New to this? Read the plain English guide first.
See how a starting amount and regular deposits can grow over time.
Compound interest means you earn growth on your growth. Each month your gains are added to your balance, and the next gains are figured on the bigger amount. Time does most of the work, which is why starting early matters.
Future value = start x (1 + r/12)^(12 x years) + monthly deposit x (((1 + r/12)^(12 x years) – 1) / (r/12)), where r is the yearly rate as a decimal.
Want the full story with a worked example? Read the Compound Interest guide, or see all of our free calculators. For learning only, not advice.