Paint Calculator

Enter room dimensions to calculate gross wall area (perimeter × height), ceiling area, and trim area. Supports individual walls, full rooms, and known areas for maximum flexibility.

Subtract doors and windows from gross wall area for a precise net paintable surface. Standard deduction of 10 sq ft per window and 20 sq ft per door, with custom opening support.

Set the number of finish coats (typically 2) and estimate primer separately. Includes a safety reserve for touch-ups and future repairs. Coverage rates are adjustable per product data sheet.

Add a customizable waste factor (typically 10%) to account for application losses and touch-ups. The formula is: Paint Required = (Area × Coats) ÷ Coverage, then × 1.1 for waste.

Convert litres or gallons into exact can combinations (1 gal, 5 gal, quarts) at the best price. Enter your local unit price per litre or gallon for an instant budget estimate from entry-level to premium paint.

Switch between feet, inches, yards, meters, and centimetres instantly. Coverage can be entered in m²/L or sq ft/gal. All calculations, can counts, and cost estimates update automatically. Fully functional offline.