This calculator helps you estimate how much you can afford to borrow based on your income, monthly debts, and desired loan term. Understanding your loan affordability is a crucial step before applying for any type of loan, whether it's a mortgage, personal loan, or car loan. It ensures that the monthly payments fit comfortably within your budget, preventing financial strain.
.calculator-container {
font-family: Arial, sans-serif;
max-width: 600px;
margin: 20px auto;
padding: 20px;
border: 1px solid #ddd;
border-radius: 8px;
background-color: #f9f9f9;
}
.calculator-title {
text-align: center;
color: #333;
margin-bottom: 15px;
}
.calculator-description {
color: #555;
line-height: 1.6;
margin-bottom: 25px;
text-align: justify;
}
.calculator-inputs {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 15px;
margin-bottom: 20px;
}
.input-group {
display: flex;
flex-direction: column;
}
.input-group label {
margin-bottom: 5px;
font-weight: bold;
color: #444;
}
.input-group input {
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
}
button {
display: block;
width: 100%;
padding: 12px 20px;
background-color: #4CAF50;
color: white;
border: none;
border-radius: 4px;
cursor: pointer;
font-size: 18px;
transition: background-color 0.3s ease;
}
button:hover {
background-color: #45a049;
}
.calculator-result {
margin-top: 25px;
padding: 15px;
border: 1px solid #eee;
border-radius: 4px;
background-color: #fff;
font-size: 18px;
text-align: center;
color: #333;
min-height: 50px; /* To ensure it doesn't collapse when empty */
display: flex;
align-items: center;
justify-content: center;
}
.calculator-result strong {
color: #4CAF50;
}
function calculateAffordability() {
var monthlyIncome = parseFloat(document.getElementById("monthlyIncome").value);
var existingDebts = parseFloat(document.getElementById("existingDebts").value);
var interestRate = parseFloat(document.getElementById("interestRate").value);
var loanTermYears = parseFloat(document.getElementById("loanTermYears").value);
var desiredMonthlyPayment = parseFloat(document.getElementById("desiredMonthlyPayment").value);
var resultDiv = document.getElementById("result");
if (isNaN(monthlyIncome) || isNaN(existingDebts) || isNaN(interestRate) || isNaN(loanTermYears) || isNaN(desiredMonthlyPayment)) {
resultDiv.innerHTML = "Please enter valid numbers for all fields.";
return;
}
if (interestRate < 0 || loanTermYears <= 0 || desiredMonthlyPayment <= 0 || monthlyIncome < 0 || existingDebts availableForLoan) {
resultDiv.innerHTML = "Your desired monthly payment ($" + desiredMonthlyPayment.toFixed(2) + ") exceeds your available income for loan payments ($" + availableForLoan.toFixed(2) + ").";
return;
}
// Calculate maximum affordable loan amount based on desired monthly payment
// Formula for loan payment: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1]
// Where:
// M = Monthly Payment (desiredMonthlyPayment)
// P = Principal Loan Amount (what we want to find)
// i = Monthly Interest Rate (annualInterestRate / 12 / 100)
// n = Total Number of Payments (loanTermYears * 12)
var monthlyInterestRate = interestRate / 12 / 100;
var numberOfPayments = loanTermYears * 12;
var principalLoanAmount = 0;
// Handle case where interest rate is 0
if (monthlyInterestRate === 0) {
principalLoanAmount = desiredMonthlyPayment * numberOfPayments;
} else {
var numerator = monthlyInterestRate * Math.pow(1 + monthlyInterestRate, numberOfPayments);
var denominator = Math.pow(1 + monthlyInterestRate, numberOfPayments) – 1;
var factor = numerator / denominator;
principalLoanAmount = desiredMonthlyPayment / factor;
}
// Ensure calculated loan amount doesn't exceed what's affordable based on available income
var maxAffordableLoanByIncome = 0;
if (monthlyInterestRate === 0) {
maxAffordableLoanByIncome = availableForLoan * numberOfPayments;
} else {
var numerator = monthlyInterestRate * Math.pow(1 + monthlyInterestRate, numberOfPayments);
var denominator = Math.pow(1 + monthlyInterestRate, numberOfPayments) – 1;
var factor = numerator / denominator;
maxAffordableLoanByIncome = availableForLoan / factor;
}
var affordableLoanAmount = Math.min(principalLoanAmount, maxAffordableLoanByIncome);
resultDiv.innerHTML = "Based on your inputs, you can afford to borrow approximately $" + affordableLoanAmount.toFixed(2) + ".";
}