THE NUMBERS, EXPLAINED
How to use this calculator.
Select actual or booked billing explicitly; tariff, consumables and policy are supplied by your facility. No minimum-charge rules are added.
Start with your inputs
Enter booked equipment time (hours), actual equipment time (hours), usage tariff (currency/hour), consumables (currency), charge basis (0 actual, 1 booked). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Booked equipment time (hours) | 10 |
| Actual equipment time (hours) | 8 |
| Usage tariff (currency/hour) | 20 |
| Consumables (currency) | 30 |
| Charge basis (0 actual, 1 booked) | 0 |
A worked example
With the example inputs above, billable equipment hours (hours) is 8. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Billable equipment hours (hours) | 8 |
| Usage charge (currency) | 160 |
| Total recharge (currency) | 190 |
| Unused booked time (hours) | 2 |
How this is calculated
Billable equipment hours (hours)
Use actual or booked time according to selected policy.
Usage charge (currency)
Multiply billable hours by tariff.
Total recharge (currency)
Add consumables.
Unused booked time (hours)
Subtract actual use from booked hours, floored at zero.
Symbols and units
- a
- Booked equipment time (hours)
- b
- Actual equipment time (hours)
- c
- Usage tariff (currency/hour)
- d
- Consumables (currency)
- e
- Charge basis (0 actual, 1 booked)
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
Select actual or booked billing explicitly; tariff, consumables and policy are supplied by your facility. No minimum-charge rules are added.
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?
Billable equipment hours (hours); Usage charge (currency); Total recharge (currency); Unused booked time (hours). 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: Select actual or booked billing explicitly; tariff, consumables and policy are supplied by your facility. No minimum-charge rules are added.
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 Prealgebra 2e — arithmetic and proportions ↗
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 →