FeiRate Support
Updated: October 14, 2026
Developer: Feirong Gao (高飞荣 / 子义飞云)
Contact: zyfly_app@qq.com
FeiRate is a free offline interest and repayment calculator in Simplified Chinese, Traditional Chinese and English. No registration, advertising or in-app purchases.
What can I calculate?
Enter a principal, assumed annual rate and duration in months. Calculate simple interest, compound interest, fixed-payment repayment or equal-principal repayment. View period-by-period figures, compare scenarios, save named scenarios and share result summaries or export CSV schedules using system controls.
Calculation conventions
Enter the annual rate as a percentage: 5 means 5%. Duration is 1–600 months. Simple interest uses the annual rate multiplied by months divided by 12. Compound interest supports annual, quarterly or monthly compounding; partial periods use a fractional exponent. Repayment calculations use monthly periods and a nominal annual rate divided by 12. Repayment amounts are rounded to two decimal places, with the final payment adjusted to settle the balance. The last payment may differ. All amounts use one consistent unit; the app does not convert currencies.
Results are mathematical estimates under fixed assumptions. They exclude fees, taxes, insurance, penalties, holidays and special contractual rules. They are not bank quotes or guarantees. Actual contracts and statements take precedence. The app does not offer financial products, arrange loans, execute transactions, assess credit or give personalized financial advice.
Where are scenarios saved?
Scenarios are stored in this device’s app storage. Reopen or delete them from the scenario list. There is no account or app-level cloud sync; system backups depend on device settings. Export any results you wish to keep before deleting the app. Result exports are not backups that automatically restore scenarios.
Offline use and export
Calculations, scenarios and built-in help work offline. Sharing or CSV export opens the corresponding system interface; you choose a destination or receiving app. A destination service may require a network connection. FeiRate does not automatically upload content.
Report a problem
Email your device model, iOS version, calculation method, inputs, expected result and actual result. A screenshot without personal information may help. Please do not send identity documents, bank account numbers or other sensitive information.