# Damuth law

First published:

Last Edited:

Number of edits:

There is a relationship between body mass and population density, namely:

$$d = aW^{-\frac{3}{4}}$$

Where $$d$$ is the density, and $$W$$ is the average body mass[].

This law is used, for example, to calculate the population density of T. Rex at any one point in time[].

It must be noted that the law is a 0-order approximation. Flesh-eating mammals have a 150-fold variation in population density for species of the same body mass[].