NRR definition
Net Revenue Retention (NRR) — also called Net Dollar Retention (NDR) in US markets — measures what proportion of recurring revenue from a cohort of customers at the start of a period is still present, and has potentially grown, at the end of that period.
The formula is: NRR = (Opening ARR + Expansion ARR − Contraction ARR − Churned ARR) ÷ Opening ARR × 100.
If a cohort of customers contributed £10m ARR at the start of the year, and at the end of the year that same cohort (excluding any new customers acquired during the year) contributes £11m ARR, NRR is 110%. The existing customer base grew by 10% through expansions net of contractions and churn — without any new sales effort.
Why NRR above 100% is so powerful
NRR above 100% is sometimes called "negative churn" — the existing customer base is expanding faster than it is losing customers. This creates a compounding growth dynamic that is extremely capital-efficient: a business with 115% NRR would grow even if it acquired no new customers whatsoever.
This matters enormously for valuation and financing. A business growing purely on the back of strong NRR is deploying minimal sales and marketing capital to achieve that growth. Its Customer Acquisition Cost is zero on the expansion portion of revenue. The margin profile improves automatically as the customer base matures. Investors routinely value high-NRR businesses at a significant premium to low-NRR peers of the same ARR size.
NRR benchmarks
SaaS benchmarks vary by customer segment and product category, but broadly:
Below 90%: a warning sign. The customer base is eroding net of expansions, and the business must run fast on new customer acquisition just to stand still. Burn increases, valuations compress.
90–100%: acceptable but not exceptional. Churn and contraction are roughly offsetting expansions. Common in SMB-focused SaaS with inherently higher logo churn.
100–110%: good. The existing base is growing and the business has clear product-market fit with its customer base. A typical target for mid-market SaaS.
110–130%+: exceptional. Enterprise SaaS leaders like Snowflake, Veeva, and Datadog have historically operated in this range. The existing base is a meaningful growth engine in its own right.
NRR in FP&A and investor reporting
NRR is a mandatory metric in any serious SaaS board pack or investor report. For FP&A teams, it anchors the ARR waterfall: understanding NRR by cohort, by segment, and over time reveals where the customer base is healthy and where retention risk is accumulating.
The key FP&A question behind NRR is: what are the drivers of expansion versus contraction? Expansion is typically driven by seat-based or usage-based pricing, upsell of premium tiers, or cross-sell of adjacent products. Contraction is driven by budget cuts, reduced usage, or competitive displacement. Understanding these drivers — often through a cohort-level model segmented by product, geography, or customer size — is the work of SaaS FP&A.
