A rate quoted as flat and a rate quoted on a reducing balance are not the same measurement, and they are not close. This converts one into the other so you can compare a quote with anything else.
Reviewed 20 August 2026
A loan quoted at 9% flat is really a 15.71% loan. It costs ₹1,02,249 more than the same headline number would if the rate were quoted on a reducing balance, which is how every home loan and most bank lending is quoted.
The reason is that a flat rate charges interest on the whole ₹5,00,000 for all 5 years, even in the final month when you owe almost nothing. By the end of the loan you are paying interest on money you repaid years ago.
| 9% flat | 9% reducing | |
|---|---|---|
| Monthly instalment | ₹12,083 | ₹10,379 |
| Total interest | ₹2,25,000 | ₹1,22,751 |
| Total repaid | ₹7,25,000 | ₹6,22,751 |
| Real rate | 15.71% | 9.00% |
As a rough rule, the real rate is between 1.7 and 1.8 times the flat rate quoted. On these numbers the multiple is 1.75×.
The multiple is remarkably stable across tenures, and slightly higher on shorter loans: about 1.8× over one to three years, easing towards 1.7× by seven. So doubling the flat rate is a reasonable mental check in a showroom, and it errs on the cautious side.
The equivalent rate is found by solving for the reducing-balance rate whose monthly instalment matches the flat loan’s. Fees and charges are not included on either side, and on the kind of lending that quotes flat rates they are frequently substantial.
A reducing-balance rate charges interest each month on what you still owe. As the balance falls, so does the interest, and the same instalment repays more principal each month. Every home loan in India works this way, and so does most bank lending.
A flat rate charges interest on the original amount for the whole term, regardless of what you have repaid. Total interest is simply principal multiplied by rate multiplied by years, fixed on day one, and the instalment is that total divided by the number of months.
To convert, this solves for the reducing-balance rate whose monthly instalment equals the flat loan’s. There is no closed form, so it is found by bisection. That equivalent rate is the only number that lets you put a flat quote next to anything else.
Fees are not in either column, and on the kind of lending that quotes flat rates they are frequently substantial. A processing fee of 1% to 2%, documentation charges, and insurance sold alongside the loan all sit outside the instalment. Add them before comparing two offers.
It assumes the flat loan is repaid to term. Prepaying a flat-rate loan often saves far less than intuition suggests, because the interest was computed up front, and many such agreements charge a foreclosure fee on top.
It does not model an agreement quoted as a monthly percentage, which is common in some consumer and gold lending, and where the same conversion is needed with an extra step.
A reducing-balance rate charges interest on what you still owe, so the interest falls as you repay. A flat rate charges interest on the original amount for the entire term, so in the final month you are paying interest on money you returned years ago.
On the defaults here, ₹5,00,000 over five years: 9% flat costs ₹2,25,000 of interest, while 9% reducing costs ₹1,22,751. Same headline number, ₹1,02,249 apart.
15.71% on a reducing balance, for a five-year loan. That is the rate whose monthly instalment matches the flat loan’s, and it is the number to write down when comparing the quote against a bank offer or a credit card. Anyone quoting a flat rate is quoting a number that cannot be compared with anything else in the market without this conversion.
Roughly double it. Across tenures from one to seven years the multiple sits between about 1.7 and 1.8, slightly higher on shorter loans. Doubling is easy to do in your head in a showroom, it errs on the cautious side, and it is close enough to tell you whether to keep listening. The tool gives the exact figure once you can sit down with the numbers.
Vehicle finance arranged at a dealership, consumer durable loans, some gold loans, and a good deal of informal and small-ticket lending. It is generally not used for home loans, and banks quoting personal loans normally quote reducing. The tell is the word itself: if a quote says flat, or gives you a total interest amount rather than a rate, convert before comparing.
Yes, provided the terms are disclosed. It is not a hidden charge and nothing is being concealed: the total interest and the instalment are both stated up front. What makes it a problem is that the headline number is not comparable with the headline number everyone else quotes, and most borrowers compare headline numbers. The defence is arithmetic rather than regulation.
Much less than on a reducing-balance loan, and sometimes almost nothing. Because the interest was calculated on the full amount at the outset, many flat-rate agreements simply require the remaining instalments regardless, or apply a rebate formula considerably less generous than the interest actually saved. Several also charge a foreclosure fee. Ask exactly what a prepayment would cost before signing, not after.
Three questions. What is the equivalent reducing-balance or annual percentage rate? What is the total amount repayable, including every fee? And what would it cost to settle early at, say, the halfway point? A lender who cannot or will not answer the first has told you something useful. All three answers should be in writing.
Sometimes, and on the converted number rather than the quoted one. A flat quote that converts to 15.71% is still cheaper than a credit card revolving at 36%, and for a small purchase over a short term the absolute rupee difference can be modest enough not to matter. The point of this page is not that flat rates are always bad, it is that you cannot tell until you have converted.
Roughly 17.5% over a five-year loan. The multiple sits between about 1.7 and 1.8 across common tenures, so doubling the flat rate is a reasonable quick check and errs slightly on the cautious side.
Because interest is charged on the full original amount for the whole term, even in the final months when most of the loan has been repaid. You end up paying interest on money you returned years earlier.
Reducing balance, universally, in India. Flat rates appear mainly in vehicle finance arranged at dealerships, consumer durable loans, some gold lending and informal credit.
No. The terms are disclosed and nothing is hidden. The difficulty is that the number quoted is not comparable with the number every other lender quotes, and borrowers compare numbers.
Total interest is principal multiplied by rate multiplied by years. Add that to the principal and divide by the number of months. It is simpler arithmetic than a reducing-balance EMI, which is part of why it persists.
No. This page exists because borrowing decisions sit alongside investment ones and a rate that cannot be compared is worth being able to convert. No lender is named anywhere on it.
Talk to the desk
A lender who cannot tell you the equivalent annual rate has told you something worth knowing. Send us the terms you have been offered and we will work out what it actually costs.
