Referral K-factor calculator

Is your referral loop worth it?

Model the loop before you build it. Set your numbers and see your K-factor, how much referrals amplify every signup, and what they add each month.

200
Your baseline before referrals.
25%
Share of signups who refer at least one person.
4
How many people an active referrer invites.
15%
Share of invited people who actually sign up.
K-factor
0.15
new signups each user drives
Amplification
1.18x
every signup, multiplied
Referrals add
35
signups per month
A real tailwind, not a growth engine. Referrals lift every signup by 1.18x (35 extra a month). The cheapest lever here is usually invite conversion. Deliverability and an invite from a real person move it most.
6 months cumulative signups
without referralswith referrals
a free tool from simplereferral

Good loop. Now the hard part: building it right.

Attribution, idempotency so retries never double-count, and invites that actually land. One API key, two calls. Private beta opens this quarter; get an early-access key.