Compound Interest Calculator

See how your savings grow with compounding over time. FV = P(1 + r/n)ⁿᵗ + PMT · [ ((1 + r/n)ⁿᵗ − 1) / (r/n) ]; TOTAL INVESTED = P + PMT * 12 * t; INTEREST EARNED = FV - TOTAL INVESTED HOW IT WORKS Is the result guaranteed? No — the calculator assumes a constant rate. Real investment returns vary year to year; treat the output as a long-run estimate, not a promise. Validation: Initial deposit, monthly contribution and time horizon must be non-negative. Compounding frequency must be positive; a zero rate uses straight addition without dividing by zero.