Quick Ratio (SaaS)
The ratio of revenue added (new + expansion + reactivation) to revenue lost (churn + contraction) in a given period, measuring the efficiency of growth by quantifying how much you add for every dollar lost.
The SaaS Quick Ratio provides a single-number summary of growth efficiency. A quick ratio of 4 means you add $4 of new revenue for every $1 lost. Above 4 is excellent and indicates efficient, sustainable growth. Between 2 and 4 is healthy. Below 2 suggests growth is a struggle, with too much revenue lost relative to what is added.
The formula is (New MRR + Expansion MRR + Reactivation MRR) / (Churned MRR + Contraction MRR). This captures the complete picture: you can grow through new customer acquisition, existing customer expansion, or bringing back former customers, and all of these must outpace losses from cancellations and downgrades.
The quick ratio is valuable for diagnosing growth quality. A company with rapid new customer acquisition but poor retention might have a quick ratio of 3, but fixing retention could move it to 6 with less effort than doubling acquisition. Conversely, a company with modest acquisition but excellent retention and expansion might already have a ratio of 5. The metric helps you understand whether to invest in pouring more water in (acquisition) or plugging the holes (retention and expansion).
Related Terms
Growth Loop
A self-reinforcing cycle where each cohort of users generates inputs (data, content, referrals) that attract the next cohort, creating compounding growth.
Churn
The rate at which customers stop using or paying for a product over a given period, typically measured as monthly or annual churn percentage.
Activation Rate
The percentage of new signups who complete a key action (the 'aha moment') that correlates with long-term retention and product value realization.
Product-Led Growth (PLG)
A go-to-market strategy where the product itself drives acquisition, activation, and expansion through self-serve experiences rather than sales-led motions.
Viral Coefficient (K-Factor)
The average number of new users each existing user brings to the product, where a K-factor above 1.0 indicates self-sustaining viral growth.
Net Revenue Retention (NRR)
The percentage of recurring revenue retained from existing customers over a period, including expansion, contraction, and churn — where 100%+ indicates growth without new customers.