Doubling time Calculator

Doubling Time Calculator

To get the doubling time for a constant growth rate, we have the Doubling Time Calculator. Use the free online tool to determine how long it will take for an amount to double in value given the growth rate per period.

What is the Doubling Time Formula?

The term “doubling time” refers to the period it will take for your investment to double in value at a specific interest rate. Rule of 70 is another name for this idea that is widely popular since it can be used to roughly calculate how long it will take for something to double. This will likewise produce a number that is very similar to that of the doubling formula. This idea is frequently used to compare investments with various interest rates and aids in our understanding of how rapidly an investment grows.

The following two methods will almost always get the same result when used to calculate doubling time:

Doubling Time \( = \dfrac{Ln (2)}{Ln (1+r)} \)

Where:

Ln – Natural Log

r – Interest Rate

Doubling Time \( = \dfrac{70}{r}\)

Use the absolute value of r rather than the decimal number in this formula. For instance, if r is provided at 5%, we shall utilize 5% rather than 0.05.

Examples

Example 1: An employee’s salary increases by 19% after every 6 months. An employee wants to find out how long it will take to double it. Calculate the doubling time?

\(= \dfrac{log(2)}{log(1+ increase)} \)

\( = \dfrac{log(2)}{ log(1+ \frac{19}{100})} \)

\(=\dfrac{log(2)}{log(1+ 0.19)}\)

\(= \dfrac{0.6931}{0.174} \)

\(=3.847\), which means there needs to have 4 increments to double the salary, it will need 2 years.

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