🦠 Viral Coefficient Calculator
A free online viral coefficient (K-factor) calculator that helps product managers and growth hackers quantify a product's viral growth potential. Enter invites sent per user and invite conversion rate to automatically calculate the viral coefficient K and growth cycle users per user. K>1 means viral growth — each user brings more than one new user — a core metric for evaluating product-market fit and growth strategy.
📖 What is Viral Coefficient?
The viral coefficient (K-factor) = Invites sent per user × Invite conversion rate. When K>1, the product achieves self-sustaining viral growth — each user brings more than one new user, creating an exponential growth loop. Dropbox famously achieved K≈1.2 through referral rewards, driving explosive growth. Most products have K-factors between 0.2-0.5 and need to optimize invite flows and conversion rates. If K<1, supplement with paid acquisition and other strategies to sustain growth.