GA4 Metrics List: What Each Metric Means, in 8 Groups

Open a GA4 report and you’ll see several metrics with similar names: Active users, Total users, New users. We counted the metrics in Google’s dimensions and metrics reference and got about 140 (as of October 2026).

This article groups them into 8 sets and lists what each one means and how it’s calculated, focusing on the metrics an online store (especially on Shopify) uses most. If you want to start with how to read GA4’s reports, read How to Use Google Analytics 4 for Ecommerce first.

Metrics vs dimensions

A GA4 report table has a column on the left and columns of numbers on the right.

	Dimensions	Metrics
What they are	How you split the data	What you count
Examples	Channel, page, item name, device	Sessions, users, revenue
Where they are in a table	The left column	The number columns to the right

This article is about metrics.

Metrics and dimensions have scopes

Each dimension and metric has a scope: whether it’s counted per user, per session, per event or per item. Purchases are a good example: Ecommerce purchases (event scope) counts orders, while Items purchased (item scope) counts product units.

Combining fields with different scopes can change what a number means, and some combinations aren’t allowed in Explorations. For example, with Item name in the rows of an exploration, you can’t use Purchase revenue or Ecommerce purchases. For how scopes work, see our GA4 custom dimensions guide.

Read GA4 metrics in 8 groups

Google’s help center sorts metrics into categories such as User, Session, Event, Ecommerce and Advertising. We’ve regrouped them into 8 sets based on how an online store uses them. Here’s the overview.

Diagram grouping GA4 metrics into 8 sets, each with the question it answers and its main metrics. Users: how many people came (Active users, Total users, New users). Sessions: how many visits (Sessions, Sessions per active user). Engagement: did visitors actually look (Engagement rate, Bounce rate, Average engagement time). Views and events: what was seen and what happened (Views, Event count). Key events: did it lead to outcomes (Key events, Session key event rate). Ecommerce: how much sold, and what (Purchase revenue, Ecommerce purchases, Item revenue). Advertising: was the ad spend worth it (Google Ads cost, clicks, cost per click). Lifetime: how much has each customer spent so far (LTV, Lifetime transactions). The ones online stores use most are Active users, Sessions, Engagement rate, Key events, Purchase revenue, Ecommerce purchases and Average purchase revenue. — The 8 groups of GA4 metrics (As of October 2026. Created by ULTRO Inc. based on Google Analytics Help's dimensions and metrics list. Click the image to enlarge.)

In table form, with links to more detail where we have it:

Group	Question it answers	Main metrics	More detail
Users	How many people came?	Active users, Total users, New users, Returning users	Users vs sessions
Sessions	How many visits?	Sessions, Sessions per active user	Users vs sessions
Engagement	Did visitors actually look?	Engagement rate, Bounce rate, Average engagement time
Views and events	What was seen and what happened?	Views, Event count	Users vs sessions
Key events	Did it lead to outcomes?	Key events, Session key event rate	Key events
Ecommerce	How much sold, and what?	Purchase revenue, Ecommerce purchases, Item revenue	This article
Advertising	Was the ad spend worth it?	Google Ads cost, Google Ads clicks, Google Ads cost per click	This article
Lifetime	How much has each customer spent so far?	LTV, Lifetime transactions	This article

The sections below go group by group, with what each metric means and how it’s calculated. Metric names follow the help center’s list; where reports use a different label, it’s noted.

User metrics

Metric	What it means	Watch out for
Active users	Distinct users who had an engaged session, or for whom GA4 collected first_visit or engagement time	“Users” in reports means this number
Total users	Unique users who logged any event	Higher than Active users
New users	Users who interacted with your site for the first time (logged first_visit)	Can be higher than Active users
Returning users	Users who had at least one previous session, engaged or not	New users plus returning users doesn’t equal Total users
DAU / MAU, DAU / WAU, WAU / MAU	Ratios of daily, 7-day and 30-day active users	A rough measure of how many people keep coming back

For how Active users differs from Total users, and why New users can exceed Active users, see our guide to GA4 users and sessions.

Session metrics

Metric	What it means	Watch out for
Sessions	Sessions that began on your site (session_start events)	By default, a new session starts after 30 minutes of inactivity
Sessions per active user	Sessions ÷ Active users	How many times each person visited during the period
Average session duration	Average length of sessions, in seconds	Google defines it only as the average session length in seconds; it isn’t based on in-focus time. To see whether people actually looked, use Average engagement time
Views per session	Average pages viewed per session	Repeated views of the same page count

For where sessions end and how to change the timeout, see our guide to GA4 users and sessions.

