HowMuchIt / Siding
How much siding do I need?
Siding is sold by the square: 100 square feet. Measure each wall, add the triangles of the gables, and add ten percent for waste; the calculator does the rest.
Work out your siding
1 square = 100 sq ft. Measure every wall without taking off windows and doors (the safer method: the extra gives spare pieces), then add 10 percent.
Measuring the house
Measure the height and width of each wall and multiply them. A gable end is a triangle: half its base times its height. Siding guides disagree on taking off windows and doors; measuring the walls without subtracting them is the common, safer method, and the extra becomes spare pieces. Trim is counted apart: J-channel goes around windows and doors to take the siding ends, by the linear foot.
Installing it right
Vinyl siding moves with the temperature. Nail horizontal panels no more than 16 inches apart and do not drive the nails tight: leave a small gap under the head. Leave about 1/4 inch at openings and trim, and overlap panel ends about an inch.
Questions people ask
How many squares for a 160 ft by 9 ft house?
1,440 sq ft plus 10 percent: about 15.8, so 16 squares, before the gables.
Why does vinyl siding buckle?
Nails driven tight stop it from moving; leave a small gap under each head.
Good to know
- Siding is ordered by the square: one square covers 100 sq ft.1,2
- Measure the height and width of each wall of the house and multiply them to get its area.1,2
- Add 10 percent to the total for waste.1,2
- Measuring the walls without subtracting windows and doors is a common, safer method: the extra gives you spare pieces.1,3
- J-channel trim goes around windows and doors to receive the siding ends.1,4
- Nail horizontal vinyl panels no more than 16 in apart.1,4,5
- Do not drive nails tight: leave a small gap under the nail head so the vinyl can move.1,4,5
- Leave about 1/4 in of expansion space where siding meets openings and trim.1,4
- Where panel ends meet, overlap them about 1 in.1,4
How we checked this page
Checked on October 27, 2026. We kept a fact only when two independent publishers agree, and each one is numbered to its sources below. Where sources give different numbers, we keep only what they share. We never write a price. This page was written with an AI assistant and checked against the sources below.
Sources
- Vinyl Siding Installation Manual (2022), Vinyl Siding Institute (Polymeric Exterior Products Association)
- Siding Calculator, Lowe's
- House Siding Buying Guide, Lowe's
- How to Install Vinyl Siding, Lowe's
- A Full Guide to Replacing Vinyl Siding, Family Handyman