Siding Calculator
- Materials
- Labor
- Profit
Removing old siding, replacing rotten sheathing and disposal are usually priced as extras.
Turn this into a quote
A one-page PDF for your customer, filled in from the numbers above. Your markup isn't shown.
How the siding calculation works
Multiply the perimeter by the wall height
A 50 × 30 ft house has a 160 ft perimeter. With 9 ft walls that is 1,440 sq ft.
Add gables and subtract openings
Each gable is ½ × width × height. Adding 150 sq ft of gables and taking off 200 sq ft of doors and windows leaves 1,390 sq ft.
Add waste and convert to squares
1,390 sq ft plus 10% is 1,529 sq ft. Siding is sold by the square (100 sq ft), so that is 15.29 squares.
Round up to boxes and price the job
At 200 sq ft per box you buy 8 boxes. Add trim and wrap, then labor and markup for the quote.
Worked example. A 160 ft perimeter with 9 ft walls is 1,440 sq ft; plus 150 sq ft of gables and minus 200 sq ft of openings leaves 1,390 sq ft. With 10% waste that is 15.29 squares, or 8 boxes of 200 sq ft at $380 ($3,040), plus $500 of trim and wrap. Labor at $3 per sq ft adds $4,170 and a 20% markup adds $1,542, for a price to quote of $9,252.
Siding FAQ
How much siding do I need?
Multiply the house perimeter by the wall height, add the gables, subtract doors and windows, and add 10% waste. Divide by 100 to get squares.
What is a square of siding?
A square is 100 sq ft of wall coverage. The Vinyl Siding Institute installation manual uses the square as the ordering unit, the same as for roofing.
How many boxes of vinyl siding do I need?
Divide the area plus waste by the coverage printed on the box and round up. If a box covers 2 squares (200 sq ft), 15.29 squares is 8 boxes.
How do I calculate the area of a gable?
Multiply half the gable width by its height from the eave line to the peak. A 30 ft wide gable that rises 5 ft is ½ × 30 × 5 = 75 sq ft.
Should I subtract windows and doors from the siding area?
The Vinyl Siding Institute says windows and doors are not usually deducted, because leaving them in gives a waste allowance. Deduct only large openings such as garage doors and sliding doors. This calculator subtracts what you enter, so enter 0 to follow that method.
Can I use this as a Hardie board or LP SmartSide siding calculator?
Yes. Enter the area one plank covers as the coverage and the price per plank. A 12 ft plank laid at a 7 in exposure covers 12 × 7 ÷ 12 = 7 sq ft, so 1,529 sq ft needs 219 planks. Check the exposure in the manufacturer's installation guide.
How many nails do I need for vinyl siding?
The Vinyl Siding Institute estimates aluminum nails at 0.005 lb per sq ft of siding, so 1,529 sq ft needs about 7.6 lb. It spaces fasteners no more than 16 in apart on horizontal panels and leaves about 1/32 in between the nail head and the panel so it can move.
How much should I charge to install siding?
Add siding, trim and wrap, your labor per sq ft or per hour, and a markup for overhead and profit. Tear-off, sheathing repairs and disposal are usually separate line items.
Sources: Vinyl Siding Institute: Vinyl Siding Installation Manual (2022)