Credit Card APR Calculator
Turn an abstract percentage into real numbers: see what your APR costs you per month and per year on your actual balance.
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.
Credit Card APR Calculator
APR (annual percentage rate) is the yearly cost of carrying a balance. The calculator above turns your APR into estimated dollar costs — per day, per month, and per year — for the balance you enter.
"24.99% APR" doesn't mean much until you see it in dollars. This calculator translates the percentage on your statement into what carrying your balance could cost.
How the Calculator Works
Enter the balance you're carrying and your APR. The calculator shows:
- Cost this month: balance × (APR ÷ 12).
- Cost per day: balance × (APR ÷ 365), the daily-rate view many issuers use.
- Cost per year (simple): balance × APR, with no compounding.
- Cost per year (compounded monthly): what accumulates if the balance and its interest revolve untouched for 12 months.
It also shows a 12-month table of a balance left to revolve with no payments — a worst-case view of the cost of doing nothing.
Formula
Daily Cost = Balance × (APR ÷ 365)
Annual Cost (simple) = Balance × APR
Annual Cost (compounded monthly) = Balance × [(1 + APR ÷ 12)12 − 1]
This is a simplified estimate, not an issuer-specific statement calculation.
Example: $4,000 at 24.99% APR, no payments
Monthly cost is about $83.30, daily cost about $2.74, and simple annual cost about $999.60. If nothing is paid and interest compounds monthly, the balance grows as shown below.
| Month | Interest this month | Cumulative interest | Balance |
|---|---|---|---|
| 1 | $83.30 | $83.30 | $4,083.30 |
| 2 | $85.03 | $168.33 | $4,168.33 |
| 3 | $86.81 | $255.14 | $4,255.14 |
| 6 | $92.34 | $526.55 | $4,526.55 |
| 9 | $98.23 | $815.28 | $4,815.28 |
| 12 | $104.50 | $1,122.42 | $5,122.42 |
After a year, about $1,122 in interest has built up — more than the $999.60 simple figure, because interest is charged on interest.
Purchase APR vs. Cash Advance APR
Many cards list several APRs: one for purchases, often a higher one for cash advances, and sometimes a penalty APR after a late payment. Cash advances typically begin accruing interest immediately and generally don't receive the same grace period that applies to purchases; the Cash Advance Calculator adds up the fee and interest on one. For credit cards, APR and "interest rate" are usually the same number, unlike mortgages, where APR bundles in certain fees.
When the Result May Differ
Treat the results as a planning estimate. Your real numbers can differ because of:
- Daily periodic rate: many issuers apply APR ÷ 365 (or 360) each day instead of APR ÷ 12 once a month, which can produce different interest.
- Average daily balance: your balance moves during the cycle as purchases post and payments arrive; this calculator uses a single month-start balance.
- Fees: annual, late, foreign-transaction, cash-advance, and balance-transfer fees aren't included unless the calculator asks for them.
- New purchases: the estimate assumes you stop adding charges. Any new spending lengthens payoff and raises interest.
- Grace period: whether new purchases accrue interest depends on whether you pay your statement balance in full and on your card's terms.
- 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.
- Variable rates: most card APRs are variable and can change when the benchmark rate (such as the prime rate) moves.
Your statement and cardholder agreement are the final word. See our methodology for how every calculator on this site works.
Want the Daily-Rate View?
For the daily periodic rate and a billing-cycle estimate, use the Daily Periodic Rate Calculator. To see how a monthly payment changes the picture, use the Credit Card Interest Calculator. If APR and interest rate sound like the same thing, see APR vs. interest rate.
Frequently Asked Questions
What does APR stand for and what does it mean?
APR stands for annual percentage rate — the yearly cost of borrowing, expressed as a percentage. On credit cards, many issuers apply it as a daily periodic rate (APR ÷ 365), so interest builds throughout the billing cycle.
Is APR the same as interest rate?
For most credit cards, yes, since cards rarely charge separate upfront loan fees the way mortgages do — APR and interest rate are effectively the same number. On other loan types they can differ because APR bundles in certain fees.
Why do cash advances and purchases have different APRs?
Issuers price transaction types differently. Cash advance APRs are commonly higher than purchase APRs, and cash advances typically begin accruing interest immediately and generally don't receive the same grace period that applies to purchases.
What is a penalty APR?
Some cards have a higher penalty APR for late payments. Under federal rules (Regulation Z § 1026.55), it can generally apply to your existing balance only if your minimum payment is more than 60 days late, and to new transactions after advance notice. Your cardholder agreement lists whether your card has one and what triggers it.
Why is the compounded annual cost higher than the simple one?
Because interest is charged on previous interest. If a $4,000 balance at 24.99% revolves for a year with no payments, simple interest is about $1,000, but monthly compounding brings it to about $1,122.
Do I pay APR if I pay my balance in full?
On cards with a grace period, paying your full statement balance by the due date typically means no interest on purchases. APR matters when you carry a balance, take a cash advance, or use a feature without a grace period.
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
- Consumer Credit – G.19 (credit card interest rates, Q3 2026) — Federal Reserve Board. Checked October 25, 2026.
- Can I withdraw money from my credit card at an ATM? — 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.