Free tool
Siding Calculator
Turn wall area minus openings into siding squares with waste — the same coverage arithmetic as Drevanto's certified vinyl-siding assembly.
Result
Results updated.
| Siding squares (100 sq ft) | 19.8squares |
|---|---|
| Material to order | 1,981sq ft |
Formula
- net area = gross wall area − openings
- material = net area × (1 + waste)
- squares = material ÷ 100
Assumptions
- 10% waste suits simple rectangular elevations; gables and many corners raise it.
- Openings are entered as total measured area of doors and windows.
What this does not cover
- Trim, soffit, fascia, housewrap, and flashing are estimated separately.
- Gable triangles and complex geometry should be measured individually.
Planning aid only — not a quote. Quantities use documented rules of thumb; verify against your plans, local codes, site conditions, and real supplier pricing before ordering or bidding.
Methodology
Siding is ordered by the square: 100 sq ft of coverage. Gross wall area minus window and door openings gives net area; apply your waste allowance (10% is a workable default for simple gables; complex elevations with many cuts need more) and divide by 100. The result rounds to one decimal because suppliers commonly sell partial squares, but accessories — starter strip, J-channel, corners, trim — are linear-foot takeoffs this tool deliberately leaves out.
Worked example: 2,400 sq ft of wall, 240 sq ft of openings, 10% waste
- Net = 2,400 − 240 = 2,160 sq ft
- Order = 2,160 × 1.1 = 2,376 sq ft → 23.8 squares
- Round to supplier increments — e.g., 24 squares if sold whole
Frequently asked questions
Do I subtract all windows and doors?
For siding, yes — openings are large relative to the wall and the cut-off waste is already covered by your waste percentage.
Why aren't trim and accessories included?
Accessories are measured in linear feet along specific edges, not by area. Estimate them separately from your elevations; a blanket factor would be wrong more often than right.
Is vinyl siding a certified Drevanto assembly?
Yes. Vinyl siding is one of the 26 certified Instant assemblies in Beta 2 — the certified roof example and methodology are public on the Benchmark page.
Certified benchmark · 2026-08-21
In 520 certified profile-mode generations across 26 supported Instant assemblies on Windows (profile/AOT) and an Android API 36 emulator, supported jobs became editable estimates in a median of 0.028 seconds (rounded); the measured 95th percentile was 48.008 milliseconds (approximately 0.048 seconds), with 0 generative-AI provider calls.
- median, supported jobs
- 0.028 sec
- certified generations
- 520
- supported assemblies
- 26
- failures · 0 AI provider calls
- 0
Certified supported jobs only. Editable output; contractor pricing and field verification remain in control. Full methodology and results
See it run on your own jobs
The private Drevanto beta is the real, editable product — not a website demo. Apply, and we will follow up by email.