# How Long Does It Take to Double Your Investment? This Formula Answers

11/28/2023
Imagine you've just made an investment. How long will it take for this money to double? A simple mathematical rule gives you insight almost instantly: the Rule of 72.

The Rule of 72 is a simple formula used in finance. It helps estimate how long it takes to double your investment with a fixed annual rate of return.

Here's the beauty of it: To find out how long it will take for your investment to double, divide 72 by the annual rate of return.

Let's break it down with an example. Suppose you've invested in a fund offering an annual return of 6%. By applying the Rule of 72, you divide 72 by 6, which equals 12. This means it will take approximately 12 years for your investment to double.

Now, you might wonder how accurate this rule is. While it's not perfect, it's close to precise, especially for rates of return between 6% and 10%. This tool helps investors plan their finances by showing how compound interest works. Plus, it avoids complicated calculations.

Remember, the Rule of 72 works best for investments with compounding interest. This is where the money your investment makes is reinvested and earns more money. This causes the snowball effect. The more frequently your investment compounds, the faster it grows.

However, it's important to note that the Rule of 72 is more of a guideline than a guarantee. It doesn't account for risks, taxes, or other factors affecting your investment. So, while it's an excellent tool for getting a quick estimate, it's always wise to consult a financial advisor for a more detailed analysis.

What's more, this rule also applies in reverse to understand the impact of inflation on your money. If you think inflation will be 3%, you can estimate your money's purchasing power will halve in about 24 years using the Rule of 72.

To be a successful investor, you need to find good opportunities and understand financial growth principles. The Rule of 72 is just one of many formulas used in investment planning.

To double the value of an investment with higher returns, use different formulas for more precise time estimates. Two rules, 71 and 73, are notable options. They are designed for various rates of return.

This rule is handy for fixed rates of return that fall below about 6%. When investments yield a lower rate of return, the Rule of 71 offers a more precise timeframe for when your money will double.

It operates similarly to the Rule of 72, but using 71 as the numerator in the calculation slightly accelerates the doubling time. For instance, if your investment has a 5% rate of return, it will take about 14.2 years for it to double. This is based on the Rule of 71, which suggests a slightly more cautious estimate than the Rule of 72.

The Rule of 73 is more reliable for investments that have rates of return above 10%. This rule changes how we calculate in situations where investing is riskier and may bring higher returns.

By using 73 as the divisor, this rule effectively extends the estimated period for doubling the investment. For instance, at a 12% return rate, the Rule of 73 estimates that the investment would take approximately 6.08 years (73 divided by 12) to double.

The Rule of 72 is a simple yet powerful tool in the investor's toolkit. It's a testament to the magic of compound interest and a reminder of the importance of patience in investing. Whether you're a seasoned investor or just starting out, knowing this rule will help you make informed decisions.

**What is the Rule of 72, And How Does It Work?**The Rule of 72 is a simple formula used in finance. It helps estimate how long it takes to double your investment with a fixed annual rate of return.

Here's the beauty of it: To find out how long it will take for your investment to double, divide 72 by the annual rate of return.

Let's break it down with an example. Suppose you've invested in a fund offering an annual return of 6%. By applying the Rule of 72, you divide 72 by 6, which equals 12. This means it will take approximately 12 years for your investment to double.

**Can You Trust the Rule of 72?**Now, you might wonder how accurate this rule is. While it's not perfect, it's close to precise, especially for rates of return between 6% and 10%. This tool helps investors plan their finances by showing how compound interest works. Plus, it avoids complicated calculations.

Remember, the Rule of 72 works best for investments with compounding interest. This is where the money your investment makes is reinvested and earns more money. This causes the snowball effect. The more frequently your investment compounds, the faster it grows.

However, it's important to note that the Rule of 72 is more of a guideline than a guarantee. It doesn't account for risks, taxes, or other factors affecting your investment. So, while it's an excellent tool for getting a quick estimate, it's always wise to consult a financial advisor for a more detailed analysis.

What's more, this rule also applies in reverse to understand the impact of inflation on your money. If you think inflation will be 3%, you can estimate your money's purchasing power will halve in about 24 years using the Rule of 72.

Alternatives to the Rule of 72Alternatives to the Rule of 72

To be a successful investor, you need to find good opportunities and understand financial growth principles. The Rule of 72 is just one of many formulas used in investment planning.

To double the value of an investment with higher returns, use different formulas for more precise time estimates. Two rules, 71 and 73, are notable options. They are designed for various rates of return.

**The Rule of 71**

This rule is handy for fixed rates of return that fall below about 6%. When investments yield a lower rate of return, the Rule of 71 offers a more precise timeframe for when your money will double.

It operates similarly to the Rule of 72, but using 71 as the numerator in the calculation slightly accelerates the doubling time. For instance, if your investment has a 5% rate of return, it will take about 14.2 years for it to double. This is based on the Rule of 71, which suggests a slightly more cautious estimate than the Rule of 72.

**The Rule of 73**The Rule of 73 is more reliable for investments that have rates of return above 10%. This rule changes how we calculate in situations where investing is riskier and may bring higher returns.

By using 73 as the divisor, this rule effectively extends the estimated period for doubling the investment. For instance, at a 12% return rate, the Rule of 73 estimates that the investment would take approximately 6.08 years (73 divided by 12) to double.

**Choosing the Right Tool for Investment Planning**The Rule of 72 is a simple yet powerful tool in the investor's toolkit. It's a testament to the magic of compound interest and a reminder of the importance of patience in investing. Whether you're a seasoned investor or just starting out, knowing this rule will help you make informed decisions.