Siding Calculator – How Much Siding Do I Need? | CalcLoft
Find out exactly how many squares of siding your walls need.
How much siding do I need?
Siding is ordered in squares — one square = 100 sq ft of wall. For a 40 × 10 ft wall: 400 sq ft, minus openings (say 3 × 20 = 60 sq ft) = 340 sq ft, plus 10% waste = 374 sq ft ≈ 4 squares.
Vinyl siding squares per wall size
| Wall | Area (minus openings) | Squares (+10%) |
|---|---|---|
| 20×10 | 180 sq ft | 2 |
| 30×10 | 280 sq ft | 4 |
| 40×10 | 374 sq ft | 5 |
| 50×12 | 550 sq ft | 7 |
Don't forget trim
Corner posts, J-channel around windows, and starter strips are sold separately — budget roughly 10-15% extra of the siding cost for trim and accessories.
Siding calculator FAQ
How much vinyl siding for a 2000 sq ft house?
Walls are usually 40-60% of floor area — roughly 1,200-1,600 sq ft = 13-18 squares for a 2,000 sq ft home.
What is a square of siding?
One square = 100 sq ft of siding, the standard unit vinyl and fiber cement are sold in.
Do gables need extra siding?
Yes — gable triangles add area. Measure them separately and add to the total.
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