The Rule of 72 (with calculator) (2024)

FAQs

What is the Rule of 72 calculator? ›

The Rule of 72 is a way to estimate how long it will take for an investment to double at a given interest rate, assuming a fixed annual rate of interest. You simply take 72 and divide it by the interest rate number. So, if the interest rate is 6%, you would divide 72 by 6 to get 12.

For example, the Rule of 72 states that $1 invested at an annual fixed interest rate of 10% would take 7.2 years ((72/10) = 7.2) to grow to $2. In reality, a 10% investment will take 7.3 years to double (1.10^7.3 = 2). The Rule of 72 is reasonably accurate for low rates of return.

The Rule of 72 is a calculation that estimates the number of years it takes to double your money at a specified rate of return. If, for example, your account earns 4 percent, divide 72 by 4 to get the number of years it will take for your money to double.

Rule of 72 Formula

You can calculate the number of years to double your investment at some known interest rate by solving for t: t = 72 ÷ R.

This means that the investment will take about 12 years to double with a 6% fixed annual interest rate. This calculator flips the 72 rule and shows what interest rate you would need to double your investment in a set number of years.

The rule of 70 is used to determine the number of years it takes for a variable to double by dividing the number 70 by the variable's growth rate. The rule of 70 is generally used to determine how long it would take for an investment to double given the annual rate of return.

The value 72 is a convenient choice of numerator, since it has many small divisors: 1, 2, 3, 4, 6, 8, 9, and 12. It provides a good approximation for annual compounding, and for compounding at typical rates (from 6% to 10%); the approximations are less accurate at higher interest rates.

The magic number

The premise of the rule revolves around either dividing 72 by the interest rate your investment will receive, or inversely, dividing the number of years you would like to double your money in by 72 to give you the required rate of return.

Try Flipping Things

Another way to double your $2,000 in 24 hours is by flipping items. This method involves buying items at a lower price and selling them for a profit. You can start by looking for items that are in high demand or have a high resale value. One popular option is to start a retail arbitrage business.

How to double 5000 dollars? ›

To turn $5,000 into more money, explore various investment avenues like the stock market, real estate or a high-yield savings account for lower-risk growth. Investing in a small business or startup could also provide significant returns if the business is successful.

Years it Takes to Double

So, to use this formula for the $100,000 investment mentioned above, with a 6% rate of return, you can determine that your money will double in 11.9 years, which is close to the 12 years you'd get if you simply divided 72 by 6.

The rule of 72 is only an approximation that is accurate for a range of interest rate (from 6% to 10%). Outside that range the error will vary from 2.4% to 14.0%. It turns out that for every three percentage points away from 8% the value 72 could be adjusted by 1.

Hence, the amount will be Rs. 62,964. How much will ₹50,000 amount in 3 years compounded yearly, if the rates for the successive years are 6%, 8% and 10% respectively?

Rules of 72, 69.3, and 69

The Rule of 72 states that by dividing 72 by the annual interest rate, you can estimate the number of years required for an investment to double. The Rule of 69.3 is a more accurate formula for higher interest rates and is calculated by dividing 69.3 by the interest rate.

It will take approximately 15.27 years to increase the $2,200 investment to $10,000 at an annual interest rate of 6.5%.

Interest on investment rate: 6% p.a. It would take 12 yearsto double an investment of $2,000.

Final answer:

It would take approximately 11.90 years for the money to grow from $5,000 to $10,000 with a 6% interest rate.