How to use it
- 1.Enter the starting principal.
- 2.Set an annual rate assumption.
- 3.Choose the duration.
- 4.Compare the result with simple interest or a different rate scenario.
Updated
Compound Interest Calculator
This calculator illustrates annual compounding from principal, rate and time. Change every input and see the estimate update immediately.
Adjust your assumptions
₹
₹0₹10,00,00,000
%
030
years
140
%
015
Your estimate
₹2,59,374
Estimated value
₹2.59 LYear 10: ₹2.59 L
Amount contributed
₹1,00,000
Estimated growth
₹1,59,374
Today’s purchasing power
₹1,44,833
Educational estimate only. Methodology 2026.08. This is not a return promise, loan offer, tax filing or financial recommendation.
Results are estimates for learning and planning only. Tax rules, interest rates and scheme terms change from time to time, and your actual figures may differ. Please talk to a qualified financial advisor or chartered accountant before making any financial decision.
Compound Interest Calculator: what it calculates.
Compound interest means growth is calculated on both the original principal and previously accumulated interest. It can describe deposits, investments or debt, but the real compounding convention must be verified.
This calculator illustrates annual compounding from principal, rate and time.
How the calculation works.
Future value = P × (1 + r)^t
- P is principal.
- r is the annual decimal rate.
- t is time in years.
Worked example. ₹1 lakh compounded annually at 10% for 10 years produces an illustrative value of about ₹2.59 lakh.
What it helps with
- Demonstrates the time value of money.
- Separates principal and growth.
- Makes assumptions explicit.
What it does not include
- The model assumes a steady annual rate.
- Fees, tax and irregular cash flows are excluded.
- Debt products may use different conventions.
Common questions.
What is a Compound Interest Calculator?
It is an educational tool that applies the disclosed compound interest method to the assumptions you enter.
Are the results guaranteed?
No. Results are estimates, not forecasts, approvals, quotations or guarantees.
Why should I change the assumptions?
Testing conservative and optimistic inputs exposes uncertainty instead of hiding it behind one number.
Does it include tax and fees?
Only when a tax or fee is shown as an explicit input or result. Otherwise it is excluded.
How accurate is the calculator?
The mathematics follows the stated methodology, while real outcomes depend on rates, timing, rules, fees and circumstances.
Can I use this result as financial advice?
No. Use it for education and scenario comparison, then verify decisions with official documents or a qualified professional.
Why is inflation shown?
Inflation translates a future amount into approximate present-day purchasing power. The default 6% is editable and is not a forecast.
How often should I recalculate?
Recalculate when rates, income, contributions, rules, goals or repayment terms change.
Can the result differ from a bank or platform?
Yes. Institutions may use different compounding dates, rounding, charges and eligibility rules.
Is my data uploaded?
No. Calculations run locally in your browser and the input values are not sent to a calculation server.