How to use the Wood / Log / Timber Cubic Feet Calculator
- Choose log for an untapered cylindrical estimate or timber for a rectangular piece. Use actual dimensions, not nominal lumber sizes.
- Choose a round log or rectangular timber. Enter actual dimensions and the number of identical pieces.
- Select Calculate. Review the result and its working; if you change an input, calculate again before copying or sharing.
Wood / Log / Timber formula
Round logs use cylindrical volume; rectangular timber uses length times width times thickness. Quantities multiply the solid volume.
Log: π × (diameter ÷ 2)² × length; timber: length × width × thickness; multiply by quantity
What the terms mean
- Length
- A measured length in the selected unit; it is converted to feet before volume is calculated.
- Log diameter
- A measured length in the selected unit; it is converted to feet before volume is calculated.
- Timber width
- A measured length in the selected unit; it is converted to feet before volume is calculated.
- Timber thickness
- A measured length in the selected unit; it is converted to feet before volume is calculated.
- Number of identical items
- The whole-number count of objects with the same entered dimensions.
Wood / Log / Timber worked examples
Estimate solid volume of a round log
Treat a straight log as a cylinder 8 ft long and 12 in in diameter. This estimates solid geometric volume, not sawn-lumber yield.
- Solid cylindrical log: π × (diameter ÷ 2)² × length
- 6.283185 ft³ × 1
Answer: 6.283185 ft³. Cubic yards: 0.232711 yd³; Litres: 177.919994 L; Solid-volume equivalent: 75.398224 board feet.
Total four pieces of sawn timber
Four timber pieces each measure 8 ft long, 6 in wide and 2 in thick. Use measured sizes rather than nominal lumber sizes.
- Sawn timber: length × width × thickness
- 0.666667 ft³ × 4
Answer: 2.666667 ft³. Cubic yards: 0.098765 yd³; Litres: 75.511591 L; Solid-volume equivalent: 32 board feet.
Wood / Log / Timber Cubic Feet Calculator FAQs
Can I enter a nominal 2 × 4?
Measure its actual width and thickness. Nominal sizes can differ from finished dimensions.
Is the board-foot figure a sawmill yield?
No. It is only the solid-volume equivalent. Sawing loss and log rules require a separate recovery model.
Measurement guide for Wood / Log / Timber
Measure actual timber thickness and width. For a round log, measure its diameter perpendicular to its length; taper and bark can affect the estimate.
Assumptions and limits
Real logs taper, carry bark and have defects. Solid cubic volume multiplied by twelve is a volume equivalent, not recoverable board feet under a log rule.
This is geometric solid volume. Logs taper and include bark; board-foot output is not a sawmill yield or log-grading estimate.
Check your result
Check radius versus diameter for logs and actual sizes for timber. The board-foot equivalent expresses solid volume and does not predict saleable sawn yield.