Marketing · Guide
How to calculate CAC
Customer acquisition cost is simple in theory: total cost to acquire customers, divided by customers acquired. In practice, the ‘cost’ side is where teams disagree. Get it wrong and you'll think you're profitable when you're not.
Last reviewed: April 2026
The formula
CAC = total acquisition cost ÷ new customers acquired in the same period.
Match the period exactly. CAC for Q1 means Q1 spend divided by Q1 new customers — not customers who eventually paid in Q2 from Q1 leads.
Paid CAC vs blended CAC
Paid CAC = paid media spend ÷ customers attributed to paid. Useful for managing channel spend, but misleading on its own.
Blended CAC = (paid media + content + tools + sales + marketing salaries) ÷ all new customers. This is the number that matches your P&L. Investors and operators care about this one.
Common mistakes
- Excluding marketing salaries — they're real cost.
- Counting trial signups instead of paying customers.
- Mixing periods (e.g. dividing this month's spend by last month's customers).
- Forgetting agency fees, creative production, and tooling costs.
Tooling
Once you have spend and customer counts, the ROAS / CAC / LTV calculator gives you CAC and the LTV:CAC ratio together.