THE NUMBERS, EXPLAINED
How to use this calculator.
IDs are user-assigned positive integers, not DOM inspection. Required IDs must be unique; repeated observed IDs are reported as revisits, and unknown IDs flag inventory gaps.
Start with your inputs
Enter required interactive element ids (positive integers), observed keyboard focus traversal ids. Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Required interactive element IDs (positive integers) | 1,2,3,4 |
| Observed keyboard focus traversal IDs | 1,3,4 |
A worked example
With the example inputs above, required controls absent from keyboard route is 2. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Required controls absent from keyboard route | 2 |
| Observed IDs absent from inventory | |
| Repeated focus entries (count) | 0 |
How this is calculated
Required controls absent from keyboard route
Find required IDs never observed in keyboard traversal.
Observed IDs absent from inventory
Identify first occurrences of unlisted control IDs.
Repeated focus entries (count)
Count repeated traversal IDs after their first occurrence.
Symbols and units
- a
- Required interactive element IDs (positive integers)
- b
- Observed keyboard focus traversal IDs
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Assumptions and limits
IDs are user-assigned positive integers, not DOM inspection. Required IDs must be unique; repeated observed IDs are reported as revisits, and unknown IDs flag inventory gaps.
Calculations use the values you enter. Blank or invalid inputs show an error instead of silently substituting zero. Results are displayed to useful precision; calculations retain the underlying numeric precision.
Questions about this tool
What does the result tell me?
Required controls absent from keyboard route; Observed IDs absent from inventory; Repeated focus entries (count). The result applies to the method and inputs described above. Check the units and assumptions before using it in a decision.
Why might another calculator differ?
Differences in units, rounding, timing or model definitions can produce different answers. Compare the input definitions and the method, rather than only the final number. For this tool: IDs are user-assigned positive integers, not DOM inspection. Required IDs must be unique; repeated observed IDs are reported as revisits, and unknown IDs flag inventory gaps.
Are my inputs stored or sent to AI?
Calculations on this page happen in your browser. The separate AI question finder sends its submitted conversation to OpenAI; these calculator fields are not sent. Favourites and recent tool names are stored locally. A shared link contains the inputs you choose to include.
Further reading
W3C Understanding Focus Order ↗
Background reading; this does not imply endorsement or independent review of SumFizz.
Review status
Software example and browser checks are recorded in our quality report. No external expert review is claimed. Created with coding assistance; calculations run as ordinary browser code.
Read the quality report →