What is a flat vs Reducing Rate Calculator?
Some lenders — especially for consumer durable, gold, or older-style personal loans — quote a "flat" interest rate, calculated on the full original principal for the entire tenure rather than on the reducing outstanding balance. A flat rate always sounds lower than it actually is: an 8% flat rate typically costs about as much as a 14–15% reducing rate, because you keep paying interest on money you’ve already repaid.
Enter the loan details as quoted (flat rate) to see the EMI it produces, and the equivalent reducing rate that would give you the exact same EMI — the number that’s actually comparable to any bank loan quoted the normal way.
How the equivalent rate is found
There’s no algebraic shortcut from a flat EMI back to an equivalent reducing rate, so this calculator solves it numerically (bisection search) — trying rates until the reducing-balance EMI formula produces the same monthly payment as the flat-rate one.
Frequently asked questions
Why is the reducing rate always higher than the flat rate?
Because a flat rate charges interest on the full principal every month, even in month 47 of a 48-month loan when you’ve nearly repaid it. A reducing rate only charges interest on what’s actually still outstanding — so a much lower reducing rate produces the same total interest as a flat rate.
How much higher is the reducing-rate equivalent, roughly?
As a rule of thumb, the equivalent reducing rate is often close to double the flat rate, though the exact multiple depends on the tenure — longer tenures push the gap even wider.
Should I always avoid flat-rate loans?
Not necessarily — but always convert the quoted flat rate to its reducing-rate equivalent before comparing it against another loan offer quoted the standard way, otherwise you’re not comparing like with like.