer

300-350

sq ft/gal • New surfaces

Expert Contributors

Why expert review matters

Every calculator is reviewed by certified professionals to ensure accuracy.Hawkin's CCP, CEP certification ensures professional-grade precision.

Pro Tips

  • Buy all paint from the same batch for consistent color
  • Add 10% extra for future touch-ups
  • Use primer when changing from dark to light colors
  • Two coats provides better coverage and durability

Common Questions

Paint for a 12x12 room?

2-3 gallons for two coats

One coat or two?

Two coats recommended

When need primer?

New drywall or color changes

How the Calculator Works

Our paint calculator uses industry-standard coverage rates to determine exactly how much paint you'll need. The calculation accounts for your room's total wall area, subtracts openings like doors and windows, and factors in your desired number of coats.

Formula

(Wall Height × Perimeter - Doors × 20 - Windows × 15) × Coats ÷ 375 = Gallons

Quick Reference

Standard door
20 sq ft
Standard window
15 sq ft
1 gallon covers
350-400 sq ft
1 quart covers
~100 sq ft