THE NUMBERS, EXPLAINED
How to use this calculator.
Contribution excludes wages and fixed overhead. All travel time and expenses are round trips.
Start with your inputs
Enter job fees by travel zone (currency), round-trip travel minutes by zone, work minutes per job, travel expense by zone (currency), materials per job (currency). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Job fees by travel zone (currency) | 100,150 |
| Round-trip travel minutes by zone | 30,60 |
| Work minutes per job | 60 |
| Travel expense by zone (currency) | 10,20 |
| Materials per job (currency) | 20 |
A worked example
With the example inputs above, contribution by zone (currency) is 70, 110. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Contribution by zone (currency) | 70, 110 |
| Contribution per occupied hour by zone | 46.666667, 55 |
How this is calculated
Contribution by zone (currency)
Deduct travel expense and materials from job fees.
Contribution per occupied hour by zone
Normalize contribution by travel plus work time.
Symbols and units
- a
- Job fees by travel zone (currency)
- b
- Round-trip travel minutes by zone
- c
- Work minutes per job
- d
- Travel expense by zone (currency)
- e
- Materials per job (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
Contribution excludes wages and fixed overhead. All travel time and expenses are round 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?
Contribution by zone (currency); Contribution per occupied hour by zone. 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: Contribution excludes wages and fixed overhead. All travel time and expenses are round 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: 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 →