Loans & EMIs · Updated October 2026 · 5 min read
Two loans can quote the same interest rate and still cost very different amounts. The reason is how the interest is calculated: on the original loan amount (flat rate) or on what you still owe (reducing balance rate). This difference often appears in consumer durable loans, some vehicle loans and smaller personal loans.
In short: A flat rate charges interest on the full loan for the whole tenure, even as you repay it. A reducing balance rate charges interest only on the outstanding amount. A 10% flat rate costs roughly as much as an 18% reducing rate.
Flat interest rate
With a flat rate, interest is calculated once on the original loan amount and spread across all EMIs. It does not fall as you repay.
Example: ₹2,00,000 at a 10% flat rate for 2 years.
- Interest = ₹2,00,000 × 10% × 2 = ₹40,000
- Total repaid = ₹2,40,000
- EMI = ₹2,40,000 ÷ 24 = ₹10,000
Reducing balance interest rate
With a reducing rate, each month’s interest is charged only on the balance you still owe. As you repay, interest falls. Most bank home loans, car loans and personal loans use this method, and it is what the standard EMI formula is built on.
Example: the same ₹2,00,000 for 2 years at 10% reducing gives an EMI of about ₹9,229 and total interest of about ₹21,500, roughly half the flat-rate cost.
Comparing them fairly
The flat-rate loan above, with an EMI of ₹10,000, actually costs about the same as a reducing balance loan at around 18% a year. As a rough rule, the true rate on a flat-rate loan is close to double the quoted flat rate for typical tenures.
- Always ask the lender: “Is this a flat rate or a reducing balance rate?”
- Ask for the APR in the Key Facts Statement. It converts everything, including fees, into one comparable yearly rate.
- Compare the total amount you will repay, not only the EMI.
Where flat rates show up
- “No cost” or low-cost EMI offers on phones and appliances. Check whether the interest is hidden in a higher product price or a processing fee.
- Some two-wheeler and used-vehicle loans.
- Some small-ticket loans from informal or smaller lenders.
Prepayment is also different
On a reducing balance loan, paying early cuts future interest because the balance falls. On many flat-rate loans, the interest is fixed upfront, so prepaying may save little or nothing. Check the terms before you count on savings. See loan foreclosure and prepayment.
Common questions
Is a flat rate ever cheaper?
Only if its true rate (APR) works out lower than the reducing rate you are offered, which is rare. Compare APRs to be sure.
How do I convert a flat rate to a reducing rate?
Work out the flat-rate EMI, then find the reducing rate that gives the same EMI. Our EMI calculator can help you test rates until the EMIs match.
Next steps: Compare personal and business loans using their reducing rate and APR.
Disclaimer: This guide is for education and is not financial advice. Rates, fees and rules change, so check the latest terms with the lender before you borrow.