About this calculator
This calculator converts a pile of timber into a volume — sawn (dimensional) timber from its section and length, or round logs using Huber's formula. Use it to check a delivery, or to convert between a piece count and a cubic-metre order.
Formula
sawn: volume per piece = width x thickness x length
total volume = volume per piece x piece count
pieces per m3 = 1 / volume per piece
round log (Huber's formula): volume per log = length x (pi/4) x mid-diameter^2
total volume = volume per log x log count
Huber's formula treats the log as a cylinder whose cross-section is measured at its mid-length — the single most common way to estimate a tapering log's volume with one diameter reading, without a species-specific taper table.
Worked example
Sawn: 100 x 50 mm timber, 4 m long, 50 pieces.
volume per piece = 0.1 x 0.05 x 4 = 0.02 m³
total volume = 0.02 x 50 = 1.0 m³
pieces per m³ = 1 / 0.02 = 50
Round log: a 4 m log with a 250 mm mid-length diameter, 10 logs.
volume per log = 4 x (pi/4) x 0.25² = 0.1963 m³
total volume = 0.1963 x 10 = 1.963 m³
FAQ
Why measure the diameter at mid-length, not the ends? A log tapers from the wider butt end to the narrower top end, so its true volume sits between what either end's diameter alone would suggest. Huber's formula uses the mid-length diameter as a single reading that already accounts for the taper reasonably well for a typical log shape, without needing two measurements or a taper table.
Why doesn't this calculator offer a top-diameter method as well? A top-diameter-only method needs an assumed taper rate to estimate the mid-diameter, and that rate varies by species and how the log was cut — supplying one would mean inventing a number this calculator has no basis for. Measuring the mid-length diameter directly avoids that assumption entirely, so only Huber's formula is offered here.
Is "pieces per m³" always a whole number? No — it is the reciprocal of one piece's volume, shown as a decimal. It tells you how many pieces of that exact size would make up one cubic metre; you would not usually buy timber in fractional pieces, but the figure is useful for converting between a cubic-metre price and a per-piece price.
Which standard does this follow? None is cited for either calculation. Sawn volume is plain geometry; Huber's formula is a long-established named formula for estimating round timber volume, not a normative standard.
Assumptions and limits
Round-log volume assumes a reasonably uniform taper along the log's length, matching what a single mid-length diameter reading can represent — a log with an unusual shape (heavy buttressing, sweep, or a broken/irregular profile) will have a real volume that differs from Huber's estimate. Sawn timber volume assumes a constant rectangular section along the full length, with no allowance for planing losses, wane, or defects that would be cut out before use. No drawing is produced — the result is a volume figure only.