Credit card payment calculator
Minimum payments can stretch a balance for years while interest rivals or exceeds the principal. This tool projects months to pay off, total interest, and total amount paid from your balance, annual rate (APR), fixed monthly payment, and fixed fees (insurance, membership).
With a $15,000 balance at 42% APR and a fixed $900/month payment (no fees), payoff takes 26 months, interest is $7,907.59, and total paid is $22,907.59. Raising the payment to $1,500/month cuts the term to 13 months and interest to $3,789.80 (about $4,118 less interest).
What this calculator shows
- Months (and years) to reach a zero balance with a fixed payment
- Total interest accrued month by month
- Total paid = principal + interest + monthly fees × months
- Interest vs principal ratio
- A warning when the payment cannot cover interest + fees (balance does not fall)
How the model works
Each month interest is charged on the remaining balance; fixed fees come out of the payment first; the rest reduces principal.
monthly_rate = annual_rate / 12 / 100
month_interest = balance × monthly_rate principal_payment = monthly_payment − month_interest − monthly_fees
if principal_payment ≤ 0 → payment is too low else → balance = balance − principal_payment
The loop continues until the balance is ~0 (safety cap: 1,200 months). This is a fixed-payment educational model; your issuer’s minimum is often a % of balance or a floor and may include other charges.
Step-by-step example (calculator defaults)
Inputs: balance $15,000 · 42% APR · $900 payment · $0 fees
- Monthly rate = 42% / 12 = 3.5%
- Month 1 interest ≈ 15,000 × 0.035 = $525; principal ≈ 900 − 525 = $375
- At a constant $900 payment, the balance clears in 26 months
- Total interest ≈ $7,907.59
- Total paid ≈ $22,907.59 (interest ≈ 52.7% of starting principal)
A $525 payment only covers first-month interest — the calculator flags payment too low.
Reference table (same engine assumptions)
Rounded figures from the calculator logic. Use the form above for your exact case.
| Balance | APR | Payment / mo | Fees / mo | Months | Interest | Total paid | Interest vs principal |
|---|---|---|---|---|---|---|---|
| $15,000 | 42% | $900 | $0 | 26 | $7,907.59 | $22,907.59 | 52.7% |
| $15,000 | 42% | $1,500 | $0 | 13 | $3,789.80 | $18,789.80 | 25.3% |
| $15,000 | 42% | $600 | $0 | 61 | $21,270.38 | $36,270.38 | 141.8% |
| $10,000 | 36% | $500 | $50 | 38 | $6,726.08 | $18,626.08 | 67.3% |
| $5,000 | 48% | $400 | $0 | 18 | $2,070.92 | $7,070.92 | 41.4% |
| $20,000 | 30% | $1,200 | $0 | 22 | $6,196.00 | $26,196.00 | 31.0% |
How to exit sooner and pay less interest
- Pay more than the minimum every month; moving from $900 to $1,500 in the example halves the term and saves thousands in interest.
- Avoid new purchases while paying down — new spend restarts interest on a higher balance.
- Put insurance and membership in monthly fees; fixed fees lengthen payoff like a lower payment.
- With multiple debts, compare payoff order in debt payoff.
- Check capacity with debt-to-income ratio before raising limits.
- If you are considering a balance transfer or personal loan, model personal loan payments and early loan payoff.
Common mistakes
- Treating the minimum as “fine” because the account stays current — it often prioritizes interest and stretches principal for years.
- Using a promo 0% rate after it expired instead of the revolving purchase APR.
- Ignoring balance protection, annual fees, or fixed commissions in the effective payment.
- Comparing only a comfortable payment and not total paid.
- Choosing a payment that only covers interest — the tool flags it; in real life the balance stalls or grows.
What is included and what is not
Included (reference model):
- Simple monthly interest on remaining balance (APR / 12)
- Fixed monthly payment
- Fixed monthly fees taken before principal
- Cap and “payment too low” alert
May differ from your statement:
- Regulated minimum or % of balance
- Grace periods, 0% installments, or promos
- Late fees, penalties, and different compounding
- Rounding, taxes on fees, or insurance that changes with balance
- Biweekly or irregular payments
This tool is educational and is not credit advice or an issuer offer. Real rates, minimums, and fees depend on your contract, credit history, and bank. Check your statement and current terms before payment or consolidation decisions.
Frequently asked questions
With a fixed payment, each month charges interest on the balance, subtracts fees, and applies the rest to principal until the balance is zero. If payment ≤ interest + fees, the debt does not fall.
The minimum often covers mostly interest and a tiny slice of principal. The term stretches and monthly compounding multiplies total cost — see the $600/month row in the table.
Approximate APR as monthly rate × 12. Example: 3.5% monthly ≈ 42% APR. Use the revolving purchase rate, not an expired 0% promo.
Balance insurance, membership amortized monthly, fixed commissions, or other auto charges that do not reduce principal. Use 0 if none apply.
Run each card separately, or sum balances only if rates are similar. To prioritize payoff order across debts, use debt payoff.
Only if loan rate + fees cut total cost and you can avoid reloading the card. Compare with personal loan and check debt-to-income ratio.