Same $250 monthly payment, 18-month 0% promo, 24% APR. Numbers from this site's public payoff engine. The $10,000 row is the same card as the balance-transfer-savings page, so the baseline (82 months, $10,318.98) lines up exactly.
The fee is only noise above about $5,000
The fee is charged once, up front, as a percentage of the balance moved. The interest a 0% transfer avoids is the interest that balance would have paid over the months it takes to clear. At $10,000 the balance runs 82 months at 24%, so the interest avoided is $10,318.98 — a 3% fee of $300 is 3% of that. At $1,000 the balance clears in 5 months, so the interest avoided is only $53.07 — the same 3% fee is $30, or 57% of it. The smaller the balance, the smaller the interest pool, and the bigger the fee's share of it.
| Balance | 3% fee | 4% fee | 5% fee |
|---|---|---|---|
| $1,000 | $23.07 | $13.07 | $3.07 |
| $5,000 | $1,283.86 | $1,233.86 | $1,183.86 |
| $10,000 | $8,198.51 | $8,098.51 | $7,998.51 |
The months barely move with the fee
The fee does not change how long the balance takes to clear — it is a one-time charge, not a rate. What moves the months is the balance and the payment. At $250 a month, $1,000 clears in 4 months with a transfer (5 without), $5,000 in 21 (26 without), and $10,000 in 48 (82 without). The fee changes the cost, not the clock.
| Balance | No transfer | 0% transfer | Months fewer |
|---|---|---|---|
| $1,000 | 5 | 4 | 1 |
| $5,000 | 26 | 21 | 5 |
| $10,000 | 82 | 48 | 34 |
Why the fee scales the wrong way
A transfer fee is linear: 3% of $1,000 is $30, 3% of $10,000 is $300 — ten times the fee for ten times the balance. The interest it avoids is not linear. At $250 a month a $1,000 balance is gone in five months, so there is almost no interest to avoid; a $10,000 balance runs 82 months, so the interest avoided is enormous. The fee grows in a straight line while the saving grows with time — which is why the fee is noise at the top and a real cost at the bottom.
What to do with this
If the balance you would move is under about $5,000 and you can pay it down at a decent clip, the 3–5% fee may eat most of what the 0% window saves — run the numbers before you pay it. Above $5,000, the fee is small next to the interest it avoids, and the transfer is clearly worth it. The break-even is not a fixed number: it moves with your payment and the promo length. At $250 a month and an 18-month window, it sits near $5,000.
Reproduce these numbers
Every figure here comes from this site's public engine. Post a single balance, its rate and its payment to /api/payoff and you get the months and the interest back. The baseline card is {"balance": 1000, "apr": 24, "minPayment": 250} — it returns 5 months and $53.07. For a transfer, the promo is zero interest for N months: the balance falls by the payment each month with no charge, then the remainder runs at 24%. On $1,000 the balance is gone inside the 18-month window, so the post-promo interest is $0 and the only cost is the fee. On $10,000 the remainder ($5,500) returns 30 months and $1,820.47, which with the $300 fee gives the 48-month, $2,120.47 total. Two conventions to know: APR goes in as a percentage (24, not 0.24), and minPayment is held fixed for the whole run — the same convention every page on this site uses.
Frequently asked
Does a 3–5% balance transfer fee still pay off?
It depends on the balance. At $10,000 a 3% fee ($300) is 3% of the $10,318.98 of interest it avoids — clearly worth it. At $1,000 the same fee is 57% of the $53.07 it avoids, and at 5% you net just $3.07. Above about $5,000 the fee is noise; below it, run the numbers first.
At what balance does the transfer fee stop being worth it?
Around $5,000 at a $250 monthly payment and an 18-month promo. At $5,000 a 5% fee eats 17% of the interest it avoids; at $1,000 it eats 94%. The exact break-even moves with your payment and the promo length, so it is a range, not a fixed number.
How much does a 5% fee cost on a $1,000 balance?
$50. The balance clears in 4 months at $250 a month, so the interest it avoids is only $53.07 — the $50 fee leaves a net saving of $3.07.
Why is the fee a bigger share at small balances?
Because the interest a transfer avoids is small when the balance clears fast. At $250 a month a $1,000 balance is gone in 5 months, so there is only $53.07 of interest to avoid; a 3% fee is $30 of that. A $10,000 balance runs 82 months, so the interest pool is $10,318.98 and the same 3% fee is a rounding error.
Does the fee change how many months it takes to clear?
No. The fee is a one-time charge, not a rate. The months are set by the balance and the payment: at $250 a month, $1,000 clears in 4 months with a transfer, $5,000 in 21, and $10,000 in 48 — the same months at 3%, 4% or 5%.
Is a 0% transfer worth it on a $1,000 balance?
Barely. At $250 a month the $1,000 clears in 5 months on its own for $53.07 of interest. A 0% transfer cuts that to 4 months and saves $23.07 at a 3% fee, $13.07 at 4%, and $3.07 at 5%. The fee is most of the saving — the transfer is not doing much work.