THE NUMBERS, EXPLAINED
How to use this calculator.
No overlapping cause attribution on the same asset-day. Lost contribution assumes demand would have filled every unavailable day.
Start with your inputs
Enter downtime rental-days by cause, total fleet calendar asset-days, lost contribution per unavailable rental-day (currency). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Downtime rental-days by cause | 5,3,2 |
| Total fleet calendar asset-days | 100 |
| Lost contribution per unavailable rental-day (currency) | 40 |
A worked example
With the example inputs above, total downtime rental-days is 10. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Total downtime rental-days | 10 |
| Downtime share of fleet calendar (%) | 10 |
| Scenario contribution lost by cause (currency) | 200, 120, 80 |
How this is calculated
Total downtime rental-days
Add mutually exclusive asset-day outages by cause.
Downtime share of fleet calendar (%)
Compare outages with fleet asset-days.
Scenario contribution lost by cause (currency)
Apply the assumed contribution opportunity per outage day.
Symbols and units
- a
- Downtime rental-days by cause
- b
- Total fleet calendar asset-days
- c
- Lost contribution per unavailable rental-day (currency)
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
No overlapping cause attribution on the same asset-day. Lost contribution assumes demand would have filled every unavailable day.
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?
Total downtime rental-days; Downtime share of fleet calendar (%); Scenario contribution lost by cause (currency). 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: No overlapping cause attribution on the same asset-day. Lost contribution assumes demand would have filled every unavailable day.
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: Describe and Identify Cost Drivers ↗
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 →