Page 223 · Module 09, Finance & Metrics · this screen continues that page
All 108 frameworksRule of 40
The single benchmark that tells investors whether your SaaS business is healthy
The prompt
Copy & paste readyLabelsReplace theseSwap the role below
Pro tip, from the book
The Rule of 40 is most useful as a framing tool in investor conversations, not as an internal operating metric. When an investor asks about your growth vs profitability tradeoff, presenting a Rule of 40 score and explaining your strategy for where it should go signals financial maturity. Most founders don't know this number. Knowing it immediately sets you apart.
Who should run this prompt
Module role profileWho should review your numbers and financial narrative? Numbers do not lie — but they can mislead when read through the wrong lens. A CFO and an investor look at the same P&L and ask completely different questions. A customer's finance team looks at your pricing and asks a question neither of them thought of. Use this page to choose who is in the room before you present, model, or decide based on your financial data.
Choose any role to drop it into the prompt above. Only the highlighted opening clause changes — the rest of the prompt stays exactly as printed.
◆◆◆◆◆ → ◆ seniority, board level down to specialist◈ outside the organisation
How to make any role sharper
- Add years of experience: "...with 15 years in enterprise SaaS" produces different depth than just the title.
- Add what they care most about: "You care most about [X]" shapes every word of the output.
- Add their communication style: "Be direct. Flag risks first. No jargon." changes the tone entirely.
Use this when
The problem it solvesYou are a SaaS or subscription business trying to balance growth and profitability. Investors ask whether you are growing fast enough or profitable enough and you are not sure how to frame the answer in a way that makes the tradeoff clear.
How the framework works
From the printed pageThe Rule of 40 was popularised by venture investors Brad Feld and Fred Wilson as a benchmark for SaaS business health. It states that a healthy SaaS company's revenue growth rate plus its profit margin should equal or exceed 40. A company growing at 60% with a -20% margin scores 40. A company growing at 15% with a 25% margin also scores 40. Both are considered healthy. The rule allows a company to trade growth for profitability or vice versa, as long as the combined score stays above 40. Below 40 signals either insufficient growth or insufficient efficiency.
The method, in four moves
Do these in orderCalculate your Rule of 40 score monthly and track the trend the direction matters as much as the level.
Early-stage companies should skew toward growth (high growth rate, negative margin) the rule becomes more relevant at $5M+ ARR.
Use the Rule of 40 to frame the growth vs profitability tradeoff in investor conversations explicitly.
If your score is below 40, use the model to identify whether the fix is growth acceleration or cost reduction. Below $5M ARR, the Rule of 40 isn't yet the right lens, investors expect growth to dominate, even at a steep loss. Applying it too early can make a normal, healthy growth-stage burn look like a problem it isn't.
Where the framework comes from
Brad Feld & Fred Wilson — Rule of 40 for SaaS, 2015
Pairs well with
As printed with this frameworkModule 09 — Finance & Metrics
Know your numbers. Own your narrative.
9 frameworks, printed on pages 206–223.
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