EMI: How Banks Calculate It.
Banks design EMI so you pay mostly interest in the first half of your loan. Most borrowers never realise this. Here is the exact formula they use — and how to use it against them.
Reducing Balance
The method used
Front-Loaded
Interest is higher early
₹32.5L Interest
On a ₹30L loan at 20 yrs
Prepay Early
Max interest saved
The EMI Formula
Every bank in India — SBI, HDFC, ICICI, Axis — uses the same formula to calculate your monthly EMI. It is called the reducing balance method (also called diminishing balance). This is important to understand because some NBFCs and personal loan apps use a flat rate method which is significantly more expensive.
EMI Formula (Reducing Balance)
EMI = P × r × (1+r)ⁿ / ((1+r)ⁿ − 1)
Worked Examples — 3 Loan Types
Home Loan: ₹30 lakh at 8.5% for 20 years
Principal
₹30,00,000
Rate
8.5% p.a.
Tenure
240 months
Monthly r
0.085 ÷ 12 = 0.007083
₹26,035/month
EMI/Month
₹62,48,400
Total Paid
₹32,48,400
Total Interest
You pay ₹32.48 lakh in interest on a ₹30 lakh loan — more than the original principal. This is why pre-payment in early years is so impactful.
Car Loan: ₹8 lakh at 9.5% for 5 years
Principal
₹8,00,000
Rate
9.5% p.a.
Tenure
60 months
Monthly r
0.095 ÷ 12 = 0.007917
₹16,798/month
EMI/Month
₹10,07,880
Total Paid
₹2,07,880
Total Interest
Shorter tenure significantly reduces total interest. Even though 9.5% seems high, the 5-year term limits total interest to ₹2.07L on an ₹8L loan.
Personal Loan: ₹3 lakh at 14% for 3 years
Principal
₹3,00,000
Rate
14% p.a.
Tenure
36 months
Monthly r
0.14 ÷ 12 = 0.01167
₹10,248/month
EMI/Month
₹3,68,928
Total Paid
₹68,928
Total Interest
Personal loans have high rates but short tenures keep total interest manageable. At 14%, you pay ₹68,928 interest on ₹3L — avoid rolling over or extending tenure.
Why Interest is Front-Loaded
On a ₹30L home loan at 8.5% for 20 years, your first EMI of ₹26,035 breaks down like this: ₹21,250 is interest, only ₹4,785 is principal repayment. By month 120 (year 10), the split is roughly ₹15,000 interest and ₹11,000 principal. Only in the final years does principal repayment exceed interest.
EMI Breakdown — ₹30L loan at 8.5%, 20 years
18% principal · 82% interest
28% principal · 72% interest
42% principal · 58% interest
65% principal · 35% interest
99% principal · 1% interest
5 Ways to Reduce Interest
Prepay in the first 5 years
Since interest is front-loaded, prepayment in early years reduces principal at its highest point — saving the most interest. A ₹1L prepayment in year 1 saves far more than the same prepayment in year 15.
Choose reduce-tenure over reduce-EMI on prepayment
When you prepay, ask your bank to reduce the remaining tenure, not the monthly EMI. Shorter tenure = fewer total EMIs = significantly less total interest paid.
Compare actual interest rate, not advertised rate
Banks advertise annual rates, but the real comparison metric is the Annual Percentage Rate (APR) which includes processing fees, insurance, etc. A 8.5% rate with ₹30,000 processing fee costs more than a 8.6% rate with no fees on a ₹20L loan.
Increase EMI by 5% every year
If you increase your EMI by 5% annually (step-up EMI), you can cut a 20-year loan to 14–15 years and save lakhs in interest. Most banks allow this.
Balance transfer when rates drop
If your current home loan is at 9% and another bank offers 8.2%, a balance transfer can save ₹500–700/month on a ₹30L loan. The break-even on transfer costs is usually 6–12 months.
EMI FAQ
What is the EMI for ₹50 lakh home loan at 8.5% for 20 years? ▾
EMI = ₹43,391/month. Total paid = ₹1,04,13,840 over 20 years. Total interest = ₹54,13,840. You pay more than double the principal in a 20-year home loan at 8.5%.
What is the difference between flat rate and reducing balance EMI? ▾
Flat rate: interest is always calculated on original principal. Reducing balance: interest is calculated on outstanding principal which decreases each month. Reducing balance is cheaper — a 12% flat rate is equivalent to roughly 21% reducing balance.
Can I close my home loan before tenure? ▾
Yes. Banks cannot charge prepayment penalty on floating-rate home loans as per RBI guidelines. Fixed-rate loans may have a 2% foreclosure charge. Always check your loan agreement.
Does paying extra EMI reduce interest? ▾
Yes. Any extra payment directly reduces your outstanding principal, reducing future interest. Even ₹1,000 extra per month on a ₹30L loan can cut 2–3 years off a 20-year tenure.
Calculate Your EMI
Know your exact numbers before signing anything
Disclaimer: All calculations are illustrative. Consult your bank for exact terms. © 2026 HQCalc.