What can I afford to pay for a customer?
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Use one period for both, a month or a quarter, so the spend and the customers belong together.
Display only. Your figures are read in the currency you pick — nothing is converted and no exchange rate is applied.
Ads, agency and influencer fees, discounts you funded to acquire — everything you spent to win customers.
First-time buyers only. Returning customers make CAC look cheaper than it is.
Enter what you spent on marketing in a period and how many new customers you won in the same period. There is no CAC until both are supplied.
- Total marketing spend for a periodNeeded
- New customers won in the same periodNeeded
- Paid media spend and the customers it wonOptional
- Lifetime gross profit per customer, for the LTV:CAC verdictOptional
Do not have a lifetime figure? Work out what a customer is worth from your AOV, order frequency and margin, then bring it back here. For a single campaign rather than a whole period, the break-even ROAS calculator gives the line an ad has to clear.
No benchmark is used: every figure comes from the numbers you enter. The currency is a label only and nothing is converted. The worked examples further down stay in US dollars.
Nothing you type is sent anywhere. There is no account, no install and no store connection.
Blended CAC, paid CAC and what a customer is worth
Customer acquisition cost is what your marketing spends to win one new customer, so a store that spent 12,000 dollars in a month and gained 300 new customers paid 40 dollars for each of them.
No benchmark and no published figure is used here. CAC comes from your own spend and customer counts, and the verdict comes from the lifetime value you supply — the CLV calculator works that figure out from your AOV, order frequency and gross margin.
Two costs and one value. The costs are easy to count; deciding which customers and which spend belong in the same period is where the answer goes wrong.
- Blended CAC
- All marketing spend in a period, spread across every new customer the store gained in that period, whether an ad found them or not. It is the honest average, and it is also the figure most likely to look better than the cost of the next customer, because the free ones are in it.
- Paid CAC
- Paid-media spend spread across only the customers paid media brought in. It is the price the next ad dollar actually pays, which is why this calculator judges the verdict on it whenever you supply it.
- Lifetime gross profit (LTV)
- What a customer leaves you over every order they will ever place, after the cost of the goods, not the revenue they bring. Using revenue here instead of gross profit makes every CAC look affordable. The CLV calculator works this figure out from your AOV, order frequency and margin.
- LTV:CAC ratio
- How many times over a customer repays what they cost to win. Below 1 : 1 they never pay it back; at 2 : 1 acquisition takes half of their lifetime gross profit. The bands on this page are the tool reading that share back to you, not an industry figure.
- Headroom
- Lifetime gross profit left over after acquisition, per customer. It is what pays for staff, software, rent and profit, so a customer who only just covers their CAC is not free money, they are break-even.
Nudgesmart is available on the Shopify App Store. Browse the template library or see what it costs.
What a customer costs, and whether they pay it back
Illustrative arithmetic in US dollars, not customer data. Every row is produced by the same function the calculator above runs.
| Scenario | Blended CAC | Paid CAC | Lifetime gross profit | LTV:CAC | Verdict |
|---|---|---|---|---|---|
| Apparel store, one month of spend | $40.00 | — | $110.00 | 2.75 : 1 | Pays back |
| Supplements subscription, strong reorders | $80.00 | — | $420.00 | 5.25 : 1 | Room to spend more |
| Home goods, paid media split out | $30.00 | $75.00 | $70.00 | 0.93 : 1 | Never pays back |
| Electronics accessories, one-off buyers | $40.00 | — | $35.00 | 0.88 : 1 | Never pays back |
| Skincare brand, blended and paid close together | $50.00 | $52.08 | $95.00 | 1.82 : 1 | Pays back |
| Pet food, customers stay for years | $60.00 | — | $310.00 | 5.17 : 1 | Room to spend more |
| Gift shop, CAC only | $25.00 | — | — | — | Each new customer costs $25.00 |
Where a CAC figure flatters you
Returning customers inflate the count
If the customer figure includes people who had bought before, CAC comes out too low. Count only first-time buyers in the period, which is what your store reports as new customers.
Spend and customers must cover the same window
Spend that lands this month often wins customers next month, most of all around a big sale. Measuring both over a quarter smooths that lag out; measuring both over a single week usually does not.
Lifetime value is a forecast you supplied
The LTV:CAC ratio is only as sound as the lifetime figure behind it, and that figure is made of orders that have not happened yet. A young store should read a healthy ratio as a hypothesis until customers have had time to reorder.
Paid attribution comes from the platform
The number of customers paid media won is usually the ad platform reporting on itself. If it claims more than it delivered, paid CAC looks cheaper than it is — and the blended figure is the check on it.
Payback timing is not in this ratio
Two stores with the same ratio can be in very different cash positions: one earns its CAC back on the first order, the other waits a year for the third. If cash is tight, compare the CAC with the gross profit on a single order too.
Customer acquisition cost questions
How do you calculate customer acquisition cost?
Enter what you spent on marketing over a period and how many new customers you gained in that same period, and the calculator returns the cost of one customer. 12,000 dollars of spend and 300 new customers is a CAC of 40 dollars. Add your paid-media spend and the customers it won to see paid CAC beside it.
What is the difference between blended CAC and paid CAC?
Blended CAC counts every new customer, including the ones who came from search, word of mouth or a repeat visit, so it is lower. Paid CAC counts only the customers the ads won, so it is what scaling the ads will actually cost. In the third worked example the blended figure is 30 dollars and paid media is paying 75.
What is a good LTV to CAC ratio?
One that leaves enough lifetime gross profit to run the business once the customer is paid for. This page does not grade against a published average, because the figures in circulation vary with how lifetime value and CAC are counted. It shows the share of lifetime gross profit your CAC takes instead: at 2 : 1 that is half, at 4 : 1 it is a quarter.
Should I use revenue or profit for lifetime value?
Gross profit. A customer worth 300 dollars in revenue at a 40 percent margin leaves you 120, and it is the 120 that pays for their acquisition. Setting a CAC ceiling against revenue is how stores end up growing and losing money at the same time.
How can I lower my CAC without cutting ad spend?
Convert more of the visitors you already paid for. A shopper who leaves without buying but gives you an email address can be sold to again for the cost of an email, which spreads the same ad spend across more customers.
Does this tool need my store or an account?
No. It runs in the page with numbers you type, and sends nothing about your store anywhere.
Paying for the click is the easy half. Keeping the visitor is the job.
Nudgesmart works the session you already paid for — a capture popup targeted on what the shopper is doing — and reports revenue per signup.
