**Metabolic allometry**

Metabolic rate (**MR**) scales to a fractional power of body mass in almost all taxa:

MR = mass coefficient * mass ^mass exponent

Usually the mass exponent is approximately 0.67-0.8 (there is considerable disagreement over the cause of this particular range of exponents). To estimate the 'minimal' metabolic rate (**BMR****, ****RMR****, **or** ****SMR**), select the taxon and the output units from this set of menus and adjust the body mass and temperature compensation data to appropriate values. Use the **'Compute'** button after adjusting variables, and the **'Store'** button to hold results for comparison to other data.

The **'Save'** button, if present, lets you save the current mass coefficient and mass exponent values for future use, accessed as **'Custom coefficent and exponent'** option in the Taxon popup. The 'Save' button is accessible __only__ if the units are set to **ml O2/min**. **NOTE:** you will have to click the **'Save Current Preferences'** button in the **Preferences** window if you want to have your custom values available the next time you run the program.

• The Hemmingsen equations for standard metabolic rates (SMR) of unicellular organisms and for poikilothermic and homeothermic metazoans are generalized for an extremely diverse array of organisms. If possible, use a more specific equation (available in the submenus).

Hemmingsen AM (1960) *Rep Steno M. Hosp (Copenhagen)* 9:1-10