GA4 (formally GA App + web) is the latest version of the analytics platform provided by Google. While the product isn’t complete yet, it is certainly where Google is focusing development effort and should be considered as part of your measurement strategy. If you are thinking what is GA4? – take a look at an earlier post providing an introduction here.

In this post I want to focus on one of the obvious missing metrics in GA4, conversion rate. If you’ve used pretty much any web analytics solution in the past you will know one of the key performance indicators (KPIs) is conversion rate. How many of the sessions that visit your website convert to the desired goal you have. In ecommerce this will most likely be a purchase, if your website is focused on generating leads this will be form submissions or contact page viewed.

Conversion rate can be measured by implementing a Goal or Ecommerce tracking in GA3, the conversions and rate then exists in all core reports.

Setup a conversion in GA4

In GA4 conversions are created in the ‘Configure’ menu, GA4 is an event-based model so first you need to create an event before marking it as a conversion.

GA4 provides several events automatically, page_view, first_visit, scroll and file_download are few examples. Most likely you will need to identify a parameter that will be available in the data layer. In this example I’m looking at an ecommerce site so have setup an event to look for the ‘purchase’ parameter. Once setup you simply check the box to mark the event as a conversion.

Once marked as a conversion you then see this appearing in the reports, though the obvious missing value is the rate at which these conversions occur.

One reason for leaving this metric out of GA4 could be related to the move from a session-based data model to an event model. However, the concept of a session does still exist in GA4 and there is also the possibility to use another metric in ‘Total Users’ to calculate conversion rate.

There are pros and cons to using conversion rate as a primary KPI, but I don’t think it can be denied as being one of the most used metrics in ecommerce, marketing and lead focused optimisation.

GA4 Conversion Rate - how to use it

We have two options to measure conversion rate using GA4 data

Export the table into Excel or Google Sheets and calculate the metric outside of GA.
Use Data Studio to create a custom metric (Conversion Rate). Here is some sample data I’ve been looking at in Data Studio comparing GA3 (Universal) and GA4 for the same website.

If you have any questions or would like to discuss your own website measurement strategy get in touch.