Plumbing service Annual Plan Discount Ceiling
Maximum discount = (1 − annual cost / ((1 − margin) × monthly price × 12)) × 100
Gather a completed job sheet, supplier quotes and a crew schedule. Include fittings, access time, and travel. The starting figures are examples. Replace them with your own records.
Formula and worked example
Maximum discount = (1 − annual cost / ((1 − margin) × monthly price × 12)) × 100
| Input | Example |
|---|---|
| Monthly customer price | 100 |
| Annual delivery and support cost | 600 |
| Required annual margin | 30 % |
| Calculated result | 28.5714 % |
Choose reliable inputs
Plan materials, travel and crew time before committing to a price. For this plumbing service calculation, use a completed job sheet, supplier quotes and a crew schedule and a consistent definition of one service visit.
- Fittings: include the portion belonging to this service visit or reporting period, and record where the value came from.
- Access time: include the portion belonging to this service visit or reporting period, and record where the value came from.
- Travel: include the portion belonging to this service 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.
Can collecting annual cash justify any discount?
This margin test excludes the value of earlier collection. A negative ceiling means the undiscounted price misses the target.
What if this input changes?
If monthly customer price rises by 10%, this example changes by 6.4935 %. 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.