How to use this calculator
- Enter loan principal, initial nominal annual rate (%), nominal rate after reset (%), months before rate reset, 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
Reset must occur before the loan ends. It is a two-stage scenario, without rate caps, index data, fees or later resets.
Worked example
A 12,000 loan over 12 months at 0% pays 1,000 monthly; resetting after six months to another 0% leaves the payment unchanged.
What the result means
Model a single rate reset and inspect the change in installments and remaining interest.
Common questions
How is the calculation performed?
Calculate an initial amortizing payment over the full term; after the entered reset month, recalculate payment from the remaining balance, new rate and remaining term.
What does the model leave out?
Reset must occur before the loan ends. It is a two-stage scenario, without rate caps, index data, fees or later resets.
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.