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EMI Calculator

Computes the equated monthly instalment (EMI) of a home, car or personal loan from the loan amount, annual interest rate and tenure in months, with the total interest and total amount payable; identical to the standard amortizing-loan payment formula.

When to use

You want the EMI for a loan quoted with an annual rate and a tenure in months, as is customary in India and other markets that use the EMI term.

Do not use when: You need the year-by-year breakdown (use amortization-schedule), or a flat-rate loan where interest is charged on the original principal for the whole term (multiply principal × flat rate × years instead).

Formula

r = annual_rate_percent / 1200; n = tenure_months; EMI = loan_amount × r × (1 + r)^n / ((1 + r)^n − 1); loan_amount / n when r = 0

Reducing-balance (diminishing) interest with payments at the end of each month, the formula used by Indian banks and identical to the annuity payment in loan-payment. Processing fees and prepayment charges are not included.

Inputs

Parameter	Type	Unit	Required	Description
`loan_amount`	number		yes	Principal borrowed. Range: > 0, ≤ 1000000000000
`annual_rate_percent`	number	%	yes	Reducing-balance annual rate in percent; the monthly rate is this / 12. Range: ≥ 0, ≤ 100
`tenure_months`	integer	months	yes	Loan tenure in months (20 years = 240). Range: ≥ 1, ≤ 480

Outputs

Output	Type	Unit	Description
`emi`	number		Equated monthly instalment.
`total_interest`	number		emi × tenure_months − loan_amount.
`total_payment`	number		emi × tenure_months.
`interest_share_of_total_percent`	number	%	total_interest / total_payment × 100.

Example

10,00,000 at 8.5 % for 240 months: {"loan_amount":1000000,"annual_rate_percent":8.5,"tenure_months":240} → {"emi":8678.23,"total_interest":1082775.76,"total_payment":2082775.76,"interest_share_of_total_percent":51.99}

5,00,000 at 10 % for 60 months: {"loan_amount":500000,"annual_rate_percent":10,"tenure_months":60} → {"emi":10623.52,"total_interest":137411.34,"total_payment":637411.34}

GET https://tttkmbb.com/api/v1/calculate/emi?loan_amount=1000000&annual_rate_percent=8.5&tenure_months=240

Machine access

API: GET https://tttkmbb.com/api/v1/calculate/emi (query parameters) or POST with a JSON body {"inputs": {...}}
Schema: https://tttkmbb.com/api/v1/calculators/emi · Markdown: https://tttkmbb.com/finance/emi.md · JSON definition: https://tttkmbb.com/finance/emi.json
MCP: server https://tttkmbb.com/mcp, tool run_calculator with calculator_id="emi"
OpenAPI operationId: calculate_emi
Freshness: static. Authentication: none. Rate limit: fair use (see rate limits).

Sources

Investopedia – Equated Monthly Installment (EMI): Definition and Formula (reference)
Wikipedia – Equated monthly installment (reference)
Wikipedia – Amortization calculator (annuity payment formula) (reference)

FAQ

Is EMI the same as a loan payment?

Yes. EMI is the Indian-English term for the level monthly payment of an amortizing loan; loan-payment gives the same number for the same inputs (with the term in years and/or months).

What is the difference between a reducing-balance and a flat rate?

A flat rate charges interest on the full original principal every year, so a 10 % flat rate costs roughly the same as an 18 % reducing-balance rate over 5 years. Enter the reducing-balance rate here.

Related calculators

Loan Payment Calculator — Same formula with the term in years or months.
Amortization Schedule Calculator — Year-by-year principal and interest split.
Debt Payoff Calculator — Payoff time for a chosen payment.