# How to Calculate Doubling Time?

A simple tutorial on what is doubling time? and how it is calculated with the simple examples.

## Calculating Population Doubling Time

Doubling time is the time gap required for a quantity to become double in size or value. It is useful in the calculation of population growth, inflation, resource extraction, consumption of goods, compound interest, resource extraction, the volume of malignant tumors and anything that tend to grow double the size over a time. Any quantity undergoes an exponential growth when its relative growth rate and doubling time is constant. Use our online tutorial to know how to calculate Doubling time with the formula. Doubling Time Formula:
Td=log2 / log(1+r)

where,
Td = doubling time
r = Constant growth rate Calculating Doubling Time Example:
Consider the population of a country has an exponential growth rate of 15%. Calculate the doubling time.
Step 1:
Given,
Constant Growth Rate - 15 % = 15 / 100 = 0.15 Step 2: Substituting the value in the formula for calculating population doubling time.
Td = log2 / log(1+r)
= log2 / log(1+ 0.15)
= log2 / log(1.15)
= 0.301/0.0606
= 4.95
Hence the doubling time is 4.95 