Viral coefficient measures how each existing user helps bring in new users to your product. This basic growth metric shows whether your product has the potential to grow on its own through user sharing. A viral coefficient of 1 means each user brings in one new user, while anything above 1 indicates viral growth.

The formula for calculating viral coefficient is simple: multiply the number of invites sent per user by the conversion rate of those invites. For example, if users send an average of 5 invites, and 20% of those invites convert to new users, the viral coefficient is 1 (5 × 0.2 = 1).

Understanding your viral coefficient helps identify opportunities to improve sharing and conversion. Teams can work on making invites easier to send, more appealing to receive, or better targeted to potential users. Regular measurement of this metric shows if sharing features and referral programs are working effectively.