Last updated Jan 13 2020
Google Analytics dimensions and metrics
Metrics and dimensions are the building blocks of Google Analytics that help you segment, organize, and analyze your traffic data—so let's dive into the distinction between the two, and how they can be combined.
✍️Editor's note: after covering dimensions and metrics, we’ll also take a look at why even the most powerful combinations of the two won’t be enough to tell you what’s really happening on your website. Keep reading!
What’s the difference between metrics and dimensions?
Google Analytics reports are made of dimensions and metrics. Throughout most reports, metrics are the quantitative measurements of data and dimensions are the labels used to describe them—or, in even easier terms: metrics are always expressed by numbers (number values, %, $, time), while dimensions are expressed by non-numerical values.
Now let’s drill down into each separately.
What is a dimension in Google Analytics?
Dimensions are the attributes that can be used to describe and segment, organize, and sort the data by. Examples of dimensions include:
- Device Category
Each dimension accepts different values: for example, the dimension ‘Device Category’ indicates the type of device used to visit a website, accepts ‘desktop, mobile, and tablet’ as values, and can help sort traffic between the three devices.
Primary and secondary dimensions
Each GA report comes with a pre-selected primary dimension that gives high-level insight into how the dimension performs in relation to a set of metrics.
Across most reports, a full list of dimensions can be seen by clicking on ‘Other’ in the Primary Dimension menu and scrolling through the drop-down option. To change the primary dimension, users can pick the most relevant one from the list of all available options.
While primary dimensions appear by default, secondary dimensions can be added to further drill down into the data.
For example: using ‘Device Category’ as a primary dimension, your data can be sorted across the values of desktop, mobile, and tablet:
But applying ‘Browser’ as a secondary dimension from the ‘Secondary dimension’ drop-down menu means that now you can also review how different browsers perform on each device:
In addition to using default dimensions, GA users can create custom dimensions to collect and measure data the tool wouldn’t automatically track—for example, information stored in a Customer Relationship Management (CRM) system that can be synced with GA data. Custom dimensions are particularly relevant for ecommerce owners, who can review data points like the total value of unpurchased items in a cart or the difference in the behavior of logged-in vs. guest customers.
Things get quite technical at this point, and Google has an exhaustive list of prerequisites and configuration options to introduce custom dimensions into your account.
What is a metric in Google Analytics?
Metrics are expressed through numbers (number values, %, $, time) in a Google Analytics report: they are quantitative measurements of data and show how a website is performing in relation to a specific dimension.
For example, the number of ‘Users’ who came from desktop, mobile, and tablet devices and their ‘Average Session Duration’ are metrics for the Device Category dimension:
Common GA metrics
The most common metrics in GA—that is, the ones you see by default as you log into GA—are usually grouped into Acquisition, Behavior, and Conversions metrics:
1. Acquisition-related metrics answer questions such as: how did people get here, and who are they?
- Users → the visitors who initiated at least one session in the date range of interest
- New users → the number of first-time users (as opposed to returning ones) in the date range
- Sessions → Google Analytics starts recording a session whenever someone visits a website and terminates it after 30 minutes of inactivity. GA keeps track of all user interactions that take place within that specified time frame.
2. Behavior-related metrics answer questions such as: how did people behave once they got here?
- Bounce Rate → the percentage of all single-page where the Analytics server did not record any interactions (e.g. where the visitor landed and left without clicking on any links and navigating to a second page)
- % Exit → the number of exits / number of pageviews for the specified page
- Pages/Session → the average number of pages viewed within a single session
- Session Duration → the average length of a session
3. Conversion-related metrics answer questions such as: how many people did convert, and how much revenue did we get?
- Ecommerce conversion rate → the percentage of sessions that included an ecommerce transaction
- Transactions → the number of transactions (i.e. completed purchases) that took place
- Revenue → the amount of money generated from the transactions
What metrics and dimensions alone can’t tell you
We promised at the top of the page that we’d dig a bit deeper into why dimensions and metrics in GA paint an incomplete picture.
First of all: dimensions and metrics are incredibly useful to help you understand the performance of your site as a whole and any of its individual pages. They help you:
- Map out your website ecosystem, showing you where users are coming from and how they move through your site
- Compare behaviors across segments, so you can review performance across different groups (e.g. desktop vs. mobile users, conversion rate across landing pages, etc.)
- Identify priorities and quantify their impact, so you can determine which pages have the potential of the biggest impact on your company’s growth goals, and optimize accordingly
However: while GA helps you keep the ultimate log of everything that is happening on your website, it still can’t tell you exactly WHY your visitors behave in the way they do.
Practical example: you learn from looking at your GA metrics that one of your newest product pages has a 75% exit rate, meaning 7.5 out of 10 people who make it there leave the website:
You can dig into the data using different dimensions (e.g. Device Category, City, Traffic Source) and form a few plausible hypotheses, but you cannot really know for sure:
- What people were actually looking for at that point
- If they left because the product was not what they needed
- If they left because the product was what they needed but they had questions about it that the page didn’t answer
- If they left because the product was what they needed, they had no further questions, but something didn’t work on the page
- If they left because the product was what they needed, they had no further questions, they even added it to cart, but something made them think your website was not trustworthy and they decided to look elsewhere
- And so on—you see where this is going.
Find out what the numbers alone don’t tell you
If you are looking to dig deeper into the drivers behind your customers’ behavior, the barriers they experience as they navigate across your site, and the hooks that ultimately get them to convert, you’ll want to combine the insights you get from GA with behavior analytics and feedback tools. They include:
- Heat maps, which reveal aggregate visitor behavior on individual pages, showing which buttons and CTAs receive the most and least interactions and whether people scroll down to the bottom of the page or fail to progress below the fold
- Session recordings, which are renderings real actions visitors take on your website such as tapping on buttons, clicking repeatedly on elements that don’t work, and navigating between pages—so you can get a sense of how they can interact with the site during the entire journey
GA + behavior analytics = 🔥
Don’t stop at dimension and metrics: there’s a lot more to find out about your website visitors, and tools like heatmaps, session recordings, and on-site surveys help you dig deeper and get to know them better. When you combine the data pulled from GA with the insight collected from behavior analytics tools, you’ll start getting a complete picture of:
- The DRIVERS that bring people to your website
- The BARRIERS that might stop them or make them leave
- The HOOKS that persuade them to convert
and change, fix, update, optimize, and/or improve your website accordingly (read more about this framework).
Go beyond dimensions and metrics
Grab a free Hotjar trial, set up Heatmaps, Recodings, and Polls and see what people actually do on your site.Free forever. Get started!