How to use it
- 1.Enter the principal lent, borrowed or deposited.
- 2.Enter the annual interest rate.
- 3.Choose the period in years.
- 4.Compare the result with compound interest at the same rate to see the difference.
Updated
Simple Interest Calculator
The simple interest calculator multiplies the principal by the annual rate and the number of years to give total interest and the final amount. Change every input and see the estimate update immediately.
Adjust your assumptions
₹
₹0₹10,00,00,000
%
030
years
140
%
015
Your estimate
₹1,40,000
Estimated value
₹1.4 LYear 5: ₹1.4 L
Amount contributed
₹1,00,000
Estimated growth
₹40,000
Today’s purchasing power
₹1,04,616
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.
Simple Interest Calculator: what it calculates.
Simple interest is charged or earned only on the original principal, not on interest already accrued. It is used for some short-term loans, informal lending and certain deposits that pay interest out rather than reinvesting it.
The simple interest calculator multiplies the principal by the annual rate and the number of years to give total interest and the final amount. It also shows that final amount in today's money using your inflation assumption.
How the calculation works.
Simple interest = P × r × t; Final amount = P × (1 + r × t)
- P is the principal.
- r is the annual rate as a decimal.
- t is the time in years.
- Interest is the same every year because it is never added to the principal.
Worked example. ₹1 lakh at 8% simple interest for 5 years earns ₹8,000 a year, or ₹40,000 in total, giving a final amount of ₹1.4 lakh. With annual compounding at the same rate, it would grow to about ₹1.47 lakh.
What it helps with
- Shows interest and final amount instantly.
- Makes the year-by-year growth easy to follow.
- Gives a baseline for comparing compound interest.
What it does not include
- Most bank deposits and loans compound interest, so this may understate their real cost or return.
- Tax, fees and late-payment charges are excluded.
- The result is an estimate based on a fixed rate.
Common questions.
What is a Simple Interest Calculator?
It is an educational tool that applies the disclosed simple 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.