CertainTeed & Allura Siding Calculator
Estimating a specific brand — CertainTeed, Allura, Diamond Kote or Boral? Get boards, squares and cost tuned to fiber cement.
Walls (feet)
Gables / triangles optional
Windows & doors to subtract
Tip: measure each wall's width × height at its widest points. A per-wall audit table appears below so you can check every number.
Your siding squares, panels and cost appear here.
Estimated from wall count and perimeter — confirm against your actual corners and openings.
Cost per sq ft: – · per square: –
| Surface | Area (sq ft) |
|---|
Brand-specific, same reliable math
The big fiber-cement names differ in color systems, warranties and finishes, but their lap products are estimated identically: coverage per board comes from the reveal and length, and your count is area over coverage. This page starts from fiber-cement defaults so you can drop in a CertainTeed, Allura, Diamond Kote or Boral coverage figure and get a number matched to that brand.
Diamond Kote and similar pre-finished lines are prized for their baked-on color warranties — worth a note on your estimate, since it affects long-term value even though it doesn't change the board count.
Using the tool in five quick moves
You don't need to prep anything special — a tape measure and two minutes will do. Work through it in this order and the estimate builds itself.
- Pick the material first. That decides the default coverage, so it's the natural place to start before you type any numbers.
- Log every wall separately. Resist the urge to average; different heights and widths each deserve their own line.
- Handle the shapes above and the holes within. Triangular gables go in as base and rise; windows and doors come out as size and count.
- Dial in waste and pricing. Keep 10% unless the elevation is busy, then nudge it up. Drop in a real per-foot price when you have one.
- Take the numbers with you. Print or copy the breakdown and it's ready for the supplier's desk.
Data sources and limitations
Two kinds of numbers feed this tool. The geometry — areas, openings, squares, waste — is fixed arithmetic and as accurate as your tape. The material coverage and the cost estimates are planning values based on common manufacturer specifications and reported US installed pricing; they vary with product line, region and labor, which is why they appear as ranges. Treat the result as a solid starting point for budgeting and ordering, subject to a field measure and your contractor's quote.
Before you place the order
Your result above answers the main question. Before you buy, run through the practical points that most affect a certainteed siding project, so the number translates cleanly into a real order.
- Confirm coverage: the default coverage is a planning figure. Check the exact coverage printed on your product's box or spec sheet and adjust it if it differs, since even a small change moves the piece count on a big wall.
- Match the waste to your walls: keep 10% for a simple rectangular house, and raise it toward 15% for gables, dormers, bay windows and lots of angled cuts, because those details generate short offcuts you can't reuse.
- Account for accessories: starter strip, trim, inside and outside corners, flashing and fasteners are all part of a complete order, not an afterthought — the takeoff above estimates each so your material list is whole.
- Keep a spare: hold back a piece or a full box for future repairs, since profiles and colors get discontinued over time and an exact match years later is hard to find.
- Time your order: have material delivered close to the start date, stored flat and dry, so it isn't sitting exposed or getting damaged before the crew arrives.
Re-run the numbers above after any change and lean on the per-wall audit to verify each surface one at a time, so what you order matches what the wall actually needs rather than a rough guess. That small habit is the difference between one clean delivery and a mid-project trip back to the supplier.
Frequently asked questions
Does this work for CertainTeed fiber cement?
Can I calculate Allura or Boral siding?
What about Diamond Kote?
Are these brands interchangeable in the calculator?
What people say
"Priced Diamond Kote against a standard Hardie order using the same counts. Clean comparison."