What is Customer Acquisition Cost?

Customer Acquisition Cost is calculated simply: take all the money spent on sales and marketing in a period (ad spend, staff salaries, tool subscriptions, events, content production) and divide it by the number of new customers acquired in that period. If you spent $50,000 in a month across all acquisition activities and acquired 100 new customers, your CAC is $500.

CAC is most meaningful when compared against Lifetime Value (LTV) — the total revenue a customer generates over their relationship with you. The LTV/CAC ratio is a key indicator of business health: a ratio of 3:1 (LTV is 3× CAC) is commonly cited as the minimum for a sustainable business. Ratios below 1:1 mean you're losing money on every customer you acquire — a situation that requires either reducing CAC or increasing LTV to survive.

CAC varies dramatically by acquisition channel. Organic SEO and referrals typically produce the lowest CAC because there's no direct media spend per customer. Paid search and social advertising often have higher, more predictable CAC. Enterprise sales with long cycles and high headcount have the highest CAC but are offset by high contract values. Understanding CAC by channel enables smarter budget allocation — shifting investment toward channels with the best LTV/CAC ratios.