Time to Double or Triple an Investment


m is 2 to double your investment, 3 to triple, etc.

r:  %

r is interest rate, write as whole number; i.e. 6% is 6

t =    years

Time to Double/Triple Investment Formula

A = Pe^rt


If r = 5%, then to find double time, the formula looks like the following;
2P = Pe^.05t

we then divide both sides by P, so the equation is now;
2 = e^.05t

multiply both sides by ln
.05t = ln2

divide by .05
t = ln2 / .05

t = 13.86 years

therefore, it will take 13.86 years to double your investment based on an interest rate of 5%


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