Rule of 40

TL;DR

A SaaS health benchmark: revenue growth rate plus profit margin should sum to at least 40%.

The Rule of 40 sums YoY revenue growth and operating margin (or free cash flow margin). A company growing 60% with -20% margin (40% total) and one growing 20% with +20% margin (40% total) both pass. The rule rewards either fast growth or strong margin without forcing the trade-off.

The rule is most relevant at $20M+ ARR. Below that scale, growth dominates and margin is a secondary concern. At larger scales, public-comp pricing increasingly weights companies that exceed the rule.

Formula

Rule of 40 Score = YoY Revenue Growth % + Operating Margin %

• YoY Revenue Growth % — Year-over-year revenue growth percentage
• Operating Margin % — Operating income as a percentage of revenue (or FCF margin)

≥ 40% is the standard benchmark for healthy SaaS at scale.

Worked example

A SaaS grows ARR 60% YoY with a −15% FCF margin. Rule of 40 = 60 + (−15) = 45 → above 40, healthy. The same company at 25% growth would need a +15% FCF margin to clear 40.

Common pitfalls

• Applying the rule too early when growth should dominate.
• Using non-GAAP margin that excludes too many real costs.
• Treating the rule as a target instead of a benchmark.

When this shows up in a pitch deck

Growth-stage SaaS decks cite the rule on the Financials or Comps slide.

See Rule of 40 in context

Rule of 40 shows up most often in these scoring rubrics and investor profiles — jump straight to who cares about it and how to pitch them.

In VC frameworks

• Tiger Global — pitch deck framework

For investor types

• Growth VC — Series A & B
• Private Equity — Profitability & Scale

Related terms

• ARR — Annual Recurring Revenue — the value of subscription contracts on a normalized 12-month basis, the headline SaaS revenue metric.
• Burn Multiple — Net new ARR divided by net burn — the dollars of capital consumed per dollar of new ARR generated.
• Magic Number — A SaaS sales-efficiency ratio: net new ARR divided by sales and marketing spend in the prior period.
• Gross Margin — The percentage of revenue remaining after subtracting cost of goods sold (COGS), reflecting the unit economics of delivering the product.
• CAC Payback Period — The number of months required for the gross profit from a customer to repay the cost of acquiring them.

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