Log Volume Calculator
Calculate log volume using Doyle, Scribner, and International 1/4 log rules. Convert between board feet, cubic feet, cubic meters, and cords. Includes wood species weight and price reference.
Single Log Results
Log Scale Comparison for Your Log
| Your LogBest | Doyle Scale | Scribner | International 1/4 |
|---|
Understanding Board Feet and Log Scales
What is a Board Foot?
A board foot (BF) is a volume measurement equal to 1 inch thick x 12 inches wide x 12 inches long (144 cubic inches). It is the standard unit for buying and selling lumber in the United States.
Formula: Board Feet = (Thickness in inches x Width in inches x Length in feet) / 12
Example: A board that is 2in x 6in x 10ft = (2 x 6 x 10) / 12 = 10 board feet.
Why Different Log Scales Exist
Different log scales were developed for different purposes and regions:
Doyle Scale (1825): Most common in the eastern US. Uses a formula that favors large logs - small logs are significantly underestimated. This is the primary reason small log sellers lose money.
Scribner Decimal C (1840s): Developed in the Great Lakes region. Based on actual board foot diagrams inscribed in log ends. More accurate than Doyle for small to medium logs.
International 1/4 Inch (1920s): The most accurate modern scale. Accounts for kerf (saw blade width) and is the industry standard for most US forests.
Converting Between Units
Board Feet to Cubic Feet: 1 BF = 1/12 cubic feet. So 100 BF = 8.33 cubic feet.
Cubic Feet to Cords: 1 cord = 128 cubic feet. So 100 cubic feet = 0.78 cords.
Cubic Feet to Cubic Meters: 1 ft3 = 0.0283 m3. So 100 ft3 = 2.83 m3.
Board Feet to Cords: Approximately 200-300 BF per cord, depending on log scale and wood species.
Doyle Scale: The Formulas
Doyle Formula: BF = (D - 4)squared x L / 16, where D = small-end diameter in inches, L = length in feet.
Why Doyle underestimates small logs: The (D-4)squared term means logs under 4 inches get zero board feet. A 10-inch log gets (10-4)squared = 36, while International gets about 50. That is a 28% underestimate.
When Doyle overestimates: Logs over 28 inches in diameter. A 36-inch log gets (36-4)squared = 1024 BF by Doyle, but International gives about 940 BF. That is a 9% overestimate.
How to Sell Logs: Tips for Landowners and Sawmill Operators
1. Know Your Scale Before You Cut
Ask your buyer which log scale they use before cutting. Different scales can yield 15-25% different results. If you are selling standing timber, negotiate which scale will be used.
2. Measure Accurately
Use a logger's tape to measure small-end diameter inside bark. Length should be measured in 2-foot increments (round down). Measure diameter at the small end, not the butt.
3. Sort Your Logs
Separate by species, grade, and size. Mixed loads are typically paid at the lowest grade price. High-value species like Black Walnut ($12/BF) should never be mixed with low-value species like Poplar ($3.50/BF).
4. Get Multiple Quotes
Prices vary significantly between sawmills. Get at least 3 quotes. Current market prices (2024): Softwood $3-5/BF, Hardwood $5-10/BF, Exotic/Premium $10-20+/BF.
5. Consider On-Site Sawing
Mobile sawmills can cut your logs into lumber on-site, potentially doubling your value. A portable bandsaw mill costs $3,000-10,000 and can pay for itself in one season.
6. Understanding Log Grades
Grade 1 (Select): Clear, straight, 12+ inches diameter. Premium price.
Grade 2 (Number 1): Sound, straight, some knots. Standard price.
Grade 3 (Number 2): More knots, slight crook. Lower price.
Grade 4 (Number 3): Many knots, crook, defects. Lowest price.
