Yield EstimatorTimber Recovery & Yield Calculator
Estimate how much usable timber you recover from logs, green sawn or rough stock through sawing, drying and finishing. Calculate waste and your true effective cost per usable unit for accurate pricing.
Why this calculation matters
Recovery decides your true cost per usable unit. A 5% recovery gain is often worth more than a 5% purchase discount, because it applies to timber you already own.
Yield Estimator
Timber Recovery & Yield Calculator
Cost per input unit, for effective output cost.
| Metric | Value | Detail |
|---|
About Yield Estimator
Every step from log to finished product loses volume - to saw kerf, slabs, drying shrinkage, planing and defect removal. The yield (or recovery) rate tells you how much usable material survives. This is the single most important number for pricing: if you only recover 55% of a log, your usable timber actually costs nearly double the log price. This tool estimates output and your true effective cost. It computes the lumber recovery factor mills track — the sawmill yield percentage from log input to sawn output — and its effect on true cost.
Where Is This Used?
Formulas Used
Output volume = Input volume x Recovery rateWaste volume = Input volume - Output volumeWaste % = (1 - Recovery rate) x 100Effective output cost = Input cost / Recovery rateTypical: log to green sawn ~65%, log to finished ~42%How the calculation works
The cost that matters is the cost of usable output, not the cost of the log. At 45% recovery, every cubic metre of sawn timber carries the cost of more than two cubic metres of log.
Show the formula
Output volume = input volume x recovery rate. Waste = input - output. Effective cost per unit of output = input cost / recovery rate.Default recovery rates sit inside the ranges reported in FPL GTR-39, but they are defaults, not your mill. Log diameter, taper, sweep, saw variation and edging practice each move recovery by several points — measure your own and enter it as a custom yield.
References and what each one provides
- USDA FPL GTR-39 — Factors Determining Lumber Recovery in SawmillingSteele, P.H. (1984). Identifies and quantifies the seven factors that govern how much lumber a log yields, including kerf, edging and trimming practice, saw variation and log taper.The seven factors that determine how much lumber a log yields, and their relative size.
Unverified values are marked as such rather than presented as sourced.
Limitations of this calculation
Estimates recovery from the inputs given. It does not account for log defect distribution, grade recovery, operator skill, sawing pattern changes within a run, or drying degrade after conversion.
Do not use this for Contractual recovery guarantees or mill purchase agreements.
Figures are engineering estimates from the inputs and assumptions shown. Verify against the actual material and, where the result affects structure or safety, against a qualified professional.
- Recovery-factor method; effective cost = input cost ÷ usable output
Formula checked against the sources above by an automated regression test (tests/verify-phase2.js) that derives each expected value independently of this page. Last reviewed .
How to use this tool
- Enter the trade details below, then press Calculate.
- Pick your conversion process from the dropdown.
- Fill in input volume, custom yield.
- Press Calculate.
Worked example
Common mistakes to avoid
- Expecting sawn yield from log volume without deducting slabs, kerf and edging. Even good mills lose 30–50%.
- Ignoring log sweep and crook. A curved log yields far less than its scale volume suggests.
- Comparing yields between different log rules. Doyle under-scales small logs, so 'yield' looks better than it is.
Frequently Asked Questions
Wood species data
Density, hardness and movement for 60 timbers