Vinyl Siding Calculator

Vinyl is sold by the square, and one square covers 100 square feet of wall. Most vinyl also ships two squares to a box, so once you know your square count the box count follows. The tricky part isn't the arithmetic — it's making sure you've captured every wall, gable and dormer before you multiply. That's why this tool breaks the house into separate lines instead of asking for one lump figure.

Enter each wall's width and height, add any triangular gable sections, then list your windows and doors so their area comes out. You'll get vinyl panels, squares and boxes, an accessory list (starter, J-channel, corners) and a cost band you can take to a contractor.

A single-story ranch with 1,900 sq ft of net wall area, after subtracting a picture window and two doors, needs roughly:

• 19 squares before waste, about 21 squares with a 10% allowance
• Around 11 boxes of standard double-4 vinyl
• Starter strip along the full base, plus J-channel around every opening

Enter your own wall sizes above to get numbers matched to your house.

Reliable enough to plan and shop with, and honest about its limits. The core arithmetic — area, openings, squares, waste — is exactly what an estimator or a building-supply desk uses, so the quantities are sound when your measurements are. The coverage and price defaults come from typical manufacturer specs and widely reported installed costs, not a single source, which is why we show ranges rather than false precision. Your final order should still be confirmed against a field measure and a real quote.

Getting the panel and box count is step one. Most people then run into the same handful of follow-up questions before they actually order, so here's the rest of it in one place.

• Ordering by color run: ask your supplier to pull all your boxes from a single production lot. Vinyl color varies slightly batch to batch, and mixing lots can show on a long wall.
• Trim and accessories: beyond panels you'll need starter strip along the bottom, J-channel around windows and doors, undersill at the top, and outside/inside corner posts. The tool estimates these so nothing is forgotten.
• Underlayment: most installs go over housewrap and often a foam backer or fanfold insulation. Add that to your budget separately from the panels.
• Leftover for repairs: keep one or two spare panels. Profiles get discontinued, and a matching piece years later is worth its weight.

Once you've settled those, the estimate above is your shopping list. Change the waste percentage if your walls are cut up, and re-run it before you place the order.