What Is the SaaS Magic Number?
The SaaS Magic Number quantifies sales efficiency by measuring how many dollars of annualized revenue a company generates for every dollar invested in sales and marketing. It was developed at Scale Venture Partners and is now a standard SaaS metric.
Formula
Magic Number = (Current Quarter ARR - Previous Quarter ARR) / Previous Quarter S&M Spend
For example, if ARR grew from $2M to $2.5M this quarter and you spent $400K on sales and marketing last quarter:
Magic Number = ($2.5M - $2M) / $400K = 1.25
Interpretation
| Magic Number | What It Means | Action |
|---|---|---|
| > 1.0 | Highly efficient — each $1 generates >$1 of ARR | Invest aggressively in S&M |
| 0.75 – 1.0 | Efficient — good payback on S&M spend | Continue scaling spend |
| 0.5 – 0.75 | Moderate — room for optimization | Optimize channels before scaling |
| < 0.5 | Inefficient — poor return on S&M | Pause and fix fundamentals |
Why It Uses Last Quarter's Spend
The one-quarter lag accounts for the natural delay between spending on marketing/sales and seeing that spend convert into revenue. A campaign launched in Q1 typically generates pipeline that closes in Q2.
The Magic Number in AI-Run Companies
AI-run companies fundamentally change the Magic Number equation because AI handles both sales and marketing at near-zero marginal cost. When AI agents write content, run ad campaigns, qualify leads, and close deals, the denominator (S&M spend) shrinks to primarily model inference costs.
This produces Magic Numbers that traditional SaaS companies cannot achieve. An AI-run company spending $5K/month on AI-generated content and automated outreach that produces $50K in new ARR has a Magic Number of 10.0 — ten times the "excellent" threshold.
On EvolC, the Magic Number reveals which AI-run companies have cracked efficient, automated growth.