30 Years Fixed
20 Years Fixed
15 Years Fixed
10 Years Fixed
Your Refinance Summary
New Monthly Payment:
Monthly Savings:
Break-Even Period:
Total Savings (over 5 years):
function calculateRefinance() {
var loanBalance = parseFloat(document.getElementById('loanBalance').value);
var currentPayment = parseFloat(document.getElementById('currentPayment').value);
var newRate = parseFloat(document.getElementById('newRate').value);
var newTerm = parseInt(document.getElementById('newTerm').value);
var closingCosts = parseFloat(document.getElementById('closingCosts').value);
if (isNaN(loanBalance) || isNaN(currentPayment) || isNaN(newRate) || isNaN(closingCosts)) {
alert("Please fill in all fields with valid numbers.");
return;
}
var monthlyRate = (newRate / 100) / 12;
var numberOfPayments = newTerm * 12;
// Mortgage Formula: P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var x = Math.pow(1 + monthlyRate, numberOfPayments);
var newMonthlyPayment = (loanBalance * x * monthlyRate) / (x – 1);
var monthlySavings = currentPayment – newMonthlyPayment;
var breakEvenMonths = closingCosts / monthlySavings;
var fiveYearSavings = (monthlySavings * 60) – closingCosts;
document.getElementById('resNewPayment').innerText = '$' + newMonthlyPayment.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resMonthlySavings').innerText = '$' + monthlySavings.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
if (monthlySavings <= 0) {
document.getElementById('resBreakEven').innerText = "Never (Payment increases)";
document.getElementById('resFiveYearSavings').innerText = "N/A";
} else {
document.getElementById('resBreakEven').innerText = Math.ceil(breakEvenMonths) + " Months";
document.getElementById('resFiveYearSavings').innerText = '$' + fiveYearSavings.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
}
document.getElementById('refiResults').style.display = 'block';
}
How to Use the Mortgage Refinance Savings Calculator
Deciding whether to refinance your home is a major financial move. Our mortgage refinance calculator helps you determine if the monthly savings outweigh the upfront costs of a new loan. By inputting your current loan details and comparing them with new market rates, you can visualize your "break-even" point—the exact moment your savings pay for the refinance fees.
Key Metrics Explained
Remaining Loan Balance: The total amount you still owe on your current mortgage.
Monthly Savings: The difference between your current principal and interest payment and your projected new payment.
Closing Costs: These typically include appraisal fees, title insurance, and lender fees, usually totaling 2% to 5% of the loan amount.
Break-Even Period: How many months you need to stay in the home to recover the closing costs. If you plan to move before this date, refinancing might not be profitable.
Example Calculation
Imagine you have a $300,000 balance at a 7% interest rate with a monthly payment of $1,995. If you refinance into a new 30-year loan at 5.5% with $6,000 in closing costs:
Your new payment drops to approximately $1,703.
Your monthly savings would be $292.
Your break-even point would be 21 months ($6,000 / $292).
When Should You Refinance?
A common rule of thumb is to refinance if you can lower your interest rate by at least 0.75% to 1%. However, with today's high closing costs, it is more important to look at the time horizon. If you intend to live in your home for at least 5 to 10 years, even a smaller rate reduction can result in tens of thousands of dollars in interest savings over the life of the loan.
Pro Tip: Don't forget that refinancing restarts your loan clock. If you are 10 years into a 30-year mortgage and refinance into a new 30-year term, you may pay more in total interest over time even if your monthly payment is lower. Consider a 15-year or 20-year term to build equity faster.