Credit cards • Carried-balance estimate
Credit Card Interest Calculator
Estimate how a carried balance may change under a fixed annual rate, monthly payment and optional continued charges. The tool is educational and does not reproduce an issuer's daily statement method.
Enter card assumptions
Use zero to model no new spending or charges.
View month-by-month balance schedule
How to use the calculator
- Enter the balance being carried.
- Use the annual rate from current card terms.
- Enter a fixed monthly payment.
- Add expected monthly charges, or use zero.
- Review the payoff schedule and compare a higher payment.
Formula and assumptions
Interest = opening balance × APR ÷ 12 ÷ 100
Closing = opening + interest + new charges − actual payment
The last payment is limited to the amount due. The model stops at 600 months and assumes one smooth monthly rate rather than daily compounding.
Worked Indian example
A cardholder models ₹60,000 at 36% annually, pays ₹6,000 monthly and continues ₹500 of monthly charges.
| First-month interest | ₹1,800 |
|---|---|
| Estimated payoff time | 14 months |
| Total interest | ₹13,781 |
| Total new charges | ₹7,000 |
| Total paid | ₹80,781 |
The example shows how even modest continued charges delay debt reduction.
Common mistakes
- Using a monthly rate in the annual-rate field.
- Ignoring new transactions after creating a payoff plan.
- Paying after the due date despite planning a larger amount.
- Assuming all card transactions receive identical treatment.
Practical tips
- Pay the required amount by the due date.
- Stop new card spending while clearing the balance.
- Keep enough bank balance for autopay.
- Check for residual interest after the final payment.
- Contact the issuer early if repayment becomes difficult.
Related calculators and guides
Frequently asked questions
What does this estimate?
First-month interest, payoff time, total interest, charges and total paid.
Why can my statement differ?
Daily balance methods, dates, fees and taxes vary.
What are monthly charges?
Optional new amounts added for scenario testing.
Can APR be zero?
Yes.
Why reject a low payment?
It cannot reduce the balance after interest and charges.
Are late fees included?
Only if you include them in the monthly-charge field.
How is payoff different?
This tool can model recurring new charges.
Is it a settlement quote?
No.
Educational disclaimer
This simplified calculator is not a card statement, settlement quote or personalized debt recommendation. Verify current balance, interest method, taxes, fees and allocation rules with the issuer.