EMI Calculator
Understanding EMI
EMI stands for Equated Monthly Installment. It's a fixed amount that you pay
towards your loan every month on a specific date. The EMI includes both the
principal amount (the original loan amount) and the interest charged by the
lender. Over the tenure of the loan, these monthly payments gradually reduce
your outstanding loan balance until it becomes zero.
How EMI is Calculated
The formula used to calculate EMI is:
$E = P \times \frac{r \times (1+r)^n}{(1+r)^n – 1}$
Where:
- E = Equated Monthly Installment
- P = Principal Loan Amount
- r = Monthly interest rate (Annual interest rate / 12 / 100)
- n = Loan tenure in months
Example Calculation
Let's say you take a loan of ₹10,00,000 (Principal Amount) at an annual
interest rate of 8.5% for a tenure of 10 years (120 months).
- Principal (P) = ₹10,00,000
- Annual Interest Rate = 8.5%
- Monthly Interest Rate (r) = 8.5 / 12 / 100 = 0.00708333
- Loan Tenure (n) = 10 years * 12 months/year = 120 months
Using the EMI formula, the EMI would be calculated as follows:
$E = 1000000 \times \frac{0.00708333 \times (1+0.00708333)^{120}}{(1+0.00708333)^{120} – 1}$
$E \approx 1000000 \times \frac{0.00708333 \times (2.34707)}{2.34707 – 1}$
$E \approx 1000000 \times \frac{0.0166346}{1.34707}$
$E \approx 1000000 \times 0.0123488$
$E \approx ₹12,349$
So, the EMI for this loan would be approximately ₹12,349.
function calculateEMI() {
var principal = document.getElementById("loanAmount").value;
var annualInterestRate = document.getElementById("annualInterestRate").value;
var tenureMonths = document.getElementById("loanTenureMonths").value;
var resultDiv = document.getElementById("result");
if (principal === "" || annualInterestRate === "" || tenureMonths === "") {
resultDiv.innerHTML = "Please fill in all the fields.";
return;
}
var p = parseFloat(principal);
var annualRate = parseFloat(annualInterestRate);
var n = parseFloat(tenureMonths);
if (isNaN(p) || isNaN(annualRate) || isNaN(n) || p <= 0 || annualRate < 0 || n <= 0) {
resultDiv.innerHTML = "Please enter valid positive numbers for all fields.";
return;
}
var r = (annualRate / 100) / 12; // Monthly interest rate
var emi = p * (r * Math.pow(1 + r, n)) / (Math.pow(1 + r, n) – 1);
// Handle cases where interest rate is 0
if (annualRate === 0) {
emi = p / n;
}
var totalPayment = emi * n;
var totalInterest = totalPayment – p;
resultDiv.innerHTML =
"
Your EMI: ₹" + emi.toFixed(2) + "" +
"
Total Interest Payable: ₹" + totalInterest.toFixed(2) + "" +
"
Total Payment (Principal + Interest): ₹" + totalPayment.toFixed(2) + "";
}
.calculator-container {
font-family: Arial, sans-serif;
max-width: 700px;
margin: 20px auto;
padding: 20px;
border: 1px solid #ddd;
border-radius: 8px;
box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}
.calculator-title {
text-align: center;
color: #333;
margin-bottom: 25px;
}
.calculator-inputs {
display: grid;
grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
gap: 15px;
margin-bottom: 20px;
}
.input-group {
display: flex;
flex-direction: column;
}
.input-group label {
margin-bottom: 5px;
font-weight: bold;
color: #555;
}
.input-group input[type="number"] {
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 1rem;
}
.calculator-inputs button {
grid-column: 1 / -1; /* Span across all columns */
padding: 12px 20px;
background-color: #007bff;
color: white;
border: none;
border-radius: 4px;
cursor: pointer;
font-size: 1.1rem;
transition: background-color 0.3s ease;
}
.calculator-inputs button:hover {
background-color: #0056b3;
}
.calculator-result {
margin-top: 20px;
padding: 15px;
background-color: #f8f9fa;
border: 1px solid #e0e0e0;
border-radius: 4px;
text-align: center;
font-size: 1.1rem;
color: #333;
}
.calculator-result p {
margin: 8px 0;
}
.calculator-explanation {
margin-top: 30px;
border-top: 1px solid #eee;
padding-top: 20px;
color: #444;
line-height: 1.6;
}
.explanation-title, .explanation-subtitle {
color: #333;
margin-bottom: 15px;
}
.explanation-subtitle {
margin-top: 20px;
}
.calculator-explanation ul {
margin-left: 20px;
padding-left: 0;
}
.calculator-explanation li {
margin-bottom: 8px;
}
.calculator-explanation p strong {
color: #555;
}