.calculator-wrapper {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
color: #333;
line-height: 1.6;
}
.calc-container {
background: #f8f9fa;
padding: 30px;
border-radius: 8px;
box-shadow: 0 4px 15px rgba(0,0,0,0.05);
margin-bottom: 40px;
border: 1px solid #e9ecef;
}
.calc-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
margin-bottom: 25px;
}
@media (max-width: 600px) {
.calc-grid {
grid-template-columns: 1fr;
}
}
.input-group {
display: flex;
flex-direction: column;
}
.input-group label {
font-weight: 600;
margin-bottom: 8px;
font-size: 0.95rem;
color: #495057;
}
.input-group input {
padding: 12px;
border: 1px solid #ced4da;
border-radius: 4px;
font-size: 1rem;
transition: border-color 0.2s;
}
.input-group input:focus {
border-color: #007bff;
outline: none;
}
.calc-btn {
background-color: #0056b3;
color: white;
border: none;
padding: 15px 30px;
font-size: 1.1rem;
font-weight: bold;
border-radius: 4px;
cursor: pointer;
width: 100%;
transition: background-color 0.2s;
}
.calc-btn:hover {
background-color: #004494;
}
.results-box {
margin-top: 30px;
background: white;
border-radius: 6px;
padding: 20px;
border-left: 5px solid #28a745;
display: none;
}
.results-header {
font-size: 1.25rem;
font-weight: 700;
color: #28a745;
margin-bottom: 15px;
border-bottom: 1px solid #eee;
padding-bottom: 10px;
}
.result-row {
display: flex;
justify-content: space-between;
margin-bottom: 12px;
padding-bottom: 12px;
border-bottom: 1px dashed #eee;
}
.result-row:last-child {
border-bottom: none;
}
.result-label {
color: #6c757d;
}
.result-value {
font-weight: 700;
font-size: 1.1rem;
}
.highlight {
color: #28a745;
}
.content-section h2 {
margin-top: 40px;
color: #2c3e50;
}
.content-section p {
margin-bottom: 15px;
color: #555;
}
.content-section ul {
margin-bottom: 20px;
padding-left: 20px;
}
.content-section li {
margin-bottom: 8px;
}
.error-msg {
color: #dc3545;
font-weight: 600;
margin-top: 10px;
display: none;
}
function calculateMortgageSavings() {
// Get inputs
var balanceInput = document.getElementById('mep_balance').value;
var rateInput = document.getElementById('mep_rate').value;
var yearsInput = document.getElementById('mep_years').value;
var extraInput = document.getElementById('mep_extra').value;
var errorDiv = document.getElementById('mep_error');
var resultDiv = document.getElementById('mep_results');
// Reset UI
errorDiv.style.display = 'none';
resultDiv.style.display = 'none';
errorDiv.innerHTML = ";
// Validate
if (!balanceInput || !rateInput || !yearsInput) {
errorDiv.innerHTML = 'Please fill in current balance, rate, and remaining years.';
errorDiv.style.display = 'block';
return;
}
var balance = parseFloat(balanceInput);
var annualRate = parseFloat(rateInput);
var years = parseFloat(yearsInput);
var extraPayment = extraInput ? parseFloat(extraInput) : 0;
if (balance <= 0 || annualRate < 0 || years <= 0 || extraPayment 0) {
monthsElapsed++;
var interestForMonth = currentBalance * monthlyRate;
var principalForMonth = actualMonthlyPayment – interestForMonth;
// Handle last month
if (currentBalance 1000) break;
}
// Results Processing
var monthsSaved = totalMonthsOriginal – monthsElapsed;
var interestSaved = originalTotalInterest – totalInterestNew;
// Formatting Time
var yearsNew = Math.floor(monthsElapsed / 12);
var monthsNewRem = monthsElapsed % 12;
var newTimeText = yearsNew + " years, " + monthsNewRem + " months";
var yearsSaved = Math.floor(monthsSaved / 12);
var monthsSavedRem = Math.floor(monthsSaved % 12); // Use floor to avoid decimals
var savedTimeText = yearsSaved + " years, " + monthsSavedRem + " months";
// Formatting Currency
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 0,
maximumFractionDigits: 0,
});
// Display
document.getElementById('res_new_time').innerHTML = newTimeText;
document.getElementById('res_time_saved').innerHTML = savedTimeText;
document.getElementById('res_interest_saved').innerHTML = formatter.format(interestSaved);
document.getElementById('res_total_interest').innerHTML = formatter.format(totalInterestNew);
resultDiv.style.display = 'block';
}
How Extra Payments Accelerate Mortgage Freedom
Paying off a mortgage early is a financial goal for many homeowners. By applying extra money directly to the principal balance of your loan, you drastically reduce the amount of interest charged over the life of the loan. This calculator demonstrates the "snowball effect" of extra payments: as your principal decreases faster, the interest calculated on that principal drops, allowing even more of your monthly payment to go toward equity.
Understanding the Math
Mortgages are typically amortized, meaning the early payments consist mostly of interest. When you make an additional payment specifically towards the principal, you skip ahead in the amortization schedule. For example, a single extra payment of $500 today might save you over $1,000 in future interest costs depending on your rate and remaining term.
Example Scenario
Consider a homeowner with the following mortgage details:
- Current Balance: $200,000
- Interest Rate: 6.0%
- Remaining Term: 25 Years
If they continue making only the standard payments, they will pay approximately $186,500 in interest alone over the next 25 years. However, by adding just $200 per month to their payment:
- The loan is paid off in roughly 18 years instead of 25.
- They save approximately $58,000 in interest payments.
- They become debt-free 7 years earlier.
Frequently Asked Questions
Does the extra payment go to principal or interest?
To maximize savings, you must ensure your lender applies the extra payment to the principal balance, not towards future monthly payments (pre-payment). Most lenders offer an option on their online portal or payment slip to specify "Principal Only."
Is there a penalty for paying off my mortgage early?
While rare in modern conforming loans, some mortgages do have "prepayment penalties." It is crucial to check your loan documents or call your servicer to confirm that you can make extra principal payments without incurring a fee.
Should I invest or pay off the mortgage?
This depends on your interest rate versus expected investment returns. If your mortgage rate is high (e.g., above 6%), the guaranteed "return" of saving that interest is often comparable to or better than stock market returns, with zero risk. If your rate is very low (e.g., 3%), you might earn more by investing the extra money instead.