Follower Growth Projection Calculator

This calculator projects follower growth using standard compound growth math, applied to a growth rate you supply but nudge with your posting frequency. Your monthly growth rate gets a small bonus based on posts per week above a baseline of 3 — each extra post above that baseline adds 0.1 percentage points, capped at a 0.5-point bonus — reflecting the general finding that more frequent posting correlates with somewhat faster growth, though the effect here is modest and capped rather than open-ended. That adjusted rate is then compounded monthly to project followers at 3, 6, and 12 months, the same math behind compound interest: multiply current followers by (1 + rate) raised to the number of months. Doubling time uses the standard logarithmic formula (ln 2 divided by ln(1 + rate)) to answer how many months it takes to double your following at that adjusted rate — useful for sanity-checking whether a growth rate is realistic over a longer horizon.

Projected engagement rate models a real and well-documented phenomenon: engagement rate erodes as an audience grows, since new followers are typically less personally invested than early ones. The calculator captures this by decaying your current engagement rate based on the logarithm of your projected 12-month growth multiple, with a floor so engagement never drops below half its current value. The biggest assumption to flag is that growth rate is treated as constant over the whole projection period — real growth is rarely this smooth, and a rate measured from a recent viral spike or slow month will distort all three horizons equally.