The Rule of 40

The Rule of 40 is a SaaS benchmark that adds a company's annual revenue growth rate and profit margin together. If the sum reaches 40% or higher, the company is considered financially healthy.

What is the Rule of 40?

The Rule of 40 states that a SaaS company's annual revenue growth rate plus its profit margin should equal or exceed 40%.

It's a quick way to assess whether a company is striking the right balance between growth and profitability. A company growing at 30% with a 10% profit margin passes. So does one growing at 5% with a 35% margin. The rule accepts many combinations, as long as the total reaches 40.

The Rule of 40 does not apply outside SaaS. Other industries use different benchmarks that reflect their own profitability and growth dynamics.

Why the Rule of 40 matters to investors

Investors use the Rule of 40 because SaaS companies don't fit neatly into traditional profit-first evaluation models.

A SaaS business can have very high margins. Serving 100,000 customers doesn't cost dramatically more than serving 1,000, especially when delivery is automated and infrastructure scales through a hosting provider. Margins above 75% are achievable. That makes profit margin alone a reasonable signal of health.

But margin isn't the whole story. A company burning cash to acquire users aggressively may show low or negative profit margins while building a user base that will eventually be highly profitable. Investors recognize that growth at this stage can be worth more than current profit.

The Rule of 40 captures both signals in one number. A company with strong growth and thin margins scores well. So does one with modest growth and strong margins. Either path can indicate a sound business. What investors want to avoid is a company that scores poorly on both.

Even if a company falls short of 40, around 30% tends to be a practical floor for risk-conscious investors. Falling meaningfully below that on both dimensions is a harder case to make.

How to calculate the Rule of 40

Rule of 40 Score = Revenue Growth Rate (%) + Profit Margin (%)

Example: A company with 25% revenue growth and 18% profit margin scores 43. It passes.

Example: A company with 10% revenue growth and 15% profit margin scores 25. It does not pass.

The inputs are straightforward, but the profit margin figure used can vary. Some apply EBITDA margin; others use free cash flow margin or operating profit margin. The choice affects the output, so it's worth knowing which version a benchmark or investor report is using before comparing scores.

Why you should track the Rule of 40

Understanding what you can afford to spend

The Rule of 40 is a valuable SaaS metric for deciding how much to invest in operations without becoming less attractive to investors or undermining your own financial position.

Consider a company running at 20% growth and a 20% profit margin. It decides to hire a senior engineer expected to accelerate growth significantly. If that hire drops the margin from 20% to 10% but lifts growth from 20% to 35%, the company still scores 45. The trade-off was worth it.

If the hire underperforms and growth only reaches 25%, the score drops to 35. That's a signal to reassess, not a crisis, but a clear indicator that the investment didn't pay off as planned.

SaaS companies typically prioritize growth until they approach market saturation. At that point, the focus shifts toward margin. The Rule of 40 gives you a framework for managing that transition without losing sight of either dimension.

Knowing when to deprioritize profit

For early-stage SaaS companies, deprioritizing profit isn't reckless. It's often the right call.

Winning market share quickly matters enormously in SaaS. A competitor with a larger user base has more data, more brand recognition, and more leverage with enterprise buyers. Spending aggressively to grow that base, even at the cost of near-term profit, can be the move that determines long-term outcomes.

Investors understand this. They'll accept negative profit margins if the growth rate is strong enough to justify it. It can take seven years or more for a SaaS company to reach profitability in a traditional sense. Early investors price that timeline in when growth signals are strong.

The Rule of 40 makes this readable. A company growing at 60% with a -15% margin scores 45. That's a pass. The growth is doing the work that profit isn't yet doing.

Comparing investment opportunities

The Rule of 40 gives investors a single, comparable number across companies with very different profiles. A high-growth, low-margin company and a slow-growth, high-margin company can both score 40+. The rule doesn't penalize either path, which makes it useful for comparing opportunities that don't look alike on the surface.

