Ecommerce Conversion Rate: Formula, Calculation and Shopify

An ecommerce conversion rate is the share of visits to an online store that end in a purchase: conversion rate = sessions with a purchase ÷ total sessions × 100. Shopify uses that session-based definition, with the formula "sessions that completed checkout / sessions" (Shopify Help Center, as of October 7, 2026).

This guide writes out the formula, works through a fictional example, compares the variants and what each measures, shows where to read the rate in Shopify and what changed in its measurement in September 2026, then covers the usual mistakes and the levers you control. It quotes no "average conversion rate": such figures depend on how sessions are counted, and a rate without its method cannot be compared with yours.

What is an ecommerce conversion rate?

It measures how well a store turns visits into orders. Three terms need a definition before the formula means anything:

• Session: a visit. On Shopify, a session ends after 30 minutes of inactivity, and the same visitor can have several sessions.
• Visitor: a person, or more exactly a device. Shopify's example: one person visiting 5 times counts as 1 visitor but 5 sessions.
• Conversion: here, a completed purchase. Other conversions exist (a signup, an add to cart), and they have their own rates.

What is the conversion rate formula?

Conversion rate = sessions that completed checkout ÷ total sessions × 100

The same logic gives a rate for each step before the purchase. Shopify's analytics fields reference defines three of them:

Source: Shopify Help Center, as of October 7, 2026.

How do you calculate it? A worked example

The store and the figures below are fictional. They show the arithmetic.

Over one month, a store records:

Rates over total sessions:

1. Added to cart rate = 3,200 ÷ 40,000 × 100 = 8%
2. Reached checkout rate = 1,600 ÷ 40,000 × 100 = 4%
3. Conversion rate = 1,000 ÷ 40,000 × 100 = 2.5%

Rates from one step to the next:

1. Cart to checkout = 1,600 ÷ 3,200 × 100 = 50%
2. Checkout to purchase = 1,000 ÷ 1,600 × 100 = 62.5%

The two readings complement each other. The first tells you where the store stands overall. The second tells you where sessions are lost: in this example, half of the carts never reach checkout, and 600 of the 1,600 checkouts started are not completed.

What the rate is worth in revenue

Conversion rate links traffic to sales:

Revenue = sessions × conversion rate × average order value

With an average order value of $60 (fictional): 40,000 × 2.5% × $60 = $60,000.

If the rate moved from 2.5% to 2.75%, with the same traffic and the same order value: 40,000 × 2.75% × $60 = $66,000. A quarter of a point is worth $6,000 a month in this example. The same formula shows why conversion rate cannot be read alone: our guide to average order value covers the third term.

Which variants of the formula exist?

The variants give different numbers on the same store. Continuing the fictional example, with 25,000 unique visitors and 1,050 orders:

• Session-based: 1,000 ÷ 40,000 = 2.5%
• Visitor-based: 1,050 ÷ 25,000 = 4.2%
• Order-based: 1,050 ÷ 40,000 = 2.625%

All three are correct. They answer different questions, and this is the first reason two tools, or two stores, rarely agree. Shopify itself points out one of the gaps: a customer can make several purchases during a single session, so the order count and the count of sessions that completed checkout "might not be the same" (Help Center).

Where do you find your conversion rate in Shopify?

Shopify documents three places, all in the behavior reports and the Analytics dashboard.

The Analytics dashboard

Go to Analytics in your Shopify admin. The dashboard displays your session metrics, conversion rate included, on metric cards. Clicking the title of a card opens the matching report. If you don't use the Online Store channel, the metrics related to online store sessions aren't displayed.

Conversion rate over time

1. From your Shopify admin, go to Analytics > Reports.
2. Click the Category filter, then Behavior.
3. Open Conversion rate over time.
4. Use Group by to display the rate by day, week or month.

The report has six columns: the time grouping, Sessions, Sessions with cart additions, Sessions that reached checkout, Sessions that completed checkout and Conversion rate. Shopify defines "reached checkout" as sessions where there was user input during checkout, for example a key press or mouse click.

Conversion rate breakdown

This report shows the path as a funnel, in this order: All sessions, Sessions with cart additions, Sessions that reached checkout, Sessions that completed checkout. An Open Funnel toggle switches between two readings:

Source: Shopify Help Center, as of October 7, 2026.

Shopify notes that the rate for each step is the number of sessions for that step divided by total sessions. The list of behavior reports also includes a Checkout conversion rate report and a Conversion rate (online store) report.

