Relative Growth Rate Calculator

Formula

The formula to calculate the Relative Growth Rate (RGR) is:

\[ \text{RGR} = \frac{\ln(S2) - \ln(S1)}{t2 - t1} \]

Where:

\( \text{RGR} \) is the Relative Growth Rate
\( S2 \) is the size at Time 2
\( S1 \) is the size at Time 1
\( t2 - t1 \) is the change in time between Time 2 and Time 1 (in days)
\( \ln \) denotes the natural logarithm

What is Relative Growth Rate?

Relative Growth Rate (RGR) measures the rate at which a population, organism, or system grows in relation to its initial size over a specific time period.

It is calculated using the natural logarithm of the ratio of sizes at two different times divided by the time difference between those two times.

Example

If:

Size at Time 1 (\( S1 \)) = 10 units
Size at Time 2 (\( S2 \)) = 30 units
Time 1 (\( t1 \)) = 0 days
Time 2 (\( t2 \)) = 10 days

Calculate the Relative Growth Rate:

\[ \text{RGR} = \frac{\ln(30) - \ln(10)}{10 - 0} \]

\[ \text{RGR} = \frac{3.401 - 2.302}{10} \]

\[ \text{RGR} = \frac{1.099}{10} = 0.11 \text{ units per day} \]

Therefore, the Relative Growth Rate (RGR) is 0.11 units per day.