"EMI calculator" is searched more than any other finance tool in India, but most people use one without knowing what it does. Understanding the formula is what lets you spot a bad loan.
The formula
EMI = P × i × (1 + i)^n ÷ ((1 + i)^n − 1)
- P = principal
- i = monthly interest rate = annual rate ÷ 12 ÷ 100
- n = number of monthly instalments
For ₹10,00,000 at 11.5% for 5 years: i = 0.009583, n = 60 → EMI ≈ ₹21,993. Total paid ₹13.2 lakh; interest ₹3.2 lakh.
Why early EMIs are mostly interest
Interest is charged on the outstanding balance each month. In month 1 you owe the full ₹10 lakh, so interest is ₹9,583 and only ₹12,410 of your ₹21,993 reduces the principal. By month 48 the balance is small and most of the EMI is principal.
| Month | Interest | Principal | Balance after |
|---|---|---|---|
| 1 | 9,583 | 12,410 | 9,87,590 |
| 12 | 8,190 | 13,803 | 8,40,700 |
| 36 | 4,731 | 17,262 | 4,76,570 |
| 60 | 208 | 21,785 | 0 |
This is the reducing-balance method — what every bank and NBFC uses. Download the full schedule as CSV from the EMI calculator.
The flat-rate trap
Some lenders (and many two-wheeler/consumer-durable financiers) quote a flat rate: interest on the original principal for the whole tenure. A "10% flat" loan for 5 years costs ₹5 lakh interest on ₹10 lakh — equivalent to about 17.3% reducing. Always ask for the reducing-balance rate or the APR. If they won't say, walk.
Four ways to pay less
1. Shorter tenure
₹10 lakh at 11.5%: 3 years → ₹3.97 lakh EMI? No — ₹32,975/month, ₹1.87 lakh interest. 7 years → ₹17,380/month, ₹4.6 lakh interest. Tenure is the biggest lever on total interest.
2. Prepay early
Because early balances are largest, a ₹1 lakh prepayment in month 6 saves roughly ₹55,000 of interest on this loan; the same prepayment in month 48 saves under ₹8,000. Prepayment charges on floating-rate loans to individuals are nil; on business loans, 2–4% is common — check.
3. Negotiate the rate, not just the EMI
A 1% lower rate on ₹10 lakh over 5 years saves ~₹28,000. MSME loans are priced on your credit score, banking history and collateral; a Udyam certificate and clean GST filings get better pricing.
4. Count the fees
A 2% processing fee on ₹10 lakh is ₹20,000 — equivalent to about 0.8% extra interest per year over 5 years. The calculator shows the effective cost including fees.
Business-loan specifics
- Working-capital vs term loan. Overdrafts/cash-credit charge interest only on the amount used — cheaper if your need is seasonal.
- Mudra (up to ₹20 lakh) and CGTMSE-backed loans are collateral-free for Udyam-registered MSEs.
- Invoice discounting on TReDS is often cheaper than a term loan for receivables from large buyers.
- Interest on a business loan is a deductible expense; the principal repayment is not.
When a loan makes sense
Only if the return on what you buy exceeds the loan's rate plus risk. A ₹5 lakh machine that adds ₹15,000/month of profit returns 36% a year — borrowing at 12% makes sense. Run it through the ROI calculator before signing.
FAQ
Does EMI change if interest rates change?
On a floating-rate loan, yes — lenders usually keep the EMI and change the tenure, or vice versa. Ask which.
What is the difference between reducing and flat rate?
Reducing charges interest on the outstanding balance; flat charges it on the original amount for the full tenure. A flat rate is roughly 1.7–1.8× the equivalent reducing rate.
Is there a penalty for missing an EMI?
Typically 2–3% of the overdue instalment per month, plus a credit-score hit. Contact the lender before the due date if you'll be short.
Can I get tax benefit on a business loan?
Interest is deductible as a business expense. Principal is not.