What is the LTV:CAC ratio?
Growth costs money up front and pays back over time. LTV:CAC puts those two sides in one number: the value a customer brings, against the cost of bringing them in.
It's a ratio finance teams and investors trust because it connects marketing spend to business value in terms they already use. It started in subscription businesses and now shows up wherever customers buy more than once.
How do you calculate LTV:CAC?
LTV:CAC = customer lifetime value / customer acquisition cost. CAC = total sales and marketing cost to acquire customers in a period / new customers acquired in that period.
CAC payback, the companion metric, is the number of months until a customer's profit covers what it cost to acquire them: CAC / monthly gross profit per customer.
| Choice | Flattering version | Honest version |
|---|---|---|
| LTV basis | Revenue | Gross profit |
| CAC costs | Media spend only | Media, agency, tools, and sales and marketing salaries |
| Customers counted | All customers, including those who'd have come anyway | New customers, ideally incremental ones |
| Level | One blended number | By channel and by cohort |
What is an example of an LTV:CAC ratio?
A healthy average hiding a problem
A brand's blended LTV:CAC is 3.2:1, which looks healthy. Split by channel, organic and referral customers come in at 8:1, and paid social at 1.4:1.
Paid social is barely covering its costs, and the cheap organic customers are carrying it. The team caps paid social at the spend level where its ratio stays above 2.5:1 and moves the rest toward channels with better cohorts.
LTV:CAC vs. ROAS vs. CAC payback
| ROAS | LTV:CAC | CAC payback | |
|---|---|---|---|
| Time frame | The attribution window | The customer's lifetime | Months until costs are covered |
| Uses profit | No | It should | Yes |
| Answers | Did the ads drive revenue now? | Is a customer worth what they cost? | How long is cash tied up? |
Why does LTV:CAC matter?
It's the number that lets marketing and finance agree on how much growth to buy. Too low and each new customer loses money. Very high can mean the business is under-investing and leaving growth on the table.
- A shared language. Finance can treat acquisition as an investment with a return.
- Cash discipline. Payback shows how long money is tied up before it comes back.
- Channel choices. Ratios by channel show where the next dollar earns the most over time.
The ratio is only as good as the LTV behind it. When LTV is a forecast for young cohorts, pair the ratio with payback, which depends less on the long-range guess.
How does Alli do this?
LTV:CAC depends on agreeing what counts: which costs go into CAC, what margin goes into LTV, and who counts as a new customer. Alli Semantic Layer defines each metric once, so marketing and finance see the same numbers in every dashboard and model.
Alli Datasources brings first-party systems such as Salesforce and Adobe together with media data, so acquisition cost and the value customers bring later sit in one place. Alli Scenario Planner then shows predicted revenue and ROAS for each channel's spend range before budget moves.
Explore Alli Semantic LayerLTV:CAC ratio FAQ
What is a good LTV:CAC ratio?
3:1 is a common benchmark. Below about 1:1, acquisition loses money. Much higher than 5:1 can mean a business is spending too little to grow. The right target depends on margins, cash, and how reliable the LTV estimate is.
How do you calculate CAC?
Divide the total cost of sales and marketing to acquire customers in a period by the number of new customers acquired in that period. Include media, agency, tools, and team costs for a fully loaded CAC.
What is CAC payback?
The number of months it takes for a customer's gross profit to cover what it cost to acquire them. Shorter payback means cash comes back sooner.
Should LTV use revenue or profit?
Profit. Revenue-based LTV makes every ratio look better than it is, because it ignores what the products cost to make and deliver.
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