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CAC Calculator
Enter Sales spend, Marketing spend and New customers acquired plus 1 more input — every figure updates as you type. Nothing you type leaves your browser.
How do you calculate CAC?
Blended CAC
$500
Total spend across every new customer. The figure investors mean by 'CAC'.
- Paid CAC
- $833Spend across only the customers it produced. The figure that tells you what to do next.
- Total acquisition spend
- $75,000Sales plus marketing for the period, fully loaded.
Results are rounded for display; the calculation runs at full precision.
The maths
How CAC is calculated
The formula this calculator runs, written out so you can check it against your own model rather than trust a black box.
CAC = (Sales spend + Marketing spend) ÷ New customers acquired- Sales spend
- Fully loaded cost of the sales function for the period: base salaries, commission, benefits, CRM and prospecting tools. Not just the variable portion.
- Marketing spend
- Advertising, agencies and contractors, content and design production, events and sponsorships, plus marketing salaries and benefits.
- New customers acquired
- Customers who started paying in the period. Exclude trials that have not converted, reactivations of former customers, and internal or test accounts.
Reading the result
What the number is telling you
Bands are directional, not verdicts. Stage, price point and contract length move every one of them, so treat these as a starting point for the conversation rather than a grade.
- Paid CAC within 10% of blended CAC
- Almost every customer is bought. Growth is a direct function of budget, which makes forecasting straightforward and makes the business fragile to rising ad costs. There is no organic base to fall back on if a channel degrades.
- Paid CAC between 1.1× and 2× blended CAC
- Roughly 10–50% of new customers arrive without attributable spend. A healthy mix: paid channels are doing real work while brand, referral and content carry a meaningful share. Plan against the paid figure and report the blended one.
- Paid CAC above 2× blended CAC
- The majority of customers arrive organically and blended CAC is flattering you badly. Marginal spend is far less efficient than the headline suggests. Worth checking whether the organic share is genuinely unattributable or simply untracked, because those call for opposite responses.
- Blended CAC returns 0
- No new customers were recorded for the period, so the division has no denominator. Check that the period is long enough to contain conversions and that trials converting to paid are being counted as new customers rather than excluded.
What belongs in the numerator
The single largest source of variation between two companies' CAC figures is not their marketing efficiency, it is what they chose to count. A fully loaded CAC includes the people, not only the programmes.
- Include: salaries, commission and benefits for everyone in sales and marketing; advertising and paid distribution; agency and contractor fees; content, design and video production; events, sponsorships and travel; sales and marketing tooling.
- Exclude: customer success time spent on existing accounts; product and engineering; general and administrative overhead; the cost of serving customers, which belongs in gross margin and therefore in LTV instead.
The ambiguous case is customer success. If the team's job is renewals and expansion, that cost sits against retained revenue, not acquisition. If they are effectively closing new business during onboarding, a share belongs in CAC. Pick a rule, write it down, and keep it stable — a CAC that improves because the definition changed is worse than no CAC at all.
Blended and paid CAC answer different questions
Blended CAC divides all spend by all new customers, including the ones who arrived through word of mouth, direct search or a referral. It is the right number for the question "what does growth cost this business?" and it is what an investor means when they ask for CAC without qualification.
Paid CAC divides the same spend by only the customers that spend produced. It is the right number for the question "what happens if we increase the budget?" At the defaults above the two differ by more than 300 — the blended figure is being subsidised by organic demand that will not scale with the ad budget. A company that plans against blended CAC and then doubles spend usually discovers this the expensive way.
Match spend to the customers it actually produced
Dividing this month's spend by this month's customers is only correct when the sales cycle is roughly zero. With a 60-day cycle, the customers who signed in March were produced by January and February spend, and a month where budget jumped will show an artificially high CAC while the resulting customers are still in the pipeline.
Two practical corrections: measure over a quarter rather than a month so the lag mostly washes out, and offset the numerator by the length of your average sales cycle when the cycle is longer than about a month. Neither is exact, but both are closer than the naive division. Once you have a CAC you trust, take it to the LTV:CAC ratio and the payback period — CAC on its own says nothing about whether acquisition is working.
Definition
Where CAC gets argued about
A calculator settles the arithmetic, not the definition — and the definition is where most disagreements about this number actually live. The glossary entry covers the conventions, the edge cases and how Bastle handles each one.
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LTV:CAC Ratio Calculator
The LTV:CAC ratio divides margin-adjusted lifetime value by fully loaded acquisition cost to show how much contribution each acquisition dollar returns.
Learn moreCAC Payback Period Calculator
CAC payback period is the number of months a customer's gross margin must run before it repays what you spent acquiring them.
Learn moreLTV Calculator
Customer lifetime value is the gross margin a customer contributes before they churn — not the revenue they pay.
Learn moreFrequently asked questions
What should be included in customer acquisition cost?
Should I report blended CAC or paid CAC?
What time period should CAC be measured over?
How do I handle a long sales cycle?
Does Bastle calculate CAC automatically?
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