eCommerce guide
Ecommerce metrics: what to track, how to calculate it, and what it tells you
Most stores track too many ecommerce metrics and act on too few. This guide lists the key ecommerce metrics with their formulas and where to find them, shows how they connect from first visit to repeat order, and explains which ones to put on your weekly dashboard.
Short answer
Ecommerce metrics are the numbers an online store uses to see how well it attracts visitors, turns them into buyers, earns from each order and keeps customers coming back. The key ones are conversion rate, average order value, revenue per visitor, cart and checkout abandonment, customer acquisition cost, repeat purchase rate and gross margin, plus sessions by traffic source.
- Good metrics connect to one another, so when revenue moves you can see which step moved it.
- Use one source and the same date range for both parts of any formula.
- Funnel metrics show the step where shoppers stopped, which turns a number into a place to work.
- Revenue per visitor combines conversion rate and order value, which makes it a strong number to judge changes by.
- Compare customer lifetime value with acquisition cost: a customer who costs more to win than they are worth is a loss.
What are ecommerce metrics?
Ecommerce metrics are the numbers an online store uses to see how well it attracts visitors, turns them into buyers, earns from each order and keeps customers coming back. Good ecommerce metrics connect to one another, so that when revenue moves you can see which step moved it: more visitors, more of them buying, bigger orders, or more repeat customers.
That connection is the point. Revenue on its own tells you what happened. The metrics underneath tell you why, and where to work next.
Which ecommerce metrics matter most?
The ecommerce metrics that matter most for nearly every store are conversion rate, average order value, revenue per visitor, cart and checkout abandonment, customer acquisition cost, repeat purchase rate and gross margin, plus sessions split by traffic source. Together they describe the whole path from first visit to repeat order, and each one points to a different kind of fix. Most of them live in your analytics; the guide to conversion analytics in GA4 shows where.
- Sessions by source: how many visits you get, and from where.
- Conversion rate: how many of those visits end in an order.
- Average order value: how much each order is worth.
- Revenue per visitor: the two above combined into one number.
- Cart and checkout abandonment: where buyers who were close drop out.
- Customer acquisition cost: what it costs to win a new customer.
- Repeat purchase rate: how many customers come back.
- Gross margin: how much of each sale you keep.
Ecommerce metrics and their formulas
Each ecommerce metric below comes with its formula, what it tells you, and where the numbers usually live. Use one source for both parts of any formula and the same date range, or the result will mislead you. Where a free Convertica calculator exists, it is linked.
| Metric | Formula | What it tells you | Where to find it |
|---|---|---|---|
| Sessions by source | Count of sessions, split by source or medium | Which channels bring visitors | Analytics |
| Bounce rate | Sessions not engaged / all sessions | Pages that lose people on arrival | Analytics (see the bounce rate guide) |
| Conversion rate | Orders / sessions x 100 | How many visits end in an order | Analytics or store platform (calculator) |
| Add to cart rate | Sessions with add to cart / sessions x 100 | Whether product pages persuade | Analytics ecommerce events |
| Cart abandonment rate | (1 - orders / carts created) x 100 | How many carts never become orders | Analytics (see the cart abandonment guide) |
| Average order value | Revenue / orders | How much each order is worth | Store platform |
| Revenue per visitor | Revenue / sessions | Conversion and order value in one number | Analytics or store platform |
| Gross margin | (Revenue - cost of goods sold) / revenue x 100 | How much of each sale you keep | Accounts or store platform |
| Net sales | Gross sales - returns - discounts | Revenue you actually keep from orders | Store platform |
| Customer acquisition cost | Marketing spend / new customers | What a new customer costs | Ad platforms plus store data |
| Cost per acquisition | Spend / conversions, for one campaign or channel | What each conversion from a channel costs | Ad platforms (CPA guide) |
| Return on ad spend | Revenue from ads / ad spend | Revenue each ad dollar brings back | Ad platforms (ROAS guide) |
| Repeat purchase rate | Customers with 2+ orders / all customers x 100 | Whether customers come back | Store platform |
| Customer lifetime value | Average order value x orders per customer x gross margin | What a customer is worth over time | Store platform and accounts |
| Return rate | Items returned / items sold x 100 | Whether products match their pages | Store platform |
Customer lifetime value has many versions. The one above is a simple, margin-based estimate that works for most small and mid-sized stores. Whatever version you use, compare it with customer acquisition cost: a customer who costs more to win than they are worth over time is a loss, however good the first order looks.
Ecommerce funnel metrics: where shoppers drop out
Ecommerce funnel metrics measure each step from viewing a product to completing a purchase. A single conversion rate tells you how many visitors bought; funnel metrics tell you at which step the rest stopped. That is what turns a number into a place to work.
| Step rate | Formula | A weak rate usually points to |
|---|---|---|
| Product view rate | Sessions with a product view / sessions | Navigation, search and category pages |
| Add to cart rate | Sessions with add to cart / sessions with a product view | Product pages: price, images, delivery, reviews, stock |
| Cart to checkout rate | Sessions starting checkout / sessions with add to cart | Costs shown in the cart, the cart page itself |
| Checkout completion rate | Sessions with a purchase / sessions starting checkout | Forms, account creation, delivery options, payment |
Split every step by device. Phones and desktops often lose shoppers at different steps, and a store-wide rate can hide a mobile checkout that fails. The guide to the conversion funnel shows how to build this report in GA4 and how to work through it, and the guide to mobile conversion optimization covers the phone side.
Average order value: how to calculate and raise it
Average order value is total revenue divided by the number of orders in the same period. If a store takes 12,000 in revenue from 300 orders, its average order value is 40 in the store's currency. Raising it means each buyer spends more per order, which adds revenue without needing more visitors.
