What is CAC (Customer Acquisition Cost)?

CAC (customer acquisition cost) is the total sales and marketing spend needed to win one new customer over a period, and B2B companies use it to judge whether growth is paying for itself.

At a glance

• Formula: CAC = total sales and marketing cost in a period ÷ new customers won in that period.
• Fully loaded CAC includes salaries, commissions, tools, agencies, ad spend and events, not only media.
• Benchmarkit’s 2025 B2B SaaS benchmarks put the median new CAC ratio at $2.00 of sales and marketing spend per $1.00 of new customer ARR, up 14% in a year.
• David Skok’s widely used rules of thumb: recover CAC in under 12 months, and keep lifetime value at least three times CAC.
• CAC on its own says little. Read it with payback and LTV:CAC.

How to calculate CAC

Add up everything spent to acquire customers in the period: sales and marketing salaries and commissions, software, ad spend, content, events, agencies and outsourced teams. Divide by the number of new customers won in the same period. If your sales cycle is long, lag the spend by roughly one cycle, because this quarter’s customers were mostly paid for last quarter.

Example (illustrative): in a quarter you spend $180,000 on sales salaries and commissions, $40,000 on tools and $80,000 on marketing, $300,000 in total, and win 25 customers. CAC is $12,000. If each pays $1,000 a month at 80% gross margin, payback is $12,000 ÷ $800, or 15 months, which is above Skok’s 12-month guide.

Split CAC by channel and segment when you can. A blended number can hide an expensive channel behind a cheap one.

Blended vs paid CAC

Blended CAC divides all acquisition spend by all new customers, including the ones who arrived through referrals or word of mouth. Paid CAC counts only the customers and spend tied to paid channels. Blended makes the business look cheaper to grow than it is when referrals dry up, so track both.

Common CAC mistakes

• Leaving out people costs. Salaries and commissions are usually most of CAC, not ad spend.
• Counting leads instead of customers. That’s cost per lead, a different number.
• Mixing new and expansion revenue. Spend on account management belongs to expansion, not new-customer CAC.
• Cutting spend to lower CAC. CAC falls, and so does pipeline. The goal is better conversion, not less selling.

How CAC shows up in a revenue system

CAC moves when conversion moves: a tighter list, a better message and reps who already know the buyer turn the same spend into more customers. DigitalOcean saw 37% lower CAC with a regional outbound team we hired, trained and ran inside its commercial organization. Read the DigitalOcean story.

Terms that sit next to CAC

CAC payback period tells you how long a customer takes to repay it, and customer lifetime value tells you what you get back in total. Both depend on churn rate, because a customer who leaves early never pays back what it cost to win them.