:root {
–primary-color: #2c3e50;
–accent-color: #27ae60;
–bg-color: #f8f9fa;
–text-color: #333;
–border-radius: 8px;
}
body {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: var(–text-color);
max-width: 1200px;
margin: 0 auto;
padding: 20px;
}
.calculator-wrapper {
background: #fff;
padding: 30px;
border-radius: var(–border-radius);
box-shadow: 0 4px 6px rgba(0,0,0,0.1);
margin-bottom: 40px;
border: 1px solid #e1e4e8;
}
.calc-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 40px;
}
@media (max-width: 768px) {
.calc-grid {
grid-template-columns: 1fr;
}
}
.input-section h3, .result-section h3 {
margin-top: 0;
color: var(–primary-color);
border-bottom: 2px solid var(–accent-color);
padding-bottom: 10px;
margin-bottom: 20px;
}
.form-group {
margin-bottom: 15px;
}
.form-group label {
display: block;
margin-bottom: 5px;
font-weight: 600;
font-size: 0.9rem;
}
.input-wrapper {
position: relative;
}
.input-symbol {
position: absolute;
left: 10px;
top: 50%;
transform: translateY(-50%);
color: #777;
}
.input-symbol-right {
position: absolute;
right: 10px;
top: 50%;
transform: translateY(-50%);
color: #777;
}
.form-control {
width: 100%;
padding: 10px 10px 10px 25px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 1rem;
box-sizing: border-box;
}
.form-control.pr-25 {
padding-right: 25px;
}
.btn-calculate {
background-color: var(–accent-color);
color: white;
border: none;
padding: 12px 24px;
font-size: 1rem;
border-radius: 4px;
cursor: pointer;
width: 100%;
font-weight: bold;
margin-top: 10px;
transition: background-color 0.2s;
}
.btn-calculate:hover {
background-color: #219150;
}
.result-box {
background-color: #f1f8e9;
padding: 20px;
border-radius: var(–border-radius);
text-align: center;
margin-bottom: 20px;
border: 1px solid #c8e6c9;
}
.result-value {
font-size: 2.5rem;
font-weight: bold;
color: var(–accent-color);
margin: 10px 0;
}
.result-label {
font-size: 0.9rem;
text-transform: uppercase;
letter-spacing: 1px;
color: #555;
}
.breakdown-table {
width: 100%;
border-collapse: collapse;
font-size: 0.9rem;
}
.breakdown-table td {
padding: 8px 0;
border-bottom: 1px solid #eee;
}
.breakdown-table tr:last-child td {
border-bottom: none;
font-weight: bold;
padding-top: 15px;
}
.breakdown-label {
color: #666;
}
.breakdown-value {
text-align: right;
color: #333;
}
.article-content {
background: #fff;
padding: 30px;
border-radius: var(–border-radius);
box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}
.article-content h2 {
color: var(–primary-color);
margin-top: 30px;
}
.article-content p {
margin-bottom: 15px;
}
.article-content ul {
margin-bottom: 15px;
padding-left: 20px;
}
.article-content li {
margin-bottom: 8px;
}
Comprehensive Mortgage Payment Calculator
Understanding the true cost of homeownership goes beyond just the listing price. This Mortgage Payment Calculator with Taxes and Insurance is designed to give you a complete picture of your monthly financial commitment. By factoring in principal, interest, taxes, insurance, and HOA fees (PITI), you can make smarter decisions when financing your new home.
How the Mortgage Calculator Works
To get the most accurate result, it's essential to understand the different inputs required for the calculation:
- Home Price: The purchase price of the property.
- Down Payment: The upfront cash you pay towards the home. A higher down payment reduces your loan amount and monthly principal/interest payments.
- Interest Rate: The annual cost of borrowing money from your lender, expressed as a percentage. Even a small difference (e.g., 0.5%) can save or cost you thousands over the life of the loan.
- Loan Term: The duration of the mortgage, typically 15 or 30 years. Shorter terms have higher monthly payments but lower total interest costs.
Understanding Your Monthly Payment Breakdown (PITI)
Most first-time homebuyers focus solely on the mortgage loan itself, but your monthly bill usually includes four key components, often referred to as PITI:
1. Principal
This is the portion of your payment that goes directly toward paying down the outstanding balance of your loan. In the early years of a typical amortization schedule, the principal portion is small, but it grows over time.
2. Interest
This is the fee the lender charges for lending you the money. In the beginning of a 30-year mortgage, interest makes up the majority of your monthly payment.
