Siding Cost by Number of Squares
Contractors often price by the square (100 sq ft). Multiply your square count by your price per square, add any add-ons, and apply a contingency.
15 squares at $700.00 per square plus add-ons is about $11,550.00. Contractors often price siding by the square (100 sq ft); enter your quoted price per square and your square count from the how-much-siding tool.
1 Enter your numbers
Siding is bought and quoted by the “square” — a fixed 100 square feet of coverage — and many contractors price the whole job that way: so many squares at so many dollars each. If that is how your estimate reads, cost it in the same currency. Bring your square count from the how-much-siding tool (which already folds in waste and rounds up), enter the price per square, and add the extras.
The square is a genuinely stable unit — it is always 100 sq ft, forever — which is why it is a clean basis for planning. The only variable is the price per square, and that is yours to enter from a real quote.
Formula
total = (squares × $/square + add_ons) × (1 + contingency%)
Because a square is 100 sq ft, a price per square is just the installed $/sq ft × 100: $7/sq ft is $700/square. Use whichever unit your quote uses and keep it consistent.
Worked example
15 squares at $700 per square, no add-ons, 10% contingency:
subtotal = 15 × $700 = $10,500total = $10,500 × 1.10 = $11,550
Those 15 squares are the rounded-up answer for a 1,336 sq ft house at 10% waste (14.7 squares → 15). Note the built-in margin: you already rounded the quantity up to a whole square, and the contingency adds a further buffer on the money — two independent safety factors, one on material, one on cost.
Keeping the units honest
- Round squares up. Siding sells in whole squares (and whole boxes/bundles inside them). The how-much-siding tool already does the ceil; do not round back down here.
- Waste lives in the square count. If your 15 squares already includes a 10–15% waste factor, do not add waste again in the price — the contingency is for cost surprises, not for more material.
- $/square = $/sq ft × 100. Convert before you compare a per-square quote to a per-square-foot one.
- Add-ons are separate. Tear-off, trim, house wrap and permits are not in the per-square field price unless the contractor says so — list them.
Reference table
| Material | Per square (100 sq ft, installed) |
|---|---|
| Vinyl siding | $300–$800/square |
| Engineered wood / LP SmartSide | $400–$900/square |
| Aluminum siding | $400–$900/square |
| Steel siding | $600–$1,200/square |
| Wood / cedar siding | $500–$1,200/square |
| Fiber cement / James Hardie | $600–$1,300/square |
Derived from the installed $/sq ft bands (×100). A “square” is always 100 sq ft; contractors often price by the square, so a $7/sq ft job is about $700 a square. Labeled planning guide only — enter your own quoted price per square.