Do you know the Rule of 72? It's an easy way to calculate just how long it's going to take for your money to double.
Just take the number 72 and divide it by the interest rate you hope to earn. That number gives you the approximate number of years it will take for your investment to double.
As you can see, a one-time contribution of $10,000 doubles six more times at 12 percent than at 3 percent.
| Years | 3% | 6% | 12% |
| 0 | $10,000 | $10,000 | $10,000 |
| 6 | | | $20,000 |
| 12 | | $20,000 | $40,000 |
| 18 | | | $80,000 |
| 24 | $20,000 | $40,000 | $160,000 |
| 30 | | | $320,000 |
| 36 | | $80,000 | $640,000 |
| 42 | | | $1,280,000 |
| 48 | $40,000 | $160,000 | $2,560,000 |
How many doubling periods do you have in your life?
This table serves as a demonstration of how the Rule of 72 concept works from a mathematical standpoint. It is not intended to represent an investment. The chart uses constant rates of return, unlike actual investments which will fluctuate in value. It does not include fees or taxes, which would lower performance. It is unlikely that an investment would grow 10% or greater on a consistent basis.
FAQs
Do you know the Rule of 72? It's an easy way to calculate just how long it's going to take for your money to double. Just take the number 72 and divide it by the interest rate you hope to earn. That number gives you the approximate number of years it will take for your investment to double.
What is the Rule of 72 in simple terms? ›
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. In this case, 18 years.
Does the Rule of 72 really work? ›
The Rule of 72 is reasonably accurate for low rates of return. The chart below compares the numbers given by the Rule of 72 and the actual number of years it takes an investment to double. Notice that although it gives an estimate, the Rule of 72 is less precise as rates of return increase.
What is the Rule of 72 69? ›
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.
What are the flaws of Rule of 72? ›
Errors and Adjustments
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.
How to double $2000 dollars in 24 hours? ›
How To Double Money In 24 Hours – 10+ Top Ideas
- Flip Stuff For Profit.
- Start A Retail Arbitrage Business.
- Invest In Real Estate.
- Play Games For Money.
- Invest In Dividend Stocks & ETFs.
- Use Crypto Interest Accounts.
- Start A Side Hustle.
- Invest In Your 401(k)
If you need to double your financial investment in 10 years, a savings account with a 5% interest rate, for instance, wouldn't help achieve your goals. You'd need something with a higher rate of return (at least 7.2%) to make that 10-year milestone happen.
What is the golden Rule of 72? ›
1) Rule of 72
The 'Rule of 72' gives you an estimate of the number of years it will take to double your money in a particular investment tool. You need to divide the rate of returns by 72 to know the time it would take you to double your investments.
What is better than the Rule of 72? ›
Choice of rule
Since daily compounding is close enough to continuous compounding, for most purposes 69, 69.3 or 70 are better than 72 for daily compounding. For lower annual rates than those above, 69.3 would also be more accurate than 72. For higher annual rates, 78 is more accurate.
What is the Warren Buffett Rule? ›
The Buffett Rule is the basic principle that no household making over $1 million annually should pay a smaller share of their income in taxes than middle-class families pay. Warren Buffett has famously stated that he pays a lower tax rate than his secretary, but as this report documents this situation is not uncommon.
Final answer:
It will take approximately 15.27 years to increase the $2,200 investment to $10,000 at an annual interest rate of 6.5%.
Why is the Rule of 72 useful if the answer will not be exact? ›
The rule of 72 can help you get a rough estimate of how long it will take you to double your money at a fixed annual interest rate. If you have an average rate of return and a current balance, you can project how long your investments will take to double.
How many years does it take to double your money? ›
Very few investors know how long it takes to double their money. Rule of 72 can be of help. Divide 72 by the expected rate of return and the answer is the number of years required to double your money. For example, if a bond offers 6 percent rate of interest per year, then you will double your money in 12 years.
What is the Rule of 72 at 10? ›
Using the Rule of 72, you can realize the power of compounding interest and better plan for future financial goals. If $5,000 was invested with an annual growth rate of 10%, the original investment would double to $10,000 in 7.2 years. After 7.2 years $10,000 doubles to $20,000.
