Balance Transfer Savings Calculator

Interest on Current Card is not your literal current credit card bill — it's a counterfactual simulation of what you'd pay in interest if you kept the balance on the current card at Current Card APR for exactly Promo Period (Months) (lines 58-69), which is also, by construction, identical to Interest Avoided (line 78): with a 0% promotional rate, every dollar of interest you would have paid on the old card is a dollar "saved" by transferring, so those two figures always match to the penny. Balance Transfer Fee is a flat percentage of Current Balance alone (line 74) — Current Card APR, Promo Period (Months), and Monthly Payment all measure exactly zero effect on it, because the fee is charged on the balance at the moment of transfer, regardless of how long the promo lasts or how aggressively you pay it down. Current Balance dominates Interest on Current Card: its ±10% span is about 34% of Interest on Current Card, ahead of Current Card APR (about 24%) and Monthly Payment (about 14%, moving it down as you pay faster) — the starting balance sets the scale everything else is computed against.

Balance Transfer Fee is the one input that means nothing for Interest on Current Card or Interest Avoided (both measure exactly zero effect from it) but does meaningfully reduce Net Savings once it's subtracted out at the end (line 79). This calculator does not account for interest that would continue accruing after the promo period ends if the balance isn't fully paid off, or the new card's regular APR once the promotional rate expires.