Enter the size and two different time periods and the total time that has passed between periods into the calculator to determine the relative growth rate.

## Relative Growth Rate Formula

The following equation is used to calculate a relative growth rate.

RGR = (ln (S2) – ln (S1) ) / (t2-t1)

- Where RGR is the relative growth rated
- S2 is the size at time 2
- S1 is the size at time 1
- t2-t1 is the change in time

## Relative Growth Rate Definition

A relative growth rate, or RGR for short, is defined as the growth rate relative to size of the sample size. It’s also sometimes referred to as the exponential growth rate.

## Relative Growth Rate Example

How to calculate a relative growth rate?

**First, determine the initial size.**Calculate or measure the initial size.

**Next, determine the final size.**Calculate or measure the final size.

**Next, determine the change in time.**Calculate the total change in time from the initial to final sizes.

**Finally, calculate the relative growth rate.**Calculate the relative growth rate using the formula above.

## FAQ

**What is a relative growth rate?**

A relative growth rate is defined as the growth rate of a number relative to it’s size.