Acquisition metric
CAC (Customer Acquisition Cost)
Customer Acquisition Cost (CAC) divides total marketing and sales spend by the number of new paying customers acquired in the same window. Indie SaaS founders should track two versions: blended CAC (all marketing including organic) and paid-only CAC (only paid channels). They tell different stories.
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Formula
CAC = (marketing spend + sales spend + tooling) / new paying customers acquired in same period
Where:
- marketing spend = Paid ads, content production cost, marketing-team comp, paid tools attributed to marketing.
- sales spend = Sales-team comp, CRM cost, demo tools, sales-attributed time of the founder.
- tooling = Analytics, email automation, scheduling tools tied to acquisition.
- new paying customers acquired in same period = Customers who paid for the first time during the same window the spend was incurred.
Worked example
In Q3, you spent $4,000 on ads, $0 on sales staff (you are solo), and $200 on analytics + email tools. You acquired 50 new paying customers. Blended CAC = ($4,000 + $0 + $200) / 50 = $84.
What it tells you
- The cost-side of unit economics. CAC paired with LTV is the fundamental health check.
- Whether paid acquisition is sustainable at current pricing.
- Where to allocate marketing budget — channels with lower CAC at acceptable scale.
What it does NOT tell you
- Whether the customers acquired are good fit. Low CAC at acceptable quality is the goal; low CAC at terrible quality is the trap.
- Long-term acquisition trends. CAC fluctuates; a single quarter is a snapshot, not a trend.
- Whether the customers will retain. CAC is paid up front; LTV is realized over months. Both matter.
Common miscalculations
- Including only ad spend; excluding tooling and time costs. Founder time has a real cost.
- Calculating CAC for one channel only. Channel-specific CAC is useful for budget allocation; blended CAC is the unit-economics number.
- Counting trials or free-tier signups as 'new customers'. CAC denominator is paying customers, not signups.
- Allocating a quarter of marketing spend to one month of customers. Spend window and customer window must match.
What is a good CAC?
See the directional range on the customer acquisition cost (CAC) benchmark page →
Frequently asked
- Should I count my own time as a CAC cost?
- Yes, with a realistic hourly rate. Excluding founder time produces flattering numbers that hide the real economics. Even an estimate ($50-$200/hour depending on your alternative use) gives an honest baseline.
Diagnose your funnel, not your spreadsheet
Metrics tell you what is happening. The free 90-second Launch Diagnostic tells you WHY — labels Wrong Person, Weak Offer, or Weak Belief, with the specific fix.