How to Calculate Your Customer Acquisition Cost

Calculate CAC by dividing total acquisition spending by new customers acquired in the same period.

1. Define your measurement period. Pick a consistent timeframe — monthly, quarterly, or annually. Monthly gives you faster feedback for optimization. Quarterly smooths out seasonal variations. Annual captures full-cycle businesses but delays course corrections.
2. Tally all acquisition spending. Include paid ads, sales team salaries and commissions, marketing software subscriptions, content creation costs, trade show expenses, and referral bonuses. Exclude retention spending like customer success salaries or product development. When in doubt, ask: would we spend this money if we weren't trying to acquire new customers?
3. Count new customers acquired. Use paying customers, not leads or trials. Count them in the period they first paid, not when they signed up. For subscription businesses, count when the first payment processes. For one-time purchases, count at transaction completion.
4. Run the calculation. CAC = Total Acquisition Spending ÷ New Customers Acquired. Example: $10,000 in acquisition spending and 100 new customers = $100 CAC. Recalculate monthly to track trends.
5. Segment by acquisition channel. Calculate CAC separately for paid search, social media, referrals, and direct sales. Allocate shared costs like sales salaries proportionally based on time spent or deals closed. This reveals which channels deliver customers most efficiently.
6. Compare against customer lifetime value. Your CAC should be 3:1 to 5:1 lower than customer lifetime value (LTV). CAC payback period should be under 12 months for most businesses, under 6 months for cash-constrained operations. If CAC exceeds these ratios, your unit economics don't work.