Siding Calculator

Free

Siding · Pieces, starter, corners and trim · default waste 10%

Enter your measurements

Numbers start at typical defaults — change anything. Every result states the inputs and assumptions used.

Total wall length (horizontal run)(ft)

Wall height(ft)

Gables

Gable width(ft)

Gable height (peak above wall)(ft)

Openings to deduct(sq ft)

Windows (for trim)

Doors (for trim)

Outside corners

Siding type

Waste factor(%)

Applied once to each material quantity, then rounded up to the orderable increment.

Product assumptions — editable8

Sheet sizes, coverage rates, bundle counts, bag yield and similar come from the product you are buying. Change any of them to match your supplier — whatever you set is shown again with the result.

Exposed face per piece(in)

Lap siding shows 4–7 in per course; panels show their full width. Confirm against the product installation guide for your wind zone.

Piece length (stock)(ft)

Starter strip linear ft(linear ft)

Defaults to the bottom perimeter (the wall run). Starter strips are normally 10 ft long.

Corner trim stock length(ft)

Trim per window(linear ft)

Trim per door(linear ft)

Fasteners per sq ft

Fasteners per box

Enter your measurements and press "Calculate materials" to see the calculated quantity, waste-adjusted quantity and recommended order quantity.

What this calculator does

•Wall area = wall length × wall height
•Gable area = 0.5 × gable width × gable height × number of gables
•Siding area = wall area + gable area − openings
•Siding linear ft = siding area ÷ exposed face; pieces = linear ft ÷ piece length
•Starter strip = bottom perimeter (linear ft)
•Corner pieces = corners × ⌈wall height ÷ corner stock length⌉
•J-trim = windows × trim per window + doors × trim per door

Deterministic by design: no AI, no lookups, no network calls — the same inputs always give the same numbers. Product values such as coverage rates and bundle counts are editable and shown with the result.