Credit card payoff vs balance transfer calculator

Balance transfer math — fee vs intro APR savings

Balance transfer cards offer 0% APR for 12-21 months in exchange for a one-time fee (typically 3-5% of transferred balance). The transfer is worth it when:

Interest avoided during intro period > Transfer fee

When balance transfer wins big

• High starting APR (20%+) + substantial balance + enough discipline to pay off during intro period
• A $10k balance at 24% APR generates $2,400/year in interest. A 3% transfer fee on that balance is $300. Net savings if paid off in 12 months: $2,100.

When it's a wash or loses

• Low APR to start (sub-15%) — the transfer fee approaches the interest you'd have paid anyway
• You can't realistically pay off during intro period — post-intro APR usually matches your current APR
• Small balance — fixed transfer minimum + risk of missing intro window not worth it

The trap

The 0% intro APR ENDS. If you're still carrying balance when it does, the new APR (22-29%) applies retroactively in some cards (deferred interest), or starts the day after the intro ends. Either way, you've replaced one high-APR debt with another, plus paid the transfer fee. Worse than not transferring at all.

How to actually use balance transfers

1. Calculate monthly payment to fully zero the balance + fee within intro period
2. Set up autopay for that exact amount, day after billing date
3. Stop using the card — new charges typically don't get the 0% rate
4. Don't open new credit during the intro period — utilization spikes hurt your score

What this calc captures

• Interest saved during intro period
• Cost of transfer fee
• Post-intro interest if balance isn't fully paid in time
• Total months to fully payoff under each scenario

What it doesn't capture

• Deferred interest (some cards retroactively charge intro-period interest if not paid in full by end date — read the fine print)
• Credit score impact of opening a new card and the resulting utilization shift
• Annual fees (most balance transfer cards have $0 AF, but check)
• The behavioral risk of having a freed-up credit line and re-charging it