The time required for a given Principal to double (assuming Conversion Period) for Compound
Interest is given by solving
where Ln is the Natural Logarithm. This function can be approximated by the so-called ``rule of 72'':
The above plots show the actual doubling time (left plot) and difference between actual and time calculated using the rule of
72 (right plot) as a function of the interest rate .
See also Compound Interest, Interest
Avanzini, J. F. Rapid Debt-Reduction Strategies. Fort Worth, TX: HIS Pub., 1990.
© 1996-9 Eric W. Weisstein