Paint Calculator

Estimate how much paint you need for walls or ceilings in gallons or litres.

Paint Calculator helps you estimate paint volume from wall area, coats, and coverage. Enter surface area, coats, coverage, and waste, review the breakdown, and use the guidance below to understand what the number means — and what it does not. What the Paint calculator does Paint Calculator is built for materials, areas, volumes, and jobsite estimates. Estimate paint volume from wall area, coats, and coverage. You enter surface area, coats, coverage, and waste, then Simple Calculators computes the result instantly. Formulas match common contractor and DIY references for rectangular and simple shapes. How the math works Paint = (area × coats ÷ coverage) × (1 + waste). Default coverage is 350 ft²/gal or about 8.6 m²/L. The formula: Paint = area × coats ÷ coverage × (1 + waste). Coverage is the area one gallon (or liter) paints in one coat, printed on the can.