Growth is not free, so measure its cost
A growth efficiency ratio measures how much growth a company generates per dollar of spend, capturing whether growth is being bought efficiently. Growth alone is an incomplete story: a company can grow quickly while burning cash wastefully, which works only while capital is cheap and patient. Efficiency ratios add the missing dimension, asking not merely how fast the company is growing but how much it is spending to grow that fast. That question determines whether the model is durable and how the market values it.The common ratios and what each isolates
Several specific metrics all serve as growth efficiency ratios, each focused on a different slice of spend:
| Ratio | Relates | Focus |
|---|---|---|
| Magic number | New revenue to S&M spend | Sales and marketing efficiency |
| Burn multiple | Cash burned to net new ARR | Total cash efficiency |
| Rule of 40 | Growth plus profitability | Balance of the two |
Why efficient growth wins
The reason growth efficiency has become central is that inefficient growth is fragile. A company growing on heavy, undisciplined spend depends on continued cheap capital, and when that tightens, the model breaks. A company growing efficiently, converting each dollar of spend into a strong return, can sustain and even accelerate through tighter conditions, and it commands better valuations because the growth is trusted to continue. Efficiency ratios also connect to unit economics: a healthy CAC payback period at the customer level rolls up into efficient growth at the company level. Measuring growth without measuring its efficiency tells only half the story, and it is the half that looks best right before an inefficient model runs out of room. Tracking a growth efficiency ratio keeps the company honest about whether the growth it is proud of is actually worth what it costs.
Frequently Asked Questions
What is a growth efficiency ratio?
It is any metric that measures how much growth a company produces per dollar of spend, capturing whether growth is being bought efficiently. Common versions include the magic number, which relates new revenue to sales and marketing spend, and the burn multiple, which relates cash burned to net new ARR. All answer whether the growth is worth its cost.
Why measure growth efficiency, not merely growth?
Because growth bought at any cost is not sustainable. A company can post strong growth while burning cash inefficiently, which works only as long as capital is cheap. Efficiency ratios reveal whether growth is being generated with discipline or purchased wastefully, which determines whether the model can endure and how investors value it.
Which growth efficiency ratio should you use?
It depends on the question. The magic number focuses on sales and marketing efficiency; the burn multiple captures total cash efficiency against growth; the Rule of 40 balances growth with profitability. Most companies watch more than one, since each isolates a different aspect of whether growth is being generated efficiently.
Put these metrics to work
ORM builds custom revenue forecast models that turn concepts like growth efficiency ratio into prescriptive action for your team.
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