THE NUMBERS, EXPLAINED
How to use this calculator.
Empirical sample proportions only; recovery is available after scheduled running time. No probability extrapolation beyond observed trips.
Start with your inputs
Enter observed running times (min), scheduled running time (min), additional recovery allowance (min). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Observed running times (min) | 40,45,50,55 |
| Scheduled running time (min) | 50 |
| Additional recovery allowance (min) | 5 |
A worked example
With the example inputs above, trips exceeding schedule (%) is 25. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Trips exceeding schedule (%) | 25 |
| Trips exceeding schedule plus recovery (%) | 0 |
| Worst observed remaining delay (min) | 0 |
How this is calculated
Trips exceeding schedule (%)
Count observed running times exceeding scheduled minutes.
Trips exceeding schedule plus recovery (%)
Count observed times beyond the schedule plus recovery.
Worst observed remaining delay (min)
Subtract scheduled time and recovery from the largest observation.
Symbols and units
- a
- Observed running times (min)
- b
- Scheduled running time (min)
- c
- Additional recovery allowance (min)
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
Empirical sample proportions only; recovery is available after scheduled running time. No probability extrapolation beyond observed trips.
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?
Trips exceeding schedule (%); Trips exceeding schedule plus recovery (%); Worst observed remaining delay (min). 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: Empirical sample proportions only; recovery is available after scheduled running time. No probability extrapolation beyond observed trips.
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
OpenStax: Solve proportions and their applications ↗
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 →