You can also ask Sidekick, Shopify's assistant. The Help Center suggests a prompt such as "Show my conversion rate by device type for the last 30 days".

What does Shopify count, and what changed in September 2026?

Since the rate is a ratio, everything depends on how sessions are counted. Four points from Shopify's documentation.

Cookie consent. In the fields reference, Shopify states that sessions are "only counted when visitors consent to cookies through your cookie banner", and that other analytics platforms calculate sessions differently. A store with a consent banner can therefore count fewer sessions than it receives visits.

The online store only. The definition refers to online store visits. Orders from other channels are not part of this rate.

The session measurement update. Shopify rolled out a change from September 21 to 23, 2026, described on a dedicated page:

Shopify spells out the effect: "A higher or lower conversion rate after this update isn't automatically good or bad." Fewer sessions (bots removed) raise the rate. More sessions (visits without a pageview) lower it. Orders, sales and customer counts aren't affected. Its advice is to use data from after the update as a new baseline.

Comparisons across the update. Historical data isn't deleted or reprocessed, but bot classification applies only to sessions from October 7, 2025 and after. A year-over-year comparison that straddles these dates mixes two measurement methods. Shopify recommends using the same Human or bot session filter setting on both periods, in reports that support it, and reviewing orders and sales alongside sessions.

What are the common mistakes when reading a conversion rate?

Comparing rates built on different definitions. A session-based rate from Shopify and a visitor-based rate from another tool are two metrics. Before comparing, check the numerator, the denominator and the scope.

Comparing with an "industry average". A published average blends stores, countries, devices and tracking setups. Without its method, you cannot tell whether your rate is above or below it. Your own history is the comparison that holds.

Reading the rate without the traffic mix. A campaign that brings many first-time visitors lowers the rate without anything being wrong on the site. Returning customers and email clicks convert differently from cold ad traffic. Segment by channel before you conclude.

Ignoring the device split. A store can have a stable rate on each device and a falling overall rate, simply because the share of mobile sessions grew. Look at each device separately.

Drawing conclusions from small numbers. With 300 sessions and 6 purchases, the rate is 2%. One purchase more or less moves it to 2.33% or 1.67%. On small volumes, look at longer periods.

Optimizing the rate against revenue. A deep discount can raise conversion rate and lower margin. A price increase can lower the rate and raise profit. The target is what the three terms produce together: sessions × conversion rate × average order value, then margin.

Forgetting what happens after. Conversion rate stops at the order. Returns, refunds and repeat purchases are not in it. Our guide to customer lifetime value covers what happens after the first order.

Mixing periods across a measurement change. As Shopify notes for its September 2026 update, a change in method changes the rate without any change in behavior.

Which levers does a merchant control?

The funnel shows where to act. Each step has its own causes.

A few of these are documented by Shopify itself.

Shipping. Shopify's shipping strategy page states that free shipping usually has a positive impact on cart conversion, and that carrier-calculated rates, which can't be displayed before checkout, might lead to more abandoned checkouts. Our guide to Shopify shipping rates explains the options.

Speed. In its behavior reports documentation, Shopify writes that optimizing web performance can improve the shopping experience and increase conversion, and it measures performance through 3 Core Web Vitals.

Answers at the moment of doubt. A question about size, delivery or returns that goes unanswered ends the session. A chat on the storefront, such as Shopify Inbox, or a messaging channel the customer already uses, keeps the conversation going.

Abandoned checkouts. In the fictional example, 600 checkouts were started and not completed. Recovering part of them raises orders without any extra traffic. Shopify includes abandoned checkout emails, and apps add other channels. Kanal, a WhatsApp marketing and sales app for Shopify stores, handles abandoned cart recovery on WhatsApp. Our guide to abandoned cart recovery strategies compares the approaches.

Traffic quality. The rate has a denominator. Paying for sessions that have no intent to buy lowers the rate and the return on ad spend at the same time. Our guide to ROAS covers that side.

Whatever you change, change one thing at a time and compare equal periods, by device and by channel, so you can attribute the difference to what you did.

Ecommerce conversion rate in short

• Formula: sessions that completed checkout ÷ sessions × 100.
• Variants: session-based, visitor-based, order-based, checkout conversion. Same store, different numbers.
• In Shopify: Analytics dashboard, Conversion rate over time and Conversion rate breakdown under Analytics > Reports > Behavior.
• Measurement: sessions depend on cookie consent, bot filtering and session rules. Shopify changed these on September 21 to 23, 2026.
• Comparison: your own rate over time, by channel and device, with the same definition.
• Reading: always next to traffic, average order value and margin.