The Rule of 72 | Primerica (2024)

FAQs

The Rule of 72 | Primerica? ›

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.

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.

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.

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.

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.

One of the easiest ways to double $1,000 is to invest it in a 401(k) and get the employer match. For example, if your employer matches your contributions dollar for dollar, you'll get a $1,000 match on your $1,000 contribution.

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.

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.

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.

What is the rule of 144? ›

An extension of Rule of 72, the Rule of 144 estimates how long it takes to quadruple your investment if you can estimate the annual rate of return. Mutual Fund Investments are subject to market risks, read all scheme related documents carefully.

Lower or higher rates outside of this range can be better predicted using an adjusted Rule of 71, 73 or 74, depending on how far they fall below or above the range. You generally add one to 72 for every three percentage point increase. So, a 15% rate of return would mean you use the Rule of 73.

You can also apply the Rule of 72 to debt for a sobering look at the impact of carrying a credit card balance. Assume a credit card balance of $10,000 at an interest rate of 17%. If you don't pay down the balance, the debt will double to $20,000 in approximately 4 years and 3 months.

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.

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.

Basically, the rule says real estate investors should pay no more than 70% of a property's after-repair value (ARV) minus the cost of the repairs necessary to renovate the home. The ARV of a property is the amount a home could sell for after flippers renovate it.

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%.

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.

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.

By dividing 72 by the average inflation rate, you can estimate how long it'll take for the cost of living to double, aiding in long-term financial planning. Visualize the Power of Compounding: By visualizing how quickly investments can grow, the Rule of 72 underscores the importance of compounding.