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Customer acquisition cost calculator

Customer acquisition cost (CAC) is the total you spend on marketing and sales in a period, divided by the number of new customers you gained in that period. Blended CAC counts all of that spend against every new customer, while paid CAC counts only paid media spend against the customers the ad platforms claim.

This calculator works out what one new customer costs you, in four steps: step 1 takes four numbers and under a minute, and the other three are optional.

Free · No signup · Nothing is sent unless you ask for a written read

Nothing is saved yet. Step 4 keeps a month by month record in this browser.See step 4

Step 1 · Blended CAC and paid CAC

What a customer costs you

You enter four numbers for one month. You get what one new customer costs with all spend counted, what the ad platforms say one costs, and the share of customers no ad brought.

Not started

Your four numbers, for one month
Everything spent to win customers in the month: ads, tools, content, creators, salaries.
The part that went to the ad platforms themselves in the same month.
Every new customer in the same month, wherever they came from.
The conversions your ad dashboards report for the month, added up.
Labels, if yours differ
Currency symbol

A label only. Nothing is converted.

Your numbers cover one

Wording only. Your numbers are never multiplied.

Step 1 resultsFor one month

Waiting for total marketing and sales spend, paid media spend, total new customers and customers the ad platforms claim.

Cost of one customerFill in the four figures to draw this
Blended CAC
No figure yet
What one new customer costs with all spend counted: total spend / total new customers.
Paid CAC
No figure yet
What the ad platforms say one costs: paid media spend / customers the platforms claim.
Customers with no paid click
No figure yet
The customers no ad brought: total new customers minus the ones the platforms claim, as a share of the total.
Step 2 · Lifetime value and payback · Optional

Is a customer worth it

You enter what a customer pays, your margin and how often they buy. You get what one customer brings back, how that compares with what they cost, and the months until they have paid it back.

Not started

How customers pay
Revenue from one order, before any costs.
What is left of the price after making and delivering the product, as a percent.
Count the first order. A customer who buys once a year is 1.
Months to count

The period the lifetime value covers. You choose it; the page does not assume one.

Step 2 resultsOver 12 months

Waiting for average order value, gross margin, orders per customer per year and the four numbers in step 1.

CAC payback
No figure yetmonths
Months until a customer has paid back their cost: blended CAC / gross profit per customer per month, with orders spread evenly over the year.
Lifetime value over 12 months, on gross profit
No figure yet
What one customer brings back: gross profit per order x orders per year x months counted / 12.
LTV to CAC
No figure yetAgainst blended CACNo figure yetAgainst paid CAC
What a customer brings back for each 1 they cost: lifetime value on gross profit / CAC.
Gross profit per order
No figure yet
Average order value x gross margin
Break-even CAC
No figure yet
Equal to the lifetime value above: the most one customer can cost before the gross profit from these 12 months is gone.
Orders to pay back one customer
No figure yet
Blended CAC / average order value, before margin
Step 3 · Scenario · Optional

What if more came on their own

You enter the share of customers who arrive with no paid click. You get your cost per customer at that share, next to today's.

Not started

Arithmetic on your own figures, not a forecast. It shows what the numbers would be at a different share. It does not say you will get there.

What is held constant

Holds your total spend, your paid spend and your paid customers where they are, and adds customers with no paid click until they reach the share you set.

Fill in the four numbers in step 1 first, with at least one customer the platforms claim.
Step 3 resultsToday and the scenario

Waiting for the four numbers in step 1.

Your figures today next to the scenario
TodayScenario
Total spendNo figure yetNo figure yet
Customers with a paid clickNo figure yetNo figure yet
Total customersNo figure yetNo figure yet
Blended CACNo figure yetNo figure yet

The scenario column fills once step 1 is complete.

Total customers = customers with a paid click / (1 - share). Blended CAC = total spend / total customers.

SummaryDrawn from every step you filled in

What your numbers say

Fill in the four numbers in step 1 and a short read of them appears here. It restates your own numbers and ends on one question. It does not grade them.

Share these figures

These buttons send nothing anywhere and keep nothing. The link holds your figures in the address itself, and only once you press the button.

