Compound Interest Explained
Compound interest is often called the eighth wonder of the world: your money earns interest, and then that interest earns interest too. Over years, this snowball does the heavy lifting.
Simple vs compound interest
Simple interest pays only on your original amount. Compound interest pays on the original plus all the interest already earned — so each period grows a little faster than the last.
Why time matters most
With compounding, starting early beats saving more later. A modest amount left to grow for decades often ends up larger than a bigger amount invested for only a few years.
The rule of 72
For a quick estimate, divide 72 by your yearly return to see how many years it takes to double your money. At 8% a year, that is about 9 years — without adding a single extra franc.
Make it work for you
Invest regularly, reinvest the returns, and give it time. Our compound interest calculator shows exactly how an amount grows at your rate over your chosen period.