CAC Calculator
Work out customer acquisition cost from sales and marketing spend and new customers, by channel, with the LTV:CAC ratio and the months to pay CAC back. Add salaries, tools and overhead for a fully loaded CAC, and every result shows the working.
Your numbers
Ads, events, content, agencies and marketing software for the period.
Commissions, travel, demos and sales costs for the same period.
Lines you did not already put in the two spends above.
New paying customers in the same period as the spend, not leads or trials.
Needs what an average customer pays you each month.
Customer acquisition cost (CAC)
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- Total acquisition cost
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- Marketing cost per new customer
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- Sales and other cost per new customer
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Spend and customers must cover the same period. If deals take months to close, compare spend with customers won one sales cycle later.
The calculation runs in your browser and ParrotNotes does not store your numbers. They sit in the page address so you can bookmark or share the result.
Blended CAC: spend divided by new customers
Customer acquisition cost is the total sales and marketing spend in a period divided by the new customers won in that period. Enter marketing and sales spend, and if they do not already include them, turn on the line for salaries, tools and overhead to get a fully loaded CAC. The page also splits the result into marketing cost and sales cost per new customer.
Use the same period for both numbers, and count new paying customers only, not leads, trials or renewals. If your deals take three months to close, this quarter's customers came from last quarter's spend: compare spend with the customers won one sales cycle later, or use a longer period such as a year.
CAC by channel, and why blended CAC can mislead
In "CAC by channel", add a row for each channel: paid search, events and trade shows, referrals, outbound, field sales visits and so on, with what it cost and how many new customers it brought. Each channel's CAC is its own spend divided by its own customers. Costs that belong to no single channel, such as the team's salaries and tools, go in their own line and count only in the blended CAC.
a16z's startup metrics warn against relying on a blended CAC that includes customers who came in organically: it is not wrong, but it does not tell you how well paid campaigns work. A channel at $3,000 a customer can hide behind a blended $1,500 when referrals bring customers in for almost nothing.
CAC payback and LTV:CAC
Turn on "Add payback and LTV:CAC" and enter the average revenue per account per month (ARPA), your gross margin and, for lifetime value, the monthly churn. The payback is CAC ÷ (ARPA × gross margin), the months of gross profit it takes to earn the acquisition cost back. Lifetime value is ARPA × gross margin ÷ monthly churn, the same formula the customer lifetime value calculator uses, and LTV:CAC divides it by CAC.
A common rule of thumb is an LTV:CAC above 3 and a payback under 12 months. Both come from SaaS investors' guidelines, and the page labels them that way: a business with plenty of cash can live with a longer payback, and an LTV built on a churn guess is only as good as the guess.
How this differs from the LTV and churn calculators
The customer lifetime value calculator starts from what a customer is worth and takes CAC as a number you already know. This page works CAC out: from spend lines and new customers, or channel by channel. The churn rate calculator works out the monthly churn you can bring here for the lifetime value. Use the three together for the full picture: what a customer costs, what they are worth and how long they stay.
For sales leaders
CAC is half sales. Commissions, travel, demos and the hours reps spend on deals that never close all sit in it, so a field team that wins a customer in two visits instead of four moves the number as much as a cheaper ad. When the budget review asks which channel to cut, bring CAC by channel, and write down what was decided and who owns it.
Sources, each read on 2026-11-01. Results are arithmetic on your own numbers; the 3 to 1 and 12-month figures are rules of thumb:
- ChartMogul, SaaS metrics library: CAC (total sales and marketing spend ÷ new customers; fully loaded includes salaries, commissions, tooling and events)
- a16z, 16 Startup Metrics (2015): blended and paid CAC, CAC as the full cost per customer
- Baremetrics Academy, CAC payback period: CAC ÷ (ARPA × gross margin %)
- David Skok, SaaS Metrics 2.0, Detailed Definitions: LTV:CAC above 3 and months to recover CAC under 12, as guidelines
Related: the customer lifetime value calculator for what a customer is worth, the churn rate calculator for the monthly churn, and the MRR calculator for monthly recurring revenue and ARPA.
More for sales leaders: SaaS sales, B2B SaaS sales, Sales KPIs.
The number starts the budget review
CAC by channel shows where a customer costs the most; the review decides what to cut and what to back. Record the meeting in ParrotNotes and you get a transcript, a summary and the action items, so the decisions and who owns them are written down.
Get Started FreeRelated tools
- Customer Lifetime Value CalculatorWork out customer lifetime value from revenue, gross margin and churn or customer lifespan, and compare it with what it costs to win the customer.Open the tool
- Churn Rate CalculatorWork out customer churn and revenue churn for a month, quarter or year, with net revenue retention and what the rate means for a customer's lifetime.Open the tool
- MRR and ARR CalculatorWork out monthly and annual recurring revenue from your plans and customers, with new, expansion, contraction and churned MRR for the month.Open the tool