Search results
Results From The WOW.Com Content Network
In finance, the rule of 72, the rule of 70 [1] and the rule of 69.3 are methods for estimating an investment's doubling time. The rule number (e.g., 72) is divided by the interest percentage per period (usually years) to obtain the approximate number of periods required for doubling.
The Rule of 72 works best in the range of 5 to 10 percent, but it’s still an approximation. To calculate based on a lower interest rate, like 2 percent, drop the 72 to 71. To calculate based on ...
This "Rule of 70" gives accurate doubling times to within 10% for growth rates less than 25% and within 20% for rates less than 60%. Larger growth rates result in the rule underestimating the doubling time by a larger margin. Some doubling times calculated with this formula are shown in this table. Simple doubling time formula:
Using the Rule of 72, your money should double every 10.3 years. So, by age 45, you should have around $200,000 in retirement savings. By age 55, you should have around $400,000.
The Summa de arithmetica of Luca Pacioli (1494) gives the Rule of 72, stating that to find the number of years for an investment at compound interest to double, one should divide the interest rate into 72. Richard Witt's book Arithmeticall Questions, published in 1613, was a landmark in the history of compound interest.
For premium support please call: 800-290-4726 more ways to reach us
What links here; Related changes; Upload file; Special pages; Permanent link; Page information; Cite this page; Get shortened URL; Download QR code
For premium support please call: 800-290-4726 more ways to reach us