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OOH Impression Calculation Formula for Digital Billboards

For most screens, Lucit uses the average daily impressions number to generate a number of impressions for each play that happens on your screens

This document describes the process for calculating digital out-of-home impressions using an avg daily number. If your digital signage software supports sending real-time impressions for every play or hourly impressions, then this document does not apply to you.


  • Play sometimes called a Spot, is when your creative appears on screen for the alloted slot length for that screen.

  • Slot Length   Typically this is anywhere from 7 to 15 seconds depending on the settings for your screen. This is how long each individual ad appears on the screen before switching to a new ad.

  • Avg Daily Impressions The average daily impressions is the TOTAL impressions (on average) that your screen receives in a day. If you have been provided a Weekly Impression Number, you can divide that by 7 DAILY_IMPRESSION = (WEEKLY_IMPRESSIONS / 7) to get the Avg Daily Impressions number

  • 86,400 - This is the total number of seconds in 1 day (24x60x60)

  • Time On Screen : Total amount of seconds that your ad was on screen.

Impressions per Play

From these numbers, you can calculate the number of impressions for a single play.


For example, let's use:

  • Avg Daily Impressions : 52,000

  • Slot Length : 8 seconds

Your average impressions per spot will be

(52,000 / 86,400 ) x 8 = 4.81 impressions per play

Total Impressions

Using this number, you can calculate the total impressions for a campaign based on the total number of plays

If a campaign received 40,000 plays in a 4 week period

40,000 * 4.81 = 192,000 impressions

Time on Screen

The total time on screen for your campaign is simply


Using our example of 40,000 plays and an 8 second slot length

40,000 x 8 = 320,000 seconds = 88 Hours, 53 Minutes, 16 Seconds


These numbers are all based on averages over the course of a campaign, and because of the nature of digital billboards, the math is a bit different than just calculating total impressions for a static billboard over the course of a week


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