Use this paint calculator before buying paint for a room. It works from the room length, width and wall height, then deducts the standard areas allowed for doors and windows and applies the number of coats and paint coverage you enter.
It is useful when comparing a single feature wall with a whole room, or when you want a sensible quantity before visiting a supplier. The result shows both the exact amount and a recommended purchase quantity, including the quart note shown by the calculator.
Paint Calculator
Work out how much paint you need for a room, allowing for doors, windows and extra coats.
Your Result
Gross wall area
Less doors & windows
Net paintable area (one coat)
Total area to cover (all coats)
Paint needed (exact)
Recommended to buy
How to Use This Tool
- Choose feet or metres and select the number of coats.
- Enter the room length, room width and wall height.
- Check the paint coverage figure and change it if your tin states a different rate.
- Enter the numbers of doors and windows so their allowances are deducted.
- Select Calculate Paint Needed and review the net area, total area, exact paint needed and recommended amount to buy.
Treat the result as a planning estimate. Surface condition, texture, colour change, application method and the coverage printed on the chosen paint can all affect how much you actually use, so keep the product details with your measurements when ordering.
Planning the whole room? Browse our free online tools and measure the room first with the Room Area Calculator.