Customer Acquisition Cost Calculator
CAC computed three ways from one set of numbers — media spend only, fully loaded with salaries and tooling, and blended across organic. The arithmetic is a division; which figure you quote is the part that actually moves the answer.
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The arithmetic is spend divided by customers. The argument is what goes in the numerator, so this customer acquisition cost calculator shows all three readings at once — and names who uses each, because two companies quoting different ones look very different on identical numbers.
Ads, sponsorships, paid placements.
Loaded cost of everyone in the function.
CRM, creative, contractors, trade shows.
Attributable to the spend above.
Including everyone who arrived organically.
Optional — gives the LTV:CAC ratio.
Optional — gives the payback period.
Quoting media spend alone gives $24.00; counting salaries and tooling gives $40.00. 40% of what you spend to acquire a customer is not media. Spreading the same spend across the 150 organic customers too brings it to $30.77 — flattering, and the reason investors ask which one you mean.
At $16.00 of gross profit a month, the loaded CAC takes 2.5 months to earn back.
Acquisition cost is what you pay for growth you did not build in. If you are building the product largely on your own, Tekk turns what you want into specs your coding agent can actually execute.
The formula
CAC = sales and marketing spend ÷ new customers acquired
One division, and nobody argues about it. The argument is entirely about what goes above the line and what goes below it.
What belongs in the numerator
WallStreetPrep's list is the one most finance teams work from:
- Sales and marketing salaries
- Ad spend and campaigns
- Creative and production costs
- Technical tools — CRM, automation, analytics
- Content and SEO
- Events, including travel
- Third-party services and consulting fees
The contested line is salaries, and it is contested because including them often doubles the answer. A team spending $12,000 on ads and $8,000 on the people running them has a real acquisition cost of $20,000, whatever the ad dashboard reports.
Three readings, one set of numbers
Using $12,000 of media, $6,000 of salaries, $2,000 of tooling, 500 customers from paid and 650 in total:
| Reading | Working | Result | Who quotes it |
|---|---|---|---|
| Paid-only | $12,000 ÷ 500 | $24.00 | The ads team, measuring channel efficiency |
| Fully loaded | $20,000 ÷ 500 | $40.00 | Investors and finance |
| Blended | $20,000 ÷ 650 | $30.77 | Board decks, often unlabelled |
Same quarter, same business, and a spread of $16 per customer between the highest and lowest figure — a 67% difference driven entirely by definition rather than performance.
The fully loaded figure of $40 is the one this page treats as canonical, and the one the ratio and payback are computed against.
Reading it against value
CAC alone says nothing. A $40 acquisition cost is excellent against a $200 customer and fatal against a $30 one.
LTV : CAC = lifetime value ÷ fully loaded CAC
At $200 of lifetime value that is 5.0x, comfortably past the 3.0x figure usually cited for software. Below 1.0x the business loses money on every customer it wins. Far above 3.0x is not automatically good news — it often means acquisition is underfunded and growth is being left on the table.
The companion measure is payback: at $16 of monthly gross profit, a $40 CAC returns in 2.5 months. When cash is short that number matters more than the ratio, because it is about when the money comes back rather than whether it eventually does.
Three things that distort it
Lag. Spend in March buys customers in May. Measure over a quarter, not a month, or a spending ramp will look like a collapse in efficiency.
Attribution. Move a customer from organic to paid in the CRM and CAC changes without anything real changing. Reclassifications are the most common explanation for a sudden jump.
Retention costs. Customer success and support are not acquisition. They belong in gross margin, where they reduce lifetime value — putting them here produces a number nobody can compare to anything.
How it works
- 1
Split the spend into its three parts
Paid media, sales and marketing salaries, and everything else — CRM, creative, agencies, events. Keeping them apart is what lets this customer acquisition cost calculator show the difference between the number your ads team reports and the number due diligence asks for.
