Carrying a $5,000 balance on a card charging 22.99% APR means roughly $96 of every first month goes straight to interest — before you have paid down a single dollar of what you actually spent. A 0% balance transfer credit card lets you move that debt onto a new card and pause the interest clock for an introductory period, usually 12 to 21 months. This balance transfer calculator shows you exactly whether that move is worth it for your numbers, because a 3%–5% transfer fee can quietly eat into the savings if you do not do the math first.
The engine runs two side-by-side payoff scenarios with the same monthly budget. In the keep scenario, your debt sits on the old card at its current APR and interest compounds every month. In the transfer scenario, you move the balance, pay a one-time transfer fee, pay 0% during the intro period, and then pay the post-intro rate on whatever is left over. Compare the months to pay off, the total interest, and the net savings after the fee.
How to Use
- Enter your Current Credit Card Balance — the high-interest amount you want to escape.
- Set your Current Interest Rate (APR). If you are not sure, check your latest statement; most US cards run 18%–26%.
- Choose the length of the 0% Intro APR Period on the offer you are considering. Common offers are 12, 15, 18 or 21 months.
- Enter the APR After Intro Period. This is the rate that hits any remaining balance once the 0% window closes — typically around 22%–26%.
- Type the Balance Transfer Fee as a percentage. The vast majority of cards charge 3% or 5% of the amount moved (some rare promotions run 0%).
- Set the Monthly Payment You Can Make. This fixed amount is applied to both scenarios so the comparison is fair.
The result card then shows how many months it takes to clear the debt under each path, the one-time fee, the interest paid after the intro period, your Net Interest Saved, and the Break-Even Month — the point at which the interest you avoided outweighs the fee you paid.
How the Math Works
Each month, interest accrues as balance × (APR ÷ 12), then your fixed payment is subtracted from the balance. That repeats until the balance reaches zero. On the keep side, a $5,000 balance at 22.99% with a $400 payment takes about 15 months and costs roughly $771 in interest. On the transfer side, you start at $5,150 (the $5,000 plus a 3% fee), pay 0% for the first 18 months, and clear the debt in about 13 months with $0 of interest. Subtracting the $150 fee, you net about $621 saved.
The break-even line matters: with a 3% fee ($150) against roughly $96 of interest avoided in month one, you break even in about the second month. If your intro offer is long enough to pay off most of the balance before the post-intro rate kicks in, a balance transfer is almost always a win. If you will still owe a large balance when the 0% period ends, the higher post-intro APR can erase the benefit.
Examples
Example 1 — The classic win. You owe $5,000 at 22.99% and can pay $400 a month. An 18-month 0% card with a 3% fee costs $150 up front but saves about $621 net and finishes the debt two months earlier. Break-even lands in month two.
Example 2 — A zero-fee promotion. You owe $4,000 at 20% and can pay $350 a month. A rare 12-month offer with a 0% transfer fee moves the whole balance for free; the keep path costs about $475 in interest and takes 13 months, while the transfer path takes 12 months and pays no interest at all — the entire $475 becomes savings.
Example 3 — A large balance stress test. On a $1,000,000 balance at 24% with a $50,000 monthly budget, the keep path takes 26 months and pays about $289,873 in interest, while a 12-month 0% offer with a 5% fee ($50,000) finishes in 23 months and nets about $186,356 saved. The engine handles balances of this magnitude without rounding errors.
FAQ
Is a balance transfer actually worth it?
It usually is when your interest rate is high (above roughly 18%), you can pay off most of the balance before the 0% intro period ends, and the transfer fee is 3% or less. The break-even month shown by this calculator tells you how quickly the avoided interest outweighs the fee — if that number is well within your intro window, the move pays off.
How is the balance transfer fee calculated?
The fee is a percentage of the amount you move, typically 3% or 5%. On a $5,000 transfer at 3%, the fee is $150, and it is added to your new balance — so you start owing $5,150. A handful of promotional cards offer a 0% fee, which makes the transfer pure savings.
What happens if I do not pay off the balance before the intro period ends?
Any remaining balance starts accruing interest at the card's standard post-intro APR, which is often 22%–26%. That is why the calculator includes the post-intro rate: if you will still owe a lot when the 0% window closes, the higher rate can eat into — or erase — your savings.
How much can I transfer?
Balance transfer cards cap transfers at a percentage of your credit limit, often around 75%–90% of it. A card with a $10,000 limit might let you move $7,500–$9,000. You cannot transfer a balance from one card to another issued by the same bank, and the offer usually must be used within 60–120 days of opening the account.
Does a balance transfer hurt my credit score?
The new credit inquiry and new account can cause a small temporary dip, but utilization and age of credit usually improve once the debt moves and you pay it down. Closing the old card afterward can shorten your credit history and raise utilization, so many people keep the old account open and simply stop using it.
What monthly payment should I use?
Use the highest fixed amount you can comfortably afford. The comparison is fair because the same budget is applied to both scenarios — raising it shortens both payoff dates, but it shortens the transfer path more, because every dollar chips away at a balance that is not growing during the 0% window.
Disclaimer
This balance transfer calculator is provided for informational purposes only and does not constitute financial, credit, or tax advice. Estimates are based on the inputs you enter and a standard month-by-month amortization model; actual card offers, fees, post-intro APRs, credit limits and approval vary by issuer and credit profile. Transfer offers are time-limited and may not be available to all applicants. Always confirm the terms directly with the card issuer before applying or transferring a balance.