The Rule of 72 | Primerica (2024)

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The Rule of 72 | Primerica? ›

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.

Here's how the Rule of 72 works. You take the number 72 and divide it by the investment's projected annual return. The result is the number of years, approximately, it'll take for your money to double.

The Rule of 72 is not precise, but is a quick way to get a useful ballpark figure. For investments without a fixed rate of return, you can instead divide 72 by the number of years you hope it will take to double your money. This will give you an estimate of the annual rate of return you'll need to achieve that goal.

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.

The classic approach of doubling your money involves investing in a diversified portfolio of stocks and bonds and is probably the one that applies to most investors. Investing to double your money can be done safely over several years but there's more of a risk of losing most or all of your money if you're impatient.

A common rule of thumb, the rule of 72, states that you can know how long it'll take for your investment to double by dividing 72 by the rate of return. A 10% annual return means your money should double every 7.2 years.

One of those tools is known as the Rule 72. For example, let's say you have saved $50,000 and your 401(k) holdings historically has a rate of return of 8%. 72 divided by 8 equals 9 years until your investment is estimated to double to $100,000.

Summary. Learn about the 8-4-3 rule of compounding, where investments double within 8, 4, and 3 years, showcasing exponential growth. It emphasizes staying dedicated to investment plans, guarding against inflation, and adapting to market changes.

It's worth noting, the “rule of 72” definition isn't necessarily perfectly accurate because past market results do not predict future market behavior. However, it's a “back of the napkin” way to determine where your portfolio might potentially be in the years ahead.

What is the Rule of 72 trick? ›

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.

No, Albert Einstein did not invent the rule of 72.

The person who invented the rule of 72 was Luca Pacioli, who was a mathematician.

It is not an exact value and can only provide a general estimate of the time required to double the investment. If the interest rate changes due to some factor, the Rule of 72 becomes null and void. The Rule of 72 does not apply to changing interest rate investments or basic interest investments.

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.

For a quick return on a $5,000 investment, consider options like stock trading, especially in high-growth sectors or investing in a diversified mutual fund. Short-term P2P lending can also be a way to see quicker returns, though it carries higher risk.