A 0% balance transfer can save a lot of interest, or quietly cost more than it saves. The difference usually comes down to three numbers and one honest question about the payoff plan.
1. Compare the fee with the interest you'd pay
Most transfers charge a one-off fee, often 3-5% of the amount moved. On a $5,000 balance that's $150-$250 up front. Then estimate the interest you'd pay on the current card over the same period. If the interest is clearly bigger than the fee, the transfer is in the running.
2. Divide the balance by the promo months
$5,000 over an 18-month 0% period means about $278 a month. If that monthly amount fits the budget, the transfer can clear the debt before regular interest starts. If it doesn't, work out what will be left when the promo ends and at what rate.
3. Read the three lines people skip
- When the 0% period starts (often from account opening, not from the transfer date)
- What rate applies to new purchases on the card (often not 0%)
- What happens after a late payment (some cards end the promo rate)
4. Set the payment on autopay
Schedule the full monthly target from step 2 as an automatic payment, not just the minimum. The minimum payment is usually far too small to clear the balance in time.
5. Stop the old card from refilling
The most common way transfers fail is a cleared card that slowly fills up again. Keep it open if it has no annual fee (it helps credit utilization), but take it out of daily use.
Free tools
- Balance transfer calculator (fee vs interest saved, monthly payment needed): https://smartbudgetsheets.surge.sh/calculators/balance-transfer-calculator/?utm_source=mataroa
- Full guide: https://smartbudgetsheets.surge.sh/blog/is-a-balance-transfer-worth-it/?utm_source=mataroa
- Credit card payoff calculator: https://smartbudgetsheets.surge.sh/calculators/credit-card-payoff-calculator/?utm_source=mataroa
- Debt Payoff Planner ($6.49, Excel / Google Sheets, full payoff schedule)
- 42 free budget templates, pay what you want ($0 is fine)
General information, not personal financial advice.