A 3% fee buys eighteen months of escape from a 22.99% rate
Moving $5,000 from a 22.99% card costs $150 up front. That balance would otherwise accrue about $95.79 of interest a month, so eighteen promotional months avoid $1,724 — a net saving of $1,574. The fee is recovered in 1.57 months, and everything after that is gain.
The break-even has a clean shortcut: divide the fee percentage by the monthly interest rate. Here 3% divided by 1.916% is 1.57 months, and the balance size cancels out entirely. A 3% fee against an 18% APR breaks even in exactly two months; against a 12% APR, in three. Any promotional period comfortably longer than that break-even makes the transfer worth doing on the arithmetic alone.
The figure assumes the balance never falls, which is the opposite of what you should do
The avoided-interest calculation holds the full $5,000 in place for all eighteen months. Anyone actually paying the balance down carries less debt each month and therefore avoids less interest than shown. Pay $278 a month and clear the balance exactly at the end of the promotion, and the real interest avoided is closer to half the headline figure.
That is not an argument against transferring — it is an argument for reading the number correctly. The saving is largest for someone who would have made minimum payments anyway, and smaller for a disciplined repayer, who nonetheless gets the far more valuable benefit: every dollar paid during the promotion reduces principal rather than servicing interest.
$278 a month clears $5,150 before the rate resets
A transfer only helps if the balance is gone before the promotional rate ends. Divide the transferred balance plus the fee by the number of promotional months: $5,150 over eighteen is $278 a month. Pay that and the debt is settled having cost $150. Pay the minimum instead and a large balance is still sitting there when the go-to rate applies, usually at a rate no better than the card you left.
Set the payment as a standing instruction on the day the transfer completes rather than intending to pay more later. The promotional window is the entire value of the product, and it is the only period in which paying down this debt is unusually efficient.
A missed payment can end the promotional rate immediately
Most agreements allow the issuer to terminate the promotional rate if a payment is late, at which point the remaining balance reverts to the standard APR. Some apply deferred interest, charging the full accrued amount retroactively if the balance is not cleared in time — a materially worse structure than a simple promotional rate, and worth identifying before accepting.
Two further details matter. New purchases on a transfer card usually do not share the 0% rate, and payments are typically applied to the lowest-rate balance first, so spending on the card can leave purchase interest accruing that you cannot pay off until the transferred balance is gone. And transfers must usually be completed within a window, often sixty days, to qualify for the advertised fee and rate.
Approval, credit limit, and the effect on your file
The calculation assumes you are approved for a limit large enough to take the whole balance. Issuers commonly approve a lower limit, leaving part of the debt behind at the original rate, and the advertised fee and promotional length are typically reserved for the strongest applicants. A transfer also involves a hard credit enquiry and a new account, both of which nudge a credit file — usually slightly and temporarily.
Nothing here models the behaviour that created the balance. A transfer that frees up the old card and is followed by new spending leaves a household with more debt at more rates than before. The product is a tool for repaying faster, and it is only that if the repayment actually happens.
Frequently Asked Questions
How does the transfer fee work?
Most cards charge a one-time fee of about 3-5% of the amount moved, added to your new balance. On a $5,000 transfer, a 3% fee is $150. You earn back that fee through the interest you avoid, so the larger your old rate, the faster it pays for itself.
What happens when the 0% promo period ends?
Any balance still owed when the promotion expires begins accruing interest at the card’s standard APR, which can be similar to or higher than your old rate. The 0% offer applies only during the intro window, so the goal is to finish paying before it closes.
Does a balance transfer hurt my credit score?
Applying adds a hard inquiry and a new account, which can dip your score briefly. Over time it can help: moving debt to a new card raises your total available credit and can lower your overall utilization, especially if you keep the old card open.
What is the difference between 0% APR and deferred interest?
A true 0% intro APR charges no interest during the promo, and only future balances accrue afterward. Deferred interest, common on store financing, quietly accrues interest the whole time and bills all of it retroactively if any balance remains at the end. Read the offer carefully to know which one you have.
Can I transfer more than one card to a new balance transfer card?
Often yes, up to the new card’s credit limit. Combining several high-rate balances onto one 0% card can simplify payments and pause interest on all of them, but each transferred amount is still subject to the transfer fee.
Sources & References
Figures on this page are checked against primary, authoritative sources. Links open in a new tab.
Interest avoided assumes the full balance sits at the old APR for the whole promo period.
Where it stops
After promo ends, remaining balance accrues at the new card’s regular APR.
The interest-avoided figure is an upper bound: it assumes the full balance stays put for the entire promo. Actually paying the balance down lowers both the interest you would have paid and the benefit shown here.
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These are planning estimates based on the numbers you enter. Interest rates, fees, and lender terms vary and change over time. This is educational information, not financial or credit advice.
Built and maintained by Jay Sudha, who runs a rice mill and trading business in Kashipur, India, and works with pricing, margins, working capital and bank credit as part of it.
Published the calculator with its formula, worked example, assumptions, limitations and FAQs, and added an automated formula test suite covering it.
Documented and tested the no-paydown simplification behind the avoided-interest figure, and confirmed the break-even point depends only on the fee percentage and the rate, not on the balance size.
Frequently Asked Questions now show on the page: 5 answers, checked in a page-by-page audit.
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