What Is Customer Acquisition Cost (CAC)?

Customer acquisition cost is the total sales and marketing spend required to win one new paying customer. If you spend $50,000 in a month and sign 125 customers, your CAC is $400. It is the price tag on your growth: multiply CAC by your growth target and you know exactly how much cash the plan consumes. Paired with customer lifetime value, it answers the question every business model lives or dies on — is a customer worth more than they cost to acquire?

How CAC Is Calculated

The formula is simple; the discipline is in what you include. Blended (fully-loaded) CAC counts everything — ad spend, content, tools, agency fees, plus sales and marketing salaries and commissions. Marketing-only CAC strips out sales costs and is useful for judging channel efficiency, but it flatters the real number. Investors will always ask for fully-loaded, which is why this calculator shows both side by side.

What Is a Good CAC?

A dollar figure alone means nothing — $400 CAC is superb for a $99/month product and catastrophic for a $9/month one. CAC is judged through two ratios:

• LTV:CAC ratio of 3:1 or better — a customer should generate at least three times their acquisition cost in lifetime gross profit
• CAC payback under 12 months — the standard SaaS benchmark; under 6 months is excellent, 12–18 is tolerable for enterprise sales with long contracts, over 18 usually burns cash faster than the business can sustain
• For context, widely cited industry surveys put average B2B SaaS CAC in the hundreds of dollars for SMB products and thousands for enterprise — but your own payback and ratio matter far more than industry averages

How to Use This Calculator

Enter your marketing spend, sales spend, and new customers acquired over the same period — a month or a quarter both work, as long as all three match. The calculator returns your blended and marketing-only CAC instantly. Add average monthly revenue per customer and gross margin (typically 70–85% for SaaS) and it also computes your gross profit per customer and CAC payback period, then grades the result against the 12-month benchmark used across the industry, as laid out in David Skok's widely referenced SaaS metrics guide.

Worked Example

A SaaS company spends $30,000 on marketing and $20,000 on sales in a month, winning 125 customers: blended CAC is $50,000 ÷ 125 = $400. Each customer pays $49/month at 80% gross margin, generating $39.20 of monthly gross profit. Payback is $400 ÷ $39.20 = 10.2 months — inside the 12-month benchmark, so this acquisition engine is efficient enough to scale, provided customers stay well beyond the payback point.

How to Reduce CAC

• Fix conversion before adding spend: doubling your signup-to-paid rate halves CAC across every channel simultaneously
• Kill unattributable channels: spend you can't trace to customers inflates blended CAC invisibly
• Lean on retention-driven growth: referrals and word of mouth acquire customers at near-zero marginal cost
• Target narrower segments: a smaller audience with higher intent almost always beats broad reach on cost per customer
• Revisit pricing: raising price doesn't lower CAC, but it shortens payback — often the faster fix

CAC in Context: The Metric Chain

CAC never stands alone. Compare it against LTV to judge unit economics, feed it into your burn rate to see how acquisition spend affects survival, and check your gross margin first — because margin sits inside the payback formula, a margin improvement automatically shortens payback without touching your marketing budget. If you're deciding how much acquisition spend your model can support at all, start from your break-even point.

Frequently Asked Questions