# Nilson formula

Estonians use this formula developed by Arthur Nilson to calculate the volume of logs. This method uses both a formula and a support table with coefficients, depending on the tree type.

**Formula:**

cbm = (d² * L*(a1+a2*L)+a3*L²)/10 000

Where:

d – small-end diameter

L – length in dm

a1, a2, a3 – coefficients, that are defined by the tree species

Species | a1 | a2 | a3 |
---|---|---|---|

Pine | 0.0799 | 0.000146 | 0.0411 |

Spruce | 0.07995 | 0.00016105 | 0.04948 |

Birch and other hardwoods | 0.0783 | 0.000236 | 0.045 |

other conifers | 0.0800 | 0.000154 | 0.0453 |