Free marketing calculator · Customer acquisition
Customer Acquisition Cost (CAC) Calculator
Calculate how much you spend to acquire each new customer and put acquisition efficiency on a consistent, commercially useful basis.
CAC is simple to calculate but easy to define inconsistently. The important part is matching the acquisition costs and customer count to the same period and deciding which costs genuinely belong in your acquisition calculation.
What is Customer Acquisition Cost?
Customer Acquisition Cost (CAC) is the average acquisition spend required to gain one new customer. For a blended CAC, acquisition spend can include the marketing and sales costs associated with winning new customers rather than media spend alone.
Example: £10,000 of acquisition spend ÷ 100 new customers = £100 CAC.
What should you include in CAC?
The answer depends on what you are trying to measure. A paid-media team may monitor a narrower channel-level acquisition cost, while a business-level CAC can include advertising, agency or platform costs, sales costs and other acquisition activity. What matters is that the definition is explicit and applied consistently.
Do not mix a broad cost numerator with a narrow customer denominator. If your spend includes all acquisition channels, your customer count should represent customers acquired across the corresponding scope and period.
CAC and CPA are not always the same thing
The terms are sometimes used interchangeably, but CPA can mean cost per acquisition or cost per action and may refer to a lead, registration, purchase or another conversion event. CAC specifically refers to acquiring a new customer. If your advertising platform reports CPA, check what conversion event sits behind it before treating it as CAC.
How do you know whether CAC is sustainable?
CAC becomes much more informative when compared with customer value. A £100 CAC may be attractive for a customer expected to generate substantial contribution over several years and unsustainable for a low-margin one-off purchase.
That is why CAC is commonly analysed alongside customer lifetime value, contribution margin and CAC payback. The question is not simply “How low is our CAC?” but “Does the value created by the customers we acquire justify what we spend to acquire them?”
Connect CAC with customer value
The Customer Economics Calculator combines CAC with revenue and contribution CLV, CLV:CAC, payback and maximum sustainable CAC so you can see acquisition cost in context.
CAC calculator FAQs
Should CAC include existing customers?
No. CAC is concerned with acquiring new customers. The denominator should therefore be new customers acquired during the period represented by the acquisition spend.
Should I include sales costs in CAC?
If you are calculating a fully loaded business-level CAC, sales costs involved in customer acquisition can be relevant. For a narrower marketing or channel measure, you may intentionally exclude them. Label the metric clearly so comparisons use the same definition.
Is lower CAC always better?
Not in isolation. Lower acquisition cost is useful only in relation to customer quality, volume and value. A higher CAC can still make commercial sense if it acquires customers with sufficiently higher contribution or lifetime value.
What period should I use?
Use a period that matches your acquisition cycle and reporting needs, and keep spend and new-customer counts aligned. Businesses with longer sales cycles may need cohort-based analysis because customers acquired today can result from spend incurred earlier.