About Net Dollar Retention (NDR)
Net Dollar Retention (NDR), sometimes referred to as Net Revenue Retention (NRR), is one of the most critical metrics for SaaS (Software as a Service) and subscription-based businesses. It measures the percentage of recurring revenue retained from existing customers over a specific period, accounting for upgrades (expansion), downgrades (contraction), and cancellations (churn).
How is NDR Calculated?
The Net Dollar Retention formula provides a snapshot of how well your business retains and grows its existing customer base. The calculation is as follows:
Where:
- Starting MRR: Monthly Recurring Revenue at the beginning of the period.
- Expansion MRR: Additional revenue from existing customers (upsells, cross-sells).
- Downgrade MRR: Lost revenue from customers moving to lower tiers.
- Churn MRR: Lost revenue from customers cancelling entirely.
Interpreting Your NDR Score
Your NDR percentage tells a powerful story about your business health:
- > 120%: Exceptional. The company is growing efficiently purely through its existing customer base. This is typical for top-tier IPO-ready SaaS companies.
- 100% – 120%: Healthy. Your expansion revenue is outpacing your churn and downgrades.
- < 100%: Warning. Churn and downgrades are shrinking your business faster than you can expand existing accounts. You are reliant on new customer acquisition to maintain revenue levels.
Difference Between NDR and GRR
While NDR includes expansion revenue, Gross Retention Rate (GRR) does not. GRR only looks at retained revenue relative to the starting revenue, excluding upsells. GRR can never exceed 100%, whereas NDR can (and should) exceed 100% for high-growth companies.
Why NDR Matters for Valuation
Investors scrutinize NDR because it indicates the "stickiness" of the product and the efficiency of growth. A high NDR implies that the Customer Lifetime Value (LTV) is increasing, and the company does not need to spend as much on Customer Acquisition Costs (CAC) to grow.