# Rule of 40

## Quick Definition
A benchmark stating that a SaaS company's growth rate plus profit margin should equal or exceed 40% to be considered healthy.

## What is the Rule of 40?
The Rule of 40 states that a healthy SaaS company's growth rate plus profit margin should equal or exceed 40%. It's a balancing test that allows for different strategies while ensuring overall efficiency.

A company growing 50% with -10% margins scores 40. A company growing 20% with 20% margins also scores 40. Both are considered healthy by this benchmark.

## Why the Rule of 40 Matters
The Rule of 40 acknowledges that growth and profitability are trade-offs. Young companies sacrifice profits for growth. Mature companies sacrifice growth for profits. This metric lets you compare them fairly.

Investors use it as a quick health check. Companies consistently above 40 command premium valuations. Those below 40 face harder questions about their path to efficiency.

## How to Calculate the Rule of 40 Step by Step

**Step 1: Calculate your revenue growth rate.** Use trailing 12-month ARR growth. Pull your ARR from 12 months ago and your current ARR.

- ARR 12 months ago: $1,200,000
- Current ARR: $1,920,000  
- **Revenue Growth Rate = ($1.92M - $1.2M) ÷ $1.2M = 60%**

**Step 2: Calculate your profit margin.** You can use EBITDA margin, operating margin, or free cash flow margin. EBITDA margin is most common for this calculation.

- Trailing 12-month revenue: $1,800,000
- Trailing 12-month EBITDA: -$180,000  
- **EBITDA Margin = -$180K ÷ $1.8M = -10%**

**Step 3: Add them together.**

- **Rule of 40 Score = 60% + (-10%) = 50** ✓

You're above 40 — growth is more than compensating for your losses.

**Step 4: Understand what the score means for your stage.**

- Pre-Series A: Focus on growth rate. Negative margins are fine if growth is 80%+
- Series A-B: Should be trending toward 40. Acceptable to be below if growth is strong
- Series C+: Should consistently hit 40+. Investors expect efficiency at scale

**Step 5: Track the components over time.** The Rule of 40 is most valuable as a trend. Are you improving toward 40, or drifting away? If growth is slowing, margins should be improving to compensate.

**Common mistakes founders make:**

- Mixing up revenue growth rate with MRR growth rate (use ARR YoY growth)
- Using gross margin instead of EBITDA/operating margin
- Comparing against companies at different stages (a $2M ARR startup shouldn't benchmark against a $100M company)
- Ignoring that the Rule of 40 is a guideline, not a law — context matters

## Rule of 40 Benchmarks

- Below 20: Struggling. Neither growing fast nor profitable.
- 20-40: Acceptable. Room for improvement.
- 40-60: Healthy. Well-balanced business.
- Above 60: Elite. Top-tier SaaS performance.

**Formula**
Rule of 40 Score = Revenue Growth Rate (%) + Profit Margin (%)  
Profit Margin can be EBITDA margin, operating margin, or free cash flow margin  
Target: Score ≥ 40

## Example
**Company A (Growth-focused):**

- Revenue growth: 60%
- Profit margin: -15%
- Rule of 40 score: 60 + (-15) = 45 ✓

**Company B (Profitable):**

- Revenue growth: 20%
- Profit margin: 25%
- Rule of 40 score: 20 + 25 = 45 ✓

Both pass. Different strategies, same efficiency outcome.