TikTok isn't a social graph — it's a recommendation engine. That single fact rewrites engagement math, because your audience is the algorithm's, not yours. This calculator measures resonance against the reach the machine actually gives you.
Followerless reach changes the ratio
On follower-fed platforms your ER is capped by how many followers saw the post. TikTok serves videos to strangers at scale, so the denominator (views) is huge and the ER is about whether content earns the next push.
Resonance, not retention
Shares and rewatches drive the loop more than likes do. Measuring them explicitly — via share rate and per-1k interactions — separates content that merely performs from content the algorithm compounds.
Frequently asked questions
By views, 3–9% is typical — higher than Instagram because TikTok's reach is algorithmic and non-follower. Above 15% is outstanding.
The denominator is views, not followers, so most of the audience never follows you. That makes ER a measure of content, not audience loyalty.
Shares are a direct distribution signal — each one hands the video to a fresh audience and drops it into a new recommendation pool.