The easy formula to calculate true CAC across all your marketing channels

Why Traditional CAC Calculations Fall Short

Before diving into the formula, let’s address why most CAC calculations miss the mark. Traditional approaches typically isolate each channel:

• Paid Ads CAC:Ad spend ÷ customers acquired through ads
• Content CAC:Content costs ÷ attributed conversions
• Partner CAC:Partnership fees ÷ referred customers

This siloed approach ignores the reality of modern customer journeys. A customer might discover your brand through content, research on social media, and finally convert through a paid ad. While this is a win, it doesn’t give the full story on its success. What other information could be left unconsidered, like, “Which channel gets credit?” or, “How do you account for brand marketing that supports all channels?”.

The answer lies in calculating blended CAC and true CAC, which account for multi-channel complexity.

Understanding the Two Types of Multi-Channel CAC

Blended CAC: Your Starting Point

Blended CAC gives you a high-level view by combining all marketing costs and dividing by the total customers acquired:

Blended CAC = Total Marketing Spend ÷ Total New Customers

Example:

• Paid ads: $50,000
• Content marketing: $30,000
• Partnership fees: $20,000
• Brand marketing: $15,000
• Total spend:$115,000
• New customers:500
• Blended CAC:$230

$230 (Blended CAC) = $115,000 (Total Spend) ÷ 500 (New Customers)

While blended CAC provides a valuable benchmark, it doesn’t help you optimize individual channels or allocate budget effectively.

True CAC: The Complete Picture

True CAC goes deeper by accounting for shared costs, attribution complexity, and indirect channel influence. Here’s the comprehensive formula:

True CAC = (Direct Channel Costs + Allocated Shared Costs + Sales Costs) ÷ Attributed Customers

Let’s break down each component.

The True CAC Formula Components

1. Direct Channel Costs

These are expenses directly tied to specific channels:

• Paid ads:Ad spend, platform fees, creative production
• Content:Content creation, SEO tools, freelancer fees
• Partners:Referral fees, co-marketing costs, partnership management

2. Allocated Shared Costs

Shared costs support multiple channels and must be allocated proportionally:

• Marketing operations:CRM, analytics tools, automation platforms
• Brand marketing:PR, events, sponsorships that benefit all channels
• Marketing team salaries:Personnel costs for cross-channel work

Allocation method:Distribute shared costs based on each channel’s percentage of total direct spend or customer volume.

Example allocation:

• Paid ads represent 50% of direct costs → Gets 50% of shared costs
• Content represents 30% → Gets 30% of shared costs
• Partners represent 20% → Gets 20% of shared costs

3. Sales Costs

Include sales expenses that support customer acquisition:

• Sales team salaries and commissions
• Sales tools and technology
• Lead qualification and nurturing costs

Pro tip:For B2B companies, sales costs often represent 20-40% of total acquisition costs. Read more on reducing customer acquisition costs here.

Handling Multi-Touch Attribution

The biggest challenge in true CAC calculation is attribution. Here are three approaches:

First-Touch Attribution

Credits the first channel that introduced the customer to your brand.

Last-Touch Attribution

Credits the final channel before conversion.

Multi-Touch Attribution (Recommended)

Distributes credit across all touchpoints in the customer journey.

HubSpot’s approach:Our analytics platform tracks the complete customer journey and uses a time-decay model that gives more credit to recent interactions while still acknowledging earlier touchpoints.

Real-World CAC Calculation Example

Let’s walk through a complete true CAC calculation for a SaaS company:

Monthly Costs

• Paid advertising:$75,000
• Content marketing:$45,000 (includes content creation, SEO tools)
• Partner program:$30,000 (referral fees, partner management)
• Shared costs:$25,000 (marketing ops, brand marketing, tools)
• Sales costs:$40,000 (inside sales team supporting inbound leads)

Customer Acquisition

• Paid ads:120 customers (first-touch attribution)
• Content:80 customers (first-touch attribution)
• Partners:50 customers (direct referrals)
• Multi-touch influenced:180 customers (involved multiple channels)

Allocation Calculation

Step 1:Allocate shared costs based on direct spend percentage

• Paid ads: 50% of direct costs → $12,500 of shared costs
• Content: 30% of direct costs → $7,500 of shared costs
• Partners: 20% of direct costs → $5,000 of shared costs