Get a written read on these numbersFrom a person, by email, within three days. Nothing is sent until you press send there.

Step 4 · Monthly history · Optional

Save this month and track it

You enter a month, and the four numbers come from step 1. You get a table and a trend line that grow every month you come back.

Not started

Year and month, like 2026-11. It starts on this month. One entry per month.
What will be savedThe four numbers from step 1, as they stand now. Change them there.
Total spend
No figure yet
Paid media spend
No figure yet
New customers
No figure yet
Customers the platforms claim
No figure yet
Your own number, if you have one. It is drawn as a dashed line. The page does not suggest one.

Fill in step 1 first. Still missing: total marketing and sales spend, paid media spend, total new customers and customers the ad platforms claim.

Step 4 resultsSaved months

No months saved yet. The table appears with the first one, and the trend line with the second.

Cost of one customer, by monthSave two months to draw this

Grey is paid CAC, orange is blended CAC. A month with no customers has no CAC, so the line breaks there.

Your saved data

The history lives in this browser only. Clearing your site data removes it, and it does not follow you to another device, so export a CSV to keep a copy.

Everything above is arithmetic on your own numbers. If you want a person to read them and write back, that is the form below. It is optional.

Written readFree · No call

Get a written read on these numbers

The read above is arithmetic. This one is written by a person. Tell us what you sell and where to see it, and within three days you get a written read of what brings you customers today and what we would build first. No call. It is yours to keep.

We build organic short-form video engines for consumer companies: apps, ecommerce and DTC brands, games, marketplaces and products before launch. If you sell to other businesses, we are the wrong shop, and the calculator is still yours to use.

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CAC calculator figures (one month, €)
Total spend: -
Paid media spend: -
New customers: -
Customers the platforms claim: -
Blended CAC: -
Paid CAC: -
No paid click share: -

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Made with the free CAC calculator at underbossmedia.com/cac-calculator

How to calculate customer acquisition cost

Pick one period, a month or a quarter, and use it for every figure. Then do two divisions. Blended CAC is your total marketing and sales spend divided by every new customer you gained in the period. Paid CAC is your paid media spend divided by the new customers the ad platforms claim.

The third figure is the one most calculators skip. Take your total new customers and subtract the ones the platforms claim. What is left is the customers who arrived with no paid click. Divide that count by total new customers and you have their share.

Blended CAC
Total marketing and sales spend, divided by total new customers.
Paid CAC
Paid media spend, divided by the new customers the ad platforms claim.
No-ad share
Total new customers minus the customers the platforms claim, divided by total new customers.
Payback in orders
Blended CAC, divided by your average order value.

LTV to CAC and payback, in plain words

CAC says what a customer costs. It does not say whether that is too much. For that you need what the customer brings back, counted on gross profit, because revenue still has the product to pay for.

Lifetime value, or LTV, is the gross profit one customer brings in over a period you choose. LTV to CAC puts the two side by side. Payback tells you how many months pass before a customer has returned what it cost to win them, which is a question about cash.

Gross profit per order
Average order value, multiplied by your gross margin.
Lifetime value
Gross profit per order, multiplied by the orders one customer places in the months you choose to count.
LTV to CAC
Lifetime value, divided by CAC. Work it out against blended CAC and against paid CAC.
CAC payback
CAC, divided by the gross profit one customer brings in per month. The answer is in months.
Break-even CAC
The lifetime value itself: the most one customer can cost before the gross profit from those months is gone.

Why paid CAC and blended CAC give different answers

The two numbers answer different questions. Paid CAC tells you what the ad account pays for the customers it can see. Blended CAC tells you what the whole business pays for a customer, counting the ones no ad touched.

They pull apart for two reasons. Blended CAC carries costs that paid CAC leaves out, such as salaries, tools and content. And blended CAC is spread over more customers, because people also arrive by searching your name, by word of mouth, or from a video they watched last week.

When the no-ad share grows, blended CAC falls even if the ad account stays exactly as it was, because the customer count rises and the spend does not. When it shrinks, every customer has to be bought, and your cost per customer follows auction prices up.

