How to use this calculator
- Enter Gross wall area in sq ft.
- Enter Openings in sq ft.
- Press Calculate. The highlighted row is your order quantity; the note beneath it translates the number into real-world terms.
Formula & constants
Net wall area = gross walls − openings, ÷ 100 = squares. Add 10% waste for lap siding, 15% for gables and complex elevations. A 2,000 sq ft two-story averages 22–26 squares. Every default in the fields above is editable — when your supplier’s spec sheet lists a different density, coverage rate or price, enter that number instead. The waste and compaction allowances follow common trade practice; see our methodology page for the derivation of each formula and the standards it references.
Where this fits in the project
Coating and finish quantities are coverage-rate problems: true surface area divided by the product’s rated coverage, plus a waste allowance. Prep drives success — a coating over unprofiled or damp concrete fails regardless of quantity accuracy.
How this connects to your project
No quantity stands alone — each material in the chain depends on the ones around it. These are the planning steps that pair with the siding calculator:
- Roofing Calculator — Roofing covers the top; siding covers the walls.
- Insulation Calculator — Siding is installed over wall insulation.
- Plywood Calculator — Siding is installed over plywood or OSB sheathing.
- Paint Calculator — Vinyl siding vs painted wood exterior.
- Window Cost Calculator — Siding projects often include window replacement.
- Door Cost Calculator — Exterior door replacement accompanies siding work.
- Roofing Cost Calculator — Siding and roofing are often done in the same project.
Frequently asked questions
How is siding sold?
By the square (100 sq ft) for vinyl and fiber cement panels; board products per piece by exposure coverage.
Does fiber cement need special handling?
Yes — shear or dust-collecting saws (silica dust), 2 in fastener penetration and painted cut ends.
Last verified: — prices reflect current national averages. See our methodology.
Estimates are for planning. Material densities, coverage rates and prices vary by region and supplier — confirm final quantities before ordering, and check local code where structural or electrical work is involved.