What a credit card balance really costs once you revolve

How credit card interest is charged in India, why paying the minimum keeps the balance almost still, and what losing the interest-free period actually costs.

The short answer: A credit card is free credit until the statement due date and one of the most expensive borrowings available the moment it is not. Revolving rates in India are commonly quoted per month — often somewhere around 3 to 3.5% — which annualises to well above 40%, and two features make it worse than the headline suggests: interest is typically charged from the transaction date rather than the statement date once you revolve, and the interest-free period does not apply to new purchases while a balance is outstanding. Paying the minimum is not a partial payment; on a typical balance it barely covers the interest, which is why a balance paid at the minimum moves almost imperceptibly.

Key points

Card rates are quoted monthly; annualise before comparing them to any loan or any expected investment return.
Once you revolve, new purchases usually attract interest from day one — the interest-free period is suspended.
The minimum payment is designed to keep the account current, not to reduce the balance meaningfully.
Clearing a card balance is a guaranteed return at the card's rate, which outranks any investment decision you could make.

The rate, annualised

Annualising a monthly card rate: Annual rate = (1 + m)^12 − 1

m — the monthly rate shown on your statement, as a decimal.
At m = 0.030 → about 42.6% a year.
At m = 0.035 → about 51.1% a year.
Simple multiplication by 12 understates it, because the interest itself compounds.

The monthly presentation is the reason cards are underestimated. Three per cent sounds like a small number and is one of the highest borrowing rates a household will ever encounter. Nothing in a normal financial life competes with it: no investment reliably returns forty per cent, and no other consumer debt charges it.

What the minimum payment actually does

A minimum payment is commonly a small percentage of the outstanding balance. Its purpose is to keep the account in good standing, not to reduce what you owe, and on a typical balance most of it is consumed by that month's interest.

A ₹1,00,000 balance at 3.2% a month, paying only the minimum

Monthly interest: ₹1,00,000 × 3.2% = ₹3,200
Minimum payment at 5%: ₹5,000
Applied to principal: ₹5,000 − ₹3,200 = ₹1,800
Balance after one month: ₹98,200
Reduction achieved: 1.8% of the balance, in a month

At that pace the balance is still substantial years later, and the total interest paid vastly exceeds the original purchase. The minimum is not slow progress — it is close to no progress, and it is designed that way.

This is also why a card balance outranks everything else in a payoff plan. Clearing it is a guaranteed return at the card's rate, and no portfolio offers a guaranteed forty per cent.

Getting out, in order

Stop using the card entirely until the balance is cleared. While a balance revolves, each new purchase starts accruing interest immediately, so continuing to spend on it is borrowing at the full rate.
Find a cheaper rate for the existing balance. An EMI conversion from the issuer, a personal loan, or a balance transfer — checking fees and total cost over the term, not the monthly payment.
Direct everything spare at it. It is almost certainly your highest-rate debt and therefore first under the avalanche method by a wide margin.
Keep a small buffer while you do. Without one, the next unexpected expense goes back on the card and the progress reverses.
Then set up full-balance auto-payment, which is the mechanism that stops this recurring.

Used with the balance cleared every month, a card is a genuinely useful instrument — a free short-term float, a purchase record, and a factor in what moves a credit score. The entire difference between useful and expensive is whether the statement is paid in full.

Expense Tracker: The balance that revolves is almost never the purchase anybody remembers making — it is the accumulation of ones nobody logged. A month of recorded spending in the Expense Tracker shows which category is actually filling the statement, and that is the one to attack first.

Frequently asked questions

What does a credit card actually cost per year?

Take the monthly rate on your statement and compound it: a rate of 3.2% a month is (1.032)^12 − 1, or roughly 46% a year. Rates vary by card and issuer and the range commonly quoted in India sits around 3 to 3.5% a month, so annualised figures in the forties are typical. Use your own statement rather than any published figure.

Why did I get charged interest even after paying most of the bill?

Because on most cards the interest-free period applies only when the statement is cleared in full. Pay 90% and the remaining balance typically attracts interest from each transaction date rather than from the due date, and new purchases in the following cycle usually lose their interest-free period too. Paying "most of it" is meaningfully different from paying all of it.

Is a card balance worth converting to an EMI?

Frequently yes, because a card issuer's EMI conversion rate is usually far below the revolving rate — but check the processing fee, whether GST applies, and the total cost over the tenure rather than the monthly figure. A personal loan at a lower rate can be better again. Any of these beats revolving, which is the comparison that matters most.

Sources

Reserve Bank of India — credit card and debit card directions