THE NUMBERS, EXPLAINED
How to use this calculator.
Undiscounted user-specified horizon, resale and use assumptions. Availability, financing and taxation are excluded.
Start with your inputs
Enter forecast use (days), external subhire rate (currency/day), purchase price (currency), expected resale proceeds after horizon (currency), owned variable cost (currency/use-day), owned fixed cost over horizon (currency). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Forecast use (days) | 50 |
| External subhire rate (currency/day) | 100 |
| Purchase price (currency) | 6000 |
| Expected resale proceeds after horizon (currency) | 2000 |
| Owned variable cost (currency/use-day) | 20 |
| Owned fixed cost over horizon (currency) | 500 |
A worked example
With the example inputs above, subhire total (currency) is 5,000. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Subhire total (currency) | 5,000 |
| Owned net cost over horizon (currency) | 5,500 |
| Subhire minus owned cost (currency) | -500 |
| Break-even use days | 56.25 |
How this is calculated
Subhire total (currency)
Multiply forecast usage by external day rate.
Owned net cost over horizon (currency)
Deduct expected resale and add owned variable and fixed costs.
Subhire minus owned cost (currency)
Compare complete horizon costs.
Break-even use days
Divide fixed ownership net cost by per-day saving.
Symbols and units
- a
- Forecast use (days)
- b
- External subhire rate (currency/day)
- c
- Purchase price (currency)
- d
- Expected resale proceeds after horizon (currency)
- e
- Owned variable cost (currency/use-day)
- f
- Owned fixed cost over horizon (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
Undiscounted user-specified horizon, resale and use assumptions. Availability, financing and taxation are excluded.
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?
Subhire total (currency); Owned net cost over horizon (currency); Subhire minus owned cost (currency); Break-even use days. 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: Undiscounted user-specified horizon, resale and use assumptions. Availability, financing and taxation are excluded.
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: Calculate a Break-Even Point in Units and Dollars ↗
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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