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, although this is still being debated.

We have provided two useful calculators below to work out your Viewability Rate as well as the number of Viewable Impressions you will have for any given Viewability Rate. Feel free to experiment with different scenarios in order to help you better understand this metric.

## Viewability Rate Formula

The Viewability Rate equation is:

*Viewability rate is expressed as a percentage, so for easy of use x 100 is added to the above equation.*

**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.

## Our Viewability Rate Calculators:

if you know how many viewable impressions vs measured ad impressions you have then you can work out your viewability rate:

## Viewability Rate Calculator

Once you have your overall percentage, you can use this calculator for individual deals:

## Viewable Impressions Calculator

*Find out more*

### ★ Viewability Rate Definition

### ★ CPvM Definition