MEASURE. ESTIMATE. BUILD.
Estimate vinyl siding in squares and boxes for your walls.
Change any measurement to update your estimate.
Most vinyl siding is sold by the square (100 ft²); this tool adds a 10% waste factor by default.
Vinyl siding is sold by the square (100 ft²) in boxes that cover about two squares each. This view assumes a 10% waste factor; bump it toward 15% if your walls have several gables or dormers.
Waste climbs with corners, not square footage. A plain gable end runs 10%; a house with dormers, bays, and multiple gables can waste 15% because every angled cut leaves an unusable offcut. Measure each wall separately and subtract only the big openings — trying to net out every window invites a shortfall. Buy one extra square and keep it for storm repairs; dye lots shift between orders.
The math behind the tool:
wall area ft² = Σ(wall height × wall length) − openings
squares = wall area ÷ 100 × (1 + waste%)Sources: Polymeric Exteriors Alliance (formerly Vinyl Siding Institute) (siding coverage and installation standards).
Divide your total wall area (in ft²) by 100 to get siding squares, then add 10% for waste. A 1,500 ft² wall area needs about 16.5 squares of siding.
Add about 10% for straight walls and 15% for homes with many corners, gables, or dormers, since angled cuts create more offcuts.