What Is Customer Acquisition Cost (CAC)? Formula, Examples

Customer acquisition cost (CAC) tells you how much it costs to win one new customer. Add up what you spent on sales and marketing in a period, divide by the number of new customers you won in that period, and you have your CAC. On its own it’s just a number. Compared with what a customer is worth, it tells you whether your growth is profitable.

Key takeaways

• CAC = total sales and marketing cost ÷ new customers won, for the same period.
• Include people and tools, not just ad spend, or CAC will look better than it is.
• Track blended CAC (all channels) and channel CAC (for example, paid search only) separately.
• Judge CAC against customer lifetime value and payback period, not in isolation.

The CAC formula

CAC = (sales costs + marketing costs) ÷ new customers acquired

What to include

Include	Often forgotten
Ad spend on every platform	Salaries and commissions for sales and marketing staff (or the share of time spent)
Agency and freelancer fees	Sales and marketing software: CRM, email, analytics
Content, design and video production	Events, travel and sponsorships
	Free trials or onboarding costs that exist only to win the sale

Leaving out salaries and tools is the most common way teams flatter their CAC. If you want a “media-only” number for optimizing ads, call it that and keep it separate.

Worked examples

Blended CAC. An illustrative quarter: $18,000 ad spend, $12,000 agency fees, $24,000 share of salaries, $3,000 tools. Total: $57,000. New customers: 19. CAC = $57,000 ÷ 19 = $3,000.

Channel CAC. In the same quarter, paid search cost $9,000 in spend and fees and produced 6 customers. Paid search CAC = $1,500. Channel CAC needs a consistent attribution rule; see marketing attribution.

Payback period. If each customer pays $500 a month with a 70% gross margin, they contribute $350 a month. Payback = $3,000 ÷ $350 ≈ 8.6 months.

Why CAC matters

CAC is the cost side of growth. Combined with customer lifetime value (CLV), it tells you how much you can afford to spend to win a customer, and which channels deserve more budget.

• 3x+ lifetime value to CAC ratio seen in the best SaaS businesses David Skok, For Entrepreneurs, SaaS Metrics 2.0
• 5–7 months time in which many of the best SaaS businesses recover CAC David Skok, For Entrepreneurs, SaaS Metrics 2.0

Skok presents these as guidelines, not laws, and they come from SaaS. Service businesses with large upfront projects can work with different ratios. Use them as a starting point.

Myth vs fact

MythA lower CAC is always better.

FactA very low CAC can mean you're under-investing and missing growth. What matters is CAC relative to customer value and how fast you recover it.

MythCAC is a marketing metric.

FactIt covers sales and marketing together. Long sales cycles, discounting and slow follow-up raise CAC as much as expensive ads do.

Example from our work

When CAC climbs, teams usually look at ad costs first. I look at the sales side too: how long it takes to reply to a new lead, how many follow-ups happen, how often deals stall waiting on a proposal. Slow follow-up quietly wastes the money you already spent getting attention. Fixing response time is often cheaper than finding a new channel.

How to lower customer acquisition cost

Five levers, in the order we'd check them

1. Fix conversion first

   Improving landing pages and forms lowers cost per lead on every channel at once. See conversion rate optimization.

2. Tighten targeting

   Cut keywords, audiences and placements that bring leads who never buy. Measure to customers, not leads.

3. Shorten the sales cycle

   Respond to inbound leads quickly and give sales the proof and pricing buyers ask for.

4. Invest in compounding channels

   SEO, referrals and email to existing contacts cost less per customer over time than paid channels alone.

5. Retain and expand

   Customers who stay and buy more raise CLV, which lets you afford a higher CAC where it's worth it.

Related terms

• Customer lifetime value: the other half of the equation.
• Marketing attribution: how you split CAC by channel.
• Conversion rate optimization: the fastest way to lower it.
• Sales funnel: where CAC is won or lost between lead and customer.

Frequently asked questions

What is a good customer acquisition cost?

There's no universal number. A good CAC is one you recover quickly and that's well below customer lifetime value. Skok's SaaS guideline is an LTV to CAC ratio above 3 and payback within about a year at most. Compare your CAC with your own margins, not other industries.

What is the difference between CAC and cost per lead?

Cost per lead divides spend by leads. CAC divides total sales and marketing cost by paying customers. A channel can have a cheap cost per lead and an expensive CAC if those leads rarely buy, which is why CAC is the better decision metric.

How often should I calculate CAC?

Monthly for tracking and quarterly for decisions, because B2B sales cycles make monthly numbers noisy. Match the period of costs with the period customers closed, or use a lag equal to your typical sales cycle.

Should CAC include existing customer upsells?

No. CAC measures the cost of winning new customers. Track expansion revenue separately, and include it in customer lifetime value instead.

How TechDella can help

Our paid ads service optimizes campaigns to cost per customer, not cost per click, and reports channel CAC alongside blended CAC.