Calculate paintable wall area, not floor area
For a rectangular room, multiply its perimeter by wall height, then subtract the total area of doors and windows. Add separate rooms before calculating containers when they share one paint colour.
A worked wall-paint example
12 × 10 ft with 8 ft walls: 2 × (12 + 10) × 8 = 352 sq ft of walls. Subtract 20 sq ft of openings to get 332 sq ft. At 350 sq ft per gallon and two coats, the exact estimate is 664 ÷ 350 = 1.897… US gallons. Two one-gallon cans cover that illustrative estimate.
Coverage and coats change the result
Apply your optional extra allowance, then round to available containers.
Manufacturer ranges use their lower coverage value by default. A quoted “up to” coverage is not a guarantee on every surface. Check porosity, colour change, application method and preparation; adjust the form to your current label.
Are the displayed prices current?
Store prices are dated snapshots. After seven days, product-based costs are withheld; quantities remain available for up to 30 days before specifications also need a refresh. Manual details use the numbers you enter.
Can I mix litres and US gallons?
Choose the matching country tool and label units. A US gallon and an imperial gallon are different. This pilot does not convert a UK product into a US product or combine their offers.
Valspar Signature® Interior Paint + Primer
Valspar Ultra® Interior Paint + Primer
Valspar® Core™ Interior Paint + Primer
Valspar Signature® Ceiling Paint + Primer
Valspar® Ultra Ceiling Paint + Primer
Valspar® PVA Primer/Sealer
Valspar® High-Hiding Primer/Sealer