How is paint quantity calculated?

First, find the total wall surface area: 2 x (Length + Width) x Height. Subtract any excluded door or window areas, then multiply by the number of paint coats. Divide by the paint coverage rate (m²/L) to get the liters required.

Should I include the ceiling in the calculation?

This tool calculates wall area only. To include the ceiling, calculate its area separately (Length x Width) and add it to the final paint area requirement.

How much extra paint should I buy beyond the calculated amount?

Buy 10-15% more paint than the calculated volume to account for touch-ups, roller absorption, and surface texture variations. Textured walls may absorb up to 25% more paint than smooth surfaces. Unopened cans can typically be returned if you overestimate.

Are the calculations on Paint Calculator | Coverage Area & Cost Estimator Tool private?

Yes, completely. All calculations are performed entirely locally inside your browser using JavaScript. No inputs or personal metrics are ever transmitted to or stored on our servers.

Paint Calculator | Coverage Area & Cost

Wall Paint Calculator – Coverage EstimatorMetriova provides free online calculators for finance, business, health, and construction. Calculate loans, investments, fitness metrics, and project materials in seconds.How Much Paint Do I Need for a Wall?One gallon covers 350-400 sq ft (one coat). Most walls need two coats. Formula: Total Paint (gallons) = (Wall Area - Doors - Windows) / 175. Buy 10% extra for touch-ups.

Room Size

Wall Area

Paint (2 coats)

Small bathroom

120 sq ft

0.6-0.7 gal

Standard bedroom

384 sq ft

1.9-2.2 gal

Living room

560 sq ft

2.8-3.2 gal

Large room

800 sq ft

4.0-4.6 gal