Software agency Customer Acquisition Cost
CAC = (marketing + sales costs) / new customers
Gather project time logs, licence invoices and retainer scopes. Include engineering, review, and project management. The starting figures are examples. Replace them with your own records.
Formula and worked example
CAC = (marketing + sales costs) / new customers
| Input | Example |
|---|---|
| Marketing spend | 3,000 |
| Sales labour and software | 1,000 |
| New paying customers | 20 |
| Calculated result | 200 per customer |
Choose reliable inputs
Include software licences, delivery time, revisions and ongoing support when costing a project. For this software agency calculation, use project time logs, licence invoices and retainer scopes and a consistent definition of one project.
- Engineering: include the portion belonging to this project or reporting period, and record where the value came from.
- Review: include the portion belonging to this project or reporting period, and record where the value came from.
- Project management: include the portion belonging to this project 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.
Should sales labour be included in acquisition cost?
A media-only cost per acquisition excludes proposal and selling work. Report the included cost categories so comparisons remain meaningful.
Use aligned periods and an explicit definition of new paying customer.
What if this input changes?
If marketing spend rises by 10%, this example changes by 15 per customer. 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.