What Is Customer Acquisition Cost?
Customer acquisition cost is the total amount a business spends on sales and marketing to acquire one paying customer. It is calculated by dividing the total acquisition spend in a period by the number of new customers won in that same period. The result tells you the average price of each new customer relationship.
Bottom Line
Customer acquisition cost, or CAC, measures the sales and marketing spend required to win one new customer during a specific period.
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Definition
Customer Acquisition Cost
Customer acquisition cost is the total amount a business spends on sales and marketing to acquire one paying customer. It is calculated by dividing the total acquisition spend in a period by the number of new customers won in that same period. The result tells you the average price of each new customer relationship.
Why it matters
CAC shows whether your growth is affordable. A business that spends $500 to acquire a customer who generates $200 in lifetime gross profit is shrinking with every sale. Pairing CAC with payback period and LTV turns a single number into a decision tool. CAC alone tells you the cost; the ratios tell you whether the model works.
How it works
Add up every dollar spent on sales and marketing during a period — salaries, advertising, tools, commissions, and overhead directly tied to acquisition. Divide that total by the number of new customers won in the same window. Segment the calculation by channel when you can. Blended CAC hides wide variation: a channel costing $100 per customer and one costing $900 average to $500, which looks acceptable but masks one that is not.
Example
A SaaS company spends $48,000 on sales and marketing and closes 120 new customers in one month.
Sales and marketing spend
$48,000
New customers
120
CAC
$400
The business spent $400 to acquire each new customer during the month. Whether $400 is healthy depends on gross margin per customer and how long they stay.
Key Takeaways
CAC is only meaningful when the period and channel rules stay consistent across comparisons.
Payback period adds the time dimension that CAC alone misses — it tells you how long until a customer covers their acquisition cost.
Segment-level CAC often reveals better decisions than one blended number across all channels.
Related Terms
Try These Tools
Run the numbers next
CAC Calculator
Calculate customer acquisition cost, payback period, and LTV:CAC efficiency.
Open →Unit Economics Calculator
Evaluate LTV:CAC ratio, payback period, and per-customer viability.
Open →Customer Lifetime Value Calculator
Calculate CLV, CLV:CAC ratio, and acquisition payback from purchase patterns.
Open →FAQ
Questions people ask next
The short answers readers usually want after the first pass.
Sources & References
- Customer Acquisition Cost (CAC): What It Is and How to Calculate It — HubSpot
- Customer Acquisition Cost (CAC) — Investopedia
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