Spike's Calculators

# International 1/4-inch Log Rule (Clark)

Calculate the amount of board feet in a log using the International 1/4-inch Log Rule online.

The International 1/8-inch Log Rule was developed by Judson F. Clark in 1906 while working for the Province of Ontario. In 1917, it was modified to allow for a 1/4-inch kerf. The International 1/4-inch Log Rule is considered the most accurate mathematical log rule for calculating board feet.

The first result listed is what the calculator is intended to calculate.

The conversions for the other volume measurements are derived from the first one.

Board Foot * 0.0833333 = Cubic Foot
Board Foot * 0.00235974 = Cubic Meter

Diameter Measured Inside Bark = DIB
Length of Log in Feet 4' Log 8' Log
12' Log
16' Log 20' Log
DIB of Log Small End in Inches in

#### Results:

 All values are rounded to the nearest multiple of 5 board feetand lengths over 20 feet are to be scaled as two or more logs. Board Feet: bf Cubic Feet: ft³ Cubic Meter: M³

#### Calculator

1. select the length of your log
2. the diameter measured inside the bark at the small end of the log in inches

#### Results

1. the number of board feet in your log
2. the board feet converted to cubic feet
3. the board feet converted to cubic metres

### Conversions:

```one board foot (bf) = 0.0833333333333333 cubic feet (ft³)
one board foot (bf) = 0.002359737216 cubic metres (m³)

```