Breakdown:
Current Card Total Interest: $0.00
New Card Total Interest: $0.00
Balance Transfer Fee Cost: $0.00
function calculateCCComparison() {
// 1. Get Inputs
var debt = parseFloat(document.getElementById('totalDebt').value);
var payment = parseFloat(document.getElementById('monthlyPayment').value);
var currentAPR = parseFloat(document.getElementById('currentAPR').value);
var currentAnnualFee = parseFloat(document.getElementById('currentAnnualFee').value) || 0;
var newIntroAPR = parseFloat(document.getElementById('newIntroAPR').value);
var introMonths = parseFloat(document.getElementById('introDuration').value);
var btFeePercent = parseFloat(document.getElementById('btFeePercent').value);
var newRegularAPR = parseFloat(document.getElementById('newRegularAPR').value);
var newAnnualFee = parseFloat(document.getElementById('newAnnualFee').value) || 0;
var errorBox = document.getElementById('errorMsg');
var resultsArea = document.getElementById('resultsArea');
// 2. Validation
if (isNaN(debt) || isNaN(payment) || isNaN(currentAPR) || isNaN(newIntroAPR) || isNaN(introMonths) || isNaN(btFeePercent) || isNaN(newRegularAPR)) {
errorBox.style.display = 'block';
errorBox.innerHTML = "Please fill in all required fields with valid numbers.";
resultsArea.style.display = 'none';
return;
}
// Check if payment covers interest
var minInterestCurrent = debt * (currentAPR / 100 / 12);
if (payment 0 && monthsCurrent < 600) {
var interest = balCurrent * (currentAPR / 100 / 12);
var principal = payment – interest;
if (balCurrent 0
if (monthsCurrent % 12 !== 0) {
totalFeeCurrent += (currentAnnualFee / 12) * (monthsCurrent % 12);
}
var totalCostCurrent = debt + totalInterestCurrent + totalFeeCurrent;
// 4. Calculation – New Card
var btFeeCost = debt * (btFeePercent / 100);
var balNew = debt + btFeeCost; // Balance starts higher due to fee
var totalInterestNew = 0;
var monthsNew = 0;
var totalFeeNew = 0;
while (balNew > 0 && monthsNew < 600) {
// Determine applicable APR
var effectiveAPR = (monthsNew < introMonths) ? newIntroAPR : newRegularAPR;
var interest = balNew * (effectiveAPR / 100 / 12);
var principal = payment – interest;
// Check if payment is sufficient for new card rate (especially after intro)
if (principal introMonths) {
// Payment too low for regular APR
// We'll just break and mark as infinite/high
monthsNew = 999;
break;
}
if (balNew < principal) {
// Final partial month
interest = balNew * (effectiveAPR / 100 / 12);
principal = balNew;
}
totalInterestNew += interest;
balNew -= principal;
monthsNew++;
// Add annual fee every 12 months
if (monthsNew % 12 === 0) {
totalFeeNew += newAnnualFee;
}
}
// Add pro-rated fee
if (monthsNew % 12 !== 0 && monthsNew 0) {
document.getElementById('resSavings').className = "value positive";
} else {
document.getElementById('resSavings').className = "value negative";
}
document.getElementById('resCostCurrent').innerHTML = "$" + totalCostCurrent.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
// Handle case where new card never pays off
if (monthsNew >= 600) {
document.getElementById('resCostNew').innerHTML = "Infinite";
document.getElementById('resMonths').innerHTML = "> 50 Years";
} else {
document.getElementById('resCostNew').innerHTML = "$" + totalCostNew.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resMonths').innerHTML = monthsNew;
}
document.getElementById('breakdownIntCurrent').innerHTML = "$" + totalInterestCurrent.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('breakdownIntNew').innerHTML = "$" + totalInterestNew.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('breakdownBTFee').innerHTML = "$" + btFeeCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
}
Credit Card Rate Comparison: Is a Balance Transfer Worth It?
Managing credit card debt requires strategic thinking. One of the most effective tools for reducing debt is transferring a balance from a high-interest card to one with a lower rate or a 0% introductory offer. However, balance transfer fees and expiration dates can complicate the math.
This Credit Card Rate Comparison Calculator allows you to simulate the costs of sticking with your current card versus switching to a new offer. By analyzing the APR spread, transfer fees, and your monthly budget, you can calculate exact savings.
How to Use This Calculator
To get the most accurate comparison, you will need details from your current credit card statement and the "Terms and Conditions" of the new offer you are considering.
Current Debt Situation: Enter your total balance and how much you can afford to pay monthly. This establishes your baseline payoff timeline.
Current Card Details: Input your current APR. Most rewards cards range from 19% to 29%.
New Card Offer:
Introductory APR: Often 0% for balance transfers.
Intro Period: The number of months the promotional rate lasts (typically 12, 15, 18, or 21 months).
Balance Transfer Fee: A one-time fee added to your debt immediately upon transfer, usually 3% or 5%.
Post-Intro APR: The rate you will be charged on any remaining balance after the promotional period ends.
Understanding the Math: When to Transfer
A balance transfer is not always the right move. The math works in your favor only if the interest you save during the promotional period exceeds the upfront balance transfer fee.
Example Scenario
Let's say you have $5,000 in debt on a card with 24.99% APR and you pay $200/month.
Staying Put: You will pay approximately $1,900 in interest and take about 34 months to pay it off.
Transferring: You find a card with 0% APR for 18 months and a 3% fee ($150).
The Result: Your new balance is $5,150. With 0% interest, your $200 payments go entirely to principal. You pay it off in roughly 26 months. Even though the rate jumps after month 18, you save over $1,500 in total interest.
Key Metrics to Watch
1. The Break-Even Point
The calculator highlights the "Total Interest Saved." If this number is negative, the cost of the balance transfer fee is higher than the interest you would have paid on your old card. This usually happens if you plan to pay off the debt very quickly (e.g., within 3 months).
2. Post-Intro Risk
If you cannot pay off the entire balance before the introductory period ends, the remaining balance will be subject to the "New Regular APR." Our calculator accounts for this switch automatically. If your monthly payment is too low, you might find yourself still in debt when the high rates return.
3. Annual Fees
Don't ignore annual fees. A card with a great 0% offer but a $95 annual fee might cost you more in the long run than a card with a low fixed rate and no fee.
Disclaimer: This calculator provides estimates based on the data provided. Credit card interest is often calculated using Average Daily Balance methods which may vary slightly by issuer. Always read the cardmember agreement for exact terms.