Compound Interest Calculator

Calculate compound interest with flexible compounding, begin/end deposits, tax, and inflation.

Compound Interest Calculator helps you project growth with recurring contributions and compound interest across all common frequencies. Enter starting amount, contribution per period, annual return, and years, review the breakdown, and use the guidance below to understand what the number means — and what it does not. What the Compound interest calculator does Compound Interest Calculator is built for money decisions — loans, savings, payments, and taxes. Project growth with recurring contributions and compound interest across all common frequencies. You enter starting amount, contribution per period, annual return, and years, then Simple Calculators computes the result instantly. Rates, fees, and tax rules vary by lender and country, so treat results as planning numbers, not a contract. How the math works Contributions are applied at the compounding frequency you choose. Optional tax lowers the effective rate; inflation reports real purchasing power. The formula: FV = P × (1 + r ÷ n)^(n × t) + D × ((1 + r ÷ n)^(n × t) − 1) ÷ (r ÷ n). P is the starting amount, D is the deposit each period, r is the yearly rate, n is compounding periods per year, and t is years. Deposits at the start…