Enter the weight at the beginning of the period (g), the weight at the end of the period (g), and the period length (days) into the Specific Growth Rate Calculator. The calculator will evaluate the Specific Growth Rate.

- All Rate Calculators
- Bacteria Growth Rate Calculator
- Relative Growth Rate Calculator
- Constant Growth Rate Calculator

## Specific Growth Rate Formula

The following formula is used to calculate the Specific Growth Rate.

SGR = (LN(WE) - LN (WB))*100 / (t)

- Where SGR is the Specific Growth Rate (%)
- WB is the weight at the beginning of the period (g)
- WE is the weight at the end of the period (g)
- t is the period length (days)

To calculate the specific growth rate, divide the change in weight by the period length, then multiply by 100.

## How to Calculate Specific Growth Rate?

The following two example problems outline the steps and information needed to calculate the Specific Growth Rate.

**Example Problem #1**

- First, determine the weight at the beginning of the period (g).
- The weight at the beginning of the period (g) is calculated to be : 100.

- Next, determine the weight at the end of the period (g).
- The weight at the end of the period (g) is measured to be: 150.

- Next, determine the period length (days).
- The period length (days) is found to be: 3.

- Finally, calculate the Specific Growth Rate using the formula above:

SGR = (LN(WE) – LN (WB))*100 / (t)

The values provided above are inserted into the equation below and computed.

SGR = (LN(150) – LN (100))*100 / (3) = 13.51 (%)

**Example Problem #2**

The variables required for this problem are provided below:

weight at the beginning of the period (g) = 50

weight at the end of the period (g) = 400

period length (days) = 20

Test your knowledge using the equation and check your answer with the calculator.

SGR = (LN(WE) – LN (WB))*100 / (t) =** **(%)