Log Weight Calculator
Calculate log weight accurately for your build. Get material quantities, waste allowances, and project cost breakdowns.
Formula
Weight = pi x (D/24)² x L x Density (lbs/cu ft)
Calculate log volume as a cylinder using pi times the radius in feet squared times the length in feet. Multiply by the species density in pounds per cubic foot. Use green density for freshly cut logs and dry density for seasoned wood.
Frequently Asked Questions
How do you estimate the weight of a log?
To estimate log weight, calculate the volume using the cylinder formula (pi times radius squared times length) and multiply by the wood density. Green (freshly cut) wood is significantly heavier than dry wood because it contains 30 to 100 percent moisture by weight. A green red oak log 12 inches in diameter and 8 feet long weighs approximately 400 pounds, while the same log dried to 12 percent moisture would weigh about 275 pounds. Always use green wood density for transport and handling calculations since logs are typically moved shortly after felling.
What is the difference between green and dry wood weight?
Green wood contains significant moisture, often 50 to 100 percent moisture content by weight in hardwoods and up to 200 percent in some softwoods. This means green wood can weigh nearly twice as much as the same wood after drying. For example, green white pine weighs about 46 lbs per cubic foot compared to 25 lbs dry, nearly double. Wood is considered air-dried at around 12 to 20 percent moisture content and kiln-dried at 6 to 8 percent. The heartwood of a living tree is typically drier than the sapwood, so logs with more heartwood weigh somewhat less per cubic foot.
How are log volumes measured in board feet?
Board feet in logs are estimated using log scaling rules, with the Doyle and Scribner scales being the most common. The Doyle rule uses the formula (D-4)^2 x L / 16 where D is the small-end diameter inside bark and L is the log length in feet. The Scribner rule uses a diagram-based approach that accounts for taper and saw kerf. The Doyle rule significantly underestimates lumber yield for small logs under 28 inches but is more accurate for larger logs. The International 1/4-Inch rule is considered the most accurate for all log sizes and is used by the US Forest Service.
How do I interpret the result?
Results are displayed with a label and unit to help you understand the output. Many calculators include a short explanation or classification below the result (for example, a BMI category or risk level). Refer to the worked examples section on this page for real-world context.
Can I use the results for professional or academic purposes?
You may use the results for reference and educational purposes. For professional reports, academic papers, or critical decisions, we recommend verifying outputs against peer-reviewed sources or consulting a qualified expert in the relevant field.
Can I share or bookmark my calculation?
You can bookmark the calculator page in your browser. Many calculators also display a shareable result summary you can copy. The page URL stays the same so returning to it will bring you back to the same tool.