Compound interest formula
Understand the formula, or solve its missing value.
Calculated future value
For illustration only. Read the assumptions below for the full picture.
Understand your result.
Explore the standard compound-interest relationship by solving for future value, principal, nominal annual rate or time. The unused input is hidden for the selected calculation.
Check which quantity you are solving for before interpreting the answer. A required rate is a mathematical target, not evidence that such a return is available.
A worked example.
Using this calculator’s default inputs, calculated future value is ₹2,21,964. This is an illustration of the stated formula, not a forecast.
See the example inputs
| What would you like to find? | Future value |
|---|---|
| Investment amount | ₹1,00,000 |
| Nominal annual rate | 8 % |
| Period in years | 10 year fraction |
| Compounding frequency | Monthly |
A common mistake to avoid
Using this single-principal formula for a sequence of monthly contributions.
Questions you might have.
Can it solve for a negative rate?
The rate-solving mode can return a negative result when the final value is below the principal. Entered growth-rate scenarios in other modes use the stated range.
Does time have to be a whole year?
No. The time input and solved result can be fractional years.
Prepared by INDwise · Calculation checks: 29 October 2026 · How we check the maths · Report a correction
How we calculate it
A = P(1+r/n)^(nt). Rearranged: P = A/(1+r/n)^(nt); r = n[(A/P)^(1/nt)−1]; t = ln(A/P)/[n ln(1+r/n)].
Assumptions & things to know
Single principal, no deposits or withdrawals. Only inputs relevant to the selected unknown are used. Rate results are nominal annual rates. Time is in years and can be fractional. Before tax and fees.
Your privacy & sharing
Your financial inputs are used only within this page. Saved calculators use this browser’s local storage. Sharing creates a link with the entered values, so anyone with that link can see those values. A downloaded summary stays on your device.