CAC payback calculator
Most CAC payback calculations use revenue instead of gross margin and leave half the cost out of CAC, which makes payback look months shorter than it is. They are also usually blended across segments, so a slow-paying segment hides behind a fast one. This calculator uses fully loaded sales and marketing cost, divides by gross-margin-adjusted new revenue, and does it by segment and channel.
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What you get
- A segment calculator for CAC and payback months, with every formula written out
- A blended row that shows how averaging hides a slow segment
- A channel view for comparing outbound, inbound, and partner acquisition
- A fully loaded CAC inputs sheet listing what belongs in the numerator
- A checklist for making the number match what finance reports
Who it's for
- RevOps leads reporting unit economics to leadership
- Finance partners who own the CAC definition
- Sales and marketing leaders deciding where to add spend
What's inside
6 sections, each listed with its own size. The first is previewed below; the remaining 5 come with the download, with blank rows ready to fill in.
| Section | Size | Previewed |
|---|---|---|
| CAC payback by segment | 8 columns, 4 worked example rows | Below |
| Formulas | 3 columns, 5 worked example rows | In the download |
| CAC payback by channel | 7 columns, 2 worked example rows | In the download |
| Fully loaded CAC inputs | 7 fields to complete | In the download |
| Before you report the number | 7-point checklist | In the download |
| What the blended number hides | Guidance notes | In the download |
Preview of section 1
CAC payback by segment
Worked example for one quarter. Gross margins are illustrative; use your own from finance.
| Segment | Sales and marketing spend | New customers | CAC | Average new MRR per customer | Gross margin | Gross-margin MRR per customer | Payback (months) |
|---|---|---|---|---|---|---|---|
| SMB | 150,000 | 50 | 3,000 | 250 | 80% | 200 | 15.0 |
| Mid-market | 300,000 | 20 | 15,000 | 1,000 | 80% | 800 | 18.8 |
How to use it
1. Fully load the cost
Include salaries, commissions, benefits, tools, program spend, and a share of sales and marketing management for the period. Leaving out commissions or tools is the most common way payback gets understated.
2. Use gross margin, not revenue
Payback months = CAC / (New MRR per customer x Gross margin). A dollar of revenue with 75% gross margin only pays back 75 cents of acquisition cost. Using revenue shortens payback by a quarter or more.
3. Calculate by segment before blending
Enterprise and SMB have very different CAC and deal sizes. Compute each separately; the blended number is useful for the board, but decisions about where to invest need the segment view.
4. Match cost and customers to the same period
If your sales cycle is long, this quarter's spend is acquiring next quarter's customers. For cycles over a quarter, lag the spend by one period or use trailing twelve months on both sides.
Frequently asked questions
How do you calculate CAC payback?
CAC payback (months) = CAC / (Average new MRR per customer x Gross margin). CAC is total sales and marketing spend to acquire new customers divided by the number of new customers in the same period.
Should CAC payback use revenue or gross margin?
Gross margin. Acquisition cost is recovered from the profit on each customer, not their revenue. Using revenue makes payback look shorter by roughly the inverse of your gross margin.
What is a good CAC payback period?
It depends on your segment, retention, and cash position, so compare against your own history and your finance plan instead of an external benchmark. Payback is only meaningful alongside retention; a short payback on customers who churn in a year is worse than a longer one on customers who stay five.
What should be included in CAC?
All sales and marketing cost aimed at acquiring new customers in the period: salaries, benefits, commissions, program spend, tools, and an agreed share of management overhead. Exclude costs for serving or expanding existing customers if you measure expansion separately.