Balance Transfer Cards: Doing the Arithmetic First
A balance transfer is a deadline, not a solution.
At a glance
Figures checked 1 Sep 2026
Time needed
30 minutes
Effort
Moderate
Have to hand
Current balances, rates and the offer terms
What you get
Interest savings if the balance clears within the promotional window
What to take away
- Transfer fees typically run 3–5% of the amount moved.
- Divide the balance by the promotional months — that is the required monthly payment.
- New purchases on the card may not share the 0% rate.
Moving $8,000 at 22.9% to an 18-month 0% card with a 3% fee costs $240 upfront and saves well over $1,000 in interest — provided the balance is gone before month nineteen.
The test
- Calculate the fee: balance times the transfer percentage.
- Calculate interest avoided: roughly balance times rate times the promotional period.
- Divide the balance by the promotional months to get the required payment.
- If you cannot commit to that payment, the transfer probably is not worth it.
When the promotional period ends, the standard rate applies to whatever remains. Some cards also apply payments to the lowest-rate balance first, so new purchases can sit accruing interest while you clear the transfer.
Common questions
A new application adds a hard inquiry and lowers average account age slightly. The improvement in utilisation from the extra available credit often outweighs both.