How the wall paint calculator works
Wall area = 2 × (length + width) × wall height − excluded openings. Total coat area = wall area × number of coats. Estimated gallons = total coat area ÷ product-specific coverage (sq ft per gallon per coat).
Worked example
A 12 × 10 ft room with 8 ft walls has 352 sq ft of wall area. Subtract 40 sq ft, then multiply by two coats: 624 sq ft of coat coverage. At 350 sq ft per gallon, this is about 1.78 gallons.
Before you order
Porous surfaces, texture, primer requirements, application methods, and changes of color affect real coverage. Coverage rates vary by product.
All results are planning estimates, not a guarantee of installed material quantity or a quote. Measure the actual project, verify product labels, and follow the manufacturer’s instructions.
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