The power of compound interest


Interest: %

Age:

Let's say you want to be a millionaire by age 40, by investing one lump sum.

With the sliders opposite, you can adjust the age at which you make the investment and the interest rate. The text underneath will tell you how much you would have to invest.

What interest rate would a 20-year-old need to turn a single 50K investment into a million pounds?

If investing on behalf of a new child, what's the smallest sum you could turn into a million pounds with the interest rates available?

This button switches between a logarithmic (log) axis and linear money axis.


When the axis is logarithmic, the constant interest rate appears as a straight line with a constant gradient. This is a key advantage of the log axis.