Viewability Rate [VR]

What is a Viewability Rate?

Viewability Rate is the percentage of ads which are actually seen by a user.

By this we mean, the viewability rate is the percentage of ad impressions which count as being viewed. A viewed impression is described as being at least 50% on screen for one second. For example if a website has 10 ad impressions, of which five are counted as viewable, then the site will have a Viewability Rate of 50%.

Calculator IconWork out the VR of your website with our Viewability Rate Calculator >

What does Viewability Rate mean?

Viewability Rate is a new advertising metric which defines how many of ad impressions on a site are actually viewed by users. The standard definition is that any ad which is at least 50% on screen for one second counts as being viewed. This definition is still being debated however.

This metric is important as the ad pricing model CPvM only pays out on viewable impressions.


Viewability Rate Formula

The Viewability Rate equation is:

Viewability Rate Formula

Click to enlarge

Viewability Rate = (Viewable Ad Impressions / Ad Impressions) x 100


Note: “Measured ad impressions” are used in the above formula (as opposed to regular ad impressions). This is because viewability/verification vendors are unable to measure 100% of total ad impressions. As a result measured ad impressions are always lower than ad impressions.

Measured ad impressions are simply the amount of ad impressions measured by a company.


What it looks like

What a viewable ad impression looks likeClick to enlarge


Top Tip

Place your ads above the fold to make sure your ads are all viewable. This will help even for users who don’t scroll down.


Find out more

Viewability Rate Calculator

CPvM Definition

Author: Justin Driskill

Justin is the founder of The Online Advertising Guide and a freelance Digital Projects Manager.

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