With the illustrative inputs below, the result is -400 monthly cost difference.
Try this with your own numbersFormula and worked example
Overtime cost difference = extra hours × overtime rate − extra staff monthly cost
| Input | Example |
|---|---|
| Extra hours needed monthly | 80 |
| Overtime hourly cost | 45 |
| Monthly extra staff cost | 4,000 |
| Calculated result | -400 monthly cost difference |
Choose reliable inputs
Plan materials, travel and crew time before committing to a price. For this garage door service calculation, use a completed job sheet, supplier quotes and a crew schedule and a consistent definition of one repair visit.
- Parts: include the portion belonging to this repair visit or reporting period, and record where the value came from.
- Site time: include the portion belonging to this repair visit or reporting period, and record where the value came from.
- Vehicle overhead: include the portion belonging to this repair visit 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.
Does the cheaper option always have enough capacity?
Check actual available hours, skills, schedules, and service requirements before using a cost-only comparison.
Negative means overtime is cheaper on entered costs only; fatigue, coverage, and hiring costs are excluded.
What if this input changes?
If extra hours needed monthly rises by 10%, this example changes by 360 monthly cost difference. 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.