Dimensions come in all sorts of shapes and sizes — literally. There are the dimensions you double check when buying furniture for your home. There are the multitude of dimensions from your favorite cinematic comic book universe. And there are the dimensions we encounter within Google Analytics.
While dimensions were a component of Universal Analytics, their significance has been amplified with the introduction of Google Analytics 4. This is mainly because GA4 introduces a range of new dimensions and metrics that were not available in the previous version. This has prompted marketers to question, "What exactly is a dimension in GA4?" and "How does it differ from a metric?"
Wonder no more. Today, we're going to break it all down for you.
Dimensions vs. metrics
You'll find both dimensions and metrics in your reports, audience, and segment builders on GA4. So, what are they?
- Metrics are quantitative measurements — things you can actually measure, such as pages per session or the number of page views. You'll find dozens of metrics on GA4 for advertising, e-commerce, events, revenue, and more.
- Dimensions are data attributes that tell you more about the people visiting your website. For example, Google calls the gender of your website visitors a dimension. If 100,000 people visit your website, you can find out how many of those people are male or female.
Data generated from gender dimension and sessions metric
One way to understand this concept is to imagine it as a table. The table would have a metric, like the number of sessions or users, and it could be organized or divided into different categories or segments based on dimensions such as traffic source, geography, or platform device. See the example below that shows the metric (new users and sessions) broken down by the dimension traffic source.
Screenshot taken from Funnel's Data Explorer.
With that said, dimensions can help you reveal all kinds of attributes and characteristics of website visitors. You can choose different dimensions based on your specific marketing objectives. Here is a selection of default dimensions available in Google Analytics:
- City: The city from which a visitor originates
- Browser: The internet browser used by a visitor
- Device Category: The type of mobile device used by a visitor
- First user campaign: The marketing campaign that acquired the visitor
- Page location: The URL of one of your websites pages
- Percent scrolled: The percentage of the page on your website that the visitor scrolled
- Item coupon: The coupon code used by a website visitor
This is just the tip of the iceberg, though. You'll find dimensions for demographics, traffic sources, attributions, events, and much more. Check out this full list of dimensions and metrics.
Dimension name vs dimension value
A quick example to explain what is meant with 'dimension value' is the dimension 'Country'. The Dimension name is Country, and some dimension values for that dimension can be:
- United States
- United Kingdom
- India
It works similar with metrics. For example, the metric 'Users' may have a numerical value of 700 on Sunday, and 1260 on Monday.
It's important to note that Google Analytics dimensions are non-quantitative, because (unlike metrics) they are not calculations. There are some exceptions, though. For example the dimension 'Screen resolution', which has dimension values such as '1920x1080'. It is a numerical value, but it is still a dimension.
Getting started with dimensions in Google Analytics 4
You can view dimensions in Google Analytics in many different locations, including:
- In the left-hand columns of the data tables on your dashboard, which you can find by scrolling down past the graphs.
- By clicking on "Explore" in the left-hand menu and selecting dimensions.
- Using the Google Analytics Data API, which allows you to access your dimensions information from outside of Google Analytics. This can be helpful if you prefer to view data insights on a third-party platform like Funnel.
You can automatically populate some dimensions on reports and explorations in GA4. Other times, you'll need to populate dimensions using parameters. For example, if you want to use the "method" dimension, which tells you the method a website visitor used to sign up or log into your website, you'll need to populate the dimension with the method parameter.
Also, not all Google Analytics dimensions operate with all metrics, and vice versa. If you notice a dimension or metric is grayed out, it means it's incompatible with another dimension or metric you selected. You'll learn what combinations work well together as you become more familiar with GA4.
Analytics may prevent selecting dimensions or metrics in explorations by graying them out.
If you see "No data available" or a warning that the request is incompatible, it means there's no data for the specified criteria.
How metrics and dimensions work together
The trick is to combine dimensions and metrics to get a more comprehensive overview of all your website visitor data. Dimensions add extra context to the metrics you already use in Google Analytics, such as page views and customer churn. This context helps you learn about user behavior on your website.
Say you want to find out how many pages per session that males have accessed on your site compared to females. You can combine a dimension (in this case, gender) with a metric (pages/session) to learn this information.
Using secondary dimensions
Using a secondary dimension allows you to dive deeper than with just a single dimension, and create smaller 'buckets'.
As an example, say you want to know how many people visited your website after clicking an ad in a social media channel in the US vs the UK. You can see this by combining Google Analytics dimension 'Session default channel group' (known as the primary dimension) with the dimension 'Country' (the secondary dimension) with the metric 'sessions' to unlock this insight.
The primary dimension 'Session default channel group' is combined with 'Country' to get more granular data.
Standard reports
If you don't want to manually choose dimensions and metrics and just want an overview of your marketing, you can use GA4's reports. For example, you could use the user acquisition Google Analytics report to learn how many new people found your website and visited it for the first time. This report contains primary and secondary dimensions, such as:
- First user/source medium: The source and medium that resulted in new users arriving on your website
- First user campaign: The campaign that leads to new users arriving on your site
- First user Google Ads ad network type: The location of your ad that leads to new users arriving on your site
Track new user discovery with the User Acquisition Report.
Google Analytics custom dimensions
Default GA4 dimensions are available for you to use right now, like those listed earlier in this guide. Custom dimensions let you analyze data that GA4 doesn't track out of the box. Then, you can dig deeper into how customers interact with your website and other online properties.
For example, you can create a custom dimension to understand if visitors have logged into your website or not. Or you might want to create custom dimensions to learn about users in the experiment variant of an A/B test.
You can create a custom dimension or metric by importing the data you want to analyze via a tracking code or the Google Analytics API. Just be aware that Google Analytics imposes limits on the number of custom dimensions and metrics for both premium and standard properties. For example, you can only create 25 user-scoped custom Google Analytics dimensions — dimensions that analyze user attributes on your website — in your Google Analytics account.
Also, if you want to more flexibility when creating custom metrics and dimensions, consider moving Google Analytics data to a third-party platform like Funnel. Funnel makes it possible to organize and transform your data, giving you more insights into your marketing performance and at the same time saving a lot of time on reporting.
Why you should know the difference between dimensions vs. metrics in Google Analytics
Knowing the difference between dimensions and metrics in Google Analytics is essential for every marketer. Combining them together allows you to create smaller buckets of data, and compare those buckets with each other. This way you'll generate more intelligence about your website and the people who use it. GA4 has plenty of dimensions and metrics already built into the platform and will likely add more as time goes on. Play around with the platform and see if you can track entire customer journeys from start to finish.
If you get stuck with dimensions and metrics, Google has plenty of resources—for example, step-by-step guides and video tutorials about how to set up custom dimensions. You can also check out Funnel's content library for more information about getting the most from GA4.
You may also find this interesting: How to diagnose Google Ads performance drops
