Free Tool

Log Weight Calculator

Estimate the weight of a log based on tree species, diameter, and length. Perfect for crane picks.

Average diameter of the log section. Measure inside the bark if possible.
24 in
Length of the piece you plan to cut or lift.
10 ft
Hardwoods like Oak or Hickory are significantly denser and heavier than softwoods like Pine.
Heavy Hardwood
(Oak, Hickory, Beech)
Medium Hardwood
(Maple, Ash, Elm)
Heavy Softwood
(Yellow Pine, Fir)
Light Softwood
(White Pine, Spruce)
Estimated Green Weight
0 lbs
Estimated Volume: 0 cubic feet

Run a Tree Service?

Track your equipment capacities, manage your fleet, and dispatch crews safely with TreeOS.

Try TreeOS Free

Why is calculating log weight important?

Accurately estimating the weight of a log is arguably the most important safety calculation an arborist makes on a job site. Whether you are rigging a piece out of a tree over a house, loading a log truck, or planning a crane pick, underestimating log weight can lead to catastrophic equipment failure.

How Log Weight is Calculated

To determine the weight of a log, you must calculate its geometric volume and multiply it by the "green density" of that specific tree species. Green wood (freshly cut wood) contains a massive amount of water, which makes it significantly heavier than seasoned firewood.

  • Volume Formula: The log is treated as a cylinder. The formula is Volume = π × r² × Length. Because arborists measure diameter in inches and length in feet, the radius must be converted to feet before the math is done.
  • Green Density: Density is measured in pounds per cubic foot (lbs/ft³). A heavy hardwood like live oak can weigh over 70 lbs/ft³ when green, meaning a section of oak can literally weigh twice as much as the exact same sized section of white pine (which averages ~35 lbs/ft³).
  • Taper factor: Trees are not perfect cylinders; they taper toward the top. For very long logs, calculating the volume based solely on the base diameter will result in an overestimate. To be more accurate, measure the diameter at the midpoint of the log.

Safety Margins for Crane Operators

If you are using this calculator to plan a crane pick, always add a generous safety margin. Our calculator provides mathematical averages, but a tree that has absorbed excessive water after a rainy season, or a log with a large unseen crotch or burl, will weigh more than the formula suggests. Shock-loading from improper rigging can also multiply the effective weight on your ropes and hardware by several times.