- 2
Separate paid customers from all customers
Enter how many new customers came from paid channels and how many arrived in total. The gap is your organic. Dividing all spend by all customers gives the blended figure, which is lower and is the one most often quoted without saying so.
- 3
Add lifetime value for the ratio
CAC on its own is a cost, not a verdict. With a lifetime value entered you get LTV:CAC against the 3.0x benchmark, and with monthly gross profit you get the payback period. Both are computed against the fully loaded figure, never the flattering one.
Frequently asked questions
- How do you calculate customer acquisition cost?
- Divide sales and marketing spend for a period by the number of new customers acquired in that period. $20,000 of spend against 500 new customers is a CAC of $40. The formula is settled; what belongs in the $20,000 is not, which is why the customer acquisition cost calculator above itemises the numerator instead of asking for one total.
- Should salaries be included in CAC?
- Yes, if you want a number anyone else will accept. WallStreetPrep's list of what counts includes sales and marketing salaries alongside ad spend, creative and production, technical tools like CRM, content and SEO, events, and third-party consulting. Excluding salaries produces a figure that flatters the channel and misleads the business.
- What is the difference between blended and paid CAC?
- Blended CAC divides all acquisition spend by all new customers, including those who arrived organically. Paid CAC divides it only by customers attributable to paid channels. Blended is always the lower number, and a cost of customer acquisition calculator that reports only one of them hides which you are looking at.
- Which CAC should I report to investors?
- The fully loaded, paid-only figure, unless you say otherwise. Investors assume salaries and tooling are in the numerator and that organic customers are not diluting the denominator. Presenting blended CAC without labelling it is the fastest way to lose credibility in a diligence conversation — run the customer acquisition cost calculator above and quote the loaded figure.
- What is a good CAC?
- There is no absolute figure — it only means something against what a customer is worth. A $500 CAC is excellent for enterprise software and ruinous for a consumer app. The measure that travels is the ratio to lifetime value, where 3.0x is the commonly cited target for software businesses.
- What period should a cost of customer acquisition calculator cover?
- Long enough to smooth out the lag between spend and conversion, which usually means a quarter rather than a month. Spend in March often produces customers in May, so a monthly cost per customer acquisition calculator run during a spending ramp will systematically overstate CAC and understate it when spend falls.
- How do I handle customers who came through organic search?
- Count them in the total but not in the paid figure — which is what the two customer fields above do. The honest position is that organic is rarely free, since content and SEO cost money and sit in the same budget. That is precisely why both readings are shown rather than one.
- What is the LTV to CAC ratio?
- Lifetime value divided by acquisition cost — how much gross profit each acquisition dollar eventually returns. Around 3.0x is the usual software target. Below 1.0x you lose money on every customer; far above 3.0x usually indicates underinvestment in growth rather than exceptional efficiency.
- What is CAC payback period?
- How many months of gross profit it takes to earn the acquisition cost back. Under 12 months is generally healthy for a business selling to other businesses. It often matters more than the ratio, because it is about when the cash returns rather than whether it eventually does — see the payback period calculator for the general version.
- Why did my CAC jump this quarter?
- Usually one of three things: spend increased before the customers it bought have converted, a channel saturated and the marginal customer got more expensive, or the denominator changed because attribution was reclassified. Check whether the cost per customer acquisition calculator inputs shifted before concluding the marketing got worse.
- Does this include the cost of retaining customers?
- No. CAC is acquisition only. Customer success, support and renewal costs belong in gross margin, where they reduce lifetime value rather than increasing acquisition cost. Mixing them produces a number that is neither and cannot be compared to anyone else's.
- Do you store the numbers I enter?
- No. The calculation runs entirely in your browser. Nothing is sent to a server, nothing is logged, and there is no account. Disconnect from the internet and it will still work.
- Why is this free, and what is Tekk?
- Tekk is a spec-driven development platform for people building software with AI coding agents. This calculator costs us nothing to run, and the founders working out their unit economics are often the same people building the product. No signup, no run limit, no upsell inside the tool.
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