Paint Calculator
Calculate how much paint you need for a room. Enter room dimensions, doors, and windows to get the exact gallons required. Supports multiple rooms and coats.
Paint Needed
6.9 liters
Total Wall Area
352 sq ftMinus Openings
50 sq ftPaintable Area
302 sq ftHow to Use Paint Calculator
- Enter the room dimensions (length, width, height) in feet.
- Enter the number of doors and windows in the room.
- Select the number of coats (default is 2).
- Click "Add Room" to calculate paint for multiple rooms.
- View the total gallons and liters needed.
About the Paint Calculator
Estimating paint quantities before a project prevents waste and extra trips to the store. This calculator uses industry-standard coverage rates and accounts for doors and windows to give you an accurate estimate of how much paint to buy.
Calculation Method
The calculator computes wall area using the room perimeter (2 x length + 2 x width) multiplied by height. It subtracts 20 square feet for each standard door and 15 square feet for each standard window. The remaining paintable area is divided by 350 (sq ft coverage per gallon) and multiplied by the number of coats.
Tips for Accurate Estimates
Measure your rooms carefully and round up to the nearest foot. If your windows or doors are significantly larger or smaller than standard sizes, adjust the count accordingly. For textured walls, brick, or rough surfaces, plan on about 20% more paint than smooth surfaces require.
Planning other home improvements? Try our Electricity Cost Calculator or Mortgage Calculator.