Skip to main content

Paint Calculator

Calculate how much paint you need for your room. Enter dimensions, doors, and windows for an accurate estimate.

Paint Calculator

Calculate how much paint you need for your room

Most paints cover 300-400 sq ft per gallon. Check your paint can for specific coverage.

Formula

Paint Needed = (Wall Area - Doors - Windows) x Coats / Coverage

Wall Area = 2 x (Length + Width) x Height. Standard door = 20 sq ft, window = 15 sq ft.

How to Use

  1. 1
    Measure your roomMeasure length, width, and wall height in feet.
  2. 2
    Count doors and windowsThese areas will be subtracted from total wall area.
  3. 3
    Choose number of coatsMost projects require 2 coats for best coverage.
  4. 4
    Check paint coverageMost paints cover 300-400 sq ft per gallon.
  5. 5
    Get your resultsSee how many gallons you need to purchase.

Frequently Asked Questions

How much paint do I need for a 12x12 room?

For a 12x12 room with 8-foot ceilings, you need about 334 sq ft of coverage after subtracting doors/windows. With 2 coats, you'll need approximately 2 gallons.

How many square feet does a gallon cover?

Most interior paints cover 300-400 sq ft per gallon. Premium paints may cover up to 400 sq ft, while budget paints might only cover 250-300 sq ft.

Should I buy extra paint?

Yes, buy 10-15% extra for touch-ups and to account for textured walls or porous surfaces.

How many coats of paint do I need?

Most projects require 2 coats. You may need 3 coats when painting over dark colors with light paint.