What is ER in Telegram and how to calculate it
ER (Engagement Rate) is the key audience quality metric for Telegram channels. Formula: ER = (reactions + forwards + comments + star reactions) / views × 100%. Benchmarks: 3–5% is good, 5–10% is excellent, above 10% is exceptional. ER below 1% with more than 10,000 subscribers is a serious red flag for fake followers. Channel OS calculates ER automatically for every post and tracks trends over 7, 30-day and custom periods.