Interest Difference Calculator
A quarter of a percent barely registers on a brochure, and on short tenures it costs about nothing. Spread over a large principal and several years the same sliver turns into real money — which is why two FD offers, a prepayment decision or a refinanced loan deserve a rupee-by-rupee comparison rather than a glance at the headline rates. This page runs one amount through both rates and reports the gap.
Enter values
Results
- Difference in interest
- ₹33,388.17
- Interest at 7%
- ₹2,01,275.87
- Interest at 8%
- ₹2,34,664.04
How is the Interest Difference calculated?
Enter the principal, identical on both sides, then the two rates you are choosing between and the number of years. Interest is compounded annually at each rate, and the calculator reports what each one pays before giving the difference between them as the headline figure. Because the comparison is symmetrical, entering the rates in either order produces the same gap.
Formula
I₁ = P × ((1 + r₁ ÷ 100)^T − 1) and I₂ = P × ((1 + r₂ ÷ 100)^T − 1); difference = |I₁ − I₂|. P is the shared principal, r₁ and r₂ are the two annual rates in percent, and T is the term in years. Both sides compound yearly so the comparison stays like for like.
Example
₹5,00,000 held for 5 years, offered at 7% and at 8%. At 7% the deposit earns ₹2,01,275.87; at 8% it earns ₹2,34,664.04. That single percentage point is worth ₹33,388.17 — more than six percent of your principal, for a difference that fits in one line of an advertisement. On a loan the same gap is interest you pay rather than receive.
Things to remember
Rate gaps widen the longer the money stays put, so re-run this comparison whenever a tenure or a quote changes. If one side compounds quarterly while the other pays monthly, convert both to effective annual rates first; for loans, remember that reducing-balance interest falls as the outstanding amount shrinks.
Frequently Asked Questions
How much is one percent worth on five lakh rupees?
Over 5 years compounded annually, moving from 7% to 8% on ₹5,00,000 pays ₹33,388.17 more: ₹2,34,664.04 against ₹2,01,275.87. Longer tenures widen the gap quickly, because every year's interest then earns interest at the higher rate as well.
Can I compare a flat rate with a reducing rate here?
Not directly — a 10% flat rate costs far more than a 10% reducing rate because the flat figure never falls. Convert them with the flat-versus-reducing calculator first, then use this page for two offers that are already measured on the same basis.
Does compounding frequency change the result?
Yes, which is why both sides must use the same schedule. This calculator compounds annually at each rate; when two products differ in frequency, convert each to an effective annual rate first so extra compounding does not masquerade as a genuinely better rate.
Is the higher rate always the better deal?
For a deposit it is, assuming the issuer is sound and the terms match. For a loan the higher rate always costs more, and on both sides tax or premature-withdrawal penalties can overturn a gap of a few thousand rupees.
Related Calculators
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- EMI CalculatorLoan & EMICalculate your monthly EMI, total interest payable and total payment for any loan, with a worked example and repayment summary.
- Simple Interest CalculatorFinance & InterestWork out simple interest on a deposit or loan, the maturity amount and the gap against compounding.
- Effective Interest Rate CalculatorFinance & InterestTurn an advertised annual rate into the effective rate you truly earn once compounding within the year is counted.