What is the Rule of 40?
The Rule of 40 is a widely used high-level metric in SaaS to measure the balance between growth and profitability. It suggests that a company’s combined revenue growth rate and profit margin should ideally be **40% or higher**.
The Trade-off: Growth vs. Profit
As of the current market, investors increasingly favor balance over pure growth-at-all-costs:
- The Rocketship: 60% Growth + (-20% Margin) = 40% (often still healthy if unit economics are strong)
- The Cash Cow: 10% Growth + 30% Margin = 40% (very attractive for efficiency-focused investors)
- The Danger Zone: 15% Growth + (-10% Margin) = 5% (signals need for restructuring)
How it Affects Valuation
Data shows a correlation between a company's Rule of 40 score and its revenue multiple. Companies consistently hitting >40% often command higher multiples than peers with lower scores — though many other factors (market, retention, etc.) also play a role.
Expert Tip: When to measure?
The Rule of 40 is generally applied to companies with at least $1M - $5M in ARR. Early-stage startups often have wildly fluctuating scores that don't yet represent long-term unit economics.