How to use this calculator
- Enter loan principal, nominal annual rate (%), monthly periods.
- Choose a display currency, then select Calculate. Results also update after a brief pause while you edit.
- Read the result with the assumptions below. Export details or save a second scenario to compare your choices.
Formula and method
Assumptions and limitations
This is equal-principal amortization, not equal-payment EMI. Fixed rate, no fees and unrounded intermediate balances.
Worked example
For 1,200 at 12% over 12 months, principal is 100 monthly. Payments decline from 112 to 101; interest totals 78.
What the result means
Build declining payments with an equal amount of principal repaid each month.
Common questions
How is the calculation performed?
Principal per period = original principal / periods. Monthly interest is opening balance × nominal annual rate / 12.
What does the model leave out?
This is equal-principal amortization, not equal-payment EMI. Fixed rate, no fees and unrounded intermediate balances.
Methodology and transparency
Calculation specification reviewed on 2026-10-14. Mathematical implementation is tested against independent reference fixtures. This does not imply review by a licensed financial professional. Read the testing and precision policy.