CAC Calculator

What this tool does

CM8-365 works out what a customer costs to acquire, channel by channel and month by month. It counts every cost — media, agency, creative, tools and the people time nobody counts — and shows the media-only figure beside it so the difference is impossible to miss.

Everything runs inside this single file — no account, no upload, no network request of any kind. What you spend and what it returns is nobody else's business.

What CAC actually is

Simple arithmetic, and almost every published figure is wrong for the same reason: the numerator is incomplete. A CAC that counts only advertising spend is not a cost of acquiring customers; it is an advertising cost per customer, which is a different and much smaller number.

What one row is

One row is one channel in one month. Keep months separate — an average over a year hides the month the cost per click rose forty percent — and keep channels separate at the level you can actually make decisions about.

Split brand search from non-brand. They behave completely differently: brand search is cheap because those people were largely coming anyway, and blending the two makes paid search look far better than the part of it you actually control. The sample keeps them apart for exactly this reason.

What to include, and what people leave out

Five components, and the last two are the ones that get missed:

• Media spend — what the platform charges. Everybody counts this.
• Agency and freelance fees — management fees, retainers, contractors.
• Creative and production — photography, video, design, copy. Spread a one-off production across the months it is used rather than dropping it all into one; the sample splits a video shoot across six months.
• Tools — the software the channel needs.
• People time — see below.

People time is the big one

Include everybody, not just marketing. If sales spends a day a week working leads from one channel, those hours belong to that channel's acquisition cost. A fully loaded hourly cost — salary, employer costs, overhead — is roughly one and a half to two times the bare salary rate.

This is where the two figures diverge, and often dramatically. The outbound channel in the sample has no media spend at all: on a media-only view it costs nothing per customer, and once the calling time is counted it is the second most expensive channel in the business.

The switch to exclude people time exists so you can see what the flattering version looks like. Do not quote it.

Organic is not free

Content, SEO and word of mouth have no media cost and are among the most expensive channels most businesses run, because they consume enormous amounts of skilled time. The sample's organic channel carries seventy-six hours a month; at a realistic hourly cost that is more than the paid social budget.

An organic row with no hours against it is flagged, because it is nearly always an omission rather than a channel that genuinely runs itself.

Blended CAC against paid CAC

Both are useful and they answer different questions. Blended tells you what growth costs the business overall. Paid tells you what buying a customer costs at the margin, which is the number that decides whether to spend more.

Blended CAC is not comparable between businesses. A company where four fifths of customers arrive organically will have a low blended figure and may still be running paid channels at a loss. That is why this tool shows the channel mix as its own chart — blended CAC is unreadable without it.

Attribution, honestly

The tool counts the customers you assign to a channel. It cannot tell whether the channel deserved them, and no tool can: the customer who saw an advert in March, read three articles in April and typed your name into a search box in May is claimed by every system that touched them.

Two rules that keep this usable rather than exact: count each customer once, against whichever channel you judge did the work; and be consistent month to month, because the trend is far more reliable than any single figure. Where you genuinely cannot attribute, blended CAC is the honest answer and the tool reports it prominently for that reason.

The timing problem

Costs land in the month you spend them; customers land in the month they buy, which may be two months later. For a short sales cycle the distortion is small. For a long one, a month with heavy spend and few customers may simply be early rather than bad.

Two ways to handle it: look at a rolling three months rather than single months, or record spend in the month the customers it won actually arrived, and say in the notes which convention you used. Either is defensible; mixing them is not.

What the first order recovers

Above 100% and the channel pays for itself immediately, which is the strongest position a business can be in. Below it — which is normal — the rest has to come from what the customer does afterwards, and that is a question about lifetime value rather than about acquisition cost.

Note this uses revenue, not margin. It is a rough indicator of cash timing, not of profit.

What to do with the answer

CAC on its own decides nothing. A CAC of 400 is excellent for a customer worth 4,000 and ruinous for one worth 300. The three questions that follow are: what is a customer worth, how long until they pay back what they cost, and which channels are actually profitable — and each has a better tool than this one.

What CAC is good for on its own: comparing channels against each other, spotting a channel drifting worse month by month, and finding the ones with real spend and no customers at all.

What this does not do

• It does not do attribution. It records the judgement you made.
• It does not know about existing customers buying again. This is acquisition cost only.
• It does not tell you whether a channel is profitable — cost is only one half of that.
• It has no view on diminishing returns. Doubling the spend on the cheapest channel rarely doubles the customers, and nothing here will warn you.
• The unattributed overhead figure is spread across the whole period for the blended number only. It is deliberately not allocated to individual channels, because any allocation would be invented.

Printing and sharing

The Report tab prints the tiles, charts and both tables with a title block you fill in. The workings table is the one to take to a budget conversation — it shows every component, so the argument is about the inputs rather than about the conclusion.

Saving your work

Everything is held in this browser, on this computer, and stays there between visits. Use the backup button to write a JSON file you control; the spreadsheet download gives you the same rows.

Accuracy & disclaimer

Every figure here is one you entered. The tool adds and divides; it has no view about whether your attribution is right, whether your hourly cost is realistic, or whether a channel is worth running.