Short answer: A flat interest rate charges interest on the full original loan amount for the whole tenure, even as you repay it. A reducing balance rate charges interest only on the amount still outstanding each month. So a 12% flat rate is far costlier than a 12% reducing rate: on a ₹2 lakh, 2-year loan it works out to roughly 21.6% on a reducing basis. Always compare loans on the reducing rate or, better, the APR shown in the Key Fact Statement.
Last updated: 13 October 2026.
You can test any loan in our flat rate vs reducing rate calculator, which shows EMIs and month-by-month schedules for both methods.
How a flat rate works
Under a flat rate, total interest is simply:
Total interest = Principal × Flat rate × Tenure in years
The EMI is (Principal + Total interest) ÷ Number of months. Because interest is calculated on the original principal throughout, you keep paying interest on money you have already returned.
Example: ₹2,00,000 at 12% flat for 24 months. Interest = ₹2,00,000 × 12% × 2 = ₹48,000. EMI = ₹2,48,000 ÷ 24 = about ₹10,333.
How a reducing balance rate works
Under a reducing balance rate, each month’s interest is charged on the outstanding principal. The standard EMI formula is:
EMI = P × r × (1 + r)n ÷ [(1 + r)n − 1], where P is the principal, r is the monthly rate (annual rate ÷ 12) and n is the number of months.
Example: ₹2,00,000 at 12% reducing for 24 months. r = 1% a month. EMI = about ₹9,415. Total interest = about ₹25,953.
| Month | Opening balance | Interest (1%) | Principal repaid | Closing balance |
|---|---|---|---|---|
| 1 | ₹2,00,000 | ₹2,000 | ₹7,415 | ₹1,92,585 |
| 2 | ₹1,92,585 | ₹1,926 | ₹7,489 | ₹1,85,096 |
| 3 | ₹1,85,096 | ₹1,851 | ₹7,564 | ₹1,77,533 |
Interest falls every month and the principal share rises. That is why EMIs are ‘loaded’ with interest at the start; our article on why EMIs are initially loaded with interest explains this in detail.
Side-by-side: same headline rate, very different cost
| ₹2,00,000 for 24 months | 12% flat | 12% reducing |
|---|---|---|
| EMI | About ₹10,333 | About ₹9,415 |
| Total interest | ₹48,000 | About ₹25,953 |
| Total repaid | ₹2,48,000 | About ₹2,25,953 |
| Equivalent reducing rate | About 21.6% | 12% |
The flat-rate loan costs about ₹22,000 more, even though both say ‘12%’.
Converting a flat rate to a reducing rate
There is no exact one-line formula, but a reliable rule of thumb is that the equivalent reducing rate is roughly 1.75 to 1.85 times the flat rate for typical tenures of one to three years. Some illustrative conversions on a ₹2 lakh loan:
| Flat rate and tenure | EMI | Equivalent reducing rate (approx.) |
|---|---|---|
| 10% flat, 12 months | About ₹18,333 | About 18.0% |
| 10% flat, 36 months | About ₹7,222 | About 17.9% |
| 12% flat, 12 months | About ₹18,667 | About 21.5% |
| 12% flat, 24 months | About ₹10,333 | About 21.6% |
| 12% flat, 36 months | About ₹7,556 | About 21.2% |
To do it precisely, take the flat-rate EMI and find the reducing rate that gives the same EMI for the same principal and tenure. Our calculator does this automatically, or you can use the RATE function in a spreadsheet: =RATE(24, -10333, 200000) × 12.
Where you still see flat rates in India
- Some two-wheeler, used car and consumer durable loans offered at dealerships.
- Some microfinance and small-ticket loans quoted by agents.
- Some ‘personal loan’ ads that quote a monthly flat rate (for example ‘1% per month’), which sounds like 12% a year but is costlier if calculated flat.
- Informal lenders and chit-style arrangements.
Most bank and NBFC personal loans, home loans and education loans are calculated on reducing balance. If a quote seems unusually low, ask which method is used.
