Materials
Round timber volume
- where
- volume (m³)
- diameter (mm)
- length (m)
- count
Explain this equation
Gives the volume of round timber of constant diameter, such as posts, poles or dowels, for a number of pieces.
d is the diameter in millimetres. l is the length of each piece in metres, and n is the number of pieces. V is the total volume in m³.
Each piece is a cylinder: cross-section area times length. The end area is πd²/4. Dividing d by 1000 first turns millimetres into metres, so the result comes out directly in m³.
Two 200 mm posts 3 m long are about 0.19 m³. Doubling the diameter makes the volume four times larger.
Watch out: this assumes a true cylinder. Tapered logs and merchant measuring rules give different figures.
Calculate a constant-diameter cylindrical piece.
Enter your values to see the result.
Good to know
Diameter is in mm; length in metres. Not suitable for tapered logs or merchant grading/tally rules.
Sources
- Geometry / arithmetic
This is a calculation aid, not a structural design or compliance certificate. Every default is an example, not a specification for your project.