Rule of 114 Calculator

The Rule of 114 is a quick mental shortcut to estimate how many years it takes to triple an investment. Divide 114 by the annual compound interest rate to get the approximate tripling time. For example, at 6% per year: 114 / 6 = 19 years to triple. It is the tripling equivalent of the Rule of 72 (for doubling) and the Rule of 144 (for quadrupling).

The Rule of 114 is an approximation. The exact tripling time formula is: years = ln(3) / ln(1 + r), where r is the annual decimal rate. At 6%, the exact answer is 18.85 years; the Rule of 114 gives 19 years (error of 0.8%). At 10%, exact is 11.53 years; rule gives 11.4 years (error of 1.1%). The approximation works well for rates between 5% and 15%.

Yes. If you have a debt accruing compound interest at a fixed rate, the Rule of 114 tells you how long it takes for the debt to triple if unpaid. At 12% APR: 114 / 12 = 9.5 years for a debt to triple. This underscores the importance of paying down high-interest debt quickly.

The Rule of 72 estimates doubling time (money x 2), and the Rule of 114 estimates tripling time (money x 3). At any given rate, tripling always takes longer than doubling. For example, at 7%: Rule of 72 gives approximately 10.3 years to double; Rule of 114 gives approximately 16.3 years to triple. Tripling takes about 58% more time than doubling at the same rate (ln(3)/ln(2) = 1.585).

Yes. These rules all use the same principle of dividing a constant by the annual interest rate. Rule of 72: doubling (x2). Rule of 114: tripling (x3). Rule of 144: quadrupling (x4). The constants 72, 114, and 144 are approximations of 100 x ln(2)/ln(1+r) solved at rates near 8%, which happens to be a useful near-midpoint of common investment return assumptions.