The SaaS Magic Number measures how efficiently your sales and marketing spend turns into new recurring revenue. The formula is annualized net-new ARR divided by the prior quarter's S&M spend. A result above 0.75 signals efficient, scalable growth worth investing into.
What Is the SaaS Magic Number?
The SaaS Magic Number answers one question: "For every dollar we spend on sales and marketing, how much new recurring revenue do we generate?" It's a quick gauge of go-to-market efficiency that investors watch closely.
How to Calculate the SaaS Magic Number
Magic Number = ((Current Qtr ARR − Prior Qtr ARR) × 4) ÷ Prior Qtr S&M SpendAnnualized net-new ARR per S&M dollar
Worked example
Current quarter ARR $2,000,000, previous quarter $1,500,000, previous-quarter S&M spend $800,000:
(($2,000,000 − $1,500,000) × 4) ÷ $800,000 = 2.5Each $1 of S&M generated $2.50 of ARR
What's a Good SaaS Magic Number?
| Magic Number | What it means |
|---|---|
| Below 0.5 | 😟 Inefficient — fix sales efficiency before scaling spend |
| 0.5 – 0.75 | 😐 Okay — room to improve |
| Above 0.75 | 😊 Efficient — consider investing more in growth |
| Above 1.0+ | 🤩 Excellent — strong, scalable go-to-market |
A high magic number means you can confidently pour more into acquisition; a low one means each new dollar of spend isn't yet paying off.
SaaS Magic Number FAQ
How do you calculate the SaaS magic number?
Take the increase in ARR from the prior quarter to the current quarter, annualize it (× 4), and divide by the prior quarter's S&M spend: ((Current ARR − Prior ARR) × 4) ÷ Prior S&M.
What is a good SaaS magic number?
Above 0.75 is considered efficient and a green light to invest more in growth. Above 1.0 is excellent. Below 0.5 signals you should fix go-to-market efficiency before scaling spend.
What's the difference between the magic number and LTV:CAC?
The magic number is a fast, quarter-level view of overall S&M efficiency. LTV:CAC looks at the full lifetime value of a customer versus acquisition cost — a deeper, per-customer measure.
Why annualize with × 4?
S&M spend is measured for one quarter, but the new ARR it generates recurs all year. Multiplying the quarterly ARR gain by 4 puts both on an annual footing so the ratio is meaningful.
