Credit Card Calculator
The Credit Card Calculator calculates exact, real-time domain outputs in active voice. The Credit Card Calculator calculates exact, real-time domain outputs using verified mathematical formulas. Revolving credit card balances carry some of the highest interest rates in consumer finance (often 24% to 42% p.a.). The Credit Card Calculator shows exactly how many months it will take to eliminate your balance at your chosen monthly payment and how much interest you save by increasing that payment.
Credit Card Calculator Input Parameters & Defaults
| Credit Card Balance | 100000 | Total unpaid statement balance. |
| Credit Card Annual APR (%) | 36.0 | Annualized interest rate charged on revolving balances. |
| Planned Monthly Payment | 5000 | Fixed amount you plan to pay every month. |
Credit Card Calculator Mathematical Formula
n = -\frac{\ln\left(1 - \frac{B \cdot r}{\text{PMT}}\right)}{\ln(1 + r)}Credit Card Calculator Worked Example
Carrying a 100,000 credit card balance at 36% annual APR (3% per month) and paying 5,000 per month.
- First month interest alone is 100,000 × 0.03 = 3,000, leaving only 2,000 to reduce principal.
- Payoff time n = -ln(1 - (100,000 × 0.03 / 5,000)) / ln(1.03) = 31.0 months (31 months).
- Total paid = 154,936; Total interest = 54,936.
Doubling the monthly payment from 5,000 to 10,000 cuts the payoff time from 31 months to 13 months and slashes interest from 54,936 to 20,766.
Credit Card Calculator Glossary of Key Terms
Total unpaid statement balance.
Annualized interest rate charged on revolving balances.
Fixed amount you plan to pay every month.
The unpaid loan balance that remains after each monthly payment reduces the original principal.
The true annual rate of return that accounts for intra-year compounding across monthly or quarterly intervals.
A complete chronological table showing how each installment splits between interest charges and principal repayment.
Credit Card Calculator Topical Map & 104 Semantic Keywords
Credit Card Calculator Frequently Asked Questions
Q: What happens if my monthly payment is less than the monthly interest charge?
Your balance will grow every month (negative amortization) and never pay off. Our calculator detects this condition and displays the minimum monthly payment required to cover interest plus principal reduction.