Worked example: a dealer offer vs a bank loan
Illustrative: Sunita is buying a two-wheeler and needs ₹80,000 for 24 months. The dealer’s finance partner quotes ‘9% only’, which turns out to be a flat rate, plus a ₹2,000 file charge. Her bank offers 14% on a reducing balance with no fee.
| Dealer: 9% flat + ₹2,000 fee | Bank: 14% reducing, no fee | |
|---|---|---|
| Interest | ₹14,400 | About ₹12,185 |
| EMI | About ₹3,933 | About ₹3,841 |
| Total cost (interest + fee) | ₹16,400 | About ₹12,185 |
| Effective reducing rate | About 16.4% before the fee, about 19% after it | 14% |
The offer that sounded cheaper costs about ₹4,200 more. The numbers that reveal this, the APR and total amount payable, are exactly what a Key Fact Statement must show, so ask for it before you sign at the showroom. Related reading: how to take a two-wheeler loan.
Why the APR settles the question
Since October 2024, RBI has required every bank and NBFC to give a standard Key Fact Statement (KFS) for retail and MSME loans. It shows the Annual Percentage Rate (APR), calculated on the reducing balance and including processing fees and other charges. Comparing APRs removes the confusion between flat and reducing rates and also captures fees. Our explainer on APR vs interest rate shows how fees push the APR above the interest rate.
Prepayment: another reason reducing balance matters
On a reducing balance loan, any prepayment immediately cuts the principal and therefore all future interest. On a flat-rate loan, the interest for the full tenure is often fixed upfront, so prepaying may save little unless the lender recalculates. Check foreclosure terms in the KFS. Under RBI’s prepayment rules, floating-rate loans to individuals sanctioned from 1 January 2026 cannot carry prepayment penalties from regulated lenders.
Example: on the ₹2 lakh, 12% reducing loan above, prepaying ₹50,000 after month 6 cuts the outstanding balance immediately, so every later month’s interest is charged on a smaller amount. On the flat-rate version, ask the lender in writing how much interest would be waived before you prepay.
For loans taken through apps, the RBI Digital Lending Directions, 2025 also require the KFS and APR to be shown before you accept, and allow a cooling-off period to exit without penalty.
Checklist before you sign
- Ask whether the quoted rate is flat or reducing.
- Get the EMI, tenure and total amount payable in writing.
- Compare the APR in the KFS, not just the rate.
- Recalculate with the personal loan EMI calculator using the reducing rate.
- Check the lender is regulated; see the RBI-registered NBFC search.
Compare personal loan offers with the APR shown upfront, from RBI-regulated lenders.
More on loan maths: loan glossary and the EMI calculator.
Frequently asked questions
Is a flat rate of 10% the same as 10% reducing?
No. A 10% flat rate over one to three years is roughly equal to 18% on a reducing balance, because flat interest is charged on the full original amount for the whole tenure.
Which is better for the borrower, flat or reducing rate?
At the same headline number, a reducing balance rate is always cheaper. Compare different offers using the reducing rate or the APR in the Key Fact Statement.
Why does my EMI have more interest at the start?
On a reducing balance loan, interest is charged on the outstanding principal, which is highest at the start. As you repay, the interest part falls and the principal part rises.
Do banks in India use flat rates for personal loans?
Most bank and NBFC personal loans use reducing balance. Flat rates still appear in some vehicle, consumer durable and small-ticket loans, so always ask.
How do I convert a flat rate to a reducing rate?
Calculate the flat-rate EMI, then find the reducing rate that gives the same EMI for the same amount and tenure. Our flat vs reducing calculator or a spreadsheet RATE function does this instantly.
Sources
- RBI circular: Key Fact Statement for loans and advances
- RBI press release: Digital Lending Directions, 2025
Disclosure: FundsTiger (Gatimaan Finance Advisors Pvt. Ltd.) is a loan marketplace and lending service provider for RBI-regulated lenders. Aparampaar Finance Pvt. Ltd. (Omozing), one of those lenders, is a related party of FundsTiger. This article is general information, not financial advice. Read your loan agreement and KFS before you decide.