THE NUMBERS, EXPLAINED
How to use this calculator.
Same-day deliveries with inclusive windows, no exclusions. Early and late arrivals both count as outside the promised window; lateness measures only arrival after window end.
Start with your inputs
Enter actual arrival minutes after midnight, window start minutes, window end minutes. Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Actual arrival minutes after midnight | 550,610,680 |
| Window start minutes | 540,600,660 |
| Window end minutes | 560,620,670 |
A worked example
With the example inputs above, on-time deliveries (%) is 66.666667. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| On-time deliveries (%) | 66.666667 |
| Lateness by delivery (min) | 0, 0, 10 |
| Early deliveries | 0 |
How this is calculated
On-time deliveries (%)
Count arrivals inside their windows and divide by deliveries.
Lateness by delivery (min)
Subtract window end from arrival, floored at zero.
Early deliveries
Count arrivals before promised window start.
Symbols and units
- a
- Actual arrival minutes after midnight
- b
- Window start minutes
- c
- Window end minutes
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
Same-day deliveries with inclusive windows, no exclusions. Early and late arrivals both count as outside the promised window; lateness measures only arrival after window end.
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?
On-time deliveries (%); Lateness by delivery (min); Early deliveries. 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: Same-day deliveries with inclusive windows, no exclusions. Early and late arrivals both count as outside the promised window; lateness measures only arrival after window end.
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.
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