Compound Interest Calculator

Compound interest is the most powerful single force in personal and business finance: a sum growing at a steady rate, reinvested over time, doesn't grow linearly — it grows exponentially. This calculator projects the future value of a savings account, a business cash reserve, or an investment for any combination of starting amount, monthly contribution, rate and horizon, with annual, quarterly, monthly or daily compounding. 10,000 at 5% simple interest for 30 years grows to 25,000; the same rate compounded annually grows to 43,219 — the gap is the famous magic of compounding.

How to use this calculator

Step 1. Enter the starting amount and the monthly contribution — either can be zero: a one-off lump sum, or a monthly habit starting from nothing.

Step 2. Enter the expected annual rate (a typical GCC savings account pays 1-3%; a balanced portfolio targets 5-8%), the term in years, and the compounding frequency.

Step 3. Click Calculate to see the projected future value, the total contributed over the period, and the total interest earned — the gap between the two.

Key figures and context

• A = P × (1 + r/n)^(n×t) — with monthly contributions compounding month by month on top
• At 5% over 20 years, annual and daily compounding at the same headline rate differ by well under 5% of the balance; at higher rates the gap grows — check it when comparing products
• Projections are nominal: subtract expected inflation from the rate for the real future value
• Run a pessimistic scenario at half the rate to make sure the goal survives disappointing returns

Open the free Free Compound Interest Calculator | Xuvilo now, or browse the full business calculator suite.