Unit economicsMetric 13 of 35
CACCustomer Acquisition Cost
What it costs you, fully loaded, to land one new paying customer.
All money spent winning new customers, divided by the number of new customers in the same period. Always fully loaded: salaries, ads, content, tools, attribution noise included.
Formula
CAC = (Sales + Marketing spend) ÷ New Customers acquiredWorked example
Spend $40,000 on sales and marketing in Q1, acquire 80 new customers → CAC = $500.
Why it matters
CAC is meaningful relative to LTV and CAC Payback, not as a standalone dollar benchmark. A high CAC can work with high lifetime gross profit and enough cash to fund payback; a low CAC can still be unsustainable when retention or margins are poor.
Common mistakes
- Excluding salaries from CAC — easily understates by 50–70%.
- Using attribution-window CAC instead of period-cost CAC (the latter is what your bank sees).
- Not separating blended CAC from paid-CAC — they answer different questions.