LayoutWise

Siding Calculator

Add each wall and its gable, then the windows and doors. You get the siding in squares, boxes or planks, and the trim and housewrap that go with it.

Your house

1. Walls

One entry per wall. Add the gable height for walls with a triangle up to the roof peak.

Wall 1
Length
ft
in
Wall height
ft
in
Gable height
ft
in
Wall 2
Length
ft
in
Wall height
ft
in
Gable height
ft
in
Wall 3
Length
ft
in
Wall height
ft
in
Gable height
ft
in
Wall 4
Length
ft
in
Wall height
ft
in
Gable height
ft
in
2. Openings & corners
3. Siding

Boxes

7

13.8 squares

Net area

1,228 sq ft

walls + gables − openings

Gables

196 sq ft

triangles to the peak

Housewrap

2 rolls

9' x 100'

Wall elevation

Wall 2

Shopping list

  • ✓Vinyl siding: 13.8 squares — 7 boxes (2 squares per box)
  • ✓Outside corner posts: 4 (10 ft)
  • ✓J-channel / trim: 23 pieces (12' 6") around openings and up the gables
  • ✓Starter strip: 12 pieces (12 ft) along the bottom
  • ✓Housewrap: 2 rolls of 9' x 100', plus seam tape
  • ✓Roofing or siding nails, about 1 lb per square

Openings use typical sizes (3x5 windows, 3x7 doors). Soffit, fascia and gutters aren't included. Waste is 10%, or 12% when gables are cut.

How to measure for siding

Multiply each wall's length by its height. For a gable end, add the triangle above the wall: width x peak height ÷ 2. Then subtract the openings — about 15 sq ft for a typical window, 21 for a door and 112 for a 16' x 7' garage door.

Example: a 40' x 28' ranch with 9-foot walls and two 7-foot gables has 1,224 sq ft of wall and 196 sq ft of gables. Taking out ten windows and two doors leaves 1,228 sq ft. With 12% waste for the gable cuts that's 13.8 squares — 7 boxes of vinyl at 2 squares per box.

Squares, boxes and planks

Siding is priced by the square (100 sq ft). Most vinyl comes two squares to a box. Lap siding is counted by the plank: a fiber-cement plank 8 1/4" wide laid at 7" exposure and 12 feet long covers 7 sq ft.

Trim and accessories

Replacing the roof too? Try the roofing calculator.