Siding Area Calculator

Calculate exterior siding square footage from wall dimensions, house perimeter, wall height, gables, doors, windows, and known area. Estimate siding squares, panels, trim, waste, coverage, and project cost.

Calculate Siding Area

Siding Area = Exterior Wall Area + Gable Area − Door Area − Window Area.
Your result will appear here.

How the siding area calculator works

Perimeter and height mode:
The calculator estimates exterior wall area from house perimeter and wall height, then adds gables and subtracts openings.

Single wall mode:
The calculator multiplies wall length by wall height, then adds gables and subtracts doors and windows.

Multiple walls mode:
The calculator multiplies one wall area by the number of same-size walls.

Known area mode:
The calculator starts with your known siding area and estimates waste, siding squares, panels, trim, and cost.

Why use a siding area calculator?

A siding area calculator helps estimate square footage for vinyl siding, fiber cement siding, wood siding, metal siding, board and batten, exterior panels, and wall cladding projects.

It can help calculate gross wall area, gable area, opening deductions, net siding area, siding squares, panel quantity, trim length, waste, and estimated project cost.

What your result means

Your result shows gross exterior wall area, gable area, door and window opening area, net siding area, area with extra waste, siding squares, panels or units needed, trim length, and estimated cost.

Siding area formulas

Frequently asked questions

How do I calculate siding square footage?

Calculate the exterior wall area, add any gable areas, then subtract doors, windows, garage doors, and other openings.

What is a siding square?

A siding square equals 100 square feet of siding area. For example, 1,250 square feet equals 12.5 siding squares.

Should I subtract windows and doors from siding area?

Yes, subtracting openings gives a better siding material estimate. Some contractors may keep small openings in the estimate to allow for waste and cuts.

How much waste should I add for siding?

Many siding projects use 10% extra material. Complex walls, many corners, gables, dormers, trim, and cut-up layouts may need more.

Is this siding calculator exact?

No. It is an estimate. Actual siding needs vary by lap exposure, panel size, trim style, corners, starter strips, waste, wall shape, installer method, and manufacturer coverage.