How to Calculate Restaurant Customer Acquisition Cost

For UK restaurants, every pound needs to work harder right now. Inflation has eased in some areas, but your operating costs are still structurally higher than they were before the pandemic. Labour costs, National Insurance contributions, food prices, rent—they're all squeezing your margins. And at the same time, your guests are being more careful about where they spend.

In that environment, growth isn't just about getting more people through the door. It's about understanding what it actually costs to bring someone in for the first time, and whether that cost makes sense for how your business works. That's where customer acquisition cost (CAC) stops being marketing jargon and starts being useful.

CAC is all about getting clarity. When you understand how much you're spending to acquire new guests, you can make better calls on pricing, promotions, which channels to use, and where to invest for the long term. Whether you're an owner, a general manager, running operations, or handling the finances, CAC gives everyone a shared way to talk about growth with less guessing and more evidence.

Why customer acquisition cost matters more in 2026

According to Toast’s Voice of the UK Restaurant Industry 2025 report, profitability remains the single biggest challenge for UK operators, cited by nearly half of respondents. At the same time, 76% of surveyed restaurants still expect sales to increase, suggesting that many businesses are looking for growth within tight constraints.

That combination makes CAC particularly relevant. When demand is softer and consumers are more price-sensitive, attracting new guests often requires more spend, whether through paid digital channels, discounts, partnerships, or events. Without a clear view of acquisition cost, it is easy to mistake top-line growth for healthy growth.

CAC also matters because guest behaviour has changed. Many diners now split their loyalty across multiple venues, dine out less frequently, and actively seek deals. According to the Toast Consumer Preferences Survey 2025, a significant share of UK consumers say they are more focused on value for money when choosing where to eat out.

This means the lifetime value of a guest is less predictable than it once was. In that context, understanding the upfront cost of acquisition helps restaurants avoid over-investing in channels that deliver volume without durability.

What customer acquisition cost actually means for restaurants

At its simplest, customer acquisition cost is the total amount you spend to acquire new customers over a given period, divided by the number of new customers acquired in that time. In practice, it is rarely that clean.

For restaurants, CAC includes any spend that is specifically aimed at attracting people who have not visited you before. This can include paid social advertising, search ads, third-party marketplace promotions, launch campaigns, influencer collaborations, introductory discounts, and even the cost of printing and distributing menus or flyers.

What CAC doesn't include is the money you're spending purely to keep existing guests coming back—things like loyalty rewards for your regulars or perks that are only for repeat visits. Unless those initiatives are also clearly bringing in new customers, they sit outside your CAC calculation.

Where it gets tricky is the overlap. A lot of what you do serves multiple purposes at once. A discount might reward your loyal guests while also catching the eye of someone new. A social post might reach your existing followers and brand new people at the same time.

CAC isn't about getting it perfectly right. It's about making reasonable estimates that you can track consistently over time.

A practical way to calculate restaurant CAC

For most UK restaurants, the smartest way to calculate CAC is at the campaign level—not across your entire business. This lets you compare apples to apples and avoid averages that don't tell you much.

Start by defining a clear time window and what you're actually trying to achieve. For example, you might look at a four-week paid social campaign promoting your new brunch menu, or a two-week introductory offer aimed at first-time online orders.

Next, total the direct costs associated with that campaign. This includes media spend, creative costs if applicable, and the financial impact of any discounts offered. If you ran a “£5 off your first visit” promotion, the discount itself is part of your acquisition cost, not just the advertising spend that promoted it.

Then estimate how many genuinely new customers the campaign brought in. This is often the hardest part. Many UK operators use proxies such as first-time online orders, new loyalty sign-ups, or first-time payment tokens to identify new guests. None are perfect, but consistency matters more than precision.

Finally, divide total campaign spend by the number of new customers acquired. The result is your CAC for that initiative.

What matters is not whether your CAC is objectively “good” or “bad”, but whether it makes sense relative to your average spend per visit, contribution margin, and likelihood of repeat visits.

CAC through different operational lenses

Customer acquisition cost looks different depending on your role in the business. Owners often view CAC through the lens of long-term brand building and sustainability. A higher CAC may be acceptable if it supports a strong concept and repeat behaviour over time.

