Free tool
Customer Acquisition Cost Calculator
CAC is not your CPA. It counts everything it took to spend to turn a stranger into a customer, not just media.
Customer acquisition cost (CAC) is the total amount spent to win a new customer over a period, divided by the number of new customers. It adds advertising budget to the sales and marketing costs used to convert them. It gets compared to customer lifetime value to say whether acquisition is sustainable.
What a new customer costs
How CAC is calculated
CAC = (Advertising budget + Sales costs) ÷ New customers
6,000 € of advertising and 2,000 € of sales costs for 100 new customers give a CAC of 80 €. The CPA shown in Google Ads would have said 60 €: same month, and both numbers are correct.
The gap between them is exactly what the ad platform cannot see. CPA measures the efficiency of a channel, CAC measures the real cost of growth. Steering a budget on CPA alone means ignoring a third of the bill, and that third decides whether acquisition holds at scale.
Where CAC is actually read
- Against lifetime value, never on its own. An 80 € CAC is excellent for a customer worth 240 € in margin, impossible for one worth 90 €. The ratio is worked out in the LTV calculator.
- By channel, not blended. An average CAC blends a channel bringing customers at 40 € with one at 200 €: the average reassures, the detail decides.
- On NEW customers only. Counting existing customers in the denominator artificially crushes CAC, and it is the most common mistake in the calculation.
Frequently asked questions
How do you calculate customer acquisition cost?
Add advertising budget to sales and marketing costs for the period, then divide by new customers won. For 6,000 € + 2,000 € and 100 customers: 8,000 ÷ 100 = 80 €.
What is the difference between CAC and CPA?
CPA is a cost per conversion measured inside the ad platform, on media alone. CAC adds everything used to convert outside the platform: salaries, tools, creative, agency. CAC is therefore always equal to or higher than CPA.
Should salaries be included in CAC?
Yes, for the share genuinely allocated to acquisition. The exact convention matters less than its stability: a CAC computed differently each quarter cannot be compared to itself.
CAC climbing as you scale?
That is the normal behaviour of an account saturating its most profitable audience. What you steer is how fast it climbs, and where it crosses your LTV.
Scale With A Controlled CAC
Growth partner
Positioning, acquisition, innovation: together we build a lasting growth system.
Théo MaupiléFreelance Paid Media
Google PartnerSuperMalter
