The SaaS Quick Ratio measures growth efficiency: (New MRR + Expansion MRR) ÷ (Churned MRR + Contraction MRR). A ratio of 4 is a commonly cited healthy target, meaning a company gains four dollars of MRR for every dollar it loses. A ratio below 1 means the business is shrinking.
What is the SaaS Quick Ratio?
The SaaS Quick Ratio is a growth-efficiency metric, borrowed in spirit from the classic finance "quick ratio" concept, that measures how efficiently a company converts new and expansion revenue against the revenue it loses to churn and contraction. It compares MRR gained to MRR lost, giving a single number that captures whether growth is being built on a solid foundation or is being quietly eroded from underneath.
The four inputs are all MRR movements over the same period:
- New MRR: revenue from customers who signed up for the first time during the period.
- Expansion MRR: additional revenue from existing customers upgrading, buying more seats, or cross-buying another product.
- Churned MRR: revenue lost because a customer cancelled entirely.
- Contraction MRR: revenue lost because an existing customer downgraded, but didn't fully cancel.
Adding the first two gives total MRR gained; adding the last two gives total MRR lost. The Quick Ratio is simply the first divided by the second.
Quick Ratio vs NRR
The Quick Ratio and Net Revenue Retention (NRR) are often mentioned in the same breath, since both weigh expansion against churn and contraction. They aren't the same metric, though, and mixing them up leads to confused comparisons.
| Quick Ratio | NRR | |
|---|---|---|
| Time window | Any period, commonly monthly | Trailing 12 months |
| Includes new customer MRR | Yes | No |
| Reacts to a sudden churn spike | Within a month | Only gradually, over the year |
| Best for | Fast, leading operational signal | Slower, trailing health check on an existing cohort |
Quick Ratio formula
In words: the Quick Ratio equals New MRR plus Expansion MRR, divided by Churned MRR plus Contraction MRR.
Example
Say that in a given month:
- New MRR (from newly won customers): $20,000
- Expansion MRR (upsells and cross-sells): $8,000
- Churned MRR (cancelled customers): $5,000
- Contraction MRR (downgrades): $2,000
Quick Ratio = ($20,000 + $8,000) / ($5,000 + $2,000) = $28,000 / $7,000 = 4
A Quick Ratio of 4 means this company gained four dollars of MRR for every dollar it lost that month. That's comfortably inside the commonly cited healthy range.
Now compare a struggling month at the same company:
- New MRR: $6,000
- Expansion MRR: $2,000
- Churned MRR: $7,000
- Contraction MRR: $3,000
Quick Ratio = ($6,000 + $2,000) / ($7,000 + $3,000) = $8,000 / $10,000 = 0.8
A Quick Ratio below 1 means this company's MRR shrank that month. New and expansion revenue didn't even cover what was lost to churn and contraction, let alone add to the total.
Interpreting your Quick Ratio
As a general industry convention, a Quick Ratio around 4 is often cited as a healthy target, though the "right" number varies by stage and business model. What matters more than hitting an exact number is understanding what the ratio is telling you directionally:
- Above 1: MRR gained exceeds MRR lost, so the business is growing.
- Exactly 1: gains and losses cancel out, so MRR is roughly flat.
- Below 1: MRR lost exceeds MRR gained, so the business is shrinking, even if new logos are still being signed.
A faster complement to NRR
NRR is a trailing 12-month metric by design, which makes it excellent for judging the long-term health of a specific customer cohort, but slow to reflect what's happening right now. If churn spikes sharply this month, that spike won't fully show up in NRR for months, diluted across the trailing year.
The Quick Ratio has no such lag. Because it can be calculated for any period, including a single month, it reacts immediately to a churn spike or a big expansion win. This makes it a useful complement to NRR: NRR tells you how a cohort has performed over the long run, while the Quick Ratio tells you what's happening to your overall MRR engine right now, in near real time.
Neither metric replaces the other. A team relying only on NRR might not notice a bad month until it's already been diluted into a trailing-twelve-month average, by which point several more bad months may have followed. A team relying only on the Quick Ratio might mistake a single unusually large expansion deal for a durable trend, when NRR would show the more sober, cohort-wide reality. Tracking both together, the Quick Ratio for the current pulse, NRR for the durable trend, gives a fuller picture than either alone.
Common pitfall: small MRR bases are noisy
The Quick Ratio is a ratio of two dollar figures, and like any ratio, it's sensitive to the size of what it's dividing. For a company with a small MRR base, a single large customer churning, or a single large expansion deal closing, can swing the Quick Ratio dramatically from one month to the next. It might read as a ratio of 6 one month and 1.5 the next, with no real change in underlying business health.
As the MRR book grows larger and more diversified across many customers, individual events matter less relative to the whole, and the ratio becomes a steadier, more meaningful signal. Practically, this means young or small companies should read their Quick Ratio as a rough directional signal and avoid over-reacting to a single month's swing, while more established companies can lean on it with more confidence.