Net revenue retention (NRR)

NRR measures what happened to the revenue from a fixed cohort of customers — everyone who was a customer at the start of the period — by the end of that period. New logos acquired during the period are deliberately excluded, because the question NRR answers is “does our existing base grow on its own?”

Because expansion is included, NRR can exceed 100%. An NRR above 100% means the existing base grows even with zero new sales, which is the single strongest signal of product-market fit in B2B SaaS. Public benchmarks vary by segment, but the rough shape is: below 90% is a leaky bucket, 100–110% is healthy, and above 120% is exceptional and usually driven by usage-based or seat-expansion pricing.

The cohort definition is where the arguments start

NRR is easy to game accidentally. The number changes materially depending on whether you:

• measure over 12 months or annualise a quarter,
• include or exclude customers who were mid-implementation at the start,
• treat a downgrade-then-upgrade within the period as net zero or as both contraction and expansion,
• count usage overage as expansion or as base revenue.

None of those choices is wrong, but you have to pick one and hold it constant, or the trend line is meaningless.

Why it is hard to calculate

NRR needs the state of every subscription at two points in time, with every mid-term change in between attributed to the right movement bucket. If upgrades are quoted in a CRM, applied by hand in a billing tool, and invoiced from an accounting package, that history has to be reconstructed. When quoting, subscriptions and invoicing share a single system of record, NRR is a query rather than a reconstruction.