Customer acquisition cost (CAC) equals your total sales and marketing spending divided by the number of new customers you gained during the same period. The formula itself is simple, but getting an accurate number depends on knowing exactly which costs to include and how to interpret the result.
The Basic Formula
CAC = Total sales and marketing costs / Number of new customers acquired
Pick a time period, typically a month, quarter, or year. Add up everything you spent on sales and marketing during that window. Then divide by the number of brand-new customers (not returning ones) you acquired in the same window.
For example, if you spent $50,000 on sales and marketing in Q1 and signed 200 new customers, your CAC for that quarter is $250. That means you spent $250, on average, to win each new customer.
Which Costs to Include
The most common mistake in calculating CAC is leaving out costs that directly support acquiring customers. Advertising spend is the obvious one, but it’s rarely the whole picture. A comprehensive calculation should include:
- Advertising spend: Search ads, social media ads, display campaigns, and any paid placement you run to attract prospects.
- Salaries and commissions: The compensation for everyone on your sales and marketing teams, including base pay, bonuses, and sales commissions.
- Content production: Writers, designers, video producers, and SEO specialists creating material that brings in leads.
- Software and tools: Your CRM, email automation platform, analytics tools, and any other technology your sales or marketing teams rely on.
- Agency and contractor fees: Any outside firms or freelancers doing lead generation, creative work, or campaign management on your behalf.
- Events and sponsorships: Webinars, trade shows, conferences, and sponsorship deals aimed at generating new business.
- Allocated overhead: A portion of rent, utilities, and office costs attributable to your sales and marketing teams.
If a cost exists specifically because you’re trying to win new customers, it belongs in the numerator. Leave out spending that supports existing customers, like your customer success team or renewal operations. Those costs relate to retention, not acquisition.
A Worked Example
Suppose your company tracks these expenses over one quarter:
- Ad spend: $30,000
- Sales team salaries and commissions: $45,000
- Marketing team salaries: $25,000
- CRM and email tools: $3,000
- Freelance content creators: $5,000
- Trade show booth: $7,000
Total sales and marketing costs: $115,000. If you acquired 230 new customers that quarter, your CAC is $500.
That single number tells you the average price you paid for each new customer. But averages can hide important differences, which is why many businesses break CAC down further.
Splitting CAC by Channel
Your overall CAC blends every channel together, but not every channel performs the same way. Calculate a separate CAC for each major acquisition source (paid search, organic content, outbound sales, referrals) by isolating the costs and customers tied to that channel.
This matters because organic channels like SEO and content marketing typically produce a lower CAC than paid channels. HubSpot’s research illustrates the gap: across B2B SaaS companies, the average organic CAC is roughly $205, while inorganic (paid) CAC runs around $341. In financial services, the difference is even more dramatic, with organic CAC near $644 and paid CAC averaging $1,202.
If you only look at your blended number, you might keep pouring money into an expensive channel without realizing a cheaper one is doing the heavy lifting. Channel-level CAC helps you shift budget toward what actually works.
How CAC Varies by Industry
Your CAC means very little in isolation. What counts as “expensive” depends entirely on how much revenue each customer generates over time. A $784 average CAC in financial services sounds steep, but if those customers generate thousands of dollars annually, it’s a bargain. An $86 average CAC in ecommerce sounds cheap, but it can destroy margins if your average order value is $40.
Some rough benchmarks to help you calibrate:
- Ecommerce: ~$86 combined average CAC
- B2B SaaS: ~$239 combined average CAC
- Financial services: ~$784 combined average CAC
- Fintech SaaS: ~$1,450 CAC
These numbers are useful as a sanity check, not a target. Your own unit economics, meaning how much you earn per customer relative to what you spend to get them, matter far more than matching an industry average.
Using the LTV-to-CAC Ratio
The most useful thing you can do with your CAC is compare it to customer lifetime value (LTV), which is the total revenue you expect to earn from a customer over the entire relationship. Divide LTV by CAC and you get the LTV-to-CAC ratio, the single best indicator of whether your acquisition spending is sustainable.
A ratio of 3:1 or higher is generally considered healthy. That means every dollar you spend acquiring a customer returns at least three dollars in revenue over time, leaving enough margin to cover overhead and still profit. If your ratio sits between 1:1 and 2:1, you’re barely breaking even on acquisition costs. Below 1:1, you’re losing money on every new customer you bring in.
A very high ratio, like 8:1 or 10:1, isn’t necessarily cause for celebration either. It can signal that you’re underinvesting in growth and leaving customers on the table that competitors are happy to scoop up.
Picking the Right Time Window
CAC is sensitive to the time period you choose. Marketing spend often happens weeks or months before it converts into a paying customer, especially for businesses with longer sales cycles. If you spend heavily on advertising in January but those leads don’t close until March, a monthly calculation will make January look wasteful and March look miraculous.
For businesses with sales cycles under 30 days, monthly CAC works fine. If your typical deal takes two to six months to close, quarterly or annual calculations will be more accurate. Some companies apply a lag adjustment, matching a given month’s new customers to the marketing spend from one or two months prior. Whatever approach you pick, stay consistent so your trends are comparable over time.
Reducing Your CAC
Once you know your number, the natural next question is how to bring it down. A few levers that tend to have the biggest impact:
- Improve conversion rates: Getting more customers from the same spend is the fastest way to lower CAC. Small improvements to landing pages, email sequences, or your sales process can meaningfully change the denominator of the formula without touching the numerator.
- Invest in organic channels: Content marketing, SEO, and referral programs cost money upfront but tend to produce cheaper customers over time compared to paid advertising.
- Tighten your targeting: Broad ad campaigns bring in clicks that never convert. Narrowing your audience to the people most likely to buy reduces wasted spend.
- Shorten the sales cycle: Every extra week a prospect spends in your pipeline adds cost in the form of sales rep time, follow-up emails, and demo calls. Better qualification early in the funnel keeps your team focused on deals that will actually close.
Track CAC monthly or quarterly alongside LTV, and you’ll have a clear, ongoing read on whether your growth spending is paying off or burning cash.