THE NUMBERS, EXPLAINED
How to use this calculator.
Contribution excludes labour, fixed rent and taxes. Occupied-chair time includes unattended processing when the chair remains occupied.
Start with your inputs
Enter service prices (currency), supplies cost per service (currency), occupied chair minutes per service. Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Service prices (currency) | 60,90 |
| Supplies cost per service (currency) | 10,15 |
| Occupied chair minutes per service | 30,60 |
A worked example
With the example inputs above, service contributions (currency) is 50, 75. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Service contributions (currency) | 50, 75 |
| Contribution per occupied chair-hour | 100, 75 |
| Highest contribution-rate service (1-based) | 1 |
How this is calculated
Service contributions (currency)
Subtract service-specific supplies from receipts.
Contribution per occupied chair-hour
Normalize each service contribution to occupied chair time.
Highest contribution-rate service (1-based)
Choose the first service with the greatest chair-time contribution.
Symbols and units
- a
- Service prices (currency)
- b
- Supplies cost per service (currency)
- c
- Occupied chair minutes per service
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 labour, fixed rent and taxes. Occupied-chair time includes unattended processing when the chair remains occupied.
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?
Service contributions (currency); Contribution per occupied chair-hour; Highest contribution-rate service (1-based). 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 labour, fixed rent and taxes. Occupied-chair time includes unattended processing when the chair remains occupied.
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 →