Paint Calculator
Free online Paint Calculator.
Calculator
How to Use
- Enter the required values
- Click Calculate to see the result
- Review the detailed output
Formula
Wall Area = 2(L+W) x Height - Windows - Doors. Gallons = Area / Coverage per gallon (350-400 sq ft). Multiply by number of coats. Add 10% extra.
Example Calculations
Single Room
Input: 12x14ft room, 8ft ceilings, 1 door, 2 windows
Result: About 2 gallons for 2 coats
Whole House
Input: 1,800 sq ft, 8ft ceilings, standard openings
Result: About 12 gallons for 2 coats
Exterior
Input: 2,400 sq ft wall area, 2 coats
Result: About 14 gallons (400 sq ft coverage/gallon)
About This Calculator
Free online paint calculator. Calculate instantly in your browser with our easy-to-use tool. No sign-up required.
Our paint calculator is free, easy to use, and provides instant results. All calculations are performed in your browser for privacy and speed.
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Frequently Asked Questions
How much paint do I need?
Calculate wall area (height x width per wall), subtract windows/doors. One gallon covers 350-400 sq ft.
How many coats?
Most projects need two coats. Dark over light may need three. Primer reduces topcoat layers.
Surface type and coverage?
Porous surfaces absorb more paint. Smooth primed surfaces give best coverage. Rough textures need 20-30% more.
Interior vs exterior paint?
Exterior has UV resistance, mildew protection, flexibility. Interior focuses on low VOCs and washability.
Paint for high ceilings?
Measure each wall separately. Include ceiling if painting it. Subtract large window areas.