Customer Acquisition Cost Calculator
Calculate blended customer acquisition cost (CAC), paid-only CAC, and Marketing Efficiency Ratio (MER) across ad spend, agency fees, and software tools.
Marketing & Acquisition Expenditures
Meta, Google, TikTok, Pinterest
Customer Acquisition Cost Formula
Blended CAC = Total Acquisition Expenses / New Customers Acquired; MER = Total New Revenue / Total Marketing Spend- Total Marketing Spend: Paid ad spend (Meta, Google, TikTok), agency retainers, marketing software (Klaviyo), and introductory discounts.
- New Customers Acquired: Unique first-time purchasing customers (excluding returning buyers).
- Blended CAC: All-inclusive marketing cost to acquire one new customer across all organic and paid channels.
- Marketing Efficiency Ratio (MER): Total sales revenue divided by total marketing spend.
Step-by-Step Worked Example
Calculation Steps:
How to Use This Calculator
Assumptions & Limitations
- Customer count represents distinct new buyers, not repeat orders from existing customers.
- Excludes non-marketing operational expenditures.
Frequently Asked Questions
What is the difference between Blended CAC and Paid CAC?
Paid CAC only considers paid ad spend divided by paid ad conversions. Blended CAC factors in all marketing expenses (ads, software, agency, organic) divided by total new customers, providing a truer picture of acquisition efficiency.
What is a good Marketing Efficiency Ratio (MER) for an online store?
An MER of 3.0x or higher indicates strong profitability. An MER between 2.0x and 3.0x is typical for growing brands, while an MER below 1.8x usually signals that ad spend is eroding margins.
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