Gallons per Square Foot Calculator
Calculate the coverage rate of paint, sealer, stain or any liquid in gallons per square foot (or square feet per gallon) from a known area and quantity used.
About the Gallons per Square Foot Calculator
This calculator works backward from a real-world application to find a liquid's actual coverage rate — useful when a product label's stated coverage doesn't match your surface, or when you've tested a small area and want to plan how much more you'll need.
Formula: Coverage Rate (sq ft per gallon) = Area Covered ÷ Gallons Used; Gallons per Sq Ft = Gallons Used ÷ Area Covered
Porous, textured or previously unfinished surfaces soak up more liquid than smooth, sealed ones, so a test-patch coverage rate is often more accurate than the manufacturer's published figure. Multiply your total area by the gallons-per-sq-ft rate to plan purchases for the rest of the job.