ROI & Pricing
What Is Customer Acquisition Cost (CAC)?
Customer acquisition cost, or CAC, is the total amount you spend to win one new paying customer. You find it by adding up all your sales and marketing costs for a period and dividing by the number of new customers you gained. It includes ads, the time spent on estimates, and whatever it costs to answer the phone.
Key Takeaways
- Formula: total sales and marketing spend ÷ new customers gained.
- It includes everything it took to close, not just the ad that made the phone ring.
- CAC is always higher than cost per lead, because not every lead becomes a customer.
- A customer's lifetime value should be several times their CAC.
How Customer Acquisition Cost Works
CAC is the all-in price of a new customer.
CAC = total sales and marketing spend ÷ number of new customers
The top of the fraction should include everything that went into attracting and closing:
- Ads and marketing of every kind.
- Tools: website, call tracking, CRM, the answering service or AI receptionist.
- Time: hours spent on estimates, quotes, and follow-up calls, valued at what that time is worth.
- Commissions or referral fees, if you pay them.
The bottom is new customers only. Repeat jobs from existing customers do not count here. That is where customer lifetime value comes in.
Example of Customer Acquisition Cost
A painting contractor's numbers for one quarter:
| Item | Cost |
|---|---|
| Google and Facebook ads | $6,000 |
| Website and call tracking | $600 |
| AI receptionist (3 months on Growth) | $477 |
| Owner's time on 60 estimates, 1.5 hrs each at $75/hr | $6,750 |
| Total | $13,827 |
Those 60 estimates turned into 24 new customers.
$13,827 ÷ 24 = $576 CAC
If the average first job is $3,200 and customers come back every few years, that is a healthy number. Notice that the owner's estimate time is the biggest line. Qualifying leads on the first call so he only drives to estimates he can win is the fastest way to cut it.
What People Get Wrong About Customer Acquisition Cost
Owners count the ad spend and stop. The ads are often the smallest part. Estimate time, follow-up time, and the cost of answering the phone are all acquisition costs, and leaving them out makes CAC look better than it is.
The second mistake is trying to lower CAC by spending less. The bottom of the fraction is usually the bigger lever. The same $6,000 in ads produces more customers when every call is answered, every lead is qualified, and the job is booked on the first call instead of the third callback. That is first call resolution showing up in your finances.
CAC vs. Cost Per Lead vs. Lifetime Value
- Cost per lead is what it costs to get one contact. It is a piece of CAC.
- CAC is what it costs to turn contacts into one paying customer.
- Customer lifetime value is what that customer is worth over the whole relationship.
CPL feeds CAC. CAC is judged against LTV. If LTV is not comfortably above CAC, the business is buying customers at a loss.
Why It Matters
CAC is the number that tells you whether your marketing works, not just whether it generates calls. Two businesses can have the same ad budget and the same number of calls, and the one that answers every call and books on the first try will have a far lower CAC, because more of those calls become customers. An AI receptionist shows up in the CAC formula twice: a small cost on top, and a bigger number of customers on the bottom. See is an AI receptionist worth it for the math.
The Bottom Line
Customer acquisition cost is everything you spend on sales and marketing divided by the new customers you win. Count all of it, including your own time. Then compare it to what a customer is worth over their lifetime, and remember that answering the phone is the cheapest way to move the number.
Frequently Asked Questions
- How do you calculate customer acquisition cost?
- Add up everything you spent to attract and close customers in a period: advertising, marketing tools, the answering service, time spent on estimates and follow-up, and any sales commissions. Divide by the number of new customers you won in that period. If you spent $5,000 and gained 25 new customers, your CAC is $200.
- What is a good customer acquisition cost?
- One that is small compared to what the customer is worth over time. A common rule of thumb is that lifetime value should be at least three times CAC. If a customer is worth $1,200 to you over a few years, a $200 CAC is healthy. A $600 CAC means you are spending half of what you will ever earn just to get them.
- How does answering the phone affect CAC?
- Directly. CAC is spend divided by customers won. Missed calls lower the number of customers without lowering the spend, so CAC goes up. Answering every call, and booking on the first call instead of playing phone tag, turns more of the same leads into customers. That is one of the cheapest ways to bring CAC down.
Related Terms
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