Free Financial Calculator
Free compound interest calculator. See how your initial deposit plus regular monthly contributions grow over time with compound interest. Create a personalized savings projection.
Formula
A = P(1 + r/n)^(nt) + PMT × [((1 + r/n)^(nt) − 1) / (r/n)]
Compound interest rewards patience. Each time interest is credited, it joins your balance and begins earning interest of its own. Over years, this creates a snowball effect that turns modest regular contributions into a substantial nest egg.
Saving consistently matters as much as the rate you earn. Even small automatic monthly contributions, when combined with compounding, can grow far larger than a one-time lump sum. Use this calculator to explore what is realistic for your budget.
Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods. Instead of earning interest only on your original deposit, you also earn interest on the interest, which can significantly accelerate your savings over time.
Enter your starting balance (principal), any monthly contribution, your expected annual interest rate, and the number of years you plan to save. The calculator projects the future value using monthly compounding and shows your total contributions and the interest earned separately.
Because growth builds on itself. The longer your money stays invested, the more each interest payment adds to future growth. Starting earlier—even with smaller amounts—often beats starting later with larger ones due to the compounding effect.
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