Paint Requirement Calculator
Total Paint Needed
0 Liters / 0 Gallons
How Much Paint Do I Need?
One of the most common questions before starting a painting project is "How much paint should I buy?". Buying too little can be frustrating, and buying too much is a waste of money. This calculator helps you get a reliable estimate of your paint requirements, so you can buy with confidence.
How to Use This Calculator
The calculation updates automatically as you enter your room's details.
- Select Units: Choose whether you are measuring your room in meters or feet.
- Enter Room Dimensions: Input the length, width, and height of your room.
- Specify Coats: Enter the number of coats of paint you plan to apply. Two coats is standard for good coverage.
- Account for Doors & Windows: Enter the number of doors and windows in the room. The calculator will subtract their standard surface area from your total.
How Paint Coverage is Calculated
The calculator first determines the total surface area of the walls to be painted. It does this by calculating the room's perimeter and multiplying it by the height. It then subtracts a standard area for each door and window you specify. Finally, it divides this total area by the average coverage of a can of paint to determine how much you need.
| Factor | Standard Value Used |
|---|---|
| Paint Coverage | One gallon covers approximately 400 square feet. This is equivalent to one liter covering about 10 square meters. |
| Standard Door Area | 20 square feet (approx. 1.85 square meters). |
| Standard Window Area | 15 square feet (approx. 1.4 square meters). |
Tips for a Better Paint Job
- Always Buy a Little Extra: It is a good rule of thumb to buy about 10-15% more paint than you estimate. This covers you for touch-ups, mistakes, and any variations in wall texture.
- Consider the Surface: Porous or unprimed surfaces, like new drywall, will absorb more paint. It is highly recommended to apply a coat of primer first, which will improve coverage and the final finish.
- Factor in Ceilings and Trim: This calculator estimates the paint needed for your walls. If you are also painting the ceiling or trim, you will need to calculate those areas separately and purchase additional paint.