.mortgage-calc-wrapper {
max-width: 800px;
margin: 0 auto;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
color: #333;
line-height: 1.6;
}
.mc-calculator-box {
background: #f9f9f9;
border: 1px solid #e0e0e0;
border-radius: 8px;
padding: 30px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
margin-bottom: 40px;
}
.mc-title {
text-align: center;
color: #2c3e50;
margin-bottom: 25px;
font-size: 24px;
font-weight: 700;
}
.mc-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
@media (max-width: 600px) {
.mc-grid {
grid-template-columns: 1fr;
}
}
.mc-input-group {
margin-bottom: 15px;
}
.mc-label {
display: block;
margin-bottom: 8px;
font-weight: 600;
font-size: 14px;
color: #555;
}
.mc-input {
width: 100%;
padding: 12px;
border: 1px solid #ddd;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
transition: border-color 0.3s;
}
.mc-input:focus {
border-color: #3498db;
outline: none;
}
.mc-btn {
width: 100%;
background-color: #2980b9;
color: white;
border: none;
padding: 15px;
font-size: 18px;
font-weight: bold;
border-radius: 4px;
cursor: pointer;
margin-top: 20px;
transition: background-color 0.3s;
}
.mc-btn:hover {
background-color: #1c6ea4;
}
.mc-results {
margin-top: 30px;
background: #fff;
border: 1px solid #eee;
border-radius: 6px;
padding: 20px;
display: none;
}
.mc-result-row {
display: flex;
justify-content: space-between;
padding: 10px 0;
border-bottom: 1px solid #f0f0f0;
}
.mc-result-row:last-child {
border-bottom: none;
}
.mc-result-label {
color: #666;
}
.mc-result-value {
font-weight: bold;
color: #2c3e50;
}
.mc-big-result {
text-align: center;
padding: 20px 0;
background-color: #e8f6fd;
border-radius: 6px;
margin-bottom: 20px;
}
.mc-big-label {
display: block;
font-size: 14px;
text-transform: uppercase;
letter-spacing: 1px;
color: #555;
margin-bottom: 5px;
}
.mc-big-value {
font-size: 36px;
font-weight: 800;
color: #2980b9;
}
.mc-article h2 {
color: #2c3e50;
border-bottom: 2px solid #eee;
padding-bottom: 10px;
margin-top: 40px;
}
.mc-article h3 {
color: #34495e;
margin-top: 25px;
}
.mc-article p, .mc-article li {
font-size: 16px;
color: #444;
margin-bottom: 15px;
}
.mc-article ul {
padding-left: 20px;
}
.error-msg {
color: #e74c3c;
text-align: center;
margin-top: 10px;
font-weight: bold;
display: none;
}
function calculateMortgage() {
// Get inputs
var homePrice = document.getElementById('homePrice').value;
var downPayment = document.getElementById('downPayment').value;
var interestRate = document.getElementById('interestRate').value;
var loanTerm = document.getElementById('loanTerm').value;
var propertyTaxYearly = document.getElementById('propertyTax').value;
var homeInsuranceYearly = document.getElementById('homeInsurance').value;
var errorMsg = document.getElementById('errorMsg');
var resultBox = document.getElementById('mortgageResult');
// Reset error
errorMsg.style.display = 'none';
resultBox.style.display = 'none';
// Validate inputs
if (homePrice === "" || downPayment === "" || interestRate === "" || loanTerm === "") {
errorMsg.innerText = "Please fill in all required fields.";
errorMsg.style.display = 'block';
return;
}
var price = parseFloat(homePrice);
var down = parseFloat(downPayment);
var rate = parseFloat(interestRate);
var years = parseFloat(loanTerm);
var taxYearly = parseFloat(propertyTaxYearly) || 0;
var insYearly = parseFloat(homeInsuranceYearly) || 0;
if (price < 0 || down < 0 || rate < 0 || years = price
if (principal <= 0) {
errorMsg.innerText = "Down payment cannot be greater than or equal to Home Price.";
errorMsg.style.display = 'block';
return;
}
var monthlyRate = rate / 100 / 12;
var numberOfPayments = years * 12;
// Monthly P&I Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1]
var monthlyPI = 0;
if (rate === 0) {
monthlyPI = principal / numberOfPayments;
} else {
monthlyPI = principal * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
}
var monthlyTax = taxYearly / 12;
var monthlyIns = insYearly / 12;
var totalMonthly = monthlyPI + monthlyTax + monthlyIns;
var totalCost = (monthlyPI * numberOfPayments) + (monthlyTax * numberOfPayments) + (monthlyIns * numberOfPayments); // This is total payments including tax/ins
// Usually total cost of loan refers to Principal + Interest
var totalPrincipalInterest = monthlyPI * numberOfPayments;
var totalInterest = totalPrincipalInterest – principal;
// Formatting currency
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
});
// Display Results
document.getElementById('totalMonthlyPayment').innerHTML = formatter.format(totalMonthly);
document.getElementById('piPayment').innerHTML = formatter.format(monthlyPI);
document.getElementById('taxPayment').innerHTML = formatter.format(monthlyTax);
document.getElementById('insPayment').innerHTML = formatter.format(monthlyIns);
document.getElementById('loanAmountResult').innerHTML = formatter.format(principal);
document.getElementById('totalInterestResult').innerHTML = formatter.format(totalInterest);
document.getElementById('totalCostResult').innerHTML = formatter.format(totalPrincipalInterest);
resultBox.style.display = 'block';
}
Mortgage Payment Calculator
30 Years
20 Years
15 Years
10 Years
Please enter valid positive numbers.
Estimated Monthly Payment
$0.00
Principal & Interest:
$0.00
Property Tax (Monthly):
$0.00
Home Insurance (Monthly):
$0.00
Loan Amount:
$0.00
Total Interest Paid over Life of Loan:
$0.00
Total Cost of Loan:
$0.00
Understanding Your Mortgage Calculation
Before committing to a home loan, it is crucial to understand exactly where your money goes each month. Our Mortgage Payment Calculator breaks down the PITI (Principal, Interest, Taxes, and Insurance) to give you a realistic view of your housing costs.
The Components of Your Monthly Payment
Most borrowers focus solely on the interest rate, but your monthly check covers several buckets:
- Principal: This portion goes directly toward paying off the loan balance. In the early years of a mortgage, this amount is small, but it grows over time.
- Interest: The fee paid to the lender for borrowing the money. With a standard amortization schedule, you pay significantly more interest in the first half of the loan term.
- Property Taxes: Calculated by your local government based on the assessed value of your home. We estimate this annually and divide by 12.
- Homeowners Insurance: Protects your property against damage. Lenders require this to protect their investment.
How Interest Rates Impact Affordability
Even a small difference in interest rates can have a massive impact on your total loan cost. For example, on a $300,000 loan, a 1% increase in interest rate can add hundreds of dollars to your monthly payment and tens of thousands of dollars to the total interest paid over 30 years.
30-Year vs. 15-Year Mortgages
Choosing the right loan term is a balancing act between monthly affordability and long-term savings:
- 30-Year Fixed: Offers lower monthly payments, making it easier to qualify for a more expensive home, but you will pay significantly more interest over the life of the loan.
- 15-Year Fixed: Comes with higher monthly payments, but usually has a lower interest rate and builds equity much faster.
Frequently Asked Questions
What is PMI?
Private Mortgage Insurance (PMI) is usually required if your down payment is less than 20% of the home price. This calculator focuses on PITI; ask your lender for specific PMI quotes.
Do property taxes change?
Yes. Local governments reassess property values periodically. If your home value increases, your property taxes—and your monthly mortgage payment—will likely increase as well.