The usual ways to raise average order value:
- A free shipping threshold set a little above your current average order, with the gap shown in the cart. Convertica's free shipping threshold case study tested exactly this message on product pages.
- Bundles of products that are often bought together, priced so the bundle is clearly better value.
- Relevant add-ons on the product page or in the cart: the accessory, the refill, the larger size.
- Quantity pricing for products people use up.
Watch conversion rate at the same time. A change that raises average order value but lowers the share of visitors who buy can leave revenue flat or lower. That is why revenue per visitor is the better scorecard for these tests.
Why revenue per visitor is the metric to judge changes by
Revenue per visitor is total revenue divided by visitors, and it equals conversion rate multiplied by average order value. Because it moves when more people buy, when they spend more, or both, it is the fairest single number for judging a change to a store. It stops you celebrating a test that lifted one at the cost of the other.
Here is how that looks in practice. In Convertica's test for dScryb, a membership store, calls to action and access levels were added to search results. Clicks on those calls to action rose, paid membership sign-ups rose, and the result that settles the question, revenue per visitor, rose too.
+23.8%
Revenue per visitor, 17-day A/B test
Source: dScryb, A/B test on desktop and mobile, 98% confidence
Ecommerce KPIs vs metrics: choosing what to report
A metric is any number you can measure; a KPI is one of the few metrics you have chosen to judge progress against a goal. A store can track twenty ecommerce metrics and still set only three or four KPIs. Choose the KPIs that match your current goal and give everyone the same short list to watch.
| Your goal now | KPIs to set | Supporting metrics |
|---|---|---|
| More sales from the traffic you have | Conversion rate, revenue per visitor | Funnel step rates, abandonment, bounce rate on key pages |
| Bigger orders | Average order value, revenue per visitor | Items per order, take-up of bundles and add-ons |
| Profitable growth from ads | Customer acquisition cost, return on ad spend | Cost per acquisition by channel, gross margin |
| Customers who come back | Repeat purchase rate, customer lifetime value | Time between orders, email and subscription sign-ups |
How often to review your ecommerce metrics
Review fast-moving ecommerce metrics often and slow-moving ones rarely. Daily checks catch breakages; weekly reviews show trends in conversion and order value; monthly or quarterly reviews are long enough for retention and lifetime value to change. Looking at slow metrics every day only produces noise.
- Daily: revenue, orders, payment failures and site errors. You are looking for anything broken.
- Weekly: conversion rate, average order value, revenue per visitor, cart and checkout abandonment, all by device and source.
- Monthly or quarterly: customer acquisition cost, return on ad spend, repeat purchase rate, lifetime value, return rate and gross margin.
Common mistakes with ecommerce metrics
The most common mistakes with ecommerce metrics are mixing measurement methods, comparing unfair periods and trusting averages that hide segments. Each one can make a store change something that was working, or miss something that was broken.
- Mixing sessions and users. A conversion rate per session and one per user are different numbers. Pick one and label it.
- Comparing unfair periods. A sale week against a normal week, or December against February, tells you about the calendar, not the site.
- Adding up ad platform conversions. Each platform claims its own share of the same orders. Your store's order count is the truth.
- Trusting a sitewide average. Device, source and new versus returning customers often behave very differently.
- Celebrating one number. A higher conversion rate from heavy discounts can lower margin. Read metrics in pairs.
A metric to start watching: visits from AI assistants
Some shoppers now ask an AI assistant to research or compare products, and some assistants can visit a store on the shopper's behalf. When you see AI assistants in your referral sources, give them their own channel grouping so you can watch how those visitors convert. Then make sure your product names, prices, stock, delivery terms and returns policy are readable in the page HTML, where assistants and AI search can find them. Agent readiness is one of the eight checks in Convertica's free CRO audit.
Free calculators for your ecommerce metrics
Convertica's free calculators show their formula and a worked example, so you can check the numbers in your reports.
Ecommerce metrics questions
What are ecommerce metrics?
Ecommerce metrics are the numbers an online store uses to measure how well it attracts visitors, turns them into buyers, earns from each order and keeps customers coming back. Examples are conversion rate, average order value, revenue per visitor, cart abandonment rate, customer acquisition cost and repeat purchase rate.
What are the most important ecommerce metrics to track?
For most stores the core set is sessions by source, conversion rate, average order value, revenue per visitor, cart and checkout abandonment, customer acquisition cost, repeat purchase rate and gross margin. Together they show where visitors come from, how many buy, how much they spend, what they cost and whether they return.
What is the difference between a metric and a KPI?
A metric is any number you can measure. A KPI, or key performance indicator, is one of the few metrics you have chosen to judge progress against a goal. Every KPI is a metric, but most metrics should not be KPIs. A store might track twenty metrics and set only three or four as KPIs.
How do you calculate average order value?
Average order value = total revenue / number of orders, for the same period. For example, 12,000 in revenue from 300 orders is an average order value of 40, in whatever currency your store uses. Decide whether revenue includes shipping and tax, and use the same definition every time you compare periods.
What is revenue per visitor?
Revenue per visitor is total revenue divided by the number of visitors, or sessions, in the same period. It equals conversion rate multiplied by average order value, so it rises when more visitors buy, when they spend more, or both. That makes it the fairest single number for judging a change to a store.
How often should you review ecommerce metrics?
Check sales, orders and site errors daily, review conversion rate, average order value, revenue per visitor and abandonment weekly, and look at customer acquisition cost, retention and lifetime value monthly or quarterly. Slow-moving metrics change too little day to day to be worth daily attention.
What are ecommerce funnel metrics?
Ecommerce funnel metrics measure each step from product view to purchase: product view rate, add to cart rate, cart to checkout rate and checkout completion rate. They show where shoppers drop out, which a single conversion rate cannot. Split them by device to see whether phones lose people at a different step from desktops.