# Japanese Agricultural Standard (JAS) Calculator

Formula developed by the Japanese Ministry of Agriculture and Forestry.

### Measuring Log Length

Lengths are measured in metres and tenths of metres and rounded down to each fixed-length class

### Measuring Log Diameter

For small-end diameters less than 14 cm

Measure the shortest small-end diameter inside the bark through the centre of the log. Round down to the nearest whole centimetre.

Example: 12.00 - 12.99 cm, enter 12 cm

For small-end diameters equal to and greater than 14 cm

Measure the shortest small-end diameter inside the bark through the centre of the log.

Round down to the nearest even 2-cm interval.

Example: 16.00 - 17.99 cm, record as 16 cm

If the short axis is between 14 and 40 cm, add 2 cm to the short axis for every 6 cm of difference. If
the short axis exceeds 40 cm, add 2 cm to the short axis for every 8 cm of difference.

Example:

S=16.00 - L=22.99 cm, record as 18 cm S=16.00 - L=32.99 cm, record as 28 cm S=42.00 - L=45.99 cm, record as 42 cm S=41.00 - L=49.60 cm, record as 43 cm

#### Logging Calculators

##### Log Rule Calculators

Brereton Log Rule - ImperialBrereton Log Rule - Metric

Cubic Metre Rule

Doyle Log Rule

Francon Measure

Hoppus Rule

International 1/8-inch Log Rule

International 1/4-inch Log Rule

International 1/4-inch Log Rule (Grosenbaugh)

International 1/8-inch and 1/4-inch Log Rules

Japanese Agricultural Standard (JAS)

Nova Scotia Cubic Metre Log Scale

Ontario Log Rule

Scribner Log Rule

Scribner Decimal C

Comparing Results from Various Board Feet Log Rules

##### Log Volume Formula Calculators

Chinese National StandardHuber's Formula

Newton's Formula

Pressler's Cubic Foot Formula

Smalian's Formula - Metric

Smalian's Formula - Imperial

Spike's Rule

William Klemme

##### Log Weight and Volume Calculators

Calculate the Merchantable Volume and Green Weight of a LogVolume of Bark

Estimating the Weight of a Log

##### Wood and Moisture

Equilibrium Moisture Content of Wood - CelsiusEquilibrium Moisture Content of Wood - Fahrenheit

Moisture Content Measured On A Dry Basis

Moisture Content Measured On A Wet Basis

Proportional Weight of Wood and Water in One Pound

##### More

Converting between Wood Specific Gravity BasesDiameter of Tree from Circumference Measurement