Here’s a common question we get all the time- What exactly is a dimension when referring to Google Analytics? And thus, today’s short lesson on dimensions.

But first, here’s why you need to know this- Custom Reporting. That’s it! Google allows you to create custom reports (in Google Analytics or using tools like Google Data Studio) and it’s important to understand these concepts as to avoid creation reports which actually make no sense (and this is totally possible, no warning message to let you know you’re doing it!).  So understanding what dimensions are and what dimension/metric scope is will help you make sure that you pair the right dimensions and metrics to get the data view which you intend.

That said, if you have no plans at Google Analytics custom reporting, understanding dimensions is a great thing anyway!

Definition of a Dimension

Google Analytics dimensions are defined in short as data attributes. An easier way to think of dimensions are simple- Dimensions are non-quantitative values in Google Analytics reports.  Here’s a pretty picture to illustrate:


Examples of Google Analytics Dimensions

Sometimes the best way to explain a concept is with examples. Here is a list of just a few dimensions which are available in Google Analytics:

  • Campaign
  • Source
  • Medium
  • Device Category
  • Gender
  • Ad Content
  • Keyword
  • Day of Week
  • Month of Year
  • And 100s more!

What is the Difference Between a Dimension and a Metric?

Since dimensions are non-quantitative (they are NOT calculations), the are paired with metrics which ARE the calculations. So in the above example, if gender is the dimension, the metrics are all the calculations such as users, new users, sessions, etc…

How Do Dimensions and Metrics “Work” Together?

By now, you may realize that dimensions and metrics are paired together in tables (like above), bar charts, etc. Together, they tell the whole data story.

It’s important to note though that in Google Analytics, you cannot just combine any dimension with any metric! This is because of a concept called SCOPE. Scope basically defines the way which data is calculate and comes in three forms:

1: Hit-Level Dimensions and Metrics

Hit-level dimensions and metrics represent the individual interactions during the session, made by the user.

Samples of Hit-Level Dimensions

  • Page
  • Hostname
  • Event Category

Samples of Hit-Level Metrics

  • Pageview
  • Time on Page
  • Total Events

2: Session-Level Dimensions + Metrics

Session-level dimensions and metrics represent the aggregate of all the hits within the entire session.

Samples of Session-Level Dimensions

  • Landing Page
  • Source
  • Medium
  • Campaign

Samples of Session-Level Metrics

  • Bounce Rate
  • New Users
  • Average Session Duration

3: User Level Dimensions + Metrics

User-level dimensions and metrics represent the aggregate of all the sessions.

Samples of User-Level Dimensions

  • Age
  • Gender
  • Location

Samples of User-Level Metrics

  • Users
  • New Users

If you’re a total nerd and really want to understand all dimensions and metrics, we recommend you explore Google’s Dimension and Metric Explorer. Very cool and has way more information that you’ll likely ever need!

Question about GA Dimensions? Comment below!

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