Loan Repayment

About the Loan Repayment calculator

The same loan at the same quoted rate costs wildly different amounts depending on how the interest is computed. This builds the full schedule for each method — equal instalments, equal principal with declining interest, and interest on the original balance — then compares them side by side. For the flat method it also back-solves the equivalent annuity rate, so you can see the real number behind the advertised one.

Basis & method

• Equal instalments (annuity): A = P·i / (1 − (1+i)⁻ᴺ), with interest on the remaining balance each month.
• The rate entered is a nominal annual rate; the monthly rate is annual / 12. Promotional first-period rates and early-repayment fees are not modelled.

This tool is for reference, not tax or legal advice. A real payslip also depends on company-specific arrangements (who bears the insurance, caps on tax-exempt allowances, internal pay grades). Check with your C&B team or the tax authority before acting on it.