Free Credit Card Calculators
All tools are free, require no sign-up, and never affect your credit score.
Credit Card Comparison
Compare credit cards, BNPL, and payment plans side by side. See total cost, interest, and payoff timeline.
Rewards Calculator
Find the credit card that maximizes your rewards based on how you spend. Includes signup bonuses.
Debt Payoff Planner
Snowball vs avalanche comparison. See when you'll be debt-free and how much interest you'll save.
Minimum Payment Calculator
See the shocking true cost of making only minimum payments — years of interest and thousands wasted.
Annual Fee Calculator
Is that $95–$550 annual fee worth it? See the math — rewards vs fees vs free alternatives.
Credit Score Simulator
See how your credit score affects the interest rate you qualify for — and how much it costs you.
Loan vs Balance Transfer
Compare personal loans vs balance transfer offers to pay off debt. Which saves you more?
JSON API
Programmatic access to all calculators. Free, no auth required.
GET https://creditstud.io/api/compare?amount=2000&months=12&score=720
GET https://creditstud.io/api/rewards?monthly=3000&dining=300
GET https://creditstud.io/api/debt-planner?debts=[...]
GET https://creditstud.io/api/min-payment?balance=5000&apr=22.24
GET https://creditstud.io/api/cards
GET https://creditstud.io/api/
Full documentation: creditstud.io/api/ · OpenAPI spec: openapi.json
Card Reviews
In-depth reviews with data-driven verdicts.