Editing Jackson ratio (section)

==Calculation==
The Jackson ratio is calculated by taking the weight of the tortoise in grams and dividing it by the cube of the length of the tortoise's [[carapace]] in centimeters.<ref name=protection>{{cite web|url=http://www.tortoise-protection-group.org.uk/site/169.asp |title=Jackson Ratio for Tortoises |publisher=Tortoise Protection Group |date= |accessdate=2017-02-24}}</ref> This is essentially a value of the density of the tortoise in g/cm<sup>3</sup>. The optimal value for this ratio is 0.21 with a range of 0.18–0.22 being acceptable for hibernation. Values significantly less than this indicate an underweight tortoise and larger values are indicative of overweight tortoises.

The Jackson ratio is expressed as a graph of minimum and optimum weights for a given carapace length. This exhibits the same principle without the maths.