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
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 (1.107.3 = 2). The Rule of 72 is reasonably accurate for low rates of return.
What is the Rule of 72 trick? ›
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.
What is the Rule of 72 group of answer choices? ›
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 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.
Does the Rule of 72 really work? ›
The Rule of 72 is a simplified formula that calculates how long it'll take for an investment to double in value, based on its rate of return. The Rule of 72 applies to compounded interest rates and is reasonably accurate for interest rates that fall in the range of 6% and 10%.
What is the magic number 72? ›
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.
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 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.
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.
Do 90% of millionaires make over $100,000 a year? ›
Choose the right career
And one crucial detail to note: Millionaire status doesn't equal a sky-high salary. “Only 31% averaged $100,000 a year over the course of their career,” the study found, “and one-third never made six figures in any single working year of their career.”
How Can I Double $1000? If your employer offers a dollar-for-dollar match contribution, you can double $1,000 by investing it in your 401(k). Other than that, there's no easy or risk-free way to double $1,000—you can invest the money in individual stocks, but there will be risks involved.
How to double $2000 dollars in 24 hours? ›
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.
Who invented the Rule of 72? ›
Although Einstein is often credited with discovering the rule of 72, it was more likely discovered by an Italian mathematician named Luca Pacioli in the late 1400s. Pacioli also invented modern accounting.
Why is the rule 78? ›
The Rule of 78 is an important consideration for borrowers who potentially intend to pay off their loans early. The Rule of 78 holds that the borrower must pay a greater portion of the interest rate in the earlier part of the loan cycle, which means the borrower will pay more than they would with a regular loan.
What is Rule of Law 70? ›
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.
What is the 50 30 20 rule? ›
The 50-30-20 rule recommends putting 50% of your money toward needs, 30% toward wants, and 20% toward savings.
What is the Rule of 72 Quizlet? ›
The number of years it takes for a certain amount to double in value is equal to 72 divided by its annual rate of interest.
What is the Rule of 72 and 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 is the rule of 70 example? ›
In demographics, the Rule of 70 is useful for estimating the doubling time of a country's population under the assumption of a constant rate of growth. For instance, if India's forecasted growth rate is set at a steady 1.4%, the population is expected to double in approximately 50 years (70/1.4).
