0% Intro APR Calculator
Find the monthly payment required to clear your balance before the promotional 0% period ends, and see the cost if you fall short.
Updated · Published · Built by Ali Ahmad, Founder
Calculation method: This calculator uses a simplified monthly-interest model (APR ÷ 12). Credit-card issuers may calculate interest using daily periodic rates and average daily balances, so your actual statement may differ. See our methodology.
0% Intro APR Calculator
Divide your balance (plus any balance transfer fee) by the number of months in your 0% promotional period to find the flat payment that clears the balance before the promo ends. The calculator above does that math, checks your planned payment, and estimates the cost of any balance left over.
A 0% intro APR offer only avoids interest if you pay off the balance before the promotional period ends. This calculator tells you the payment you'd need, and what could happen if you fall short.
How the Calculator Works
Enter your balance, any balance transfer fee, the number of promotional months, your planned monthly payment, and the APR that applies after the promo. The calculator:
- Adds the balance transfer fee (usually 3% to 5%; 0 for a new purchase) to the balance, then divides by the promo months to find the required flat payment.
- Multiplies your planned payment by the promo months to see how much you'd pay off during the promo.
- Calculates any remaining balance when the promo ends.
- Estimates the interest on that remainder at the go-to APR (monthly model) if you keep paying the same amount.
Formula
Required Payment = Balance to Repay ÷ Promo Months
Remaining Balance = max(0, Balance to Repay − Planned Payment × Promo Months)
After the promo: Monthly Interest = Remaining Balance × (Go-to APR ÷ 12)
This is a simplified estimate, not an issuer-specific statement calculation. It assumes a true 0% promotion, not a deferred-interest plan.
Example: $3,000 on an 18-month 0% offer, paying $150 a month
| Item | Amount |
|---|---|
| Required payment ($3,000 ÷ 18) | $166.67 |
| Paid during the promo ($150 × 18) | $2,700.00 |
| Balance left when the promo ends | $300.00 |
| Estimated interest on the remainder at 24.99%, paying $150/mo | $9.70 |
If the $3,000 is a balance transfer with a 3% fee, you repay $3,090: the required payment rises to $171.67 a month, and paying $150 leaves $390 when the promo ends.
Here the shortfall is small, so the extra interest is small too. On a deferred-interest offer, though, missing the deadline could mean interest charged back to the original purchase date on the full amount — a very different result. Paying $166.67 a month avoids both.
When the Result May Differ
Treat the results as a planning estimate. Your real numbers can differ because of:
- Fees: annual, late, foreign-transaction, and cash-advance fees aren't included. The balance transfer fee is, if you enter it.
- New purchases: the estimate assumes you stop adding charges. Any new spending lengthens payoff and raises interest.
- Different APR categories: purchases, balance transfers, cash advances, and penalty APRs can carry different rates on the same card, and how payments are allocated between them affects the total.
- Deferred interest: some promotions (common with store cards and retail financing) charge interest retroactively if the balance isn't paid in full by the deadline. This calculator assumes a standard 0% promotion; for a deferred-interest offer, use the Deferred Interest Calculator.
- Losing the promo early: under federal rules an issuer can generally end a promotional rate on an existing balance early if your minimum payment is more than 60 days late (Regulation Z § 1026.55), and on deferred-interest plans being more than 60 days late can trigger the deferred interest.
- Minimum payments: your card's required minimum may be lower than the payment needed to clear the balance in time; paying only the minimum could leave a larger remainder.
- Payment allocation: if the card also carries balances at a higher APR, amounts above the minimum generally go to the highest-APR balance first, which can slow payoff of the promo balance.
- Daily interest after the promo: once the go-to APR applies, many issuers use a daily periodic rate on the average daily balance.
Your statement and cardholder agreement are the final word. See our methodology for how every calculator on this site works.
If the Required Payment Is Too High
Compare a transfer with a longer promotional period or a fixed-rate loan with the Balance Transfer Calculator and the Debt Consolidation vs. Balance Transfer Calculator.
Frequently Asked Questions
What happens if I don't pay off my balance before the 0% APR period ends?
Any remaining balance begins accruing interest at the card's standard go-to APR — and on some cards, deferred-interest promotions can retroactively charge interest back to the original purchase date if not paid in full by the deadline. Always check your card's specific terms.
How do I make sure I pay off my balance in time?
Divide your balance, plus any balance transfer fee, by the number of months in the promotional period — that's the flat payment needed to reach zero when the promo ends. This calculator does that division for you and flags if your planned payment falls short.
What's the difference between 0% APR and deferred interest?
With a true 0% APR, no interest accrues during the promo, and only the remaining balance is charged interest afterward. With deferred interest, interest builds in the background and may be charged back to the purchase date if the full balance isn't paid by the deadline.
Is the minimum payment enough to clear a 0% balance in time?
Often not. The minimum can be lower than the balance divided by the promo months, so paying only the minimum may leave a balance when the promo ends.
Can I lose my 0% rate early?
Under federal rules (Regulation Z § 1026.55), an issuer can generally end a promotional rate on your existing balance early only if your minimum payment is more than 60 days late. On deferred-interest plans, the CFPB notes that being more than 60 days late can also trigger the deferred interest. Check your card's terms.
Do new purchases get the 0% rate too?
Only if the offer covers purchases. Some intro offers apply only to balance transfers, so new purchases would accrue interest at the regular purchase APR.
This calculator provides estimates for educational purposes only and is not financial, tax, or legal advice. Most results use a simplified monthly-interest model (APR ÷ 12); your card issuer may use a daily periodic rate and average daily balance, plus its own fees and grace period rules, so your actual figures may differ — always confirm against your official statement.
Sources
- I got a credit card promising no interest for a purchase if I pay in full within 12 months. How does this work? — Consumer Financial Protection Bureau. Checked September 25, 2026.
- Regulation Z § 1026.55 – limits on raising APRs, including the 60-days-late rule — Consumer Financial Protection Bureau. Checked September 25, 2026.
- Regulation Z § 1026.53 – payments above the minimum go to the highest-APR balance first — Consumer Financial Protection Bureau. Checked September 25, 2026.