One acronym, four formulas
When someone says "CAC," they could mean any one of four things. The choice of numerator and denominator changes the answer by an order of magnitude. The right formula depends on what decision you're trying to make.
Paid CAC = Paid marketing spend ÷ Net new customers from paid channels
Just paid media: Google Ads, paid social, paid sponsorships, paid SEO if you outsource. Denominator is customers attributable to paid channels (last-touch or multi-touch model). Useful for: optimising the paid funnel, evaluating channel mix, comparing CPC vs CPA performance. Not useful for: comparing companies, because attribution windows and models vary wildly.
Blended CAC = Total marketing spend ÷ Total net new customers
Every dollar of marketing spend, including content, brand, events, organic, divided by every new customer regardless of source. Easy to compute, hard to misattribute. Useful for: getting a single CAC number when attribution is fuzzy or untrustworthy. Not useful for: optimising specific channels.
Fully-Loaded CAC = (Sales + Marketing + S&M overhead) ÷ Net new customers
The most defensible CAC. Includes sales team salaries, marketing team salaries, commission, BDR/SDR comp, tooling (your CRM, marketing automation, analytics), event and brand spend. This is what public-company SEC filings disclose as the ‘S&M expense’ line item. Useful for: cross-company comparison (all public companies report this the same way), unit economics, payback period.
New-Logo CAC = (S&M attributable to new-logo acquisition) ÷ Net new customers
The honest version of fully-loaded CAC. Strips out S&M spend allocated to existing-customer expansion (account management, customer success, upsell campaigns). Companies with high net-revenue retention have meaningful expansion spend buried inside their reported S&M line. Useful for: judging acquisition efficiency separately from retention efficiency. Not useful for: cross-company comparison, because the split isn't publicly disclosed and varies by company definition.
Which one do we use?
Every CAC on this site is fully-loaded blended: the total S&M expense line from SEC filings divided by net-new customers. We pick this because: