Mortgage Amortization Schedule in Excel — built for you
Enter your numbers and download an Excel workbook with live formulas: a full monthly payment breakdown, fixed and variable rate tracks, and annuity (Spitzer) or interest-only repayment.
What you get
- Fully editable, formula-driven Excel workbook — change any assumption and the whole model recalculates
- Up to 5 rate tracks: fixed unlinked (Kalatz), fixed CPI-linked, prime-linked and variable-every-5-years
- Three repayment methods: annuity (Spitzer), equal principal and interest-only with a balloon (bullet)
- Monthly CPI indexation and 5-year rate resets modelled with live formulas
- Full month-by-month amortization schedule per track, plus a combined and an annual roll-up sheet
- Summary with first and highest monthly payment, total interest, CPI differentials and total cost
- Sensitivity analysis across rate changes from −2% to +2% and alternative CPI scenarios
- Output in English or Hebrew (RTL sheets)
Free vs paid
| Feature | Free (ChatGPT / Claude) | Prompt2File |
|---|---|---|
| Quick mortgage estimate | Yes | Yes |
| Live-formula Excel workbook | No | Yes |
| Multiple interest tracks | No | Yes |
| Full amortization schedule | No | Yes |
| Rate & CPI sensitivity analysis | No | Yes |
| Editable assumptions that recalculate the whole model | No | Yes |
Simple, transparent pricing
One-time payment per deliverable. No subscriptions, no credits.
See pricingHow it works
- 1
Enter your mortgage details — property price, financing %, and interest tracks
- 2
Review the summary and pay securely
- 3
Download your Excel file with full amortization schedule
Sample preview
Sample rows from a Track sheet — 1,000,000 principal, 5% annual interest, 25 years, annuity (Spitzer). Monthly payment: 5,845.90.
| Month | Payment | Interest | Principal | Closing balance |
|---|---|---|---|---|
| 1 | 5,845.90 | 4,166.67 | 1,679.23 | 998,320.77 |
| 2 | 5,845.90 | 4,159.67 | 1,686.23 | 996,634.54 |
| 3 | 5,845.90 | 4,152.64 | 1,693.26 | 994,941.28 |
| … | … | … | … | … |
| 300 | 5,845.90 | 24.26 | 5,821.64 | 0.00 |
How the maths works
Every figure in the workbook comes from three simple rules, written out as live Excel formulas you can inspect and edit.
- Monthly payment (annuity): payment = P × r ÷ (1 − (1 + r)^−n), where P is the loan amount, r the monthly rate (annual rate ÷ 12) and n the term in months. For an equal-principal track the principal portion is fixed instead and the payment declines each month.
- Splitting each payment: interest = opening balance × monthly rate; principal = payment − interest. Early on almost all of the payment is interest; over time the principal share grows.
- Carrying the balance forward: closing balance = opening balance − principal (plus the CPI adjustment on an index-linked track). That closing balance becomes the next month's opening balance, and the last one lands on zero.
An informational calculation tool, not financial, mortgage, or investment advice. Verify with a licensed advisor before making decisions.