How to estimate paint for a room
PrepMyBuild calculates the room perimeter, multiplies it by wall height, subtracts simple allowances for doors and windows, applies the number of coats, and divides by the selected coverage rate.
Why your measurements stay editable
PrepMyBuild uses your description to help fill the fields, then calculates the result from the measurements and assumptions shown on screen. You can review and change those inputs before using the estimate.
Use the result as a purchasing conversation
Material estimates are most useful when checked against supplier packaging, delivery rules, product-specific coverage and the conditions at the actual project site. PrepMyBuild is designed to make those checks easier, not replace them.