Investors also look at total shareholder return alongside revenue growth. A company with strong revenue growth but low or negative TSR is destroying value. A company with high TSR but stagnant revenue may not be growing in a meaningful way. The Rule of 40, combined with TSR analysis, gives a more complete picture than either metric alone.

Planning the shift from growth to profitability

Growth doesn't last forever. Every SaaS company eventually reaches a point where the addressable market is largely captured and further growth requires disproportionate effort or investment.

Having a clear plan for that transition matters, whether or not you have outside investors. The Rule of 40 helps frame that plan. If your growth rate is declining, your margin needs to rise to compensate. If you can see that coming, you can prepare for it, pricing adjustments, cost discipline, or new revenue lines, before the score drops.

Meta's experience with its VR Metaverse investment illustrates the risk of the opposite approach: pursuing profitability plays before the user base is large enough to support them. The company stepped away from that effort in early 2023. The lesson is that the timing of the growth-to-profit shift matters as much as the shift itself.

When to start applying the Rule of 40

The Rule of 40 isn't useful from day one. Early-stage companies carry high startup costs and minimal revenue. Applying the rule before the business has meaningful traction produces a score that tells you very little.

A practical starting point is around $1 million in Annual Recurring Revenue. At that level, a company has enough revenue and growth history to make the calculation meaningful. Some companies reach that threshold in two or three years; others take longer. The timing matters less than having enough signal to make the score actionable.

The weighted Rule of 40

An alternative version places more weight on growth than on margin. The formula is:

Weighted Rule of 40 Score = (1.33 × Revenue Growth Rate) + (0.67 × Profit Margin)

Example: A company with 12% revenue growth and 27% profit margin scores (1.33 × 12) + (0.67 × 27) = 15.96 + 18.09 = 34.05 under the weighted version, compared to 39 under the standard version.

The weighted version is more demanding for companies that rely heavily on margin rather than growth. Investors use it for earlier-stage companies where growth is the primary value driver, and where margin improvements are expected to come later.

According to the Software Equity Group's analysis of the market in 2020, companies that perform well under the weighted rule tend to command significantly higher revenue multiples.

A reverse-weighted version, favouring margin over growth, exists but is rarely used. Mature companies with predictable revenue tend to be evaluated on other terms.

How to track the Rule of 40

Tracking the Rule of 40 requires accurate, up-to-date figures for both revenue growth and profit margin. If those numbers live in separate spreadsheets, pulled manually at quarter-end, you're always working with a lag.

A dashboard that connects your revenue data and financial metrics in one place means you know your score without having to ask someone to pull it. Klips connects to 130+ data sources and lets you build the view you need, whether that's the Rule of 40 alongside Monthly Recurring Revenue, churn, and Customer Acquisition Cost, or a simpler executive summary you can share across the team.

Frequently asked questions

Can a company score too high on the Rule of 40?

Yes. A very high score, well above 40, can indicate that a company is under-investing in growth. Investors may push for more aggressive expansion, new product lines, or reinvestment in the business rather than letting margin accumulate without a strategic purpose.

A well-diversified company is generally considered more stable than one relying entirely on a single profitable product line. If growth has stalled while margin has climbed, that's worth examining.

Should a SaaS company prioritize growth or profit margin?

It depends on the stage. Early-stage companies should generally prioritize growth, even at the cost of near-term profit. A large, loyal user base creates the conditions for strong margins later.

For mature companies with limited room to grow the core product, the focus shifts to margin. Profits from the core business can then fund new growth initiatives if the opportunity exists.

When should a SaaS company stop focusing on growth?

When growth slows visibly and the addressable market is largely captured, it's time to shift focus toward profitability. The transition should feel gradual to customers. Sudden price increases push users away. Releasing improved features or higher-value tiers at a premium tends to land better with an established user base.

How many SaaS companies beat the Rule of 40?

The number varies by year and market conditions. On average, roughly 40% of SaaS companies achieve a score of 40 or higher in a given year. Fewer than half of those sustain it for more than three consecutive years. Consistent performance above the threshold is a meaningful signal of operational discipline, not just a favourable market.