Rule 70 is a measure to get an idea of ​​how long it takes to double the money invested. This calculation determines the tears it is going to take to double up the invested money with a rate of return. In the business or banking sectors, this method is highly appreciated to compare the annual compound interest with investments. It also determines how quickly your investment can grow.

## What is the formula for the rule of 70?

The formula for the Rule of 70 is dividing 70 by the annualized return.

## How is the rule of 70 calculated?

• Getting the annual growth rate on the variable or investment is essential.
• Then the annual growth rate is divided by 70 for the results.

## What does the rule of 70 refer to?

The value of the investment as well as the annual growth of the investment is easily determined through the rule of 70. It is a very effective rule to figure out how many years it might take to double up the investment. The rule of 70 is for all investors to easily evaluate various investments. This rule is commonly used to manage different exponential growth without going through difficult mathematical calculations.

## What are the limitations of the rule of 70?

The rule of 70 is a very well calculative method but it fails to produce accurate answers at times. Something is assumed to compound continuously, so interest is calculated and credited to the account. But in recent times most banks calculate interest monthly but daily. This is how it limits the ability to forecast the growth in future. The regular CDs are also compounded monthly so continuous compounding does not make sense in this case. If there’s a small amount of growth, you’ll not notice the difference. But if it’s a large amount with a 10 percent or more interest rate. The investor should recheck before the calculation when investing in stocks and mutual funds.

The growth of the interest lifespan is generally measured by the rule of 70. The highest chances are that the banks would not change their interest policy but if it does then the calculation will not be accurate. Investors should recalculate the rate of interest regularly as the rate of return changes annually.

It is a great calculation method to determine the growth of the invested money and the time it will take to double up the money. But this is applicable when there’s a particular rate of return. If the rate of return changes every year then this method of calculation does not always produce accurate results. You’ll notice investors following the Rule of 70 formula to evaluate the period by which the invested money will be doubled. This includes growth rates of retirement portfolios as well as mutual funds.  Investors should always keep in mind that this method only forecasts the annual growth rate and the time it takes to double the invested money. If the rate is fluctuating, the calculation will not be able to produce accurate answers.

## Summary

The rule of 70 is a measuring format to get a clue about how much time it takes to double the invested money. This calculation determines the tears it is going to take to double up the invested money with a rate of return. In the business or banking sectors, this method is highly appreciated to compare the annual compound interest with investments. It also determines how quickly your investment can grow. The growth of the interest lifespan is generally measured by the rule of 70. The highest chances are that the banks would not change their interest policy but if it does then the calculation will not be accurate. Investors should recalculate the rate of interest regularly as the rate of return changes annually. It is a great calculation method to determine the growth of the invested money and the time it will take to double up the money. But this is applicable when there’s a particular rate of return. If the rate of return changes every year then this method of calculation does not always produce accurate results. The rule of 70 is a very well calculative method but it fails to produce accurate answers at times. Continuous compounding is assumed, so the interest is calculated and credited to the account. But in recent times most banks calculate interest monthly but daily. This is how it limits the ability to forecast the growth in future. If the rate of return changes every year then this method of calculation does not always produce accurate results. The investor should recheck before the calculation when investing in stocks and mutual funds.