How to Calculate Customer Acquisition Cost (CAC): Formula and Examples

The customer acquisition cost formula

Customer acquisition cost (CAC) answers one question: what does it cost, all in, to win one new customer? The formula is a single division:

CAC = Total sales & marketing spend ÷ New customers acquired

The catch is in the words "all in". CAC is a fully loaded number — paid media, salaries, software, content and agency fees all go in the numerator. Spend $50,000 across sales and marketing in a quarter and win 250 new customers, and your CAC is $200.

Two rules keep the number honest. First, the spend and the customers must come from the same period: most companies calculate CAC quarterly, or on a rolling annual basis to smooth out seasonality. Second, only first-time buyers count as new customers — returning or retained customers are won by retention spending, not acquisition, and folding them into the denominator understates the real cost of growth.

A worked example: $50,000 in spend, 250 new customers

Say a B2B SaaS company spent $50,000 on sales and marketing in a quarter and acquired 250 new paying customers. Here is the fully loaded spend, line by line:

CAC = $50,000 ÷ 250 = $200 per customer

Now count media only. The $22,000 of ad spend divided by the same 250 customers gives $88 — less than half the real figure. That is the most common way CAC gets understated, and it is why the salary line, usually the largest single cost for a B2B team, belongs in the numerator.

Because CAC is a ratio, it moves with both numbers. Win 500 customers on the same $50,000 and CAC falls to $100; win 125 and it doubles to $400. Always quote the period and the customer count alongside the figure, or the number means nothing.

What to include in the CAC calculation

Use this checklist when you build the numerator. These are the cost categories that belong in a customer acquisition calculation:

• Advertising — PPC, paid social, display, sponsorships and traditional media buys.
• Salaries and benefits — the marketers, SDRs and account executives who generate and close demand, plus commissions and freelance or contract work.
• Software and tools — CRM seats, analytics, marketing automation, email platforms, attribution.
• Content production — writers, designers, video and landing page builds.
• Discounts and promotional offers — the value of the codes and offers used to bring first-time buyers in.
• Agency and contractor fees — retainers, media management and outsourced creative.

What to leave out matters just as much. Exclude costs tied purely to serving or retaining existing customers — support, account management after onboarding, renewal incentives — because those belong to retention economics, not acquisition. Blur the two and you can no longer compare CAC against customer lifetime value, which is the only comparison that says whether your growth is affordable.

CAC benchmarks by industry in 2026

What counts as a high CAC depends on the industry and the length of the sales cycle. First Page Sage's B2B customer acquisition cost report, last updated January 26, 2026 with client data gathered between January 2022 and August 2025 across 29 industries, shows a spread of more than 13x — from $86 in B2B eCommerce to $1,143 in higher education:

Two caveats before you benchmark against this table. Organic CAC covers mostly SEO and organic social, inorganic CAC covers mostly PPC/SEM and paid social, and the combined column is weighted 75% organic and 25% inorganic — so a paid-heavy mix should be measured against the inorganic column, not the combined one. The dataset also excludes email, events, direct mail and other lead sources for lack of volume.

The pattern that repeats in almost every industry is worth noting: organic acquisition is cheaper than paid. B2B SaaS sits at $205 organic against $341 inorganic; legal services at $584 against $1,245. The trade-off is time — organic compounds over months, while paid switches on today and switches off the moment you stop funding it.

CAC vs CPA: which number do you need?

CAC and cost per acquisition (CPA) are often used interchangeably, and that is where benchmark comparisons go wrong. CPA usually measures the cost of a single conversion — a lead, a trial, an install — on one channel, counting media spend only. CAC is the blended, fully loaded cost of a paying customer across every channel and every cost line.

In the worked example above, the same quarter produces an $88 media-only CPA and a $200 company-wide CAC. Both are correct — they just answer different questions. Optimize campaigns on CPA; decide how much growth you can afford on CAC.

Is that CAC sustainable? LTV:CAC and payback

A CAC figure on its own does not tell you whether growth is affordable. It needs two companions.

The LTV:CAC ratio. The generally accepted benchmark for a healthy ratio is 3:1 or higher — every $1 of acquisition cost should return at least $3 of lifetime value. At a $200 CAC, a customer worth $960 over their lifetime returns 4.8:1, which is comfortable. Below 1:1 you are destroying value with every sale: acquire a customer for $500 who is worth $400 over the whole relationship and the growth is a loss, not an investment.

The CAC payback period. Divide CAC by the monthly gross profit each customer generates. Spend $50,000 to win 500 customers and CAC is $100; if a customer pays $100 a month and costs $20 a month to serve, monthly profit is $80, so payback is $100 ÷ $80 = 1.25 months. For SaaS, a payback of 12 months or less is typically considered healthy, and high-performing businesses recover CAC in five to seven months. A short payback funds the next cohort of customers out of operating cash; a long one means growth has to be financed up front, which is why a business can show a healthy LTV:CAC ratio and still run out of cash.

How to lower your customer acquisition cost

CAC is the output of two inputs — what you spend and how many customers that spend wins — so every lever works on one of them.

• Shift mix toward organic. Organic CAC beats inorganic in almost every industry in the 2026 benchmark set (B2B SaaS: $205 vs $341). It takes four to six months to compound, but unlike paid it does not reset to zero when the budget stops.
• Raise conversion rate. Doubling conversion from 2% to 4% halves the cost of each customer on the same traffic and the same budget.
• Tighten targeting. Bid toward higher-intent audiences so fewer paid clicks land on prospects who will never buy.
• Fix the lead-to-customer leak. Slow follow-up, weak qualification and clumsy onboarding waste leads you already paid for — the cheapest customers are the ones you stop losing.
• Cut the channels that fail the ratio. Any channel whose CAC sits above one third of the customer value it produces is not sustainable at scale; move that budget to one that clears 3:1.

Run the calculation monthly by channel, and audit the numerator quarterly to confirm salaries, tools and agency fees are still in it. A CAC that trends down because you quietly dropped costs is not an improvement — it is a smaller number measuring less of the business.