Fixed vs Reducing Interest Rate: The Difference That Quietly Costs You

Two lenders quote you “10%.” One loan costs you noticeably more than the other. How? Because “10%” can be calculated two completely different ways — flat or reducing — and the difference is one of the most quietly expensive things borrowers miss. Let me make it clear once, so no one quotes you a number you can’t decode.

The two ways interest is calculated

Flat (or fixed) rate charges interest on your full original loan amount for the entire tenure — even though you’re steadily paying the principal down. So in year three, you’re still being charged interest as if you owe the whole sum you started with.

Reducing balance rate charges interest only on what you still owe. As each EMI chips away at the principal, the interest portion shrinks too. This is the fairer and more common method for mainstream term loans.

Same headline number, very different totals — because the flat method keeps charging on money you’ve already repaid.

Why “10% flat” is not “10% reducing”

This is the trap. A flat rate always sounds cheaper than the reducing rate it’s really equivalent to. As a rough guide, a flat rate works out to roughly 1.7 to 1.9 times the equivalent reducing rate over a typical tenure. So a “10% flat” loan is, in reducing-balance terms most lenders quote, closer to 17–19%.

An illustrative example. Say you’re comparing two ₹5 lakh offers over five years. Lender A says “10.5% reducing.” Lender B says “8% flat” and it sounds like the better deal. Convert them to the same basis and B’s “8% flat” is actually the more expensive loan by a clear margin — the flat quote just hid it. The lesson isn’t which lender; it’s that you can’t compare two rates until they’re on the same basis. (Illustrative only.)

The one question to always ask

Before you compare any two loan offers, ask each lender the same thing:

“Is that rate flat or reducing balance?”

Then compare like with like. If one is flat and one is reducing, get both expressed the same way — or compare the thing that can’t be disguised: the total amount payable and the EMI. Those two numbers tell the truth no matter how the rate is dressed up.

Use the EMI, not the rate, as your anchor

Honestly, the cleanest way to cut through all of this is to stop staring at the percentage and look at what actually leaves your account: the monthly EMI and the total you’ll repay over the full tenure. Two loans with the same EMI and tenure cost you the same, whatever each calls its rate.

Our EMI calculator works on a reducing-balance basis, so you can plug in an amount, rate and tenure and see the real monthly figure — a good sanity check against any quote you’re given.

And when you’re comparing offers for real, that’s part of what we do for you: we make sure you’re comparing loans on the same footing, not being sold a flat rate dressed up to look small. For the bigger picture on what drives your rate in the first place, your CIBIL score is where it starts — and when you’re ready, tell us what you’ve been offered and we’ll help you read it straight.