Compound Interest Calculator
The Power of Compound Interest
Often cited as the "eighth wonder of the world," compound interest is the interest on a loan or deposit calculated based on both the initial principal and the accumulated interest from previous periods. Over time, this leads to exponential growth.
The Formula for Growth
To calculate the future value (A) with monthly contributions, we use:
A = P(1 + r/n)ⁿᵗ + PMT × [((1 + r/n)ⁿᵗ - 1) / (r/n)]
- P: Initial Investment (Principal).
- PMT: Monthly contribution.
- r: Annual interest rate decimal.
- n: Compounding frequency per year (12 for monthly).
- t: Time in years.
Why Use This Calculator?
- Retirement Planning: See how consistent, small monthly savings can grow significantly over decades.
- Goal Setting: Determine how much you need to save per month to reach a specific financial target in the future.
- Educational Insight: Compare how different interest rates impact your final balance due to the effects of compounding.
Risk Disclaimer: Investment simulations are based on theoretical fixed rates. In reality, market conditions fluctuate, and returns are not guaranteed. Taxes, inflation, and fees may also affect your final results. This tool is for educational use only.
100% Private
Your financial goals are your business. Octovelo processes all calculations locally on your device via JavaScript. No data about your wealth or investment plans is ever sent to our servers.