THE NUMBERS, EXPLAINED
How to use this calculator.
Undiscounted cost per assumed service year; excludes energy, reliability changes and resale. User estimates useful lives.
Start with your inputs
Enter replacement part price, fitting charge, expected extra service (years), new appliance installed price, expected new appliance service (years). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Replacement part price | 40 |
| Fitting charge | 60 |
| Expected extra service (years) | 2 |
| New appliance installed price | 600 |
| Expected new appliance service (years) | 10 |
A worked example
With the example inputs above, repair option cost per service year is 50. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Repair option cost per service year | 50 |
| Replacement cost per service year | 60 |
| Maximum total repair cost at equal annual cost | 120 |
How this is calculated
Repair option cost per service year
Add part and fitting, then divide by extra life.
Replacement cost per service year
Divide new installed price by its assumed life.
Maximum total repair cost at equal annual cost
Multiply replacement annual cost by repair extension years.
Symbols and units
- a
- Replacement part price
- b
- Fitting charge
- c
- Expected extra service (years)
- d
- New appliance installed price
- e
- Expected new appliance service (years)
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 cost per assumed service year; excludes energy, reliability changes and resale. User estimates useful lives.
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?
Repair option cost per service year; Replacement cost per service year; Maximum total repair cost at equal annual cost. 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 cost per assumed service year; excludes energy, reliability changes and resale. User estimates useful lives.
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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