1. What data is used?
To ensure our metrics reflect current performance, Lefty calculates Engagement Rate using a rolling 90-day window.
Content: We analyze every non-story, non-co-authored feed post published in the last 90 calendar days.
Metrics: We use Likes, Comments, and (for videos) the latest View count.
Shares: Share counts are included only if the influencer has authenticated (opted-in) with Lefty, as this data is not public.
2. The Formulas: Video vs. Non-Video
We split content into two "buckets" because users interact with videos differently than static images.
A) Non-Video ER (Images & Carousels)
For standard posts, we use the industry-standard formula relative to audience size.
Formula:
(Average Likes + Average Comments) ÷ Follower Count
B) Video ER (Reels)
For video content, we calculate engagement relative to the actual number of people who saw the content (Views), rather than the total follower count.
Formula:
(Total Likes + Total Comments) ÷ Total Views
Why we use "Aggregated Average" for Videos:
Instead of averaging the percentages of individual videos, we sum the total engagements of all videos and divide by the sum of all views in the period.
This treats your video content as one large body of work.
It naturally weights the data so that a viral video with 1 million views carries more weight than a niche video with 1,000 views. This makes the metric robust against "outliers" (e.g., a video with 2 views and 1 like doesn't artificially spike your ER).
3. The Final Profile ER (Weighted Average)
To provide a single Engagement Rate for an Instagram profile, we combine the two buckets based on how often the influencer posts each type of content.
How to read this:
We take the ER for Images and multiply it by the number of Images posted.
We take the ER for Reels and multiply it by the number of Reels posted.
We add those together and divide by the total number of posts in the last 90 days.
Note: If a profile has no posts in the last 90 days, or if video views are hidden/unavailable, the Engagement Rate may appear as empty (N/A) until fresh data is collected.
On influencer profiles, Instagram Engagement Rate is displayed as separate Static ER and Video ER values in the right bar and Statistics tab, alongside the blended total. Hover over the ER value to see the breakdown and any data warnings (e.g. hidden likes, no recent content).
Note: search, filters, sorts, and the ER graph use the Blended Engagement Rate.
4. Engagement Rate in Exports
Export column names reflect the Static/Video split.
Instagram ER columns:
Blended Engagement Rate: the single weighted average, previously labeled "Engagement Rate"
Static Engagement Rate: ER calculated from images and carousels only
Video Engagement Rate: ER calculated from Reels only
Other renamed columns in this update:
The Perfs sheet in Directory exports is now called Influencers Stats
Distinct Influencers in Monitoring exports is now called Distinct Influencers Stats
If you use these exports in external tools or spreadsheets, update any column references before your next export.