How do you calculate tonewood blank yield?

Divide usable blanks by total blanks graded and multiply by 100. With 8 usable out of 250 graded, yield is 8 ÷ 250 × 100 = 3.2%, which signals a failed or mis-graded billet.

What is a good tonewood yield?

For master-grade quartersawn Sitka or Adirondack tops, 50-70% off a clean billet is realistic; AAA grades and lower can hit 80%+. A 3.2% result like the example means almost the entire lot was rejected and needs investigation.

Why is my tonewood yield so low?

The usual culprits are grain runout, kiln checking, sap streaks, and insufficient stiffness for the grade you are selling. Low yield is also common when you over-grade — calling everything master grade against a strict spec.

Yield vs grade recovery — what's the difference?

Yield is pass-rate against any usable spec; grade recovery is how many blanks hit a specific tier (e.g. master vs AA). You can have high yield but poor recovery if most blanks drop to a cheaper grade.

Does the calculator tell me how far I am from target?

Yes. The yield gap line subtracts your target from actual yield. At 3.2% actual against a 95% target the gap is 91.8 points, a clear signal the run is unsellable at the quoted grade.

Should I grade per billet or per kiln load?

Per billet gives the most actionable yield because runout and checking cluster within a single log. Aggregating across a whole kiln load can mask one bad billet dragging the average down.

Musical Instruments & Acoustic Products calculator

Tonewood Blank Yield Calculator

Tonewood blank yield is the percentage of graded wood blanks that pass acoustic and cosmetic grading and actually make it into instrument bodies, tops, or backs. Lutherie shops and tonewood suppliers track it per species, billet, and quartersaw run because rejected blanks are the single largest hidden cost in a tonewood program — a kiln-checked or runout-ridden Sitka spruce top is scrap, not a second. This calculator returns your yield and the point gap to a target so a buyer can defend a price or a grader can flag a bad billet before it ruins a month. It matters because tonewood margins live and die on the difference between an 85% and a 60% yield run.

What this calculator does

Estimate the percentage of tonewood blanks that pass grading for instrument bodies, necks, and soundboards, and compare it to the target yield your shop needs to hit.
Use it when a fresh lot of spruce, maple, mahogany, or rosewood billets has been graded and you need a clean yield number plus gap to target for the daily production huddle.
It computes the percentage of graded tonewood blanks that are usable, plus how many points that yield sits above or below your target.

Formula used

Tonewood yield = usable tonewood blanks ÷ total tonewood blanks graded × 100
Yield gap to target = tonewood yield - target tonewood yield

Inputs explained

Usable tonewood blanks:
Total tonewood blanks graded:
Target tonewood yield:

How to use the result

Use it after grading each billet, kiln load, or incoming supplier lot to decide whether the run is sellable at quoted prices or needs to be reclassified.
Yield alone hides why blanks failed — runout, checking, color, or stiffness — so pair it with a reject-reason tally before blaming a supplier.

Common questions

How do you calculate tonewood blank yield? Divide usable blanks by total blanks graded and multiply by 100. With 8 usable out of 250 graded, yield is 8 ÷ 250 × 100 = 3.2%, which signals a failed or mis-graded billet.
What is a good tonewood yield? For master-grade quartersawn Sitka or Adirondack tops, 50-70% off a clean billet is realistic; AAA grades and lower can hit 80%+. A 3.2% result like the example means almost the entire lot was rejected and needs investigation.
Why is my tonewood yield so low? The usual culprits are grain runout, kiln checking, sap streaks, and insufficient stiffness for the grade you are selling. Low yield is also common when you over-grade — calling everything master grade against a strict spec.
Yield vs grade recovery — what's the difference? Yield is pass-rate against any usable spec; grade recovery is how many blanks hit a specific tier (e.g. master vs AA). You can have high yield but poor recovery if most blanks drop to a cheaper grade.
Does the calculator tell me how far I am from target? Yes. The yield gap line subtracts your target from actual yield. At 3.2% actual against a 95% target the gap is 91.8 points, a clear signal the run is unsellable at the quoted grade.

Last reviewed 2026-05-12.