Engagement metrics

Metric	What it means	Watch out for
Engaged sessions	Sessions that lasted longer than 10 seconds, had a key event, or had 2 or more page views	10 seconds is the default; you can change it in Admin
Engagement rate	Engaged sessions ÷ Sessions	Break it down by source and by page
Bounce rate	Sessions that weren’t engaged ÷ Sessions (100% − engagement rate)	Defined differently from bounce rate in Universal Analytics
Average engagement time	Total time your site was in focus in the browser ÷ Active users	Shown in reports as “Average engagement time per active user”
Average engagement time per session	Total time in focus ÷ Sessions
Engaged sessions per active user	Engaged sessions ÷ Active users

View and event metrics

Metric	What it means	Watch out for
Views	Web pages or app screens viewed (page_view and screen_view events)	Repeated views of the same page count. The equivalent of pageviews in Universal Analytics
Views per active user	Views ÷ Active users
Event count	Times users triggered events	Use the “All events” dropdown above the table to narrow to one event
Events per session	Event count ÷ Sessions
Entrances	Times the first event of a session happened on a page	Which pages people arrived on
Exits	Times the last event of a session happened on a page	Which pages people left from

For how views and events are counted, see our guide to GA4 users and sessions.

Key event metrics

Metric	What it means	Watch out for
Key events	Times users triggered an event marked as a key event	Formerly “Conversions.” Narrow to purchase or another event above the table
Session key event rate	Share of sessions in which a key event happened	Narrowed to purchase, it’s the share of sessions with a purchase
User key event rate	Share of users who triggered a key event

For choosing key events, counting method settings and why GA4 doesn’t match Google Ads, see our guide to GA4 key events.

Ecommerce metrics

This is the group an online store uses most. For these to show data, events such as view_item, add_to_cart and purchase have to be sent with item information. On Shopify, they are if you’ve connected through the Google & YouTube app.

Revenue and orders: what is Total revenue? (event scope)

Total revenue is purchases plus in-app purchases, subscriptions and ad revenue, minus refunds. For sales on a web store, use Purchase revenue, right below it.

Metric	What it means	Watch out for
Total revenue	Purchases + in-app purchases + subscriptions + ad revenue − refunds	For a web store with no ad revenue, nearly the same as Purchase revenue
Purchase revenue	Purchases + in-app purchases + subscriptions − refunds	The one to use as ecommerce sales
Ecommerce purchases	Times users completed a purchase (purchase events)
Transactions	Completed purchases on your site	For a web store, nearly the same as Ecommerce purchases
Average purchase revenue	Average purchase revenue per purchase	Average order value, in effect
Refund amount	Total refunded	How much is coming back through returns and cancellations
Shipping amount, Tax amount	Shipping and tax sent with purchase events

Purchasers

Metric	What it means	Watch out for
Total purchasers	Users who made at least one purchase during the period	Listed under the User category in the help center
First time purchasers	Users who made their first purchase during the period	Whether new customers are growing
ARPU	Total revenue ÷ Active users	Revenue per user, including people who didn’t buy
ARPPU	Purchase revenue ÷ Active users who made a purchase	Revenue per paying user
Transactions per purchaser	Average purchases per buyer during the period	How many times each buyer bought

Products (item scope)

Product-level numbers go with item-scoped dimensions such as Item name. In Explorations, they can’t be combined with event-scoped metrics such as Purchase revenue and Ecommerce purchases.

Metric	What it means	Watch out for
Items viewed	Items viewed (view_item events with an items array)
Items added to cart	Items added to a cart
Items purchased	Units of each item included in purchase events
Item revenue	Price × quantity − refunds	Excludes tax and shipping, so it’s usually lower than Purchase revenue
Item discount amount	Item discount × quantity	How coupons and sales are working

You can see product-level numbers in the Ecommerce purchases report under Drive sales. How to read it is covered in How to Use Google Analytics 4 for Ecommerce.

Advertising metrics

Metric	What it means	Watch out for
Google Ads cost	Amount spent on Google Ads	Shows up once Google Ads is linked
Google Ads clicks, Google Ads impressions	Clicks on and impressions of your Google Ads
Google Ads cost per click	Average cost per click
Non-Google cost, Non-Google cost per click, and similar	Cost and clicks for other ad platforms, such as Meta	Only when you import cost data
Days to key event, Touchpoints to key event	Days from the ad interaction to the key event, and how many ad interactions it took	Found in the Attribution section of Advertising

Ad platforms and GA4 count differently, so their numbers won’t match. See our attribution guide for why.

Lifetime metrics

Metric	What it means	Watch out for
LTV	Total purchase revenue from a user since their first visit	Use a user lifetime exploration in Explore
Lifetime transactions	Completed purchases by a user since their first visit
Lifetime sessions, Lifetime engagement duration	Sessions since the first visit, and total engagement time

Lifetime metrics don’t appear in standard reports. You use them in a user lifetime exploration, for example to compare LTV by the source that first brought each user in. For how to use Explorations, see our guide to GA4 Explorations.

Which metric answers which question

Choosing by question is easier than starting from metric names.

