Credit Card Interest Calculation — what APR really means and the interest formula, with a simple example.

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Last updated: 17 August 2026

The Formula

Interest = Average Daily Balance × Daily Rate × Days

Daily rate = APR ÷ 365. Example: APR 42% (India) → daily rate 0.115%.

Worked Example

Step | Value. Balance (30 days): ₹30,000. Daily rate (42%/365): 0.115%. Monthly interest: ₹30,000 × 0.00115 × 30 = ₹1,035. That's why full payment is the cheapest option hai — 1,035/month ka interest bachta hai.

Track in Excel

Statement ko Excel me convert karke monthly interest charge track do — agar badh raha hai to balance carry ho raha hai. EMI tracking bhi see.

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Frequently Asked Questions

Q: How is credit card interest calculated?

A: Average daily balance × daily rate (APR/365) × days. It appears in the "Interest Charged" line on the statement.

Q: What is a good APR?

A: In India, 30–48% is normal (depends on the card). USA me 18-30%. The best APR is 0% — when you pay in full.

⚠️ Important Note: Credit card rates, fees and rules vary by bank and card (and change over time). This guide is general information — confirm details with your bank's official statement, fee schedule or customer care. Our tool only helps extract your statement data into Excel — it does not provide financial advice. Poora disclaimer read.