Balance Transfer Calculator
Find out how much interest you can save by moving high-APR credit card debt to a 0% promotional offer. Accounts for transfer fees, promo period length, and your monthly payment.
About this calculator
A balance transfer moves existing credit card debt to a new card, typically offering a 0% or low promotional APR for a set period. The net savings formula used here is: savings = (currentBalance × currentAPR/100/12 × promoLength) − (currentBalance × transferFee/100) − (currentBalance × promoRate/100/12 × promoLength), plus any residual interest that would accrue on an unpaid balance after the promo period ends. The transfer fee (usually 3–5%) is a one-time cost deducted from gross interest savings. If your monthly payment is large enough to clear the balance before the promotional period ends, you pay no post-promo interest. The break-even point occurs when the fee equals the interest you would have paid on your original card — always verify this before transferring.
How to use
Say you have a $5,000 balance at 22% APR. A new card offers 0% for 15 months with a 3% transfer fee and you will pay $350/month. Interest avoided on old card = $5,000 × 22%/12 × 15 = $1,375. Transfer fee = $5,000 × 3% = $150. Promo interest = $5,000 × 0%/12 × 15 = $0. Total payments in 15 months = $350 × 15 = $5,250 > $5,000, so the balance is cleared during the promo. Net savings = $1,375 − $150 − $0 = $1,225. The transfer saves you $1,225 in interest, even after the fee.
Frequently asked questions
How do I know if a balance transfer will actually save me money?
A balance transfer saves money when the interest you avoid on your current card exceeds the one-time transfer fee plus any interest charged at the promotional rate. Use this calculator to compare both scenarios with your real numbers. Pay special attention to whether you can realistically pay off the transferred balance before the promotional period ends — any remaining balance after the promo typically reverts to a standard APR that can be 20% or higher, potentially wiping out your savings.
What happens if I don't pay off a balance transfer before the promotional period ends?
Once the promotional period expires, the remaining balance begins accruing interest at the card's standard go-to APR, which is often between 18% and 29%. Some issuers also apply deferred interest, meaning if any promotional balance remains unpaid, they charge interest retroactively to the original transfer date. Always read the card's terms carefully to determine which type of promotion applies. Plan your monthly payments so the balance reaches zero at least one month before the promo period closes.
Is a balance transfer fee worth paying if the promotional APR is 0%?
In most cases, yes — the math strongly favors transferring high-interest balances to a 0% card even with a 3–5% fee. A 3% fee on $5,000 is $150, while a single year of 20% APR interest on the same balance is roughly $1,000. The fee is worth paying as long as you commit to paying down the balance aggressively during the promo window. The strategy fails if you accumulate new charges on either card, so discipline is essential alongside the transfer.