Free Tool
CAC Calculator
Calculate your Customer Acquisition Cost from CPC and conversion data. See the full funnel from click to customer and compare against your LTV.
Customer Acquisition Cost
$257.14
Cost to acquire one paying customer
LTV:CAC Ratio
1.9x
A healthy LTV:CAC ratio is 3:1 or higher. Below 1:1 means you lose money on every customer.
Want keyword-level data?
See all keywords for this industry
CPC · Volume · Competition · Opportunity Score
View full report — free →
What customer acquisition cost actually measures
Customer acquisition cost is the total amount you spend to turn a stranger into a paying customer. It is the number that decides whether a growth channel is a business or a hobby: if CAC exceeds what a customer is worth to you over their lifetime, scaling spend accelerates losses rather than growth.
CAC = Total acquisition spend ÷ New customers acquired
The calculator above works backwards from the click, which is how paid media actually behaves. It chains four steps that each lose volume:
Clicks = Spend ÷ CPC
Leads = Clicks × Landing page conversion rate
Customers = Leads × Lead-to-customer close rate
CAC = Spend ÷ Customers
How to read the result
The LTV:CAC ratio matters more than CAC itself
A CAC of $500 is excellent if a customer is worth $5,000 and catastrophic if they are worth $400. The ratio of lifetime value to acquisition cost is the number to watch. A widely used rule of thumb in subscription businesses is 3:1: below that, margins get thin; far above it, you are probably underspending and leaving growth on the table.
Payback period is the constraint nobody models
Two businesses with identical LTV:CAC ratios can have completely different cash positions. If it takes 18 months to recover acquisition cost, growth consumes cash even while the unit economics look healthy on paper. Compare your CAC against monthly revenue per customer, not just total lifetime value.
What CPC to use
If you already run campaigns, use your own measured CPC. If you are modelling a channel you have not launched, the median for your industry is a more defensible starting point than a guess. These are the current figures in our database:
Use the median as the central case, then rerun the calculation with the 25th and 75th percentile values from your industry report to see how sensitive your CAC is to the click price. In high-dispersion verticals like legal services, that sensitivity is the whole story.
Common mistakes
- Counting only ad spend. True CAC includes agency fees, creative production, and the salary cost of the people running the channel. Media-only CAC flatters every channel equally and hides which one is actually efficient.
- Blending paid and organic. Mixing channels produces an average that describes none of them and cannot guide a budget decision.
- Using account-wide averages. CAC varies enormously by campaign, audience and keyword intent. An account-level number is a report, not a lever.
- Ignoring the time lag. Spend in one month produces customers in the next. In long sales cycles, dividing this month's spend by this month's customers understates CAC while you are growing and overstates it while you are shrinking.
- Treating CAC as fixed. CAC rises as you scale, because the cheapest, highest-intent audience gets exhausted first. Model it as a curve, not a constant.
Related calculators