Step 2:Add sales costs proportionally

• Total customers: 250
• Sales cost per customer: $160 ($40,000 ÷ 250)

Step 3:Calculate true CAC per channel

Paid Ads True CAC: ($75,000 + $12,500 + $19,200) ÷ 120 = $889

Content True CAC: ($45,000 + $7,500 + $12,800) ÷ 80 = $817

Partner True CAC: ($30,000 + $5,000 + $8,000) ÷ 50 = $860

Comparison: Simple vs True CAC

This comparison reveals that simple CAC calculations underestimate true costs by 40-45%, leading to over-optimistic projections and budget misallocation.

Advanced Considerations for Financial Decision-Makers

CAC by Customer Segment

Different customer segments often have varying acquisition costs. Calculate true CAC separately for:

• Enterprise vs SMB customers
• Geographic markets
• Industry verticals
• Customer lifetime value tiers

International Market Adjustments

When expanding globally, adjust CAC calculations for:

• Currency fluctuations
• Local market competition
• Regulatory compliance costs
• Cultural adaptation expenses

Seasonal CAC Variations

Many businesses experience seasonal fluctuations in acquisition costs. Track CAC trends by:

• Quarter-over-quarter changes
• Year-over-year comparisons
• Holiday and peak season impacts
• Industry-specific cycles

Common CAC Calculation Mistakes to Avoid

1. Ignoring indirect costs.

Mistake:Only counting direct ad spend or content costs

Fix:Include all supporting costs like tools, personnel, and operations

2. Using the wrong attribution windows.

Mistake:Using too short or too long attribution windows

Fix:Match attribution windows to your actual sales cycle length

3. Excluding sales costs.

Mistake:Treating sales as separate from marketing acquisition

Fix:Include sales costs that directly support customer acquisition

4. Inconsistent time periods.

Mistake:Mixing monthly costs with quarterly customer counts

Fix:Ensure all metrics use consistent time periods

The Impact of Accurate CAC on Business Decisions

• Budget allocation: True CAC enables data-driven budget allocation across channels. Instead of cutting spend on channels with high simple CAC, you can identify which channels provide the best return when accounting for their full impact.
• Investor relations: Investors increasingly scrutinize unit economics. Presenting true CAC demonstrates sophisticated financial understanding and provides confidence in your growth projections.
• Pricing strategy: Understanding your real customer acquisition cost is crucial for setting prices that ensure sustainable unit economics and positive LTV:CAC ratios.

Frequently Asked Questions

How do I allocate shared costs fairly across channels?

Use either revenue-based allocation (each channel gets shared costs proportional to revenue generated) or volume-based allocation (proportional to customers acquired). Choose the method that best reflects how shared resources actually support each channel.

Should I include content costs in CAC if content also supports retention?

Yes, but allocate content costs based on their purpose. If 70% of content is created for acquisition and 30% for retention, only include the 70% in your CAC calculation.

What about brand marketing impact on CAC?

Brand marketing creates a “halo effect” that reduces CAC across all channels. Include brand marketing costs in your shared cost allocation, but consider tracking brand-assisted conversions separately to measure this impact.

How often should I recalculate true CAC?

Calculate true CAC monthly for tactical decisions and quarterly for strategic planning. Annual calculations are sufficient for long-term forecasting and investor presentations.

What CAC should I report to investors?

Report both blended CAC and true CAC by channel. Blended CAC shows overall efficiency, while channel-specific true CAC demonstrates your understanding of acquisition dynamics and optimization opportunities.

The True Cost of Customer Acquisition

Calculating true CAC across paid ads, content, and partner channels isn‘t just an accounting exercise — it’s a strategic imperative. Companies that understand their real acquisition costs make better budget allocation decisions, set more realistic growth targets, and build sustainable unit economics.

Start with the formulas and frameworks in this guide, implement multi-touch attribution, and begin tracking true CAC monthly. Your future growth decisions and investors will thank you.

Ready to implement sophisticated CAC tracking? HubSpot’s Marketing Hub provides the attribution and analytics capabilities you need to calculate true CAC across all your marketing channels.