For general managers and operations leaders, CAC connects directly to service execution. If a campaign drives first-time visits but overwhelms the kitchen or front of house, the true cost may be higher than the numbers suggest due to poor experiences and low return visits.

Finance leaders tend to focus on CAC alongside contribution margin and cash flow. A campaign that looks attractive on a per-customer basis can still be risky if it requires heavy upfront spend or delivers inconsistent volume.

Bringing these perspectives together is one of the hidden benefits of tracking CAC. It creates a shared language that links marketing activity to operational reality.

How consumer behaviour shapes acquisition costs

What your guests expect directly affects how much it costs to bring them in. The Toast Consumer Preferences Survey 2025 shows that a lot of UK diners actively look for deals or promotions when they're deciding where to eat—especially in city centres.

That behaviour tends to push your CAC up, because restaurants end up competing harder on price and incentives. But here's the thing: the same research shows that many people also care deeply about experience, atmosphere, and consistency—not just what's on the bill.

For you as an operator, this creates a choice. If you lean heavily on discounting to acquire guests, you might see a lower upfront CAC—but you're also more likely to attract people who won't come back unless there's another deal. On the other hand, if your campaigns focus on the experience you offer and what makes you different, it might cost more at the start—but you're bringing in guests who stick around and are worth more over time.

CAC, technology, and visibility

One reason CAC has become more prominent in industry conversations is improved access to data. According to our Voice of the UK Restaurant Industry 2025 report, 69% of UK restaurants plan to increase technology spend in the next twelve months, often to gain better visibility into performance.

Better reporting doesn't eliminate uncertainty, but it does cut down on the guesswork. When your sales, ordering channels, and guest data are all connected, it gets easier to spot first-time visits and trace them back to the specific things you've been doing. You don't need an advanced analytics team for this. You just need to be clear about what you're trying to measure and why it matters.

If you're running multiple sites, this visibility becomes even more important. Your CAC can vary a lot depending on location, who lives nearby, and what kind of service model you're running.

A note on compliance and transparency

When tracking customer data to estimate CAC, UK restaurants should remain mindful of data protection and privacy expectations. High-level compliance with GDPR and guidance from the Information Commissioner’s Office is essential, particularly when handling personal data or payment information.

Most CAC analysis can be done using aggregated and anonymised data. The goal is insight, not individual profiling. Keeping this boundary clear protects both guests and the business.

How CAC connects to retention and loyalty

CAC is often discussed in isolation, but it rarely tells the full story on its own. It starts to make more sense when you put it next to retention. 

Industry research consistently shows that younger diners are more open to loyalty schemes and digital rewards, and the Toast Consumer Preferences Survey 2025 found that nearly half of UK diners aged 16 to 34 had redeemed a restaurant app reward in the previous six months.

That context matters. If it costs you £20 to bring someone in for the first time, but they come back several times and spend well, that initial outlay can pay for itself quickly. If they don’t return, though, even a “cheap” acquisition starts to look expensive. Over time, businesses that grow sustainably tend to be the ones that think about acquisition and retention as two sides of the same decision, not separate problems to solve.

CAC as a decision-making tool, not a target

One of the biggest risks with CAC is treating it as a benchmark to optimise endlessly downward. In reality, CAC should inform decisions rather than dictate them.

There are moments when a higher CAC makes strategic sense like opening a new location, or launching a new service model as these often require upfront investment. What matters is that the cost is intentional, measured, and aligned with realistic expectations of return.

Knowing when to slow down can be just as important as knowing when to push. If it’s getting more expensive to bring in new guests, but they’re spending less or coming back less often, that’s your business trying to tell you something. It may be worth pausing to look at where those guests are coming from, how you’re showing up in their feeds or inboxes, and whether what you’re offering still lines up with what people are actually looking for right now.

Looking ahead: CAC and sustainable growth

Operators who invest in planning and smarter systems are the ones best positioned to navigate whatever comes next.

Customer acquisition cost sits right at the intersection of everything and forces conversations across marketing, operations, and finance. It pushes you toward evidence over instinct—without losing the human side of what hospitality is really about.

As you look ahead, CAC doesn't need to be another metric weighing you down. Used well, it becomes a way to ask better questions about growth, value, and the kind of guests you actually want to build your business around.