Compound Interest Calculator
See how your savings grow over time with compound interest and optional regular contributions.
Your plan
The power of compounding
Compound interest means you earn returns not only on your original money but also on the interest it has already earned. Over long periods this snowball effect becomes the dominant driver of growth — which is why starting early and contributing regularly matters so much. The future-value figure above combines your initial deposit, every monthly contribution, and the compounded returns on both.
Frequently asked questions
How often should interest compound?
More frequent compounding produces slightly higher returns, but the difference between monthly and daily is usually small. The compounding frequency you choose should match your account's terms.
Are contributions added before or after interest?
This calculator adds each monthly contribution and then applies the period's growth, a common and slightly conservative assumption.