Credit Card Interest Cost
Estimate the interest a card balance accrues over months.
About Credit Card Interest Cost
Monthly interest is the balance times the APR divided by twelve, and carrying it for several months totals those charges linearly. Cards accrue daily, so even a modest balance carried for a year can cost more than people expect from the headline APR alone.
Formula
Credit Card Interest Cost
Interest = balance x APR x months / 12
- months carried
- How long the balance is kept without paying it down
Worked example
With the default values below, Credit Card Interest Cost returns Total Interest of $720.00. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Balanceminimum 0
- 3,000
- APRaccepts 0–100 %
- 24 %
- Months carriedminimum 1 months
- 12 months
Results
- Total Interest
- $720.00
- Interest per Month
- $60.00
- Total to Pay Off
- $3,720.00
Step by step
- 1Values used
- 2Credit Card Interest Cost
- 3Total Interest= 720.00
- 4Interest per Month= 60.00
- 5Total to Pay Off= 3,720.00
Assumptions and limits
- The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
- This is an estimate for general information and not professional financial, tax or legal advice. See the full disclaimer for the limits that apply to this kind of calculator.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Credit Card Interest Cost calculated?
Interest = balance x APR x months / 12 Monthly interest is the balance times the APR divided by twelve, and carrying it for several months totals those charges linearly.
Why does Credit Card Interest Cost matter?
Cards accrue daily, so even a modest balance carried for a year can cost more than people expect from the headline APR alone.
What values do I need to enter?
This calculator takes 3 inputs: Balance, APR, Months carried. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.