THE NUMBERS, EXPLAINED
How to use this calculator.
Travel cost per kilometre is supplied by the user and can include fuel and running cost. All travel is attributed to this shopping trip.
Start with your inputs
Enter basket saving before travel, round-trip distance (km), travel cost (currency/km), trip time (h), chosen time value (currency/h), parking and tolls. Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Basket saving before travel | 25 |
| Round-trip distance (km) | 20 |
| Travel cost (currency/km) | 0.3 |
| Trip time (h) | 1 |
| Chosen time value (currency/h) | 10 |
| Parking and tolls | 2 |
A worked example
With the example inputs above, cash travel cost is 8. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Cash travel cost | 8 |
| Net saving including time | 7 |
| Minimum basket saving to break even | 18 |
How this is calculated
Cash travel cost
Add distance cost, parking and tolls.
Net saving including time
Subtract cash travel expense and valued trip time from basket savings.
Minimum basket saving to break even
Add all cash and time costs.
Symbols and units
- a
- Basket saving before travel
- b
- Round-trip distance (km)
- c
- Travel cost (currency/km)
- d
- Trip time (h)
- e
- Chosen time value (currency/h)
- g
- Parking and tolls
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
Travel cost per kilometre is supplied by the user and can include fuel and running cost. All travel is attributed to this shopping trip.
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?
Cash travel cost; Net saving including time; Minimum basket saving to break even. 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: Travel cost per kilometre is supplied by the user and can include fuel and running cost. All travel is attributed to this shopping trip.
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: Solve proportions and their applications ↗
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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