NRR deliberately excludes new-customer revenue — it isolates what happens to the exact same existing customer cohort over the period.
How it works
Starting MRR plus expansion, minus contraction, minus churn, gives the ending MRR from that same customer cohort. Dividing by starting MRR gives NRR as a percentage — above 100% means the business grows revenue from existing customers alone, even with zero new sales.
What this does not include
This excludes new-customer MRR by design — it’s not a substitute for tracking overall MRR growth (this site’s separate SaaS churn & MRR calculator includes new customers), just a distinct, complementary lens on the existing base.
How to use this calculator
- Enter starting MRR, expansion MRR, contraction MRR, and churned MRR for the same customer cohort.
A worked example
Starting MRR $100,000, expansion $5,000, contraction $2,000, churned $6,000: ending cohort MRR = $97,000, net revenue retention = 97% — slightly below 100%, meaning the existing customer base shrank overall despite some upsells.
What the variables mean
| Variable | Meaning |
|---|---|
| Starting MRR | Monthly recurring revenue from the existing customer cohort at period start |
| Expansion MRR | Additional revenue from upsells and upgrades within that same cohort |
| Contraction MRR | Revenue lost from downgrades |
| Churned MRR | Revenue lost from customers who canceled entirely |
Edge cases worth knowing
NRR excludes new customers entirely — it only tracks the existing cohort. A company can be growing overall through new sales while still having an NRR below 100%, which is exactly why this metric is tracked separately from total revenue growth.
An NRR above 100% means expansion revenue outpaced contraction and churn combined — a strong signal that existing customers are becoming more valuable over time even without any new sales.
Frequently asked questions
What’s considered a good NRR?
Many top-performing SaaS companies target NRR above 110-120%, though what’s achievable varies by customer segment and product type — publicly reported benchmarks vary across sources.
Why exclude new customers from this metric?
Because NRR is designed to isolate the health of the existing customer relationship — how well a business retains and expands revenue from customers it already has, separate from new sales momentum.
Can NRR exceed 100% even with some churn?
Yes — if expansion revenue from upsells and upgrades among the customers who stay outweighs the revenue lost to churn and downgrades, NRR can exceed 100% despite some churn occurring.
