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Foundations of Excellence

Exterior & Fencing

Siding Calculator

This siding calculator converts wall and gable area into squares of siding; see our siding installation guide for materials and costs. Siding is priced and ordered by the square (100 sq ft of wall). Siding area is wall area — not floor area — so measure around the outside of the house, multiply by the wall height to the eaves, add the triangular gable ends, and subtract large openings like garage doors.

Results from this siding calculator are planning estimates; confirm quantities and prices with your supplier or contractor before you order.

Enter your project

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in
m

Add up the length of every exterior wall.

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in
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ft
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sq ft
m²

Windows, doors and garage doors.

%

10% simple walls; 15% for many corners and gables.

$/sq

Results

Your results will appear here

Enter your measurements and press Calculate. Defaults show a typical example.

How to use the siding calculator

  1. Measure each exterior wall and add them for the perimeter.
  2. Measure wall height from the bottom of the siding to the eaves.
  3. Add gable ends (triangles) and subtract windows, doors and garage doors.
  4. Order trim, corners and J-channel separately by linear foot.

Formula

Area = perimeter × height + Σ(½ × gable width × gable height) − openings. Squares = area × (1 + waste) ÷ 100.

Worked example

A 140 ft perimeter at 18 ft plus two 30 × 7.5 ft gables, minus 150 sq ft of openings: 2,520 + 225 − 150 = 2,595 sq ft → 28.5 squares with 10% waste.

Tips for using the siding calculator

  • Measure the perimeter at the foundation and the height to the eaves, then add gables.
  • Subtract large openings only; small windows rarely save material after waste.
  • Add trim, corners and J-channel separately; they are sold by length, not by square.
Row of two-story townhouses finished in beige horizontal lap siding over brick

Siding Calculator FAQs

How much siding for a 2,000 sq ft house?

It depends on wall height and shape, not floor area. Industry estimates note a typical 2,000 sq ft two-story house carries about 1,800–2,400 sq ft of siding after openings.

How much does siding cost?

Siding typically runs $4–$14 per sq ft by material (vinyl $4–$6, fiber cement $8–$14). See our siding guide.

What if my old siding contains asbestos?

Some older cement-based siding contains asbestos. Removal must be handled by licensed abatement professionals; removal alone often runs $6–$12 per sq ft.

Estimate before you call a contractor

Run the numbers with our free calculators so you can compare bids with confidence.

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