Free · Walls & finishes

Siding Coverage & Project Cost Calculator

Estimate siding area for different wall shapes after subtracting openings.

  • Formula & worked example
  • Private in your browser
  • No signup
Go to tool
Calculator inputs

Enter the values you know

Results update as you type. Edit a result to calculate another value, or lock a value to keep it fixed.

Doors
Calculated: 0 m²
Windows
Calculated: 0 m²
Siding material needed
%
/
Result

Your calculation

Total door area
0 m²
Total window area
0 m²

Use one currency for your figures. Mixed-currency conversions use rates captured October 5, 2026, rather than live exchange rates.

How to use this calculator

  1. Enter the values you know in the units shown. Leave unknown values blank.
  2. Results update automatically as you type. Edit a result to calculate another value, or lock a value to keep it fixed.
  3. Reset restores the starting fields. A worked example appears below.

Private by default

Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.

Formula and method

Add the areas of the selected wall shapes, subtract doors and windows, and include the material allowance. Confirm whether the supplier quotes nominal or effective coverage.

Coverage = (wall area − doors − windows) × (1 + waste fraction); cost = coverage × price per area. Choose the wall shape before entering dimensions.

Worked example

Enter these known values and leave the other values blank.

I'm putting siding on a...
wall
Height
3 m
Width
5 m
Number of doors
0
Door height
200 cm
Door width
90 cm
Number of windows
0
Window height
120 cm
Window width
90 cm
Waste factor
5 %
Total door area
0 m²
Total window area
0 m²
Siding needed
15.8 m²

Assumptions and limitations

  • Inputs must satisfy the validation rules. Editing a result can recalculate an earlier input; lock values you want to keep fixed.
  • Currency conversions use the captured source rates from October 5, 2026; they are not live exchange rates.

Common questions

What does this siding calculation tell me?

Add the areas of the selected wall shapes, subtract doors and windows, and include the material allowance. Confirm whether the supplier quotes nominal or effective coverage.

Can I calculate a different unknown?

Yes. Clear that field and enter the other known values. The calculator uses the available inverse equations.

References

The calculation equations, inverse formulas, units, and input rules were imported from this source. Bookify provides the interface and equation solver.

Explore walls & finishes or browse all construction calculators.