Updated Formulas on TikTok
Lefty’s updated TikTok Engagement Rate shows real performance by tracking engagements per view, giving you clearer insights into influencer impact.

At Lefty, we’re committed to helping brands and agencies measure influencer performance with precision and transparency. Today, we’re excited to share an important update that will improve the way you analyze your TikTok campaigns: a new formula for calculating Engagement Rate.
This change ensures that your reporting reflects the true virality and reach of your influencers’ content, so you can make better decisions, optimize strategy, and demonstrate ROI with confidence.
What's Changing?
Effective at the end of July 2025, Lefty’s TikTok Engagement Rate calculation will switch from:
Engagements / Followers
to:
Engagements / Views
This means ER will now be based on the total number of people who actually watched a video, rather than just how many followers an influencer has.
Why Update the Engagement Rate Formula?
Unlike other social platforms, TikTok’s algorithm is designed to push content far beyond an influencer’s immediate follower base. A creator with a modest following can reach millions of viewers if their video gains traction.
By calculating Engagement Rate based on views, we’re capturing this virality factor—so your reports better reflect true audience engagement and content performance.
Key benefits:
- More accurate measurement of influencer impact
- Better understanding of content reach and virality
- Clearer benchmarks for optimizing campaigns
This update is the first step in a broader evolution of performance measurement on Lefty. In the coming months, we may introduce a Virality Score for TikTok, calculated as:
Impressions / Followers
This new metric will help you understand how effectively content spreads beyond an influencer’s audience.
Additionally, since Instagram Reels also have high virality potential, we are exploring similar changes to Engagement Rate calculations for Reels in the future.
What Does This Mean for Your Campaigns?
Your historical TikTok data will remain accessible in the platform. Moving forward, all new Engagement Rate metrics will use the updated formula. We recommend aligning your internal reporting and benchmarks to reflect this more accurate approach.
If you have questions or feedback, our team is here to help.