# How Active View metrics are calculated

Learn the basics of Active View measurement

Active View metrics are calculated by finding the percentage of total impressions served that are actually viewable impressions:

• From the total impressions served, a certain percentage are eligible impressions.
• From those eligible impressions, a certain percentage are measurable impressions.
• From those measurable impressions, a certain percentage are viewable impressions.

## Active View measurement terminology

• Eligible impressions: Impressions associated with an Active View-enabled ad tag that have successfully communicated with Google’s servers.
• Measurable impressions: Impressions that can actually be measured with Active View technology; a subset of all eligible impressions.
• Viewable impressions: Impressions that were considered viewable based on MRC standards; a subset of measurable impressions.

#### Example

Measurable %

From the 1,000,000 total impressions served, 900,000 of those impressions are eligible for Active View.
From the 900,000 eligible impressions, only 800,000 are measurable. The following formula is used to calculate measurable %:

• Measurable impressions (800,000) / Eligible impressions (900,000) = 88.88%

This means that almost 89% of your eligible impressions are measurable by Active View.

Viewable %

Of these 800,000 measurable impressions, only 350,000 are viewable. The following formula is used to calculate viewable %:

• Viewable impressions (350,000) / Measurable impressions (800,000) = 43.75%

This means that almost 44% of your measurable impressions are viewable⁠—the impressions appeared within a user’s browser and had the opportunity to be seen.

The number of impressions for AMP pages viewability may differ from GPT viewability. Learn more about how AMP viewability is measured