Enter the diameter and length of a log and choose the tree species. The calculator gives the green weight of freshly cut wood in pounds, tons and kilograms, so you can plan lifting, hauling and trailer loads.
How to use the log weight calculator
- Measure the diameter at both ends and use the average, or measure at the middle of the log. Leave out the bark if it is loose.
- Enter the length of the log.
- Choose the species. If yours is not listed or you have a figure from a local sawmill, enter it as a custom weight.
- For several logs of the same size, enter how many.
Log weight formula
Volume (ft³) = π × (diameter ÷ 2)² × length (diameter and length in feet) Weight (lb) = volume × green weight of the species (lb/ft³) Tons = lb ÷ 2,000
The log is treated as a cylinder. Real logs taper, so measuring in the middle or averaging both ends gives a better volume than using the big end. The species weights are averages for green wood from Penn State Extension, worked out from the specific gravity and moisture content in the USDA Wood Handbook.
Worked example: a white oak log 16 in × 8 ft
- Radius: 16 ÷ 2 = 8 in = 0.667 ft.
- Volume: 3.1416 × 0.667² × 8 = 11.17 ft³.
- Green white oak weighs about 64 lb/ft³: 11.17 × 64 = 715 lb, or 0.36 tons.
The same log in eastern white pine at 54.9 lb/ft³ weighs about 613 lb.
Weight of an 8 ft log by diameter
| Diameter | Volume | Red oak (61 lb/ft³) | Sugar maple (59) | Loblolly pine (50.3) |
|---|---|---|---|---|
| 10 in | 4.36 ft³ | 266 lb | 257 lb | 219 lb |
| 12 in | 6.28 ft³ | 383 lb | 371 lb | 316 lb |
| 16 in | 11.17 ft³ | 681 lb | 659 lb | 562 lb |
| 20 in | 17.45 ft³ | 1,065 lb | 1,030 lb | 878 lb |
| 24 in | 25.13 ft³ | 1,533 lb | 1,483 lb | 1,264 lb |
| 30 in | 39.27 ft³ | 2,395 lb | 2,317 lb | 1,975 lb |
Why green logs are so heavy
Freshly cut wood is full of water. Penn State Extension notes that green weight depends on both the density of the wood and its moisture content, which varies between the heartwood and the sapwood. That is why the same species can weigh 10% more or less than the average, and why a log gets much lighter as it dries.
Tips for moving logs safely
- Round up. Logs often carry more water than average, especially in spring; plan for the heavier end.
- Check your equipment ratings. Compare the result with the rated capacity of your trailer, winch, chains and straps.
- Cut long logs shorter. Weight goes up with length, so bucking a log into two pieces halves each lift.
- Convert to firewood. For split and stacked wood, use the firewood cord calculator.
Questions
How much does a log weigh?
Multiply its volume by the green weight of the species. A 16 in × 8 ft white oak log is about 11.2 ft³, which at 64 lb/ft³ is about 715 lb.
How much does a cubic foot of green oak weigh?
About 61 lb for northern red oak and 64 lb for white oak, according to Penn State Extension.
How much does an 8 ft log weigh?
It depends on the diameter and species: about 380 lb for a 12 in red oak log and about 1,065 lb for a 20 in one.
Do logs weigh less when dry?
Yes. Most of the extra weight of a green log is water, and it is lost as the wood dries to the air.
Sources
- Calculating the Green Weight of Wood Species, Penn State Extension.
Used for: Average green weight by species (softwood values converted from kg/m³ to lb/ft³); method from specific gravity and moisture content in the USDA Wood Handbook. - NIST Guide to the SI, Appendix B.8: Factors for units listed alphabetically, National Institute of Standards and Technology.
Used for: Foot, inch and pound definitions; cubic foot to cubic metre conversion.