Timber Quantity Calculator

Work out timber quantity instantly with clear inputs, formula shown and shareable results.

About Timber Quantity Calculator

Timber is bought by volume, so quantity is cross-section times length times the number of members. Softwood at about 500 kg/m³ gives the handling weight, and one cubic metre equals roughly 424 board feet for anyone working from imperial supplier lists.

Formulas

Timber volume

m³ = width m x depth m x length x number of members

Board feet

bd ft = m³ x 423.8

Worked example

With the default values below, Timber Quantity Calculator returns Timber volume of 0.9000. Change any input above and every figure here is recalculated in your browser.

Inputs used

Length per memberminimum 0.1 m: 4 m
Number of membersminimum 1: 30
Member widthminimum 5 mm: 50 mm
Member depthminimum 5 mm: 150 mm

Results

Timber volume: 0.9000 m³
Total running length: 120.0 m
Approximate weight: 450.0 kg
Equivalent board feet: 381.4 bd ft

Step by step

1Values used
2Timber volume
3Board feet
4Timber volume= 0.9000 m³
5Total running length= 120.0 m
6Approximate weight= 450.0 kg
7Equivalent board feet= 381.4 bd ft

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is the Timber Quantity figure worked out?

m³ = width m x depth m x length x number of members. Timber is bought by volume, so quantity is cross-section times length times the number of members.

Is nominal or actual size used?

Actual, or dressed, size for volume. Nominal sizes are before planing and are typically 3-5 mm larger in each direction, which overstates the volume you receive.

What values do I need to enter?

This calculator takes 4 inputs: Length per member, Number of members, Member width, Member depth. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.