NRR Calculator
Net Revenue Retention, or NRR, measures how much revenue you keep and grow from your existing customers alone, and this calculator works it out from the moving parts. NRR, also called net dollar retention, takes the recurring revenue from a cohort of customers at the start of a period and tracks what happens to it: it grows through expansion as customers upgrade and buy more, and shrinks through contraction as they downgrade and through churn as they leave. Crucially, it ignores new customers, so it isolates the health of the relationships you already have. An NRR above 100 percent is the holy grail of SaaS: it means your existing customers generate more revenue over time even before you win anyone new, so the business grows on its installed base alone. The best software companies post NRR well above 110 percent. This calculator makes it clear. You enter your starting MRR, plus the expansion, contraction and churned MRR over the period, and it returns your NRR, the net change, and a verdict against the all-important 100 percent line. The results update as you type. Use it to gauge customer health, to demonstrate durable growth to investors, who scrutinise NRR closely, or to quantify the impact of upsells and churn. NRR is calculated as the starting MRR plus expansion, minus contraction and churn, all divided by the starting MRR. Above 100 percent means expansion is outrunning losses and the revenue base is growing by itself; below 100 percent means you are leaking revenue faster than you expand it, and must keep acquiring customers just to stand still. Because it captures expansion, contraction and churn in one figure, NRR is often considered the single best indicator of long-term SaaS health.
NRR = (starting MRR + expansion - contraction - churn) / starting MRR. Excludes new customers. Above 100% means the existing base grows revenue by itself. 110%+ is excellent.
How it works
NRR starts with the recurring revenue from existing customers at the beginning of the period, adds expansion from upgrades, then subtracts contraction from downgrades and churned revenue from customers who left. Dividing this by the starting MRR gives the retention rate. New customers are deliberately excluded so the figure reflects only the existing base.
Worked example
Starting with $100,000 of MRR, adding $15,000 of expansion, and losing $3,000 to contraction and $5,000 to churn, the ending revenue from the existing base is $107,000. Dividing by the $100,000 start gives an NRR of 107 percent, meaning existing customers grew revenue by 7 percent before any new sales.
Related calculators
- GRR Calculator: gross retention.
- Revenue Churn: lost revenue.
- Expansion Revenue: upsell MRR.
- MRR Calculator: recurring revenue.