Have a play with the compound interest calculator below.
You can input a starting amount and an annual contribution. I would input 7% for the interest rate. By all means, have a play around though.
Input around 25 years or 30 years to really show the benefits of compounding returns.
To get you even more excited about your compounding returns you can now get my 4% rule portfolio stress tester for FREE when you purchase my dividend tracking spreadsheet.
Check out some of my favourite books on investing and money in general.
This is my favorite online calculator.