Auto repair Usable Material Cost
Cost per usable unit = purchase cost / (purchased units × usable share)
Gather repair orders, parts invoices and technician time logs. Include parts, technician time, and shop overhead. The starting figures are examples. Replace them with your own records.
Formula and worked example
Cost per usable unit = purchase cost / (purchased units × usable share)
| Input | Example |
|---|---|
| Purchased material cost | 1,000 |
| Purchased units | 100 |
| Usable share | 90 % |
| Calculated result | 11.1111 per usable unit |
Choose reliable inputs
Separate parts, technician time and bay availability for each repair order. For this auto repair calculation, use repair orders, parts invoices and technician time logs and a consistent definition of one repair order.
- Parts: include the portion belonging to this repair order or reporting period, and record where the value came from.
- Technician time: include the portion belonging to this repair order or reporting period, and record where the value came from.
- Shop overhead: include the portion belonging to this repair order or reporting period, and record where the value came from.
Use the same currency for every money input. Do not mix weekly costs with monthly revenue, or count the same expense in both an itemised cost and allocated overhead.
Why is purchase price per unit below usable cost?
Yield must be greater than zero. Keep purchased and usable quantities in the same measurement unit.
What if this input changes?
If purchased material cost rises by 10%, this example changes by 1.1111 per usable unit. This shows the effect of one change; it does not predict what will happen.
Open the calculator, save your baseline, then change the input supported by the least reliable estimate in your records. Compare both scenarios before committing to a price or capacity promise.