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Paint Calculator

Calculate how much paint you need for any room. Get gallon estimates, account for doors and windows, and estimate costs.

How to Calculate Paint Needed

Calculating paint is straightforward once you know your wall area. This calculator handles the math automatically.

Paint Coverage Rules

  • Standard coverage: 350-400 sq ft per gallon
  • Textured walls: Reduce coverage by 20-30%
  • Primer: Usually covers 200-300 sq ft per gallon
  • Two coats: Required for most projects

When to Use 3 Coats

  • Covering dark colors with light paint
  • Painting over bright reds, oranges, or yellows
  • Using low-quality paint
  • Painting new drywall without primer

Pro Tips

  • Buy 10% extra for touch-ups and future repairs
  • Same batch numbers ensure color consistency
  • Higher quality paint often needs fewer coats
  • Use primer when changing colors dramatically

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Frequently Asked Questions

How much paint do I need for one room?

Calculate wall area (2 × (length + width) × height), subtract doors/windows, then divide by 350 sq ft per gallon. Multiply by number of coats.

How many coats of paint do I need?

Most jobs need 2 coats. Use 3 coats when covering dark colors or using light colors over dark.

How much does a gallon of paint cover?

One gallon covers 350-400 sq ft on smooth surfaces. Textured walls may need 20-30% more paint.

Should I subtract doors and windows?

Yes. Standard doors are about 21 sq ft (3×7 ft) and windows average 15 sq ft (3×5 ft).