Customer Acquisition Cost Calculator

Direct answer

Customer acquisition cost divides the sales and marketing resources used to acquire customers by the number of new customers acquired. A $12,000 cost and 300 new customers produces a CAC of $40.

The calculator also shows the cost of acquiring 100 customers if the same average CAC holds. In the example, that planning amount is $40 × 100 = $4,000. It is an extrapolation, not a forecast: acquisition cost often changes as spend and audience scale.

Choose the CAC scope before calculating

For a blended management view, include media, agencies, creative production, acquisition software and the relevant share of sales and marketing payroll. A narrower paid-media CAC can be useful for campaign work, provided it is labeled clearly.

Do not compare values with different scopes as if they measure the same thing. A low paid-media CAC can coexist with a much higher fully loaded CAC.

Worked acquisition example

Suppose a store spends $7,000 on media, $2,000 on creative and agency work, $1,000 on acquisition software and $2,000 on allocated payroll. It acquires 300 first-time customers.

Total acquisition cost is $7,000 + $2,000 + $1,000 + $2,000 = $12,000.

Blended CAC is $12,000 ÷ 300 = $40 per new customer.

If the dashboard reports 340 orders but 40 came from returning customers, the denominator remains 300 new customers. Orders, conversions and customers are not automatically interchangeable.

Keep the cohort aligned

Costs incurred this month may create customers next month. Long sales cycles require a cohort or lagged calculation instead of mechanically dividing same-month totals.

For short ecommerce purchase cycles, a monthly calculation may be a practical operating view. For longer sales cycles, compare acquisition costs with customers created from the leads or opportunities associated with those costs. Record the chosen lag so the calculation can be repeated.

Decide what to do with CAC

CAC alone cannot show whether acquisition is economical. Use a consistent sequence:

1. Compare CAC with contribution from the first order.
2. Estimate how much contribution a customer produces over time.
3. Calculate LTV:CAC with compatible definitions.
4. Check the CAC payback period because a positive lifetime relationship can still create a cash constraint.
5. Segment only where cost allocation and customer counts remain credible.

If CAC rises, separate a real efficiency change from a measurement change. A new attribution model, a delayed customer cohort or newly included payroll can raise reported CAC without the underlying campaign becoming worse.

Common mistakes

• Counting returning customers in the denominator.
• Including only ad spend while labeling the result fully loaded CAC.
• Combining costs from one period with customers acquired in another without a lag rule.
• Comparing channel CAC with blended company CAC.
• Assuming CAC remains constant when budget is scaled.
• Treating a lower CAC as better without checking customer value and retention.

Limits of this calculator

This calculator averages an entered cost pool across an entered customer count. It does not allocate shared costs, identify incremental customers, estimate payback or predict scale. Currency selection changes formatting only; all monetary inputs must already use the same currency.

Assumptions

• Costs and customer counts cover the same period.
• Only newly acquired customers are counted.

Sources and methodology

CalcMotive publishes the formula and assumptions so you can decide whether the estimate fits your use case. See our methodology standards.

• Shopify: customer acquisition cost; Shopify; accessed Jul 13, 2026
• Shopify: ecommerce customer acquisition; Shopify; accessed Jul 13, 2026