0% Intro APR Payoff Calculator

How to use

1. 01

   Enter the balance you intend to move and the transfer fee the offer charges, as a percentage. Every field here opens at zero, so the fee is not assumed — take it from the offer, where 3% and 5% are both common.

2. 02

   Enter the number of months the promotional rate runs. Count from when the transfer posts rather than from when you applied, because the clock in the offer letter usually starts at account opening and a transfer that takes two weeks to settle has already spent some of the window.

3. 03

   Enter what you can genuinely pay each month. Not the minimum, and not an aspiration — the figure you will still be paying in month fourteen, because the whole question this page answers is whether that figure finishes the job in time.

4. 04

   Enter the APR the card reverts to when the promotion ends. This is the field the offer letter calls the standard purchase APR. Leave it at zero and the page tells you it is understating the cost, because the leftover is then being priced at nothing.

5. 05

   Compare what you entered against the 'payment to finish in time' figure. If your payment is the smaller of the two, read the leftover and what it costs, then decide whether to raise the payment or to look at a fixed-rate loan instead.

Formula

The page runs in two halves, because a balance transfer is two different loans in sequence. Inside the promotion, where there is no interest at all: Transfer fee = balance x (transfer fee % / 100). Starting balance = balance + transfer fee. The fee is posted to the new card, so it is money you have to repay, not money you hand over at the door. Paid inside the window = the smaller of the starting balance and (monthly payment x months at 0%). Still owing when 0% ends = starting balance - paid inside the window, floored at zero. Payment to finish in time = starting balance / months at 0%. That last line is the one to act on. It is a plain division because there is no interest to compound against — during a true 0% promotion every dollar you pay reduces the balance by a dollar, which is the only time in consumer credit that is true. After the window the leftover becomes an ordinary card balance at the go-back APR, and the arithmetic changes completely. With r = APR / 100 / 12 and L the leftover: months to clear = ceiling of [ -ln(1 - L x r / P) / ln(1 + r) ] The interest is not a formula but a simulation: the engine walks month by month, adds L x r, subtracts the payment, and sums every charge until the balance reaches zero. The floor, and the case that catches people. If the payment is at or below L x r it does not cover a single month's interest, the balance rises instead of falling, and the tool stops reporting a date. Interest after the promotion reads 'Never repaid' and total time reads 'Never at this payment', with a hint naming the monthly interest you have to get past before any principal moves at all. Total time to clear is the promotional months plus the months after, or — where the balance clears early — the starting balance divided by the payment, rounded up.

Example

Inputs: $7,500 to transfer, a 3% transfer fee, 18 months at 0%, $350 a month, and a 24.99% APR once the promotion ends. Step 1 - The fee, which is a balance and not a charge. $7,500 x 3% = $225. The tool says it directly: you are really paying down $7,725. That $225 is the entire cost of the exercise if everything goes right, and it is worth noticing that it is 3% of the balance for the use of the money for 18 months — an annualized cost of roughly 2%, which is cheap against any card rate. Step 2 - What the promotion absorbs. $350 x 18 = $6,300. Step 3 - What survives it. $7,725 - $6,300 = $1,425 still owing on the day the rate returns. This is the headline, and it is negative for a reason: the plan did not work. Step 4 - What the leftover costs. At 24.99% a month's interest on $1,425 is about $30, comfortably under the $350 payment, so it does clear — in 5 months, for $80 of interest. Total time to clear is 18 + 5 = 23 months, which the tool shows as 1y 11m. Step 5 - The payment that would have worked. $7,725 / 18 = $429.17, which the tool displays as $429. Multiply the rounded figure back and you get $7,722 against a $7,725 balance; the engine divides the unrounded number, so pay $430 rather than $429 if you want the arithmetic to have a margin. So the whole shortfall was $79 a month. Paying $429 instead of $350 turns a $305 exercise — $225 of fee plus $80 of interest — into a $225 one. Run it at $450 and the page changes tone entirely. The primary reads 'Cleared inside the window' at $0, interest after the promotion is $0, total time is 1y 6m, and the tool says the only cost of the whole exercise is the $225 fee. That is what a balance transfer is supposed to look like. And the version that goes badly. Take a shorter offer — 6 months at 0% — and a $100 payment. Now $600 goes in during the window against a $7,725 starting balance, leaving $7,125 when the rate returns. A month's interest on $7,125 at 24.99% is $148, against a $100 payment. Interest after the promotion reads 'Never repaid'. Total time to clear reads 'Never at this payment'. The balance grows every month, forever, and the tool spells out why: you have to get past $148 a month before any of it comes off the principal at all. The payment that would have finished it inside that window was $1,288. A 0% offer does not fix a balance that is too large for the payment. It postpones it, adds 3%, and hands it back.

Definitions

Balance transfer

Moving a balance from one card to another, usually to a promotional rate. The new issuer pays the old account and you owe the new one. The debt does not shrink; it changes address and usually gains a fee on the way.

Transfer fee

A one-time charge, typically 3% to 5% of the amount moved, posted to the new card as part of the balance. It is the reason the page pays down more than you transferred, and it is charged whether or not the plan works.

Promotional (intro) APR

A temporary rate, here 0%, that expires on a date fixed in advance. 12 CFR 1026.55(b)(1) permits an issuer to raise a rate at the end of such a period only where the period is six months or longer and the issuer disclosed both its length and the rate that follows, clearly and in writing, before it began.

Go-back APR

The rate that applies when the promotion ends. On US cards this commonly lands somewhere between 20% and 30%. Under 12 CFR 1026.55(b)(1)(ii)(A) the issuer cannot apply it to transactions that occurred before the promotional period at a rate higher than the one that applied to them then.

Deferred interest

A different product that advertises the same way. Instead of charging no interest, it charges none only if the balance is cleared in full by the deadline, and bills the entire period's accumulated interest retroactively if any balance remains. 12 CFR 1026.53(b)(1)(i) recognizes these as a distinct category. This page models a true 0% promotion, not this.

Payment allocation

How an issuer applies what you pay across balances at different rates. 12 CFR 1026.53(a) requires that any payment above the required minimum go first to the balance with the highest APR, then down in descending rate order. The minimum itself is not covered by that rule, so it goes where the issuer chooses — which is why new purchases on a transfer card are dangerous.

Penalty rate trigger

Under 12 CFR 1026.55(b)(4) an issuer may raise your rate where it does not receive the required minimum payment within 60 days of the due date, provided it discloses the reason and the terms of reversal in the notice. On a 0% transfer that is the fastest way to lose the promotion you paid a fee for.

Frequently asked questions