Wood Species Reference Table
| Species | Weight (lb/ft3) | Hardness | Price/BF | Common Use |
|---|---|---|---|---|
| White Pine | 25 | 380 lbf | $3.50 | Construction, trim, molding |
| Red Pine | 28 | 350 lbf | $3.00 | Construction, crates |
| Eastern White Cedar | 22 | 320 lbf | $4.50 | Fencing, siding, shingles |
| Western Red Cedar | 23 | 350 lbf | $6.00 | Siding, shingles, outdoor furniture |
| Spruce | 27 | 400 lbf | $3.25 | Construction, framing |
| Douglas Fir | 34 | 660 lbf | $4.50 | Construction, beams, flooring |
| Hemlock | 28 | 400 lbf | $3.75 | Construction, crates |
| Red Oak ← Selected | 47 | 1290 lbf | $7.50 | Furniture, flooring, cabinets |
| White Oak | 49 | 1360 lbf | $8.00 | Barrels, boats, furniture |
| Hard Maple | 44 | 1450 lbf | $7.00 | Flooring, bowling alleys, butcher blocks |
| Soft Maple | 40 | 950 lbf | $5.50 | Furniture, paint-grade trim |
| Ash | 42 | 1320 lbf | $6.00 | Tool handles, baseball bats, furniture |
| Birch | 43 | 1260 lbf | $5.00 | Furniture, plywood, veneer |
| Cherry | 35 | 950 lbf | $9.00 | Fine furniture, cabinets, flooring |
| Black Walnut | 38 | 1010 lbf | $12.00 | Fine furniture, gunstocks, veneer |
| Poplar | 31 | 540 lbf | $3.50 | Paint-grade trim, cabinets |
| Basswood | 26 | 410 lbf | $4.00 | Carving, musical instruments, crates |
| Cypress | 32 | 510 lbf | $6.50 | Outdoor structures, siding, boats |
Log Scale Comparison Table
| Scale | Year | Region | Best For | Accuracy |
|---|---|---|---|---|
| Doyle | 1825 | US (most common) | Large logs, general sawmilling | Low for small logs |
| Scribner Dec. C | 1840s | US (Great Lakes) | Small to medium logs | Medium |
| International 1/4 | 1920s | US (standard) | Most accurate, all sizes | High (Recommended) |
Frequently Asked Questions
What is a board foot?
A board foot (BF) is a volume measurement equal to 1 foot x 1 foot x 1 inch (144 cubic inches). It is the standard unit for buying and selling lumber in the US.
How many board feet are in a cord of firewood?
One cord of firewood (4x4x8 ft = 128 cubic feet) contains approximately 200-300 board feet depending on the log scale used and wood species.
Which log scale should I use?
Use the scale your local sawmill or buyer uses. Doyle is most common in the eastern US, Scribner in the Great Lakes region, and International 1/4 is the most accurate overall.
Why is Doyle scale bad for small logs?
Doyle uses (D-4)squared, which means logs under 4 inches get zero board feet, and logs under 16 inches are significantly underestimated. A 10-inch log gets 28% less under Doyle than International.
How do I measure log diameter correctly?
Measure the small-end diameter inside the bark using a logger's tape or diameter tape. Measure at the narrowest point of the log. Do not measure the butt end.
What is saw kerf waste?
Saw kerf is the wood lost to the saw blade thickness. A typical bandsaw blade removes 1/8 inch (3mm). For a 12-inch log, this is about 8-15% waste depending on log size.
How much is my timber worth?
Timber values vary by species, grade, and market. Softwood: $3-5/BF. Hardwood: $5-10/BF. Premium species (Walnut, Cherry): $10-20+/BF. Get 3+ quotes from local mills.
References & Sources
- USDA Forest Service - Forest Products Laboratory: Wood Handbook (FPL-GTR-282). The definitive reference for wood properties and measurement standards.
- USDA Forest Service - Timber Sale Analyzer: A Guide to Log Scaling. Standard log scaling procedures for federal timber sales.
- Doyle Log Scale - Developed by Edward Doyle in 1825. Widely used in the eastern United States for sawlog measurement.
- Scribner Decimal C - Developed in the 1840s for the Great Lakes lumber industry. Based on actual board foot diagrams.
- International 1/4 Inch Rule - American Society for Testing and Materials (ASTM D1161). The most accurate log scaling method.
- National Wooden Pallet & Container Association - Industry standards for lumber measurement and grading.