Loan & EMI Calculator

What is a loan calculator?

A loan calculator is a tool that works out the fixed monthly payment (EMI), the total interest, and the total amount you will repay on an amortized loan, using the loan amount, annual interest rate, and term. It turns three simple inputs into the full cost of borrowing before you commit.

It is the fastest way to compare offers, test “what if” scenarios (a shorter term, a bigger deposit, a lower rate), and understand exactly where your money goes each month.

How is a monthly loan payment calculated?

The monthly payment is calculated with the standard amortization formula:

EMI = P × r × (1 + r)ⁿ ÷ ((1 + r)ⁿ − 1)

where:

• P = loan amount (principal)
• r = monthly interest rate = annual rate ÷ 12 ÷ 100
• n = number of monthly payments = term in years × 12

If the rate is 0%, the formula simplifies to EMI = P ÷ n. Once you have the payment, two more numbers follow:

• Total paid = EMI × n
• Total interest = (EMI × n) − P

This is exactly the method the calculator above uses. Note that r is the monthly rate, so a 6% annual rate becomes 0.5% (0.005) per month.

Worked examples you can reproduce

Example 1 — a $20,000 car loan

$20,000 at 7.5% over 5 years (60 months).

• r = 7.5 ÷ 12 ÷ 100 = 0.00625
• (1 + r)ⁿ = 1.00625⁶⁰ ≈ 1.45329
• EMI = 20,000 × 0.00625 × 1.45329 ÷ (1.45329 − 1) ≈ $400.76
• Total paid = 400.76 × 60 ≈ $24,045.54
• Total interest = 24,045.54 − 20,000 ≈ $4,045.54

Example 2 — a $250,000 mortgage

$250,000 at 6% over 30 years (360 months). Monthly rate r = 0.005.

• EMI ≈ $1,498.88
• Total paid ≈ $539,595.47
• Total interest ≈ $289,595.47

Notice the interest is larger than the original loan — a direct result of borrowing for 30 years.

Example 3 — a $15,000 personal loan

$15,000 at 9% over 4 years (48 months): EMI ≈ $373.28, total paid ≈ $17,917.23, total interest ≈ $2,917.23.

What makes up each payment — principal vs interest?

Every EMI is split into two parts: interest on the current balance and principal that reduces the balance. Because interest is charged on what you still owe, early payments are mostly interest and later payments are mostly principal. The payment never changes; the split does.

Using the $250,000 / 6% / 30-year mortgage above (EMI $1,498.88), here is how the split shifts:

Payment	Interest portion	Principal portion	Approx. balance after
Month 1	$1,250.00	$248.88	$249,751.12
Month 60 (year 5)	≈ $1,165	≈ $334	≈ $232,636
Month 223	≈ $745.78	≈ $753.09	≈ $148,400
Month 360 (final)	≈ $7	≈ $1,492	$0

On this loan, the principal portion only overtakes the interest portion at month 223 — more than 18 years in. That is why paying extra early has such a large effect.

How do you reduce the total interest on a loan?

Cut the principal, the rate, or the time — the three levers in the formula. Each one lowers total interest, and shortening the term usually saves the most.

• Choose a shorter term. The clearest win, as the table below shows.
• Make extra principal payments. Any amount above the EMI goes straight to the balance, shrinking future interest.
• Get a lower rate. Even a 0.5-point drop compounds across hundreds of payments.
• Increase your down payment. A smaller P reduces interest proportionally.

Term comparison: same loan, different terms

$250,000 at 6%, compared across two terms:

Term	Monthly payment	Total interest	Total repaid
30 years	$1,498.88	$289,595	$539,595
15 years	$2,109.64	$129,736	$379,736

Halving the term raises the monthly payment by about 41% (to $2,109.64) but saves about $159,860 in interest. Use the calculator above to find a term whose payment fits your budget while keeping total interest in check.

Fixed (flat) vs reducing balance interest

These produce very different costs for the same headline rate. Reducing-balance is what this calculator uses, and it is the standard for mortgages, car loans, and most bank lending.

	Reducing balance (amortized)	Flat / fixed interest
Interest charged on	Outstanding balance (falls each month)	Original principal (whole term)
Effective cost	Lower for the same rate	Higher — often ~1.8× the equivalent rate
Common uses	Mortgages, auto, bank personal loans	Some short-term and dealer financing
Early repayment benefit	Large — cuts future interest	Little to none

A “10% flat” loan is not the same as “10% reducing.” If a quote uses flat interest, ask for the effective APR before comparing.

Common mistakes and tips

• Entering the annual rate where a monthly rate belongs. Always divide the annual rate by 12 for r.
• Forgetting fees. EMI covers principal and interest only; APR includes fees and is the fairer comparison number.
• Comparing only the monthly payment. A low payment can hide a long term and huge total interest — check total repaid too.
• Ignoring prepayment penalties. Some loans charge for paying early; confirm before overpaying.
• Mixing currencies or units. Keep amount, rate, and term consistent. Need to recheck a percentage change? The percentage calculator helps.

Limitations and accuracy notes

This calculator assumes a fixed interest rate, equal monthly payments, and no fees, insurance, or taxes. Variable-rate loans, balloon payments, irregular schedules, and compounding that differs from monthly will give different results. The widget rounds the term to whole months (years × 12) and the displayed currency to cents, so tiny rounding differences from a lender statement are normal.

Disclaimer: This tool provides estimates for general information and education only. It is not financial advice. Your lender’s actual payment, APR, and total cost may differ due to fees, rounding, payment timing, and rate changes. Confirm figures with the lender before making any borrowing decision.

Explore more tools in Finance, or model investment income with the dividend calculator.