Exterior calculator

Siding calculator

Wall and gable siding area after openings, then squares and coverage units with a visible allowance.

Reviewed formula · v1.0.0

Project inputs

Enter field measurements. Unit conversion happens before the reviewed formula is applied.

Wall lengthftTotal wall length being sidedWall heightftFinished wall height to the eave or plateDoorscountDoor openings to deductWindowscountWindow openings to deductDoor deductionft²Editable area deducted per doorWindow deductionft²Editable area deducted per windowGable widthftGable base width; enter 0 if noneGable heightftPeak height above the wall plateNumber of gablescountIdentical triangular gables to addWaste factor%Allowance for cuts, corners and starter waste

All values can be refined when you edit the estimate. This tool does not replace field verification or local requirements.

Calculated result

3squares

Siding squares to order

FormulaEXT-SIDING-001

228 ft²

Net siding area

250.8 ft²

Area including waste

0 ft²

Gable area

Transparent cost view

Use visible planning values, then replace them with actual job costs before quoting.

Material rateUSDLabourUSDEquipmentUSDDeliveryUSDOverhead %%Contingency %%Markup %%Tax %%

Material cost$255

Direct cost$645

Overhead + contingency$65

Markup + tax$85

Estimated project total$795

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How this calculator works

A transparent siding calculator takeoff.

This calculator subtracts door and window openings from wall area, adds optional triangular gables, then converts the result into roofing-style squares after a visible cut allowance.

Worked example. Example: a 40 ft × 9 ft wall with two 21 ft² doors and six 15 ft² windows has 228 ft² of net wall. With 10% waste the coverage is 250.8 ft², which rounds to 3 siding squares.

1. Measure the wall length and height being sided.
2. Deduct actual door and window areas.
3. Add gable triangles only when they use the same siding, then apply the job's cut allowance.

Need the broader workflow? Read the exterior planning guide.

Questions

Common questions about this siding calculator.

What is a siding square?

One square is 100 ft² of coverage, the common ordering unit for many siding products.

Does this include trim and starter?

No. Starter strip, J-channel, corners, soffit and fascia are separate takeoffs.