In advertising, reaching the right audience is critical to the success of your advertisements. To make the best media planning decisions, it’s also super important to know how many people you will reach with your advertisements before they run. This will enable you to reach your desired audience with the most cost effective media plan.

But estimating the reach of the advertising placements in your media plan is no easy task. Bionic can help.

Difference between Reach and Impressions

Reach and impressions can be a source of confusion to advertising newbies or to clients and coworkers whose expertise lies elsewhere. The key difference is:

  • Impressions count the number of exposures to an advertisement.
  • Reach counts the number of unique individuals exposed to an advertisement.

Here’s a simple story you can use to help explain: A spot is placed on Jeopardy and Steve sees it on Monday. Steve’s exposure to the spot is counted as one person reached and one impression. When Steve sees the spot again on Thursday your reach will remain at one since Steve already saw the advertisement on Monday, but your impressions will increase to two.

Counting vs. Estimating Reach

If you have already run your advertisement and have the exposure data, calculating reach and impressions is simply a matter of adding up the exposures and unique exposures.  But how do you estimate your reach before you run your advertisement?  In other words, how do you predict the future? This is critical when media planning and making investment decisions.  Unfortunately, this is also where the math gets tricky.

Estimating Advertising Reach is Tricky

Anyone who has ever tried to estimate reach will tell you that it’s a complicated endeavor. There’s no exactly right way to do it. Unlike GRPs and other advertising calculations, you can’t simply look it up in an advertising textbook and find one universal formula. The math is complicated and there are many different opinions and approaches on how to best calculate advertising reach. Some advertising experts have even dedicated significant chunks of their career developing a better reach formula.

How to Estimate Reach with Bionic Media Planning Software

Thankfully, you no longer have to be a math wizard to estimate reach when media planning. As part of the July 2016 upgrade of the Bionic Media Planning Software (version 2.29) new “Reach %” and “Reach #” fields now do the calculations directly in your media plan.

  • Reach % estimates the percentage of the population that will be exposed to your advertising placement during the course of the campaign.
  • Reach # estimates the actual number of individuals who will be exposed to your advertising placement during the course of the campaign.

When you are in your media plan on a Radio or TV placement, if it’s not already entered on your behalf, simply enter your Population, Rating, and Number of Spots and your reach numbers will magically calculate.


Actually, I lied. It’s not magic. It’s just computer logic. Here’s how it works…

How Bionic Estimates Advertising Reach (in version 2.29)

In July 2016, Bionic introduced a bunch of functionality related to ratings in its version 2.29. It was a big software upgrade and many of you were anxious to get it. As such, we did not want to get bogged down with a complicated reach model. Instead, we went with a basic and typical calculation based on the Binomial Distribution Model.


Reach %

Reach % is the percentage of the Population reached by the advertisement.  Keep in mind if you broadcast 20 advertisements, many people will be exposed to the advertisement more than once. It is calculated as follows:


Reach #

Reach # is the number of people exposed to the advertisement. It is calculated as follows:


Plans for Improvements to the Reach Calculation

The Binomial Distribution Model is just one of many ways to estimate advertising reach.  Although the current reach calculation gets you into the right ballpark, it’s not the best approximation of reach in the real world of advertising. I will elaborate on this in a future article.

We’re already working on alternative reach estimation models. We’d love your input. How do you calculate reach?  How would you like Bionic to calculate reach for you?

How to Get the Advertising Reach Calculator

If you’re already using Bionic media planning software, your account has already been upgraded with this new reach estimation feature. Your account was updated last week as part of your standard Bionic subscription which includes free and automatic upgrades.  You will notice the new reach calculations on your media plans with TV or Radio placements. To get help with this new feature, contact your Customer Success Team at or (603) 676-7285.

If you don’t yet have access to Bionic, you can request a 14-day trial.