This page explains how Excelavon guides and tools are produced, checked and corrected.
What we aim for
- Every guide answers one task or question, starting with the answer and then the steps.
- Formulas are written so they can be pasted into Excel as shown. Cell references in examples are stated, so you can match them to your sheet.
- Where behaviour differs between versions (Excel for Microsoft 365, Excel 2021, 2019, 2016, Excel for the web, Mac), the guide says which versions it covers.
- Guides do not give financial, tax, legal or medical advice. Calculations such as loan payments are illustrations of how a formula works.
How the tools are checked
The calculations behind each tool are run against a fixed list of worked examples with known answers, for example a 200,000 loan at 6% over 30 years (monthly payment 1,199.10), the serial number of 1 January 2023 in the 1900 date system (44927), and the column number of XFD (16,384). The formulas the tools generate are also evaluated in a separate open-source spreadsheet engine, and the result must match the tool’s own answer. The checks are repeated whenever a tool changes.
The tools run entirely in your browser. What you type is not sent to us.
Sources
Function behaviour is described from Microsoft’s published function reference (Microsoft Support). Where a guide relies on a specific documented behaviour, such as the 1900 leap-year compatibility rule for date serials, it says so.
Updates and corrections
Guides are reviewed when a reader reports a problem or when Excel changes the behaviour described. Material errors are corrected and listed on the corrections page with the date. To report one, use the contact form or write to info@excelavon.com.