Turn monthly acquisition spending, new-customer volume, and revenue per customer into a clear view of customer acquisition cost and the time required to recover it.
This Excel workbook is designed for SaaS founders, growth teams, finance leaders, and investors who need a structured way to monitor customer acquisition cost (CAC) and CAC payback period. Users enter monthly marketing expenses, new customers, and average monthly revenue per customer; the workbook calculates CAC and estimated payback time and presents both metrics across a monthly series.
Measure acquisition efficiency
Connect marketing expense to the number of customers added and review the resulting CAC by month.
Track capital recovery
See how many months of average customer revenue are required to recover acquisition spending under the entered assumptions.
Spot trend changes
Use the monthly chart view to identify whether CAC and payback time are improving, holding steady, or moving in the wrong direction.
What does the workbook help you analyze?
CAC payback is useful because growth can consume cash before customer revenue has had time to offset acquisition spending. The template keeps the underlying drivers and calculated results together, making it easier to review acquisition economics over time and discuss them with operating or investment stakeholders.
Monthly CAC: relate marketing expenses to new-customer additions for each reporting month.
CAC payback time: estimate the number of months required to recover acquisition cost using average monthly revenue per customer.
Driver movement: review how changes in spend, customer additions, or customer revenue affect acquisition economics.
Period-to-period trends: compare monthly results rather than relying on a single blended figure.
Planning discussions: use the same metric structure when reviewing growth targets, marketing budgets, or acquisition-performance assumptions.
What is inside the workbook?
The workbook separates operating assumptions from calculated outputs. Its visible input view includes monthly marketing expenses, new customers, and average monthly revenue per customer. It then displays calculated CAC and CAC payback time for the corresponding periods, with charts that summarize how both measures change across the timeline.
Editable monthly inputs
Enter marketing expenses, customer additions, and average monthly revenue per customer in the highlighted input cells.
Calculated unit-economics outputs
Review the resulting CAC and payback period alongside the assumptions used for each month.
Trend charts
Follow CAC and payback time visually across the displayed monthly reporting horizon.
The monthly worksheet shows editable assumptions for marketing expense, new customers, and average revenue per customer, followed by calculated CAC and payback time.
Keep the metric drivers visible
The input-and-output layout helps users trace each monthly result back to the operating figures that produced it. This is useful when CAC rises unexpectedly: the team can determine whether the change came from higher spend, fewer customer additions, or a different revenue assumption instead of reviewing the output in isolation.
The chart view plots customer acquisition cost and CAC payback time across a 24-month example, making shifts in acquisition efficiency easy to locate.
Review CAC and payback as trends
A charted time series provides more context than one current-period number. It helps users see when acquisition economics changed, whether an improvement persisted, and how a lower CAC translates into a shorter payback period when the revenue assumption remains stable.
How do you use the template?
Enter acquisition spending
Add monthly marketing expenses for the periods you want to analyze.
Add customer volume
Enter the number of new customers acquired in each corresponding month.
Provide customer revenue
Enter average monthly revenue per customer so the workbook can estimate payback time.
Review calculated metrics
Check monthly CAC and payback results, then compare changes with the underlying inputs.
Use the charts in planning
Bring trend movements into budget, growth, and performance-review discussions.
Who is this template for?
The workbook is relevant for subscription and recurring-revenue businesses that monitor acquisition efficiency on a monthly basis. SaaS founders can use it when planning growth and cash needs; revenue and marketing teams can use it to connect spending with customer additions; finance teams can use it to maintain a consistent unit-economics view; and investors or analysts can use the outputs when reviewing growth quality. It is most useful when the business can provide reliable monthly acquisition spending, new-customer counts, and average revenue per customer.