3. Taxes
Property taxes are assessed by your local government to fund public services like schools and roads. These are usually calculated annually but are often divided by 12 and collected monthly by your lender into an escrow account.
4. Insurance
Homeowners insurance protects your property against damage from fire, theft, and liabilities. Like taxes, the annual premium is typically broken down into monthly installments.
Example Calculation
Let's look at a realistic scenario. If you purchase a home for $350,000 and put $70,000 (20%) down, your loan amount is $280,000.
Assuming a 30-year fixed rate of 6.5%:
- Your monthly Principal & Interest payment would be approximately $1,770.
- If annual taxes are $4,500, that adds $375/month.
- If insurance is $1,200/year, that adds $100/month.
- Total Estimated Payment: $2,245/month.
Why Use a Mortgage Calculator?
Using a calculator helps you determine "how much house" you can afford. Lenders typically look at your Debt-to-Income (DTI) ratio. A general rule of thumb is that your total housing costs should not exceed 28% of your gross monthly income. By adjusting the down payment and interest rate fields above, you can see how different scenarios impact your budget.
function calculateMortgage() {
// 1. Get Input Values
var homePrice = parseFloat(document.getElementById("homePrice").value);
var downPayment = parseFloat(document.getElementById("downPayment").value);
var interestRate = parseFloat(document.getElementById("interestRate").value);
var loanTerm = parseFloat(document.getElementById("loanTerm").value);
var propertyTaxYearly = parseFloat(document.getElementById("propertyTax").value);
var homeInsuranceYearly = parseFloat(document.getElementById("homeInsurance").value);
var hoaFeesMonthly = parseFloat(document.getElementById("hoaFees").value);
// Validation to prevent NaN
if (isNaN(homePrice)) homePrice = 0;
if (isNaN(downPayment)) downPayment = 0;
if (isNaN(interestRate)) interestRate = 0;
if (isNaN(loanTerm)) loanTerm = 0;
if (isNaN(propertyTaxYearly)) propertyTaxYearly = 0;
if (isNaN(homeInsuranceYearly)) homeInsuranceYearly = 0;
if (isNaN(hoaFeesMonthly)) hoaFeesMonthly = 0;
// 2. Perform Calculations
var loanAmount = homePrice – downPayment;
// Prevent negative loan amounts
if (loanAmount 0) {
monthlyPrincipalInterest = loanAmount / numberOfPayments;
} else {
monthlyPrincipalInterest = 0;
}
} else {
// Standard Mortgage Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var mathPower = Math.pow(1 + monthlyInterestRate, numberOfPayments);
if (mathPower === 1) { // Prevent division by zero if logic fails somehow
monthlyPrincipalInterest = loanAmount / numberOfPayments;
} else {
monthlyPrincipalInterest = loanAmount * ( (monthlyInterestRate * mathPower) / (mathPower – 1) );
}
}
var monthlyTax = propertyTaxYearly / 12;
var monthlyInsurance = homeInsuranceYearly / 12;
var totalMonthlyPayment = monthlyPrincipalInterest + monthlyTax + monthlyInsurance + hoaFeesMonthly;
var totalInterestPaid = (monthlyPrincipalInterest * numberOfPayments) – loanAmount;
if (totalInterestPaid < 0) totalInterestPaid = 0;
// Calculate Payoff Date
var today = new Date();
var payoffDate = new Date(today.setMonth(today.getMonth() + numberOfPayments));
var payoffMonthYear = payoffDate.toLocaleString('default', { month: 'short', year: 'numeric' });
// 3. Format Currency Function
function formatMoney(amount) {
return "$" + amount.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
}
// 4. Update DOM Elements
document.getElementById("totalMonthlyPayment").innerHTML = formatMoney(totalMonthlyPayment);
document.getElementById("piResult").innerHTML = formatMoney(monthlyPrincipalInterest);
document.getElementById("taxResult").innerHTML = formatMoney(monthlyTax);
document.getElementById("insuranceResult").innerHTML = formatMoney(monthlyInsurance);
document.getElementById("hoaResult").innerHTML = formatMoney(hoaFeesMonthly);
document.getElementById("loanAmountResult").innerHTML = formatMoney(loanAmount);
document.getElementById("totalInterestResult").innerHTML = formatMoney(totalInterestPaid);
document.getElementById("payoffDateResult").innerHTML = payoffMonthYear;
}
// Run calculation on load so the calculator isn't empty
window.onload = function() {
calculateMortgage();
};