Free Tool
Free vinyl siding calculator
Enter your wall area and openings to get the siding you need in squares and boxes, with a waste allowance built in. Free, no signup.
Add up every wall (length × height)
10% simple, 15%+ for lots of cuts
Private by design — everything you type stays in your browser. Nothing is uploaded, stored, or seen by us.
Order it by the square
Siding is sold by the square, which is 100 square feet, and most vinyl comes two squares to a box. Add up every wall, length times height, subtract the big openings, and the calculator turns it into squares and boxes.
Openings matter on a house with a lot of glass. The calculator takes off 15 square feet per window and 20 per door, which keeps you from paying for siding that goes in the dumpster. Do not subtract the small stuff; it disappears into the waste.
Vinyl needs more waste than most cladding. Every course is cut to length as it runs into the corners and openings, and the offcuts are rarely long enough to reuse, so 12 to 15 percent is normal and a cut-up elevation earns the higher number.
The panels are only part of the order. Starter strip along the bottom, J-channel around every opening, corner posts at each corner, and finish trim all come separately, so price those from the house once you have the field figured.
Vinyl Siding Calculator questions
How much siding do I need?
Add up the wall area, subtract the big openings, add waste, and divide by 100 for squares. The calculator does it and gives you boxes too.
What is a square of siding?
100 square feet of coverage. Most vinyl siding is packaged two squares to a box.
How much waste for vinyl siding?
Usually 12 to 15 percent, since every course is cut to length and the offcuts rarely reuse. A cut-up house takes more.
Is this really free?
Yes. No email, no signup, and nothing you type leaves your browser.
Turn the takeoff into a priced estimate
Werx turns your quantities into a branded estimate and proposal in one step, then tracks the real cost as you side it. 14-day free trial, no credit card.
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Disclaimer: These free tools and templates are provided for general information and estimating purposes only. All results — including quantities, material and cost estimates, load, sizing, and span figures, scores, and any guidance or warnings — are rough approximations that may not fit your specific project, site conditions, local building codes, or current prices. They are not engineering, architectural, structural, legal, financial, or other professional advice, and are not a substitute for a licensed engineer, architect, contractor, or other qualified professional. Always confirm quantities, sizing, and structural, electrical, mechanical, and code requirements with a licensed professional and your local authority having jurisdiction before purchasing materials or performing any work. Werx makes no warranty as to accuracy and accepts no liability for any decision made using these tools. Use at your own risk. See our Terms of Service.