English interface
Reducing-balance loan calculator
Estimate equal instalments and total interest for a fixed-rate amortizing loan.
ReviewedHigh-impact
Saves this tool's name on this device only (up to 20). No form values.
Only visible result text is included. Form fields are not read. Review sensitive values before sharing.
How to use it
- Enter principal, annual rate and the number of equal monthly instalments.
- Review the instalment and total interest calculated from a reducing balance.
- Compare the result with the lender's schedule, fees, insurance and rounding rules.
Important limitation
Floating rates, fees, insurance, day-count conventions and lender rounding may change the actual cost.
The interactive form is fully localized in English.
Reviewed 2026-09-11; next review 2026-12-11.
Fixed instalments and costs from equal monthly cash flows have been checked, including numerical edge cases. Floating rates and unentered charges are excluded.
Sources
Loan Amortization — present value of equal end-of-period paymentsOpenStax, Rice University · opens in a new tabSupports fixed-rate amortization and present value of equal end-of-period payments, not Thai lending rates.Source checked 2026-09-11การเปิดเผยข้อมูลดอกเบี้ยและค่าใช้จ่าย — เอกสารแนบ 5 หน้า 14–15ธนาคารแห่งประเทศไทย · opens in a new tabContext for disclosing assumptions and charges; does not certify this IRR formula as the regulatory EIR for every product or validate a contract.Source checked 2026-09-11Traceable review record
Site changelogReview history
This is the recorded review history available in the repository, not an inferred release history. Dates are added only when evidence is recorded.
- Current review snapshot recorded
Fixed instalments and costs from equal monthly cash flows have been checked, including numerical edge cases. Floating rates and unentered charges are excluded.
Method version: review-2026-09-11