Compound Interest Calculator
Compounding is often called the most powerful force in personal finance, but it’s easiest to understand with actual numbers. This calculator shows exactly how a principal amount grows over time as interest earns interest on itself, and what that means after tax and inflation are factored in
What is a Compound Interest Calculator?
A compound interest calculator projects how a principal amount grows when interest is added periodically and then itself starts earning interest. It’s the foundational concept behind almost every other calculator on this page, whether it’s a fixed deposit, a mutual fund, or a savings account, and understanding it makes every other projection easier to interpret.
Compounding One Amount Isn't Compounding Your Family's Wealth
This calculator shows how one principal amount compounds. A family’s actual wealth compounds across many accounts at once, savings, FDs, mutual funds, EPF, each growing at different rates, and the combined effect is only visible when all of them are tracked together rather than estimated individually.
How WealthNest.AI Helps Beyond This Calculator
WealthNest.AI shows your family’s real combined growth across every account, not just one hypothetical principal, aggregated automatically so you can see compounding actually happening across your whole financial picture.
See this alongside every other account your family holds, all in one place. Download the WealthNest.AI app to get started.
Frequently Asked Questions
Simple interest is calculated only on the original principal. Compound interest is calculated on the principal plus all previously earned interest, which is why it grows faster over time.
Yes. Interest is assumed to be credited once a year. Some instruments compound more frequently, like quarterly, which would produce slightly higher returns for the same nominal rate.
The exact number of years for your principal to double at the given rate, calculated using logarithms, sometimes called the Rule of 72 in its approximate form.
A flat 12.5% LTCG rate is applied to the interest earned as an estimate. Other instruments like FDs are typically taxed at your income slab rate instead.
Yes. WealthNest.AI aggregates your real accounts automatically so you can see actual compounding happening, not just a projection.
