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. Mismatched periods are the simplest way to make CAC look better than it is.
Paid CAC vs blended CAC
Paid CAC = paid media spend ÷ customers attributed to paid. Useful for managing channel spend, but misleading on its own because it ignores all the other costs that produced those customers (creative production, marketing salaries, tools).
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.
Use both — paid CAC to manage spend efficiency channel-by-channel, blended CAC to understand the actual unit economics of the business.
What to include in the cost side
The honest answer is: every dollar spent in service of acquiring customers. The temptation is to exclude costs that don't feel like 'marketing' — but excluding them gives you a CAC number that doesn't survive contact with the income statement.
- Paid media spend (Google, Meta, LinkedIn, partnerships).
- Creative production (in-house or agency).
- Marketing tools (analytics, CRM, ESP, ad platforms).
- Marketing and sales salaries (loaded with benefits, not just base pay).
- Content production (writers, editors, SEO tools).
- Sponsorships, events, and PR.
Common mistakes
The patterns below are the most common reasons reported CAC understates the truth. Each one is correctable; together they can hide a 30-50% gap between reported and actual CAC.
- 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.
- Excluding sales team cost in a high-touch SaaS sale.
- Treating discounts and credits as marketing — they're revenue reductions, accounted for separately.
Segment CAC by channel and cohort
A blended CAC of $200 might hide a $50 CAC from organic search and a $600 CAC from paid social. Segmenting CAC by acquisition channel reveals which channels are subsidizing which, and where to invest more or pull back.
Cohort analysis also matters: CAC for customers acquired in January may be wildly different from June if seasonality, audience saturation, or creative fatigue affected the channels.
Tooling
Once you have spend and customer counts, the ROAS / CAC / LTV calculator gives you CAC and the LTV:CAC ratio together. Pair it with the Margin & Markup Calculator to anchor the break-even discussion on real margin numbers.
Summary
Include all the costs, match the period, distinguish paid from blended, and segment by channel and cohort. Done honestly, CAC tells you the truth about your unit economics. Done loosely, it tells you whatever you want to hear.
Frequently asked questions
- Should I include sales salaries in CAC?
- Yes if sales is part of acquiring customers (typical for B2B SaaS). For PLG products where the sales team only handles expansion, exclude their cost from acquisition CAC.
- How do I handle discounts and free trials in CAC?
- Don't include discount value as CAC — discounts are a revenue reduction. Do include the cost of running the trial infrastructure if it's material. Count a customer only when they actually pay, not at trial signup.
- What's a good CAC?
- There's no universal number — what matters is the ratio to LTV. A $1,000 CAC is healthy at $5,000 LTV and terrible at $1,200 LTV. Anchor CAC to LTV:CAC and CAC payback period, not to an absolute target.