What is customer acquisition cost (CAC) and how do you calculate it?

Customer acquisition cost (CAC) is the total cost of winning a new customer. It includes everything you spend on sales and marketing divided by the number of new customers you gained in that period.

If you spend GBP 3,000 on marketing in a month and win 10 new customers, your CAC is GBP 300. That single number tells you whether your marketing is efficient, whether your pricing covers your costs and how much you can afford to spend to grow.

How to calculate customer acquisition cost

CAC = total sales and marketing costs / number of new customers acquired

The total includes everything you spent to attract, convert and onboard a customer. For marketing that is ad spend, content production, tool subscriptions and agency fees. For sales it covers salaries, commission, CRM costs and any sales enablement tools.

The key is consistency. If you include ad spend but exclude your content writer's time, your CAC looks lower than it really is. If you count every lead as a customer before they have paid, it looks lower still. Use the same definition every month so the trend tells you the truth.

What a good CAC looks like

There is no single number because every business has different margins and customer values. A GBP 500 CAC is excellent for a service that retains clients at GBP 1,000 per month. It is unaffordable for a GBP 20 product that a customer buys once.

What matters is CAC in relation to customer lifetime value. A healthy business has a CLV that is at least three times its CAC. If your CAC is GBP 300 and your average CLV is GBP 1,200, you are in good shape. If your CAC is GBP 300 and your CLV is GBP 400, you are one bad month away from losing money on every customer you win.

For a small business running digital marketing through Victory Digital, SEOSEO stands for Search Engine Optimisation — the practice of improving a website's visibility in search engine results pages. and content marketing typically have a lower CAC than paid search because the investment compounds over time. One of our manufacturing clients saw organic traffic grow by 10,000% over a 12-month programme. The CAC on those organic customers approaches zero once the content is ranking.

How to lower your CAC

Lowering CAC is not about cutting spend. It is about making every pound work harder.

• Improve your targeting. A well-defined audience costs less to reach than a broad one. Victory Digital clients in the care sector saw paid ad conversions increase by 3,446% through precise audience segmentation and landing page optimisation.

• Optimise your conversion rate. If twice as many visitors convert, your CAC halves without spending an extra penny. Landing page testing, clearer calls to action and trust signals all help.

• Use retargeting. Past visitors who already know your brand convert at a higher rate and lower cost than cold traffic.

• Invest in organic channels. Content marketing, SEOSEO stands for Search Engine Optimisation — the practice of improving a website's visibility in search engine results pages. and social media have higher upfront effort but a much lower long-term CAC. Our TrustATrader client saw a 400% increase in organic traffic through structured content and link building.

• Track channel-level CAC. Some channels will naturally have a lower CAC than others. When you know which ones those are, you can shift budget toward them and away from the expensive underperformers.

CAC is not the whole picture on its own. Track it alongside CLV, payback period and your gross margins. If your payback period (how long it takes for a customer's revenue to cover their CAC) is longer than six months, review your pricing or your retention.

Understanding CAC helps you set a realistic marketing budget, choose the right channels and know when to scale. If you would like a clearer picture of your numbers, a discovery call is a good place to start. https://victory.digital/book/discovery-call