Credit Card Payoff
Time to pay down balance
About This Calculator
The credit card payoff calculator shows how long it will take to pay off a balance given fixed monthly payments, and how much total interest you will pay. It also calculates the minimum payment required to pay off the balance within a target number of months — powerful motivation for accelerating debt repayment.
Formula
n = −log(1 − r×P/M) / log(1+r) [months to payoff]
M = minimum monthly payment, P = balance, r = monthly rate
Total interest = (M × n) − P
Example Calculation
$3,500 credit card balance at 19.99% APR, paying $100/month
- Monthly rate r = 0.1999/12 = 0.01666
- n = −log(1 − 0.01666×3500/100) / log(1.01666)
- n = −log(0.4167) / log(1.01666) = 0.8751 / 0.007228 ≈ 51 months
~51 months to pay off; ~$1,600 in total interest
Time to Pay Off $5,000 at 20% APR
| Monthly Payment | Months | Total Interest | Total Paid |
|---|---|---|---|
| $100 | 94 | $4,450 | $9,450 |
| $150 | 44 | $1,614 | $6,614 |
| $200 | 30 | $921 | $5,921 |
| $300 | 20 | $522 | $5,522 |
| $500 | 11 | $246 | $5,246 |
Frequently Asked Questions
Why does paying only the minimum take so long?
Credit card minimums are typically 1-3% of the balance or a set dollar amount. At 20% APR, most of your minimum payment goes to interest, barely reducing principal. It can take 10+ years to pay off a $3,000 balance paying only the minimum.
What is the avalanche vs snowball method?
Avalanche: pay minimums on all cards, put extra money toward the highest-interest card first (saves the most interest). Snowball: pay minimums on all, target the smallest balance first (psychologically motivating). Avalanche is mathematically optimal; snowball improves adherence.
How does credit card interest compound?
Most credit cards compound interest daily. Your balance is multiplied by (1 + APR/365) each day. Over a month, 20% APR = about 1.66% effective monthly rate. Interest compounds on your interest if not paid.
Does paying twice a month help?
Paying bi-monthly slightly reduces average daily balance and thus interest charged. A more impactful strategy is to pay more than the minimum — even an extra $20/month significantly reduces total interest and payoff time.