See how much time and interest you can save by making additional principal payments.
Your Potential Savings
Total Interest Saved$0.00
Time Saved0 Years
New Payoff Date—
Original Interest Cost: $0.00
New Interest Cost: $0.00
Why Make Extra Mortgage Payments?
Paying off your mortgage early is one of the most effective strategies for building long-term wealth. By applying extra payments directly to your loan principal, you reduce the balance on which interest is calculated. This creates a compounding effect that can shave years off your loan term and save you tens of thousands of dollars.
Understanding Amortization
Mortgages are amortized loans, meaning the early payments consist mostly of interest. As the principal balance decreases, the interest portion of your payment drops, and more goes toward equity. When you make an extra payment:
You reduce the principal immediately.
Future interest charges are calculated on a smaller balance.
The ratio of principal-to-interest in future standard payments shifts in your favor faster.
How to Use This Calculator
Current Loan Balance: Enter the amount currently remaining on your mortgage, not the original loan amount.
Annual Interest Rate: Input your current mortgage interest rate.
Remaining Term: Enter how many years are left on your loan.
Extra Monthly Payment: Enter the amount you plan to pay above your required monthly installment.
Strategies for Paying Down Your Mortgage
If a large monthly extra payment isn't feasible, consider these alternatives:
Bi-weekly Payments: Paying half your monthly mortgage every two weeks results in 26 half-payments per year, effectively making one full extra payment annually.
Round Up: Round up your payment to the nearest hundred. If your payment is $1,240, pay $1,300. The $60 difference adds up over time.
Windfalls: Apply tax refunds, work bonuses, or cash gifts directly to your principal balance.
Is Paying Off Your Mortgage Early Right for You?
While saving interest is attractive, consider your total financial picture. Before aggressively paying down a mortgage with a low interest rate (e.g., 3-4%), ensure you have:
An established emergency fund (3-6 months of expenses).
Paid off high-interest debt (credit cards, personal loans).
If your mortgage rate is lower than the expected return on investments, investing that extra money might yield a higher net worth in the long run. However, the "guaranteed return" of saving mortgage interest provides peace of mind that carries its own value.
function calculateMortgageSavings() {
// 1. Get Input Values
var balance = parseFloat(document.getElementById('loanBalance').value);
var rate = parseFloat(document.getElementById('interestRate').value);
var years = parseFloat(document.getElementById('remainingTerm').value);
var extraPayment = parseFloat(document.getElementById('extraPayment').value);
// 2. Validate Inputs
if (isNaN(balance) || balance <= 0 || isNaN(rate) || rate < 0 || isNaN(years) || years <= 0) {
alert("Please enter valid positive numbers for Balance, Rate, and Term.");
return;
}
if (isNaN(extraPayment) || extraPayment 0 && monthsPassed < 1200) { // Safety break at 100 years
// Calculate interest for this month
var interestForMonth = remainingBalance * monthlyRate;
// Add to total interest
totalInterestWithExtra += interestForMonth;
// Calculate principal portion
var principalForMonth = actualPayment – interestForMonth;
// If the remaining balance is less than the principal payment, pay it off
if (remainingBalance 0) timeSavedText += yearsSaved + " yr ";
if (remainingMonthsSaved > 0) timeSavedText += remainingMonthsSaved + " mo";
if (yearsSaved === 0 && remainingMonthsSaved === 0) timeSavedText = "0 mo";
document.getElementById('timeSaved').innerText = timeSavedText;
document.getElementById('newPayoffDate').innerText = payoffMonth + " " + payoffYear;
document.getElementById('originalInterest').innerText = "$" + formatMoney(totalInterestBaseline);
document.getElementById('newInterest').innerText = "$" + formatMoney(totalInterestWithExtra);
// Show results section
document.getElementById('resultsSection').style.display = 'block';
}
function formatMoney(number) {
return number.toLocaleString('en-US', { minimumFractionDigits: 2, maximumFractionDigits: 2 });
}