Balance Transfer Calculator: 0% APR Savings vs Staying Put
Enter your current balance, your card's APR, the transfer fee (typically 3–5%), and the length of the 0% intro period. The calculator shows the exact monthly payment needed to clear the balance before interest kicks in, how much interest you would have paid staying on your current card over the same window, and — critically — what happens to your remaining balance and first-month interest charge if you do NOT clear the full amount within the promo window.
Your current card
Balance transfer offer
Net savings vs staying put
+$1,076.87
After the $180.00 transfer fee
Payment to clear in time
$343.33/mo
Clears $6,180.00 in 18 months
Interest if you stay
$1,256.87
Over 18 months at 22% APR
Upfront transfer fee
$180.00
Added to your balance on day 1. Total owed: $6,180.00.
Clears within promo window
At $343.33/mo you will pay off the full balance before interest kicks in. You pay $0 in interest on the transfer card.
Total cost comparison over 18 months
How it works
The transfer fee is charged upfront: it is added to your balance on day one. A 3% fee on $6,000 means you owe $6,180 immediately. During the 0% intro period no interest accrues, so every dollar of your monthly payment reduces principal. Divide the total owed by the number of promo months to find the exact payment that clears the balance in time. Pay less than that and a portion carries over into the post-intro period.
The savings comparison runs month by month: it simulates what would happen to your current balance at your existing APR if you made the same payment on that card instead of transferring. The difference in interest, minus the transfer fee, is your net saving. A high existing APR and a long promo window generally make transfers worthwhile; a low APR or short window can make the fee cost more than the interest you avoid.
The honesty signature is what happens if you do NOT clear the balance before the promo ends. Whatever balance remains is immediately subject to the post-intro APR — often 20–29% — and the first month's interest charge on that balance is shown explicitly. Many cardholders underestimate how much the rate jump costs when a large balance lingers past the promo window. Run the numbers for a payment below the break-even figure to see that cost before you commit.
Frequently asked questions
Is a balance transfer always worth it?+
Not always. The math favours a transfer when the interest you avoid over the promo period exceeds the transfer fee. With a 3% fee on $6,000, you pay $180 upfront; if your current APR is 22% and you would have paid $900+ in interest over 18 months at that rate, the transfer saves you roughly $720 after the fee. But if your current APR is low (under ~5%) or the promo window is short, the fee can outweigh the saving. The calculator shows the net figure so you can decide. This is a financial estimate, not advice — your specific situation and creditworthiness matter.
What happens if I miss the payoff deadline?+
Once the 0% promotional period ends, the remaining balance reverts to the post-intro APR, which is often the card's standard purchase rate (frequently 20–29%). Critically, some cards apply deferred interest — meaning if you do not clear the entire original transferred amount by the deadline, all the interest from the intro period is added back at once. Read your card agreement carefully. The calculator's honesty section shows the first-month revert interest on whatever balance you project to carry past the deadline, making the cost visible before you sign up.
Does a balance transfer hurt my credit score?+
Opening a new card causes a hard inquiry and may shorten your average account age, which can temporarily lower your score by a small amount. On the other hand, the transfer itself reduces credit utilisation on your old card, which is a positive factor. If you keep the old card open with a zero balance, utilisation across both cards typically drops, which helps your score over the medium term. The net effect depends on your overall credit profile; the calcultor covers the financial math only — consult a credit counsellor for personalised guidance.