Follower growth rate
Follower growth rate is net new followers over a period divided by the starting count. The shape tells more than the figure: organic growth curves and occasionally spikes with attributable moments; purchased growth steps vertically without a cause; churning paid audiences sawtooth. Sustained growth with stable engagement is the healthy pattern.
Worked example
18,000 to 19,400 in a quarter is 7.8% — and the daily curve showing a smooth rise around one viral video is the actual reassurance.
Related: Fake followers · Engagement rate
Full context in the guides, or measure it yourself with the free tools.