Paid CAC Calculator
Calculate customer acquisition cost from paid channels only — isolating ad spend efficiency from organic, content, and sales-led growth.
Your Paid CAC
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Formula Paid CAC = Paid Ad Spend ÷ Paid Customers
How to use this calculator
Enter the total amount you spent on paid ads in the period and the number of customers acquired from those paid channels (not your total new customers — only the ones attributed to paid). The calculator returns your paid CAC. Use the "Calculate" selector to solve for required ad spend or customer volume when forecasting.
What is Paid CAC?
Paid CAC is the cost to acquire a customer through paid advertising only. It divides your ad spend by the customers attributed to paid channels — excluding organic traffic, referrals, content marketing, and sales-led acquisitions. Paid CAC is the right metric when you're evaluating the performance of your paid media specifically — making channel mix decisions, deciding whether to scale spend, or benchmarking campaigns against each other. Compared to Blended CAC (which includes all sales and marketing costs), Paid CAC is tactical rather than strategic.
When to use this calculator
- Evaluating the efficiency of paid channels in isolation
- Deciding whether to increase, maintain, or cut paid ad budgets
- Comparing performance across paid channels (Google, Meta, LinkedIn, TikTok)
- Setting target CAC caps for ad platforms
- Understanding how much of your customer acquisition depends on paid vs. organic
Frequently asked questions
What is a good Paid CAC?
Like all CAC metrics, a "good" Paid CAC depends on your LTV and margins. Paid CAC is typically lower than Blended CAC because it excludes salaries and overhead — but it can also hide the true cost of growth if organic channels are heavily funded. A paid CAC that's profitable against first-order revenue is generally healthy; one that requires LTV to break even is riskier.
How is Paid CAC calculated?
Paid CAC = Total Paid Ad Spend ÷ Customers Acquired from Paid Channels. If you spent $30,000 on paid ads in a month and 150 customers were attributed to paid channels, your Paid CAC is $200.
How do I determine which customers came from paid channels?
Use attribution — typically through UTM parameters, last-click or multi-touch attribution in your analytics platform, or conversion tracking in the ad platforms themselves. Attribution is imperfect, especially with iOS 14+ privacy changes and cookie restrictions. Most teams rely on platform-reported conversions combined with server-side tracking (e.g., Conversions API for Meta, Enhanced Conversions for Google).
What's the difference between Paid CAC and CPA?
CPA (cost per acquisition) typically measures cost per conversion event within an ad platform — a single purchase, signup, or lead. Paid CAC is broader and more business-oriented: it's total paid spend divided by actual new customers, and it accounts for the reality that not every conversion event becomes a real customer (trials that don't convert, free signups that churn, etc.).
Why is my Paid CAC lower than my Blended CAC?
Because Paid CAC only includes ad spend, while Blended CAC includes salaries, tools, content, and all other marketing and sales costs. It's normal and expected for Paid CAC to be significantly lower. The gap between them tells you how much of your CAC is going to non-ad expenses.
Should I optimize for Paid CAC or Blended CAC?
Tactically, optimize channels for Paid CAC. Strategically, plan the business around Blended CAC. Paid CAC tells you whether your ads are efficient; Blended CAC tells you whether your growth model is sustainable.
What's a healthy ratio between Paid CAC and LTV?
Most teams target LTV ≥ 3× Paid CAC for healthy unit economics on paid channels. But because Paid CAC excludes overhead, a strong Paid CAC:LTV ratio doesn't automatically mean the business is profitable — always cross-check with Blended CAC before scaling spend aggressively.
Related calculators
Other tools you might find useful.
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Blended CAC Calculator
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