Months and interest to clear a card at a fixed payment.
Time to clear
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Total interest
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Total paid
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Your breakdown
Updates live as you type
Item
Amount
Worked example
Take a R30,000 card balance at 20 percent a year, paying a fixed R2,000 a month. Interest is charged monthly at one twelfth of 20 percent, so the first month adds R500 to the balance. The R2,000 payment covers that R500 and knocks R1,500 off the balance. Each month the interest is smaller because the balance is smaller, so more of the fixed payment goes to principal. The card clears in 18 months, with R4,813 of total interest and R34,813 paid in all. The key test is the first month of interest: because R2,000 comfortably exceeds R500, the balance falls every month. If the payment were R500 or less it would only cover interest and the balance would never move.
Step
Amount
Starting balance
R30,000
First month interest (20% / 12)
R500
Total interest paid
R4,813
Total paid
R34,813
Time to clear
18 months
How it is calculated
The calculator simulates the card month by month rather than using a single formula, because a fixed payment against a falling balance does not have a tidy closed form. Each month it adds one twelfth of the annual rate to the balance, then subtracts your payment, and repeats until the balance is gone. Because interest is front-loaded, the early payments clear less principal than the later ones, which is why a small drop in the monthly payment can add many months to the payoff. Before it starts, the tool checks whether your payment beats the very first month of interest; if it does not, it reports that the card can never be cleared at that payment and tells you the interest you would need to exceed. The total interest is simply the sum of every monthly interest charge along the way.
Frequently asked questions
How long will it take to pay off my credit card?
It depends on the balance, the interest rate, and how much you pay each month. Interest is charged monthly on the outstanding balance, so a large part of a small payment can go to interest rather than the balance. If your payment is below the first month of interest, the balance never falls and the card cannot be cleared.
What interest rate do South African credit cards charge?
South African credit card rates are capped by the National Credit Act. The maximum prescribed rate for credit cards is the repo rate plus 14 percent per year. As of 2025 this results in a cap of roughly 22.25 percent per year, though many banks charge below that ceiling depending on the applicant risk profile.
Is credit card interest tax deductible in South Africa?
No. SARS does not allow a deduction for personal credit card interest under section 24J of the Income Tax Act. The deduction only applies to interest incurred in the production of income, meaning business or investment borrowing qualifies but consumer credit card debt does not.
What is the minimum payment required on a South African credit card?
Under the National Credit Act, the minimum payment must be at least 3 percent of the outstanding balance or R25, whichever is greater. Paying only the minimum extends the payoff period significantly and maximises total interest paid, so this calculator shows the true cost of any chosen payment amount.