Cedar Siding Calculator
Plan cedar lap, bevel or shingle coverage with the right waste factor, plus a cost range for real cedar prices.
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) |
|---|
Cedar coverage and higher waste
Real cedar is beautiful and unforgiving of sloppy estimating. Because you overlap each course and cut around every knot and defect, cedar carries a higher waste factor than manufactured siding — often 12 to 15 percent. Start from accurate wall area and apply a realistic allowance, or you'll run short of matching boards partway through.
Enter your walls and gables, subtract the openings, and the tool returns coverage in squares and boards along with a cedar-priced cost band. For bevel and clapboard specifically, the exposure you choose sets how far each board goes.
How to use this calculator
- Choose units and material. Feet is the US standard; flip to meters if that's how you measured. The material sets a sensible default coverage and price.
- Enter each wall. Width, height and how many identical walls — one line per distinct face, front, back and both sides at minimum.
- Add gables and openings. Give each gable its base and rise; give each window, door and garage door its size so the area comes out.
- Set waste and price. Ten percent fits a plain house; raise it for lots of cuts. Match the price to a real quote if you have one.
- Read and save. Squares, panels, boxes, accessories and cost appear together; print, copy or share the result.
Why cedar waste runs higher
Overlap, grading around knots, and hand-selection for the visible face all consume material. On a 1,500 sq ft wall, a 14% allowance adds ~210 sq ft of coverage — cheap insurance against a mismatched late order.
The basis for the math
Nothing here is a black box. Wall area minus the openings gives net coverage; dividing by 100 gives squares, the unit the trade orders in; a waste percentage accounts for the pieces you cut and can't reuse. Those steps are industry standard. The per-product coverage and the cost bands are drawn from manufacturer installation data and commonly cited US pricing, so they're representative rather than exact for your ZIP code. Use the result to plan, then verify with your supplier.
Making real cedar last
Cedar's beauty comes with maintenance, and the estimate is only half the story. These are the things that decide whether a cedar wall looks great in ten years or not.
- Finish all sides: seal or stain the back and edges before installation, not just the face. Unsealed backs are where cupping and rot start.
- Grade matters: clear vertical-grain cedar is stable and pricey; knotty grades cost less but move more and raise your waste.
- Fasteners: use stainless or hot-dipped galvanized nails. Cheaper fasteners bleed rust streaks down cedar.
- Maintenance cycle: plan to re-oil or re-stain on a schedule. That recurring cost is part of cedar's true price of ownership.
The higher waste factor built into the tool reflects cedar's grading and overlap — keep it at 12–15% unless your walls are very simple.
Frequently asked questions
How do I calculate cedar siding?
Why is cedar's waste factor higher?
What's the difference between cedar bevel and clapboard?
Does cedar need sealing?
What homeowners say
"The higher waste default matched my actual cedar order. No scrambling for a matching board."