Customer Acquisition Cost (CAC) Calculator
CAC = (sales + marketing) ÷ new customers, with optional payback months from ARPU and margin.
Written by Golam Rabbani, Founder & Lead Engineer
How to use this customer acquisition cost (cac) calculator
- Enter your total sales spend for the period (salaries, commissions, tools).
- Enter your total marketing spend for the same period (ads, content, events).
- Enter the number of new customers acquired in that period.
- Optionally add monthly ARPU and gross margin to also see CAC payback months.
- Press Calculate CAC. Use Copy to capture the result or Reset to clear inputs.
About this customer acquisition cost (cac) calculator
Customer Acquisition Cost (CAC) is the fully-loaded cost to acquire one new paying customer in a given period. The canonical formula from David Skok ("SaaS Metrics 2.0") is CAC = (Sales spend + Marketing spend) ÷ Number of new customers acquired during the same period. Both numerator and denominator must cover the same time window.
Worked example. Last quarter you spent $40,000 on sales and $60,000 on marketing and acquired 200 new customers. CAC = ($40,000 + $60,000) ÷ 200 = $500 per customer. If your monthly ARPU is $50 and gross margin is 70%, the monthly gross profit per customer is $50 × 70% = $35. CAC payback period = $500 ÷ $35 ≈ 14.3 months — slightly above the common SaaS benchmark of 12 months, suggesting either acquisition is too expensive, pricing is too low, or margin needs to improve.
CAC is a directional metric. Pair it with LTV (lifetime value) and segment by channel so you can see which acquisition sources scale profitably.
FAQ
- What costs should I include in CAC?
- Include all sales and marketing spend: salaries and commissions of customer-facing staff, paid media, content production, events, sales tooling, agency fees, and outbound costs. Exclude post-sale support, onboarding, and product development.
- What is a good CAC payback period?
- For B2B SaaS, the rule of thumb is 12 months or less. Consumer subscription apps often aim for 3-6 months because their churn is higher. The payback shown here is CAC ÷ (monthly ARPU × gross margin).
- Should I compute blended or paid CAC?
- Both are useful. Blended CAC uses all new customers (including organic). Paid CAC divides paid spend by customers acquired through paid channels only — a tighter measure of channel efficiency. This tool computes blended CAC by default.
- How is CAC different from CPA?
- CPA (cost per acquisition) is usually channel-level and counts conversions like signups or leads. CAC counts new paying customers and includes all sales + marketing costs, not just media spend.
- Why does the tool ask for sales and marketing separately?
- So you can see the share each function contributes. Some boards prefer reporting them split — for example, in product-led growth companies the sales line may be near zero.
- Does this tool store my numbers?
- No. Calculations run in your browser. Nothing is sent to a server and the inputs are wiped when you close the page.