Finance Explainers
Loan EMI formula: monthly payment, total interest and tenure
Understand the reducing-balance EMI formula with a worked rupee example, compare loan tenures, and see which costs a fixed-rate calculator leaves out.
A monthly payment is useful for a budget, but it is only one part of a loan estimate. The interest rate and repayment period determine how quickly the principal falls and how much interest accumulates. A fixed-rate EMI calculator makes that relationship visible before you compare actual loan offers.
Use the reducing-balance formula
For equal monthly payments at a fixed rate, EMI = P × r × (1 + r)^n ÷ ((1 + r)^n − 1). P is the starting principal, r is the monthly rate expressed as a decimal, and n is the number of monthly payments. ICICI Bank’s calculator documents this formula.
An annual rate of 12% becomes r = 12 ÷ 100 ÷ 12 = 0.01 per month. A two-year tenure means n = 24, not 2. At zero interest the formula’s ordinary denominator becomes zero, so the payment is simply principal divided by the number of months.
Sources: ICICI Bank: home-loan EMI formula
A worked ₹1,00,000 example
For ₹1,00,000 at a fixed 12% annual rate over 12 months, the unrounded payment is approximately ₹8,884.88 per month. Multiplying the unrounded payment by 12 gives approximately ₹1,06,618.55 repaid and ₹6,618.55 in interest. Display rounding can create a small difference in a manually multiplied total.
In the first month, interest is ₹1,000 under this monthly model. About ₹7,884.88 of the payment reduces principal, leaving roughly ₹92,115.12. Interest in the next month is calculated on that lower balance. Actual lenders may use different day-count, rounding or disbursement conventions.
| Same principal and rate | 12 months | 24 months |
|---|---|---|
| Monthly payment, approximately | ₹8,884.88 | ₹4,707.35 |
| Total interest, approximately | ₹6,618.55 | ₹12,976.33 |
Compare a lower EMI with a longer repayment period
The example’s 24-month payment is smaller, but the modeled total interest is larger. Change one input at a time in ToolBarKit to see the tradeoff clearly. Its principal-and-interest breakdown and repayment schedule help explain what the headline monthly figure hides.
An amortization schedule separates each payment into interest and principal. Under this fixed-rate model, the interest share generally falls as the balance falls. A flat-rate quote calculates interest differently, so do not compare the same percentage labels as if they represented the same cost.
Know what the estimate leaves out
ToolBarKit models a fixed-rate reducing-balance loan with regular monthly payments. It does not predict floating-rate changes, prepayments, lender approval, processing fees, insurance or taxes. Its result is an educational estimate, not a lender quote or a personalized borrowing recommendation.
Compare the lender’s actual schedule and full cost disclosures before deciding. If the EMI seems affordable only under the longest tenure, review the wider budget and total repayment rather than using the calculator to infer eligibility.
Common questions
Does a lower EMI always mean a cheaper loan?
No. Extending the tenure can reduce the monthly payment while increasing total modeled interest. Compare all costs and the actual lender terms.
Why might a lender’s schedule differ?
Fees, rate changes, payment dates, day-count conventions and rounding can differ from a simplified fixed monthly model. Use the lender’s documentation for the final obligation.
Sources and further reading
This guide combines the linked references with examples and the current behavior of ToolBarKit’s tools. Published by the ToolBarKit team; external guidance and tool behavior can change.