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Money, pricing & model

How do I calculate CAC (customer acquisition cost) and LTV?

CAC = total sales and marketing spend divided by new customers acquired in that period, count everything, not just ad spend. LTV = the profit (not revenue) a customer generates over their lifetime, which depends on margin and churn. Both are estimates early on; the point is to track the trend, not chase false precision.

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3 resources, 2 link-checked.

📄 Article
✓ Link checked Free Intermediate

The reference primer on the metrics and market-sizing logic investors use, including bottom-up market sizing that keeps founders honest about how big a market really is. Canonical a16z source.

16 Startup Metrics

From a16z by Andreessen Horowitz (a16z) ~15 min read

  • Size markets bottom-up from customer count and willingness to pay
  • Know the metrics that actually signal a healthy business
  • Distinguish real traction from vanity metrics
  • Use consistent definitions when comparing yourself to the market
Open a16z.com →
📄 Article
✓ Link checked Free Advanced

David Skok's For Entrepreneurs work is the foundational, near-universally cited source on SaaS unit economics and modeling. It's where the LTV:CAC and CAC-payback conventions were popularized.

SaaS Metrics 2.0, Detailed Definitions

From forentrepreneurs.com by David Skok long-form reference

  • Unit economics (LTV:CAC and months to recover CAC) reveal long-term profitability
  • Simple LTV formulas break when revenue expands over a customer's lifetime
  • Build financial models from real drivers, not top-down market-share guesses
Open forentrepreneurs.com →
📄 Article
Free Intermediate

A focused a16z piece on the single ratio that most captures a business's efficiency and drives its valuation. Great for founders who need to understand the 3:1 benchmark and its limits.

Why Do Investors Care So Much About LTV:CAC?

From a16z.com by Andreessen Horowitz (a16z) article

  • 3x LTV:CAC is a common rule-of-thumb benchmark for healthy unit economics
  • Higher LTV:CAC drives higher margins and therefore higher valuation
  • The ratio can mislead, CAC payback period matters just as much for cash
Open a16z.com →

Terms in this answer

Customer Acquisition Cost Lifetime Value Churn

People also ask

What are unit economics and why do they matter? 3 → What is a good LTV to CAC ratio? 3 → What metrics should I actually track as an early-stage SaaS founder? 3 → How do I build a simple financial model or revenue projection? 3 → What is churn and how much churn is too much? 2 → My CAC looks great but I paid for it with a founder-led discount. How do I know my unit economics without the promo? 2 →

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The same ground, over in Close deals and price right, our GTM track.

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Also in Wealth

The same ground, over in Founder money foundations, our Wealth track.

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