Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Net saving vs staying put
$1,584
Transfer fee charged up front
$210
Interest if you don't transfer
$1,794
Balance left when promo ends
$910
Payment needed to clear in the window
$401
First month's interest after revert
$19
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One click, a permanent link with your numbers baked in.
Got your number — what next?
Pick one, it takes 20 secondsHow to use this
- 1Enter balance to transfer ($).
- 2Enter current card apr (%).
- 3Enter transfer fee (%).
- 4Enter promotional 0% window (months).
- 5Enter monthly payment you'll make ($/mo).
- 6Enter rate after the promo ends (%).
- 7Read your net saving vs staying put on the right — it updates as you type.
- 8Hit Share to keep the scenario or send it to someone.
About this calculator
A 0% balance transfer is not free — the fee is charged up front, typically 3-5% of the amount moved, and the promotional rate expires on a fixed date. The transfer wins when the interest avoided during the promo exceeds the fee, and it wins decisively only if the balance is actually clear before the revert rate kicks in. This calculator compares three numbers: the fee, the interest you would pay staying put, and the balance you would still owe when the promo ends at your planned payment. That last figure is the one most people miss.
Worked example
Using the values the calculator loads with:
Inputs
- Balance to transfer: 7000 $
- Current card APR: 23.9 %
- Transfer fee: 3 %
- Promotional 0% window: 18 months
- Monthly payment you'll make: 350 $/mo
- Rate after the promo ends: 24.9 %
Results
- Net saving vs staying put: $1,584.25
- Transfer fee charged up front: $210.00
- Interest if you don't transfer: $1,794.25
- Balance left when promo ends: $910.00
- Payment needed to clear in the window: $400.56
- First month's interest after revert: $18.88
What each field means
Inputs
- Balance to transfer ($)
- The balance to transfer used in the calculation, measured in $. Starts at 7000 $ so you have a working example on load.
- Current card APR (%)
- The current card apr used in the calculation, measured in %. Starts at 23.9 % so you have a working example on load.
- Transfer fee (%)
- The transfer fee used in the calculation, measured in %. Starts at 3 % so you have a working example on load. Accepted range: 0–10 %.
- Promotional 0% window (months)
- The promotional 0% window used in the calculation, measured in months. Starts at 18 months so you have a working example on load.
- Monthly payment you'll make ($/mo)
- The monthly payment you'll make used in the calculation, measured in $/mo. Starts at 350 $/mo so you have a working example on load.
- Rate after the promo ends (%)
- The rate after the promo ends used in the calculation, measured in %. Starts at 24.9 % so you have a working example on load.
Results
- Net saving vs staying put
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Transfer fee charged up front
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Interest if you don't transfer
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Balance left when promo ends
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Payment needed to clear in the window
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- First month's interest after revert
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
What if I can't clear the balance in the promo window?
The leftover balance starts accruing at the revert rate, which is often higher than the card you left. The transfer can still be worth it — you had free months — but check the 'payment needed to clear' figure and treat it as the real target, not the minimum.
Does a balance transfer hurt my credit score?
There is a short-term dip from the new account inquiry, but a transfer that lowers overall utilisation typically helps within a few months. Keep the old card open and unused — closing it reduces available credit and pushes utilisation back up.
Can I transfer more than once?
Serial transferring works until issuers stop approving you, and each hop costs another fee. Treat the first transfer as a fixed-length window to actually eliminate the debt rather than as a renewable arrangement.
Do new purchases get the 0% rate too?
Often not. Many cards apply the promotional rate only to transferred balances while purchases accrue at the standard rate, and payment allocation rules can leave the purchase balance sitting there earning interest. Use a different card for spending during the promo.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
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Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Balance Transfer Break-Even Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/balance-transfer-breakeven
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/balance-transfer-breakeven" target="_blank" rel="noopener">Balance Transfer Break-Even Calculator — RevenueLab</a> (2026).</p>
Source: [Balance Transfer Break-Even Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/balance-transfer-breakeven) (2026).