Metrics · Finance · Ops · Quarterly · ratio · Updated 2026-07-21

What is SaaS Magic Number?

Short answer: A go-to-market efficiency ratio comparing net new annualized revenue to prior-period sales and marketing spend.

Definition

A go-to-market efficiency ratio comparing net new annualized revenue to prior-period sales and marketing spend.

Formula

(Current Quarter ARR - Prior Quarter ARR) x 4 / Prior Quarter S&M Spend

How to measure

Annualize the quarter-over-quarter ARR increase, then divide by the sales and marketing spend from the prior quarter that presumably generated it.

Why track it

A magic number above 0.75 generally justifies increasing sales and marketing investment; well below that suggests spend is outrunning returns.

Example

A company gaining $100,000 in net new ARR (annualized to $400,000) against $500,000 in prior-quarter S&M spend has a magic number of 0.8.

FAQ

What is SaaS Magic Number?
A go-to-market efficiency ratio comparing net new annualized revenue to prior-period sales and marketing spend.
How do you calculate SaaS Magic Number?
(Current Quarter ARR - Prior Quarter ARR) x 4 / Prior Quarter S&M Spend
Why track SaaS Magic Number?
A magic number above 0.75 generally justifies increasing sales and marketing investment; well below that suggests spend is outrunning returns.
What is SaaS Magic Number? Definition, formula, and growth use · Cofounderbase