What is the Flat vs Reducing Rate?
With a flat rate, interest is charged on the original loan amount for the whole tenure — even though you have been repaying principal every month. With a reducing-balance rate, interest is charged only on what you still owe.
The result is that a flat rate is roughly 1.8–1.9× the equivalent reducing rate. Consumer-durable loans, some two-wheeler loans and many informal lenders quote flat rates precisely because the number looks smaller.
Formula & worked example
Flat interest ignores repayment entirely:
Flat EMI = (P + flat interest) / N
True rate = the reducing rate that produces the same EMI
Worked example: ₹3,00,000 at a "10% flat" rate for 3 years → interest = 3,00,000 × 10% × 3 = ₹90,000, EMI = ₹10,833. Solving for the reducing rate that gives that EMI yields about 17.9%. At a genuine 10% reducing rate the interest would be only ₹48,600 — so the flat quote costs you an extra ₹41,400.
How to use this flat vs reducing rate calculator
- Enter the loan amount and the flat rate exactly as quoted to you.
- Set the tenure in years.
- Read the true reducing rate — this is the number to compare against any bank offer.
- Check "Extra You Pay" to see the rupee cost of accepting a flat-rate deal.
Smart tips
- Always ask "is that flat or reducing?" before comparing any two loan offers. It is the single most common mis-comparison.
- A quick mental rule: a flat rate is roughly 1.8× the reducing equivalent for tenures of 2–5 years.
- Flat-rate loans usually give no benefit for prepayment — the interest was fixed upfront. Check before signing.
- RBI-regulated banks quote reducing rates on home, car and personal loans. Flat rates cluster in dealer and consumer finance.
- If a lender will not state the reducing-balance APR in writing, treat that as a warning sign.
Frequently asked questions
What is the difference between flat and reducing interest rate?
Flat charges interest on the full original amount for the entire tenure. Reducing charges interest only on the outstanding balance, which falls every month. Flat is always more expensive at the same quoted number.
Is 10% flat the same as 10% reducing?
No. A 10% flat rate over 3 years is equivalent to roughly 17.9% reducing. The flat number is always the smaller, more attractive-looking one.
Which loans use flat rates in India?
Consumer-durable EMIs, many two-wheeler loans, some gold and microfinance loans, and most informal lending. Banks use reducing rates for home, car, personal and education loans.
Can I convert a flat-rate loan to reducing?
Not with the same lender mid-loan. Your option is to close it early (if allowed without penalty) and refinance at a reducing rate elsewhere.
Is a flat rate ever better?
Only when the flat number is so much lower that the converted rate still beats the alternative — for example a 4% flat scheme against a 14% reducing personal loan. Always convert before comparing.
Want the theory behind the numbers? Read our interest rate guides on the Money Blog.