If my portfolio returns 15% a year (with all returns reinvested) how long will it take to double my capital?

Question

Not a homework question! From a curious math-handicapped.

Answer 1

Rule of 72 will give you an estimated answer.
72 / rate of return = years to double your money.

in your case 4.8 so i would say 5 years.

Of course remember there is a TAX situation to consider and I would use AFTER -TAX rate of return.

Answer 2

Your investment will double in 4.8 years as per the rule of 72. This will happen only when the compunding is done annualy.

Answer 3

In general, the multiplier is 1.15^N -- where N is the number of years. So -- we need to solve for:

2 = 1.15^N

Take the log of both sides, and you get:

ln(2) = N*ln(1.15)

A little algebra gives you:

N = ln(2)/ln(1.15) = 4.95948 years

The Rule of 72 is just an approximation.

Answer 4

Yard...see if you can use this calculator to help solve it
http://www.finishrich.com/free_resources/lattecalculator.php
Save the site to faves...even if it doesn't help right here, it can work on some other figuring ( also weak in math)

Answer 5

15% a year would take 6.666667 years

Answer 6

right at 4.8 years