Determine your potential savings and break-even point for a mortgage refinance.
New Monthly Payment:
Monthly Savings:
Time to Break Even:
Total Savings Over New Term:
How the Refinancing Rate Comparison Works
A house refinancing rate calculator evaluates whether moving from your existing mortgage to a new one makes financial sense. The core logic hinges on the Break-Even Point. This is the amount of time it takes for your monthly savings to cover the upfront costs (closing fees) of the new loan.
Key Metrics for Refinancing
Remaining Principal: This is the actual amount you owe today, not your original loan amount. Your new rate will be applied to this figure.
Proposed Rate: The interest percentage offered by the lender. Even a 0.5% difference can result in significant long-term savings.
Closing Costs: These typically range from 2% to 5% of the loan amount. They include appraisal fees, title insurance, and origination charges.
Example Calculation
Imagine you have a remaining balance of $300,000. Your current payment is $2,200. You find a new rate of 6.0% for a 30-year term with closing costs of $4,500.
New Monthly Payment: $1,798.65
Monthly Savings: $401.35
Break-Even Point: $4,500 / $401.35 = 11.2 months
In this scenario, if you plan to stay in the home for more than a year, refinancing is a highly beneficial financial move.
When Should You Refinance?
Most experts suggest that refinancing is worth considering if you can lower your interest rate by at least 0.75% to 1%. However, if your closing costs are low, even a smaller reduction can be profitable. Always consider how long you intend to keep the property before committing to the fees associated with a new loan rate.
function calculateRefinance() {
var currentPayment = parseFloat(document.getElementById('currentPayment').value);
var balance = parseFloat(document.getElementById('remainingBalance').value);
var annualRate = parseFloat(document.getElementById('newRate').value);
var years = parseFloat(document.getElementById('newTerm').value);
var costs = parseFloat(document.getElementById('refiCosts').value);
if (isNaN(currentPayment) || isNaN(balance) || isNaN(annualRate) || isNaN(years) || isNaN(costs)) {
alert("Please enter valid numerical values for all fields.");
return;
}
var monthlyRate = (annualRate / 100) / 12;
var totalMonths = years * 12;
// PMT Formula: P * [r(1+r)^n] / [(1+r)^n – 1]
var newPayment = balance * (monthlyRate * Math.pow(1 + monthlyRate, totalMonths)) / (Math.pow(1 + monthlyRate, totalMonths) – 1);
var monthlySavings = currentPayment – newPayment;
var breakEvenMonths = costs / monthlySavings;
var totalSavings = (monthlySavings * totalMonths) – costs;
document.getElementById('newMonthlyVal').innerText = "$" + newPayment.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
if (monthlySavings > 0) {
document.getElementById('monthlySavingsVal').innerText = "$" + monthlySavings.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('breakEvenVal').innerText = Math.ceil(breakEvenMonths) + " Months";
document.getElementById('totalSavingsVal').innerText = "$" + totalSavings.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
} else {
document.getElementById('monthlySavingsVal').innerText = "$0.00 (No Savings)";
document.getElementById('breakEvenVal').innerText = "Never";
document.getElementById('totalSavingsVal').innerText = "$0.00";
}
document.getElementById('refiResults').style.display = 'block';
}