Board Feet in a Tree
Estimate how many board feet a standing tree will yield before you cut it. Enter DBH (diameter at breast height) and merchantable height, and the calculator applies Doyle, Scribner, or International ¼-inch to each 16-foot log segment.
Standing-tree estimates are rough. Actual yield depends on taper, defects, and how the logger bucks the tree. This calculator assumes a Girard-25 form (typical hardwood taper) and divides the merchantable stem into 16-foot logs.
Tip: Measure DBH at 4½ ft above ground on the uphill side. Merchantable height ends at the first major fork, top defect, or where SED drops below 8".
How the Standing-Tree Estimate Works
The tree is modeled as a series of 16-foot logs stacked from base to top. Each log's small-end diameter is estimated by tapering DBH downward using Girard form class 25 — a widely used hardwood taper assumption where DBH loses about 2" per 16 ft of merchantable stem.
- Subtract ~2" from DBH for bark → get inside-bark DBH.
- Subtract additional ~2" per 16 ft up the stem → estimated small-end diameter of each log.
- Apply the chosen log rule to each log independently.
- Sum log volumes → total standing-tree BF estimate.
Accuracy expectation: ±15–25% for good measurements on straight, defect-free stems. Sweep, crook, forks, and rot reduce actual yield significantly.
Measuring DBH and Merchantable Height
DBH — Diameter at Breast Height
Standard measurement point: 4½ feet above ground, on the uphill side if slope. Use a diameter tape (D-tape) for direct reading, or wrap a regular tape around the circumference and divide by π (3.14159).
Merchantable height
Distance from stump (usually 1 ft above ground) to the point where the stem becomes non-merchantable — typically the first major fork, a large defect, or where the diameter drops below 8" (for hardwood) or 6" (for softwood pulpwood/small logs).
Measuring height without climbing
- Clinometer or app — pace back a known distance, measure the angle to the top, apply trigonometry.
- Stick method — hold a stick vertical at arm's length; when it visually matches the tree height, you know the ratio.
- Rangefinder + phone app — laser distance + calculator app is fastest for repeated measurements.
Standing-Tree BF by DBH — Common Cases
For 3 typical merchantable heights (International ¼-inch, hardwood, straight stem):
| DBH (in) | 32 ft merch. | 48 ft merch. | 64 ft merch. |
|---|---|---|---|
| 12 | 110 BF | 150 BF | 180 BF |
| 14 | 160 BF | 230 BF | 280 BF |
| 16 | 230 BF | 330 BF | 410 BF |
| 18 | 320 BF | 460 BF | 580 BF |
| 20 | 430 BF | 620 BF | 790 BF |
| 24 | 680 BF | 990 BF | 1,270 BF |
| 30 | 1,150 BF | 1,680 BF | 2,180 BF |
Standing-Tree FAQ
How accurate is a standing-tree estimate?
Within ±15–25% for a straight, defect-free tree measured carefully. Real yield depends on how the logger bucks the tree, the sawyer's grading choices, and hidden defects.
What is DBH?
Diameter at Breast Height — trunk diameter measured 4½ feet above ground. Standard reference for all US forest inventory.
Should I include the top?
Only up to where the stem is still merchantable. For hardwood, that's usually where diameter drops below 8"; pulp-grade wood can go smaller.
Does taper matter?
Yes — hugely. The default here assumes typical hardwood taper (~2" per 16 ft). Softwoods often taper less; over-mature or slow-grown stems taper more.
Which log rule should I use for standing timber?
International ¼-inch is the closest to modern sawmill yield. Doyle is conservative — use it if selling to a buyer who scales in Doyle. Scribner is standard for Pacific Northwest federal timber.
Does this work for a whole stand?
Estimate each tree individually and sum. For large stands, use professional cruise methods (variable-radius plots, basal area factor).
How much is a mature oak worth as lumber?
An 18"-DBH × 48-ft merchantable red oak yields ~460 BF. At $6/BF retail 4/4 lumber that's ~$2,760 potential — but the standing tree sold to a logger is worth far less ($100–$400) due to logging, hauling, and milling costs.
Related Tools
- Main Board Feet Calculator — Log mode for felled logs
- Doyle Log Rule
- Scribner Log Rule
- International ¼-inch Rule