Balance Transfer Calculator
Enter your balance, current APR, and a 0% balance-transfer offer. We'll show you the fee, whether the balance clears inside the promo window, and the exact dollar verdict: does the transfer actually beat staying put?
Even with $28.34 in interest after the promo ends, the transfer's total cost ($208.34) beats staying on the current card ($1,638.69 interest).
- Payoff date
- August 2028
- Months to payoff
- 26
- Total interest
- $1,639
- Total cost
- $1,639
- Payoff date
- March 2028
- Months to payoff
- 21
- Total interest
- $28
- Transfer fee
- $180
- Total cost
- $208
How 0% balance transfers actually work
A balance-transfer credit card lets you move a balance from another card and pay 0% APR on it for a promotional window — commonly 12, 15, 18, or 21 months. In exchange, you pay a one-time transfer fee of 3% to 5% of the amount moved, added to your new card's balance. The headline rate is the marketing; the fee is the price.
During the promo, every dollar you pay goes straight to principal because no interest accrues. That's the entire mechanical value of the product: time without compounding. If you can pay the transferred balance (fee included) down to zero before the promo ends, your total cost is just the fee — no interest at all.
If you don't pay it off in time, the remaining balance flips to the card's regular APR — typically 17% to 28%, sometimes higher than the card you left. From that point forward you're paying ordinary credit-card interest, the same compounding trap the transfer was supposed to escape.
The fee math — when transferring beats the interest
The verdict comes down to one comparison: transfer fee plus any post-promo interest versus interest you'd pay by staying put. The transfer wins when the first number is smaller than the second.
Take a $6,000 balance at 22.99% APR with a $300 monthly payment. Staying on the current card takes about 26 months and costs roughly $1,640 in interest. Transferring to an 18-month 0% offer with a 3% fee creates a $6,180 starting balance — at $300/month you clear $5,400 during the promo, leaving $780 at the end. That $780 takes about three more months at full APR and costs about $30 in interest. Total transfer cost: $180 fee + $30 interest = $210. Versus $1,640 of interest staying put, that's about $1,430 saved.
Now run the same numbers with a $1,000 balance. Staying on the current card costs about $44 in interest over the four months it'd take to clear at $300/month. A 3% transfer fee on $1,000 is $30. The transfer saves about $14, and that's before any post-promo interest if you slow down on payments. At small balances or fast payoffs the fee usually eats most of the savings — which is exactly when the calculator's verdict line flips to red.
The breakeven rule of thumb: a transfer is worth it when your current monthly interest charge exceeds the fee divided by the promo months. At 22.99% APR on $6,000, monthly interest is about $115; a 3% fee on $6,000 spread over 18 promo months is $10 per month equivalent. Easy win. Same APR on $1,000, monthly interest is about $19; a 3% fee spread over 18 months is $1.67. Still a win — but only if you don't pay it off in five months anyway.
When a balance transfer is not worth it
- You can pay it off in a few months anyway.If the balance is small enough to clear in 4-6 months at your current payment, the interest you'd save barely exceeds the fee. Skip the application and just attack it.
- You can't commit to clearing it in the promo window.If your monthly payment leaves a large remainder at month 18 (or whenever the promo ends), much of the savings vanishes into post-promo interest. Run the numbers honestly — the calculator above doesn't guess; it shows exactly what's left.
- You haven't closed the spending tap. A balance transfer with a $0 old card is a setup, not a solution. If you put new charges on either card during the promo, the payoff math falls apart fast — and you end up with a transferred balance, a new balance, and the original problem.
- You're juggling transfers indefinitely. Stacking transfer after transfer to keep dodging interest accumulates fees with every move. After two or three, the cumulative fees can exceed what straight-line payoff at the regular APR would have cost.
- You don't qualify for the headline rate. The 21-month 0% offers go to applicants with strong credit. If your approval comes back at 12 months instead of 21, re-run the math — a shorter promo means less time to clear the balance before the regular APR kicks in.
Frequently asked questions
How is a balance-transfer fee calculated?
Almost every balance-transfer card charges a one-time fee as a percentage of the amount transferred — typically 3% or 5%, with a $5 to $10 minimum. The fee is added to the new balance, not paid separately, so transferring $6,000 with a 3% fee creates a $6,180 starting balance on the new card. You finance the fee at the promotional 0% APR like the rest of the balance, which means it doesn't accrue extra interest, but it does increase the dollars you have to pay back.
What happens after the 0% promo period ends?
Any remaining balance starts accruing interest at the card's regular APR — usually somewhere between 17% and 28%, often higher than the rate on the card you transferred from. The 0% rate is a teaser; the post-promo rate is the real product. The calculator above assumes the post-promo APR matches the APR you'd have stayed at, which is conservative — many balance-transfer cards run higher post-promo than the card you left.
Will a balance transfer hurt my credit score?
Short-term, slightly. You'll take a small dip from the hard inquiry when you apply, and opening a new account lowers your average account age. The bigger effect goes the other way: a new card with a high credit limit and a $0 balance (the card you transferred from) lowers your overall credit utilization ratio, which is one of the largest inputs to a FICO score. Net effect after a few months is usually neutral to positive — provided you don't close the old card and don't run it back up.
When is a balance transfer not worth it?
Three common cases: (1) You can already pay the balance off in a few months at the current APR — the interest you'd save is small and the transfer fee is fixed. (2) The promo period is short and your payment plan won't clear the balance before it ends, leaving a large remainder at full APR. (3) The transfer is a stress-relief move rather than a payoff plan, and you keep using the old card. A balance transfer is a debt-payoff tool, not a debt-management tool — it only helps if you actually pay it off.
Can I transfer to a card I already have?
Almost never. Balance-transfer offers are typically for new accounts only — the issuer is buying your business with the 0% rate. Existing cardholders sometimes get targeted 0% offers in the mail or through their issuer's portal, but these are usually shorter (6 to 12 months) and carry the same 3% to 5% fee. The headline offers — 15-21 months at 0% — almost always require a new application and approval.
What if my balance is too big for one transfer card's limit?
You'll be approved for whatever credit limit the issuer's underwriting gives you, which may be less than your full balance. Transfer what you can, run the calculator on the portion that moved, and treat the leftover on the old card as a separate (higher-priority) payoff target. Some borrowers split a large balance across two transfer cards — the fees stack, and so do the application inquiries, so the math has to be especially favorable to justify it.
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Estimates are educational only. The calculator assumes the transfer fee is financed onto the new card (standard practice), 0% APR for the full promo window, and that the post-promo APR matches your current card's APR. Actual balance-transfer cards often have post-promo rates that differ from your current card — check the offer terms before applying. Lender approval, credit limits, and intro-period length are not guaranteed.