A Guide to Conversion rate in Google Analytics 4

Updated: January 28th, 2023

When Google Analytics 4 was introduced, it was missing one very important metric that many people relied on in GA3, conversion rate (CR).

Even though we could see the total number of conversions, that was not enough (because the CR allowed us to see the percentage of sessions that were performing well).

Fortunately, those days are now gone, and we can use conversion rates once again. But beware, there are some changes in GA4, and I will explain them in this blog post.

 

Table of contents

– Hide table of contents –

• What is conversion?
• What is the conversion rate?
• Two types of CR in Google Analytics 4
• Session conversion rate
• User conversion rate
• Standard GA4 reports
• Building an exploration with CR
• Final words

 

Video tutorial

If you prefer video content, here’s a tutorial from my Youtube channel.

 

What is conversion?

A conversion is an important action that a visitor/user completes on a site/app. The most popular example is a purchase. Most businesses exist to serve their customers (hopefully) and generate revenue. Therefore, their goal is to generate as many sales (purchases) as possible.

If a company wants to measure its success, it has to measure purchases as conversions.

Other examples of conversions can be (but don’t limit yourself just to these):

• When someone signs up for a webinar
• When someone subscribes to a newsletter

You can learn more about conversions here.

 

What is the conversion rate?

In previous Google Analytics versions, the conversion rate was calculated like this:

Sessions with conversions divided by all sessions.

That way, you can know the percentage of how many sessions had a conversion.

But in GA4, there is a welcome upgrade. I will explain that in a moment.

 

Two types of conversion rates in Google Analytics 4

In Google Analytics 4, there are 2 types of conversions:

• Session conversion rate. This is the same as we had in the previous GA versions.
• User conversion rate where we divide users (who converted at least once) by all users

 

Session conversion rate

The session conversion rate is calculated by dividing the number of sessions with a conversion event by the total number of users.

To understand this concept better, let me give you an example.

Let’s say that we have a user who first came to your website from a Google search, and the next time he/she came from an email newsletter. Traffic sources don’t matter much in this case. In that second session, the user converted.

In total, we have two sessions, and one of them had a conversion.

That’s a 50% session CR.

Then we have a second user who landed on your website from a paid ad (google / cpc) and converted. Then in the next session, the user also converted. In this case, we have two sessions in total and two sessions with conversions.

That’s a 100% session CR (because 2 out of 2 sessions had a conversion).

In total, we had 4 sessions, and 3 of them contained conversions.

3 / 4 x 100% = $75% session CR.

But this logic has one flaw.

What if your goal is to convert the visitor/user once? All subsequent sessions/conversions don’t matter to you (but every additional visit still continues to reduce your session conversion rate).

That’s where user conversion rate becomes very useful.

 

User conversion rate

User conversion rate is all about users. If a user converts, the user conversion rate increases. But if, after that, the user keeps coming to your website, the rate stays the same (because the user has already converted in the past).

The user conversion rate is calculated by dividing the number of users who triggered any conversion event by the total number of users.

Let me explain this metric with a visual example.

A visitor comes to our website from a Google search (google / organic) and then comes back the next day from an email newsletter. None of those sessions had a conversion event. Thus the user conversion rate is 0% because there is one user and 0 users who converted.

0 / 1 x 100% = 0%.

A second visitor comes to our website and converts on the first session. Then in the next session, the visitor converts again.

We have 1 user, and that 1 user converted at least once.

1 / 1 x 100% = 100%

If we sum up the sessions of both users, we get 2 users in total and one user who had at least one conversion. 1 / 2 x 100% = 50%.

If the 2nd visitor comes back to our site once more (but does not complete a conversion event), the user conversion rate will still be 100% for that user (because that user has already converted in the past).

 

Conversion rate in standard GA4 reports

To include conversion rates in standard reports, you will need to customize them.

Go to Reports > Acquisition > Traffic acquisition and click the Pencil icon in the top-right corner.

Then click on Metrics and keep looking for the Session conversion rate.

Click Add metric. 

And keep looking for Session conversion rate. Click it and then hit Apply.

Finally, hit Save > Save changes to current report > Save. And that’s it! Now you have the session conversion rate in your traffic acquisition reports (that are session-scoped).

You can even select in the dropdown whether you want to view the CR of all conversions or just a particular event.

The same customization process applies to the User conversion rate.

 

Build an exploration with conversion rates

Let’s use conversion rate in custom GA4 reports, a.k.a. Explorations. Let’s start with the sessions.

 

Session conversion rate

On the left sidebar, go to Explore and click Blank.

Let’s build a report of session source/medium and session conversion rates.

In the Variables column of your Free form exploration, click a plus in the Dimensions section.

Select Session source / medium and hit Import.

Important: don’t use the regular “Source/medium” dimension. If you want to see data of your *sessions*, you must use a dimension that contains *session* in its title.

Now, click the Plus next to the Metrics and select metrics you want to include in the report, for example, Sessions, Total users, Conversions, Session conversion rate. Click Import.

Then drag the Session source / medium to the Rows section and all metrics to Values.

And that’s it! You now see the list of your top-performing sources, mediums, and their conversion rates.

Note. You probably remember the formula of the Session conversion rate: sessions with conversions divided by all sessions. But if you divide the number of conversions by the number of all sessions (that you see in the report), the result will not match session CR. Why?

It’s because the Conversions column includes *all* conversions. Even if 1 session had 5 conversions, all 5 conversions would be included in the Conversions column. But only 1 session, in this case, will be used by the Session conversion rate metric.

 

User conversion rate

Let’s add one more metric. Click the Plus icon in the Metrics section:

And import User conversion rate. Add it to the report.

An additional column will appear, and you will notice that this metric is higher compared to the session conversion rate.

That’s because the User CR checks the number of users who converted. If the same person has converted at least one, it will be included in the calculation. Sessions without conversions of that user are not taken into account.

 

Final words

Conversion rates allow us quickly evaluate the performance of marketing campaigns, channels, mediums, etc. The higher the percentage, the better.

If you are getting a lot of traffic from a particular traffic source, but your conversion metrics are much lower than average, this might indicate an ineffective marketing channel. Unfortunately, it’s impossible to give universal advice on what exactly should be fixed.

But with this metric, at least you know that *something* is wrong with that traffic source and something must be done by a company.

If you want to learn how to analyze conversion data and get insights, take a look at my Google Analytics 4 course, where I focus a lot on that.

Also, I really appreciate the addition of the user CR because working just with the session metric is not efficient.