Customer Acquisition Cost (CAC) Calculator

Everything you spend to win new customers: ad spend across all platforms, agency and freelancer fees, creative production, marketing software, sales salaries or commissions, and first-purchase discounts. Stores that count only the ad platform bill understate CAC by 20–40% and overspend as a result. If a cost disappears when you stop acquiring, it belongs in CAC.

There is no universal number — CAC is only good or bad relative to what a customer is worth. A common benchmark is CAC below one-third of customer lifetime value (a 3:1 LTV:CAC ratio). A $40 CAC is excellent for a store whose customers generate $200 of lifetime margin and ruinous for one selling a single $35 item.

No. CAC measures the cost of acquiring someone new; blending in repeat buyers who cost little or nothing to reactivate makes acquisition look artificially cheap. Track new customers separately (most platforms and Shopify reports distinguish first-time from returning) and measure repeat business with retention and purchase frequency instead.

Ad platforms serve your cheapest, most likely buyers first. As budgets grow, you pay to reach progressively colder audiences, so marginal CAC climbs even while the average still looks acceptable. Recalculate CAC at each budget level, and watch the CAC on the last dollar spent — that marginal number decides whether the next budget increase is profitable.