What Is the SaaS Magic Number?
Spend $300,000 on sales and marketing this quarter — how much new revenue should that actually buy? The SaaS magic number answers exactly that: it measures how many dollars of new annualized recurring revenue a company generates for every dollar spent on sales and marketing the quarter before, turning a vague sense that 'growth feels expensive' into one comparable number.
Unlike growth rate, which only tells you the engine is spinning, the magic number tells you how much fuel it needed to spin that fast. Investors read it alongside burn multiple and LTV:CAC because it isolates the sales and marketing engine specifically — pricing, product cost, and support overhead never touch it.
The SaaS Magic Number Formula, Step by Step
The formula: Magic Number = (Current Quarter Revenue − Previous Quarter Revenue) × 4 ÷ Previous Quarter S&M Spend. Multiplying the quarterly revenue increase by four annualizes it; dividing by the prior quarter's spend — not the current quarter's — accounts for the lag between a sales dollar spent and the revenue it eventually closes.
A worked example: a startup closes $500K in quarterly revenue in Q1, growing to $560K in Q2, while Q1 S&M spend was $300K. Magic Number = ($560K − $500K) × 4 ÷ $300K = $240K ÷ $300K = 0.8 — for every dollar spent on sales and marketing the prior quarter, the company generated 80 cents of new annualized revenue.
What's a Good SaaS Magic Number? Benchmarks
The scale most investors use: below 0.5 signals a real sales efficiency problem — fix the funnel before spending more. 0.5 to 0.75 is workable but under scrutiny. 0.75 to 1.0 is the 'good enough to scale' zone venture investors look for before backing a bigger go-to-market budget. Above 1.0 means the engine is efficient enough to justify pouring in more fuel; above 1.5 is rare and usually means under-investment in growth, not perfection.
The number moves with company age. A pre-PMF startup often prints an ugly magic number because it's still paying to learn which channel and segment work, not to scale one that's already proven. What matters from Series A onward is a number trending toward 1.0 as the go-to-market motion starts repeating itself.
< 0.5
Fix sales efficiency before spending more
0.75–1.0
Good enough to scale S&M spend
> 1.5
Rare — often under-investment in growth
Magic Number vs. Burn Multiple: Different Denominators, Same Question
Both metrics ask 'is this spend buying growth?' but they isolate different costs. Magic Number divides annualized revenue growth by S&M spend alone; burn multiple divides net new ARR by total net burn — salaries, infrastructure, everything. A company can post a strong magic number while a bloated non-sales headcount still wrecks its burn multiple.
Read them together: magic number diagnoses the go-to-market engine specifically, burn multiple grades the whole company. A founder who only tracks burn multiple can miss a sales team quietly overspending, because underspending elsewhere in the business masks the problem in the total.
| Magic Number | Burn Multiple | |
|---|---|---|
| Numerator | Annualized revenue growth (×4) | Net new ARR |
| Denominator | Prior quarter S&M spend only | Total net burn (all spend) |
| What it isolates | Sales & marketing efficiency | Whole-company capital efficiency |
| Good benchmark | 0.75–1.0 or higher | Under 1.5 |
Common Measurement Mistakes
The most common error is dividing by the current quarter's S&M spend instead of the prior quarter's — that erases the lag the formula is built to capture and flatters companies that just cut their sales budget. The second is using bookings instead of recognized, run-rate revenue, which inflates the numerator with deals that haven't actually started paying yet.
The third is judging one quarter in isolation. A single enterprise deal closing late can swing the ratio wildly in either direction; look at a trailing two-to-three quarter average before drawing conclusions about the sales engine's real efficiency.
How the Magic Number Shifts by Sector
The 0.75–1.0 benchmark assumes a fairly standard SaaS sales cycle; it bends hard once the buyer changes. A Health-Tech company selling into hospital procurement often shows a poor magic number for several quarters in a row — the S&M spend lands months before a signed contract clears committee, even though the eventual deal size and retention are excellent.
A Green-Tech company financing pilot programs or certification costs upfront sees the same lag from the capex side. An Edu-Tech company selling on an annual school procurement calendar can show a terrible magic number for three quarters and a strong one in the fourth, purely because of when the academic year's budget clears.
Stress-Test It in Founder Runway
Founder Runway runs a 20-turn arc from Pre-Seed to Series A, and every marketing and sales hire you fund shows up in MRR with the same real-world lag the magic number is built to measure. Push an aggressive Health-Tech sales hire and the spend hits Cash immediately while the MRR payoff waits several turns — exactly the mismatch that wrecks a magic number read too early.
Run the same budget in a Fin-Tech scenario and the shorter sales cycle changes the picture: revenue catches up to spend faster, and the same dollar of S&M produces a very different magic number by turn 20. The free burn rate calculator on the site turns a spend and revenue delta into a monthly burn figure you can pair with your own magic number math.
Conclusion
SaaS Magic Number = (this quarter's revenue − last quarter's revenue) × 4 ÷ last quarter's S&M spend: under 0.5 means fix the funnel, 0.75–1.0 means the engine is ready for more fuel. Measure it on a trailing average, not a single quarter, and read it next to burn multiple — one grades the sales engine, the other grades the whole company.
Frequently asked questions
What is the SaaS magic number?
It measures how many dollars of new annualized recurring revenue a company generates for every dollar spent on sales and marketing the prior quarter. Formula: (this quarter's revenue − last quarter's revenue) × 4 ÷ last quarter's S&M spend.
How do you calculate the SaaS magic number?
Take the increase in quarterly revenue, multiply by four to annualize it, then divide by the prior quarter's sales and marketing spend. A startup growing from $500K to $560K in quarterly revenue on $300K of prior-quarter S&M spend has a magic number of 0.8.
What is a good SaaS magic number?
Below 0.5 signals a sales efficiency problem. 0.75 to 1.0 is the range investors look for before backing more go-to-market spend. Above 1.5 is rare and usually means the company is under-investing in growth rather than achieving perfect efficiency.
What's the difference between the magic number and burn multiple?
Magic number divides annualized revenue growth by sales and marketing spend alone, isolating go-to-market efficiency. Burn multiple divides net new ARR by total net burn across the whole company, including headcount and infrastructure outside of sales.
Why use the prior quarter's S&M spend instead of the current quarter's?
Because there's a real lag between a sales dollar spent and the revenue it eventually closes. Dividing by the current quarter's spend erases that lag and flatters a company that simply cut its sales budget right before measuring.
Test this decision in the game.
Apply the same assumption across one run and see which metric weakened three turns later.