Each number hides something on its own. Watch only paid CAC and organic work looks like it does nothing. Watch only blended CAC and a weak ad account can hide behind good word of mouth. Keep both, side by side.

One caution. The share is only as good as the way the platforms count. Two platforms can claim the same sale, so read the share as a direction over several months.

What the read says, and what it leaves out

Once the four figures are in, the page writes a short read after step 3, under the heading "What your numbers say". It is a handful of fixed rules, the same for everyone, and it runs in your browser. No model writes it, and nothing is sent to produce it.

It restates what your own figures already say: what share of your customers the platforms claim, how far paid CAC sits from blended CAC, whether a customer returns more gross profit than they cost in the months you count, and how long payback takes. Then it ends on one question, the one those figures raise first.

It leaves three things out on purpose. It does not compare you with anyone, because a calculator cannot know a benchmark that fits your price, your margin and your category. It does not call a number good or bad. And it does not predict what happens next.

For a view from outside the arithmetic, the form under the tracker sends your figures and a short note to us, and a person writes back within three days. That part is optional, and it is the only time this page sends anything.

Why a monthly record beats one calculation

One month of CAC is a single photograph. A sale counted twice, a campaign that ran late or one slow week can move it, and from one figure you cannot tell which.

A run of months shows what one month hides. You see whether blended CAC is falling while paid CAC holds, which means more customers are arriving on their own. You see the month the two lines pulled apart, and you can ask what changed that month.

The tracker keeps that record. Save the four figures under a month, and the page draws paid CAC in grey and blended CAC in orange, with your own target as a dashed line if you set one. Count the same things every month, or the line measures your bookkeeping instead of your marketing.

The history stays in your browser. There is no account, and we never see it. Export the CSV file if you want a copy that outlives the browser, and import it again on another device.

What to do with the number

Run the calculator on the same period every month and save the figures in the tracker. The trend tells you more than any single month.

If the no-ad share is small, almost every customer is being bought. The work is to build the channels you own, so customers start arriving on their own.

We do not publish a good or bad CAC here, because it depends on your price, your margin and how often a customer buys again. What we can report is our own work: across Underboss Media portfolio engagements, the average CAC reduction is 35%. That is an average across engagements and no promise for yours.

Questions about CAC

Customer acquisition cost, or CAC, is what you spend on marketing and sales in a period divided by the number of new customers you gained in that period. It tells you what one new customer costs you on average.

Add up everything you spent to win customers in one period, then divide by the number of new customers in the same period. That is blended CAC. For paid CAC, divide only your paid media spend by the customers the ad platforms claim.

Paid CAC counts ad spend against the customers the ad platforms claim. Blended CAC counts all marketing and sales spend against every new customer, including the ones who arrived with no ad.

Count everything that exists to win new customers: ad spend, agency and freelancer fees, creator payments, content production, marketing tools, and the salaries of the people doing the work. Leave out the cost of making and delivering the product, and count the same things every month.

There is no single good number, and this page does not publish a benchmark it cannot source. A CAC is healthy when a customer pays it back fast enough for your cash and is worth clearly more than it over time.

It depends on your gross margin, your fixed costs and how long customers stay, so this page gives no universal number. None applies across categories. The one line the arithmetic draws for everyone is 1: below it, a customer costs more than the gross profit they bring in over the months you count.

Divide CAC by the gross profit one customer brings in per month. The answer is the number of months until a customer has paid back what it cost to win them. Use gross profit, not revenue, or the payback looks shorter than it is.

The calculator sends nothing while you type. The month tracker saves your figures in your own browser, on your device, and nowhere else. Figures reach Underboss Media only if you fill in the written read form and press send.

Yes. Save your four figures under a month, and the page keeps a table and a line of blended CAC and paid CAC, month by month. The history lives in your browser with no account, and you can export it as a CSV file.

Yes. Blended CAC divides all marketing and sales spend by every new customer, including the ones who arrived with no ad. That is why it falls when more customers come on their own and spend stays the same.

See what would bring your blended CAC down.

Send a link to your product and your channels. In three days you get a free written teardown of what brings you customers today and what we would build first. The plan is yours, whether we work together or not.

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