There are likely hundreds or even thousands of calculators on the internet and one relatively easy one to use is one that the US Securities and Exchange Commission operates. Feel free to input some number or scenarios to see how it changes things over time and over different rates of return. It defaults you to annual compounding, which is the most common, but they do allow you go change it. I wish savings compounded monthly, but that is reserved for consumer debt items instead (which is the bad side of compound interest).
It will out put nice graph showing your investment and the total value considering compound interest. You may also want to see the amount each year so they have a table as well that you can click on the button to see which shows you more detail behind the graph.
Try it out, it’s kind of fun, but hey I’m a numbers geek at heart.