Mortgage amortization workspace
Switch methods or change prepayment to reactively update payment, interest and the schedule chart.
Ready for a local calculation.
No uploadThe grace period is modeled as interest-only; an upfront prepayment reduces principal. Bank-specific rules may differ.
All inputs stay in this browser tab; no account, upload endpoint or remote storage is used.
Mortgage model features
Compare annuity and equal-principal methods with the same loan assumptions and inspect interest and balance paths.
3-step guide
- 1Enter the assumptions and choose an input mode.
- 2Run the local calculation and inspect metrics and the Chart.js visualization.
- 3Copy the summary or download the local text result.
Browser-only privacy
All inputs stay in this browser tab; no account, upload endpoint or remote storage is used.
Financial outputs are scenario estimates; verify material decisions with qualified professionals.
Frequently asked questions
How is the grace period modeled?
Each grace-period month pays interest only and does not reduce principal.
Are prepayment penalties included?
No. The input is treated as an upfront principal reduction without bank-specific penalties.
Does this replace a bank quote?
No. Actual loans depend on rounding, fees, resets and underwriting.