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Log Weight Calculator

This log weight calculator will help you estimate the weight of a freshly cut tree using its "green" density and volume.

Green timber runs 50–100%; the density table is quoted at 12%.
Clear
Weight681 lb308.9 kg at 60% moisture
Per log681 lb308.9 kg
Volume by Smalian’s rule10.9083 cu ftthe average of the two end areas × length
As a cylinder on the mid-diameter10.6901 cu ftslightly less — taper is not linear in area
Mid-diameter14 in
Taper4 in over 10 ft0.4 in per foot
Density used1,000 kg/m³Red oak, 700 kg/m³ at 12% moisture
Doyle scale40 board feetthe traditional sawlog estimate, deliberately conservative on small logs
Weight in US tons0.3405

The method

volume = π × (mid-diameter ÷ 2)² × length

Green wood is mostly water

A freshly felled oak log can be 60–80% moisture by dry weight, which means well over a third of what you are lifting is water. The same log air-dried to 12% weighs perhaps 40% less — worth knowing before hiring the equipment.

Smalian’s rule averages the areas at the two ends rather than the diameters, which matters because area goes with the square of diameter. Averaging the diameters first and squaring gives a slightly smaller answer.

The Doyle scale is not a volume. It is a nineteenth-century rule for estimating sawn output that penalises small logs heavily — a 10-inch log scales at less than half its true board footage. It survives because it is still what many mills buy on.