Log Volume Calculator
Calculate log board feet using Doyle, Scribner, and International ¼-inch rules — the three standard log scaling methods.
Log Volume Calculator
Doyle, Scribner, and International ¼" rules
Log Dimensions
Inside bark, at small end
Rule Comparison
Doyle — Most common in eastern US. Under-estimates small logs, over-estimates large logs.
Scribner — Standard in western US and government timber sales. More accurate for small logs.
International ¼" — Most accurate overall. Accounts for saw kerf. Used as benchmark.
Board Feet by Rule
Formulas Used
Doyle Rule
Where D is small-end diameter inside bark (inches) and L is log length (feet). Most common in eastern US.
Scribner Rule
More accurate for small logs than Doyle. Standard for western US and USFS timber sales.
International ¼" Rule
Most accurate overall. Accounts for ¼-inch saw kerf and 4-foot log sections. Considered the benchmark.
Understanding Log Scaling Rules
Log scaling rules estimate how many board feet of lumber a log will yield when sawn. Three rules dominate the North American timber industry, each with different strengths.
The Three Major Log Rules
Doyle Rule — Developed in 1825, this is the simplest and most widely used rule in the eastern United States. It significantly under-estimates the yield of small logs (under 20" diameter) and slightly over-estimates large logs. Buyers prefer Doyle because they get more lumber than they pay for on small logs.
Scribner Rule — Created in 1846 by drawing circles (representing boards) inside a circle (representing the log end). It's more accurate for small logs than Doyle. The Scribner Decimal C variant rounds results to the nearest 10 BF and is the official scale for all US Forest Service and BLM timber sales.
International ¼-Inch Rule — Developed in 1906, this is the most mathematically accurate rule. It accounts for a ¼-inch saw kerf and calculates yield in 4-foot sections to account for log taper. It's used as the benchmark against which other rules are compared.
Comparison: BF Yield by Rule (16-foot log)
| Diameter | Doyle | Scribner | International ¼" | |----------|-------|----------|-------------------| | 8" | 16 | 32 | 35 | | 12" | 64 | 80 | 95 | | 16" | 144 | 150 | 175 | | 20" | 256 | 250 | 275 | | 24" | 400 | 370 | 395 |
Notice how Doyle severely under-estimates the 8" log (16 BF vs 35 BF from International).
Tips for Log Buyers
- Know which rule your mill or buyer uses
- Measure small-end diameter inside bark
- Deduct for defects (rot, sweep, crook)
- Consider that actual yield depends on sawing pattern and operator skill
Frequently Asked Questions
Related Calculators
Board Foot Calculator: Lumber Volume & Cost
Calculate board feet from lumber dimensions — thickness, width, length, quantity, with waste factor and cost estimates.
Wood Weight Calculator: Lumber in lb & kg
Estimate solid lumber weight from actual dimensions or board feet, using a selected species density or your own verified density.