Formula: Engagement rate = (likes + comments + shares) ÷ base × 100, where base is views or subscribers. It shows how many viewers or subscribers interacted with the video. The benchmark label is only a rough, general guide (for views: under 2% low, 2–5% typical, 5–8% good, above 8% high); real results vary by niche, audience, and video age, and nothing here predicts future performance.