SaaS Magic Number Calculator

What the magic number measures

The SaaS magic number tells you how hard your sales and marketing dollars are working. It looks at how much revenue grew from one quarter to the next, annualizes that growth, and compares it to what you spent to generate it in the prior quarter. A magic number of 1 means every dollar of spend produced a dollar of new annual recurring revenue, which is generally considered the line where scaling up starts to make sense.

The one-quarter lag is deliberate. Spend rarely pays off the moment it goes out the door, so the metric pairs this quarter's growth with last quarter's spend to give the pipeline time to convert. That makes it a cleaner read on efficiency than comparing spend and growth in the same period.

How to calculate it

• Quarterly growth = this quarter's revenue − last quarter's revenue.
• Annualized new revenue = quarterly growth × 4.
• Magic number = annualized new revenue ÷ prior quarter's sales and marketing spend.

The calculator above runs the math, places your result on a scale with the two decision lines at 0.75 and 1.0, and translates it into a plain read on whether to spend more, hold steady, or fix efficiency first.

Reading your number

• Above 1.0. Efficient. Spend is more than paying for itself within a year, and the usual move is to invest more while the engine is working.
• 0.75 to 1.0. Acceptable. Keep spending, but watch the trend and look for efficiency gains before you pour on more.
• Below 0.75. Inefficient. Growth is costing too much, so the priority is fixing conversion, targeting, or pricing before scaling the budget.
• Above 1.5. Exceptional, and often a sign you are underinvesting. There may be room to grow faster by spending more.

If the number is low, the fixes usually live in how efficiently you sell and what it costs you. The LTV:CAC Calculator checks whether each customer earns back its acquisition cost, and the Sales Tech Stack Cost Calculator finds spend to trim. If the number is high, the Rule of 40 Calculator shows how that growth balances against your margin.

Frequently asked questions

What is the SaaS magic number?

A sales-efficiency metric. It annualizes the revenue growth from one quarter to the next and divides by the prior quarter's sales and marketing spend. A magic number of 1 means a dollar of spend produced a dollar of new annual recurring revenue.

How do you calculate the magic number?

Subtract last quarter's revenue from this quarter's, multiply the difference by four, then divide by the sales and marketing spend from the quarter before. Revenue rising from 1,000,000 to 1,150,000 against 500,000 of prior spend gives a magic number of 1.2.

What is a good SaaS magic number?

Above 1 is efficient and usually a signal to invest more, above 1.5 is exceptional, 0.75 to 1 is acceptable, and below 0.75 means the spend is not converting well enough to scale yet.

Should I use revenue or ARR in the magic number?

This calculator uses quarterly recurring revenue and multiplies the quarterly increase by four. If you work in ARR directly, enter ARR figures and read the result without the annualization, since ARR is already annual. Stay consistent so it is comparable over time.