Consumer Credit Math: Credit Cards, APR, Minimum Payments & BNPL
Turn APR into daily interest on the average daily balance, test grace periods, build minimum-payment schedules, compare avalanche vs snowball, balance transfers, BNPL late fees, personal loans and utilisation – every cell checked as you go. Educational, illustrative rates, not financial advice.
The first lesson is free — no account needed.
About this course
A consumer credit math course that runs one fictional borrower's cards, loans and pay-later plans through a spreadsheet, for anyone with a credit card, personal finance students and people who explain credit to others. You turn the APR into a daily periodic rate and calculate a statement's interest from the average daily balance, charge interest only in months the grace period is lost, build a 24-month minimum-payment schedule and compare it with a fixed payment, rank three debts for the avalanche and snowball methods and roll each cleared payment into the next, price a 0% balance transfer against its fee, turn BNPL late fees into an effective annual rate with IRR, compare a personal loan with an origination fee to carrying the balance on a card and score credit utilisation per card. Illustrative rates, educational only, not financial advice. The first lab is free.
Lessons
- APR, Daily Periodic Rate & Average Daily BalanceFree
- Grace Period Logic: Pay in Full or Pay Interest Pro
- Minimum Payment Schedules & Months to Payoff Pro
- Avalanche vs Snowball: Payoff Order, Rollover & Total Interest Pro
- Balance Transfer Offers: Fee vs Interest Saved Pro
- BNPL Instalments & Late Fees: The Effective Cost Pro
- Personal Loan vs Credit Card: PMT, Fees & Total Cost Pro
- Credit Utilisation & Simple Score Factors Pro