Regra do 72
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
Regra 72
About this calculator
The Rule of 72 is a simple and useful tool to calculate the time necessary to double your money based on the return rate.
It works based on the formula: years_to_double = 72 / rate%, where the rate is expressed as an annual percentage.
This rule is especially useful for people who want to invest or plan their personal finances in a practical and objective way.
Remember that the return rate may vary depending on the type of investment and the financial market, so it's essential to consider these factors when using the Rule of 72.
Frequently asked questions
What is the return rate to double my money in 10 years?
To calculate the return rate needed to double your money in 10 years, simply divide 72 by 10, resulting in a return rate of 7.2% per year.
Is the Rule of 72 applicable to all types of investments?
No, the Rule of 72 is more relevant for long-term investments, such as stocks, investment funds and savings. It is not suitable for short-term or high-risk investments.
How does the return rate affect the time necessary to double my money?
A higher return rate means you will need less time to double your money. For example, a return rate of 10% per year would reduce the time necessary to double your money by about half.
Is the Rule of 72 an exact rule?
No, the Rule of 72 is an approximate rule and may vary depending on market conditions and the type of investment.
Can I use the Rule of 72 with other types of investments?
Yes, you can use the Rule of 72 as a rough estimate for other types of investments, such as real estate or business investments. However, keep in mind that the rule may not be as accurate for these types of investments.