What you want to know	Metric to use
How many people came	Active users
Whether new customers are coming	New users, First time purchasers
How many visits	Sessions
Whether visitors actually looked	Engagement rate, Average engagement time
Whether it led to outcomes	Key events, Session key event rate
How much sold	Purchase revenue
How much each order was worth	Average purchase revenue
Which products stall, and where	Items viewed, Items added to cart, Items purchased
Whether ads paid off	Google Ads cost, Purchase revenue (see also our ROAS guide)
Which sources bring in long-term customers	LTV (user lifetime exploration)

Ecommerce revenue breaks down into metrics

An online store’s revenue can be written as three metrics multiplied together:

Diagram splitting online store revenue into sessions × share of sessions that purchase × revenue per purchase. Sessions (GA4 metric: Sessions), example 10,000, review traffic acquisition. Share of sessions that purchase (GA4 metric: Session key event rate filtered to purchase), example 2%, review product pages, cart and checkout. Revenue per purchase (GA4 metric: Average purchase revenue), example $80, review pricing, bundles and free shipping thresholds. Revenue (GA4 metric: Purchase revenue), example $16,000. If the purchase share drops, split it into the add-to-cart rate and the cart-to-purchase rate to see where shoppers stop. — Splitting online store revenue into three metrics (Figures are illustrative. As of October 2026. Created by ULTRO Inc. based on Google Analytics Help. Click the image to enlarge.)

Broken out:

Component	GA4 metric	What to review when it moves
Sessions	Sessions	Traffic from ads, search, social and email
Share of sessions that purchase	Session key event rate (narrowed to purchase)	Product pages, cart and checkout
Revenue per purchase	Average purchase revenue	Pricing, bundles and free shipping thresholds

For example, 10,000 sessions with 2% purchasing at $80 per purchase comes to $16,000 in revenue (illustrative numbers). When revenue drops, find which of the three dropped and you’ll know whether to look at traffic, the site itself or order value. For more on the purchase share, see our ecommerce conversion rate guide.

Here’s how we take it further. When the purchase share drops, we split it further into Items added to cart ÷ Items viewed and Items purchased ÷ Items added to cart, to see whether shoppers stall on product pages or in the cart. To see exactly which step they drop off at, use a funnel exploration in Explore.

Once it’s split, pick one component to move. Trying to nudge all three up a little at a time rarely works. Separate what your team can actually change from what it can’t, and choose one of the things you can change. In our experience, it usually pays to raise the purchase share first and then grow sessions with ads, because every extra paid session is then worth more.

What to know when the numbers don’t match

The same metric can go by different names

Some metrics are labeled differently depending on where you look (as of October 2026):

Where you see it	Also called
Users (in reports)	Active users
Average engagement time per active user (in reports)	Average engagement time (help center)
Key events	Conversions (before March 2024)
Views	Pageviews (Universal Analytics)

The calculation is the same. That’s why articles online often seem to use different names for the same thing.

Fields with different scopes may not combine

If Purchase revenue and Item revenue don’t match, or you can’t put Item name next to Purchase revenue, scope is the reason. See our GA4 custom dimensions guide for how scopes work.

Users and sessions are estimates

Active users and sessions in GA4 reports aren’t exact counts; they’re estimated with a method called HyperLogLog++. That’s why daily numbers added up don’t match the number for the whole period. For details, see our guide to GA4 users and sessions.

Explorations can be sampled

When an exploration covers a lot of data, GA4 may apply sampling, estimating the whole from part of the data. When there are too many rows, some get grouped into “(other).”

Shopify defines things differently

Shopify’s sessions and visitors and GA4’s sessions and users are counted by different systems, so they won’t match. Comparing GA4 against itself, such as week over week, is more useful.

Purchase counts are also often lower in GA4. Purchases where the tag didn’t run in the browser, and orders that never go through a browser, such as POS orders or repeat subscription orders, don’t reach GA4. To reconcile them order by order, see GA4 Not Tracking All Shopify Purchases? We built a Shopify app for the browser-side gap, GapFill. It’s our own product, so read with that in mind. It recovers missing GA4 purchase events server-side, works alongside your existing tags, and the missing purchases report is free.

Our Shopify appGapFill: Recover missing GA4 purchase events server-sideWorks alongside your existing tags. Free missing purchases report.See GapFill →

Sources

FAQ

What's the difference between metrics and dimensions in GA4?

Dimensions are how you split the data: channel, page, item name, device and so on. Metrics are what you count: sessions, users, revenue and so on. In a report table, the left column is the dimension and the number columns to the right are metrics.

What does "Users" mean in GA4 reports?

Active users: people who had an engaged session or visited for the first time. It's a different metric from Total users, which counts everyone who logged at least one event.

Should I look at Total revenue or Purchase revenue?

For ecommerce sales, use Purchase revenue. Total revenue adds ad revenue on top of purchases, in-app purchases and subscriptions. For a web store with no ad revenue, the two come out almost the same.

What's the difference between Transactions and Ecommerce purchases?

Google defines Ecommerce purchases as the number of times users completed a purchase, and Transactions as the number of completed purchases on your site. Both are populated by the purchase event, and for a web store they're nearly the same.

Why is Item revenue lower than Purchase revenue?

Item revenue is price × quantity minus refunds, and excludes tax and shipping. Purchase revenue uses the purchase event's value, which often includes them, depending on how your tag sends value.