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TG3 SaaS/Tools/Viral coefficient calculator
Free SaaS calculator

Viral coefficient calculator.

Enter how many invites the average user sends and how many convert to find your K-factor. Free, runs in your browser and nothing is stored.

The calculator

The viral coefficient calculator.

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Your K-factor
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This calculator runs entirely in your browser. Nothing you enter is sent anywhere or stored. It is a quick estimate, not financial advice.

The formula

How the viral coefficient calculator works.

The K-factor is invites per user multiplied by the conversion rate of those invites. Send 3 invites that convert at 15 percent and your K is 0.45, so every user brings just under half a new user.

A K above 1 means each user brings more than one new user and growth becomes self-sustaining. Below 1, referrals slow without dying, because each cohort still seeds part of the next.

What it means

Why a K below 1 still matters.

True virality, a K sustained above 1, is extraordinarily rare and usually short-lived. Most real referral programs run somewhere between 0.2 and 0.7 and that is not a failure.

A coefficient under 1 is a standing discount on every other channel, since each cohort partly seeds the next. Nudging the K you have upward beats chasing a mythical one above 1.

Common questions

What people ask about the viral coefficient calculator.

How is the viral coefficient calculated?+

Multiply the average number of invites each user sends by the share of those invites that convert into active users.

What does a viral coefficient above 1 mean?+

Each user brings in more than one new user, so growth becomes self-sustaining. It is rare and usually does not last long.

Is a viral coefficient below 1 bad?+

No. A K under 1 still lowers blended acquisition cost because each cohort partly seeds the next. It just does not carry growth on its own.

How do I improve my K-factor?+

Build sharing into the core product experience, cut friction from the invite flow and reward both sides of the referral.

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