Customer Concentration Risk Calculator
VC due diligence flags customer concentration risk: if your top 10 customers account for >40% of ARR, a single churn could collapse the business. Calculate your concentration ratio and compare to investor benchmarks.
Why Concentration Matters
If your top 10 customers represent 60% of ARR, losing 2-3 of them in a year cuts revenue ~15-20%. Public SaaS companies typically maintain top 10 concentration below 20%. Series A-B startups often run 40-60% — VCs accept this with a credible plan to diversify, but apply 10-30% valuation discount.
VC Concentration Benchmarks
Andreessen Horowitz/Bessemer/Sequoia rough benchmarks: largest single customer should be <15% of ARR by Series B, top 10 should be <40%. Net dollar retention >120% can offset some concentration concerns. The exception: vertical SaaS or enterprise-focused companies often run higher concentration because the TAM is naturally narrower.
Mitigation Strategies
(1) Expand sales motion to mid-market to dilute enterprise concentration. (2) Build PLG self-serve to acquire many small customers. (3) Multi-product expansion to lock in existing customers (concentration becomes less risky when each customer uses multiple products). (4) Contractual lock-in — 3-year contracts with auto-renewal reduce single-period churn risk.
Source: Bessemer Cloud 100 customer concentration analysis, OpenView SaaS Benchmarks 2024, Sequoia portfolio company best practices. Last updated: May 2026.