Paint Calculator

About this calculator

This calculator estimates how much paint a job requires by working out the total surface area to be covered from wall dimensions, then dividing that by the coverage rate a typical can of paint provides, adjusted for the number of coats planned. Doors, windows, and other unpainted areas are usually subtracted from the total so the estimate isn't inflated.

Homeowners and DIY painters use it before a shopping trip to figure out how many cans or gallons to buy for a room or an entire house exterior, avoiding both an expensive over-purchase and an inconvenient mid-project run to the store. Contractors also use similar math when quoting a job to a client.