LTV:CAC Ratio

What LTV:CAC Ratio means in practice

The LTV:CAC ratio condenses whether a business model works into a single number. Below 1:1 you lose money on every customer and growth accelerates the losses. Around 3:1 is widely treated as healthy: enough margin above acquisition cost to fund the rest of the business.

An unusually high ratio is not automatically good news. A ratio of 8:1 often means underinvestment in growth — the unit economics could support far more acquisition spend than is being deployed, and a competitor willing to spend into a 3:1 ratio can take the market while you optimise for efficiency.

The ratio inherits every weakness of its inputs. Because LTV is a projection built on churn assumptions and CAC is routinely understated by excluding salaries, a reported 4:1 can easily be a real 1.5:1. It is worth recalculating both inputs honestly before trusting the result.

How it is calculated

Worked example

Comparing two products with identical revenue but different economics.

• Product A: LTV £2,000, CAC £900 → ratio 2.2:1.
• Product B: LTV £2,000, CAC £400 → ratio 5:1.
• Product A recovers acquisition cost slowly and has little headroom.
• Product B could profitably double acquisition spend and still stay above 3:1.

Takeaway: Product B is not just more efficient — it has room to buy growth that Product A does not, which usually decides who wins the segment.

Common mistakes

• Treating a very high ratio as unambiguously good rather than as possible underinvestment in growth.
• Comparing ratios across companies that calculate LTV and CAC differently.
• Trusting the ratio without checking whether CAC includes salaries and churn is observed.
• Optimising the ratio by cutting acquisition spend, which improves the number while shrinking the business.

Related tool: CAC and LTV:CAC calculator.

Related terms

• Customer Acquisition Cost — Customer acquisition cost (CAC) is the total sales and marketing spend required to win one new paying customer, calculated by dividing all acquisition costs in a period by the number of customers acquired in that period.
• Customer Lifetime Value — Customer lifetime value (LTV) is the total gross profit you expect to earn from a single customer across the whole of their relationship with you, before the cost of acquiring them.
• CAC Payback Period — CAC payback period is the number of months it takes for the gross profit from a customer to repay the cost of acquiring them — the point at which that customer stops being a loss.
• Unit Economics — Unit economics are the direct revenues and costs associated with a single unit of your business — usually one customer — showing whether each one is profitable before overheads.