Conversion rate is the percentage of visits to a website that end in an action that matters to the business, such as a purchase, a contact form, a phone call or a booking.
It is the metric that links traffic to revenue: CTR tells you how many people click through to your site, and conversion rate tells you how many of those visitors do what you hoped they would.
How to calculate conversion rate
Conversion rate = conversions / visits × 100. Visits can be sessions or users, depending on what you want to measure (more on the difference below).
Here is an online store over one month:
- Sessions: 8,000
- Users: 5,000
- Orders: 120
By sessions: 120 / 8,000 × 100 = 1.5%. By users: 120 / 5,000 × 100 = 2.4%. Both numbers are right, but they answer different questions. The first measures how effective each visit is; the second shows what share of the people who visit end up buying, even if they only do it on their third visit.
What counts as a conversion
A conversion is any action that moves someone closer to becoming a customer and that you have decided to track. It helps to separate two levels:
- Macro conversions: actions that generate revenue or a direct sales opportunity. A purchase, a submitted quote request, a phone call, a booking or a demo request.
- Micro conversions: intermediate steps that signal interest. Adding to cart, starting checkout, subscribing to the newsletter, downloading a brochure or tapping the phone number.
Micro conversions are great for finding where people drop off, but do not add them to sales: a conversion rate that lumps purchases together with newsletter sign-ups tells you nothing useful. Calculate one rate per conversion type.
Conversion rate by channel
Your site-wide average hides big differences between channels, because each one brings people at a different point in the buying journey:
- Organic: mixes informational searches (someone learning about a topic) with transactional ones. A blog post that attracts a lot of informational traffic pulls the average down, even if those visits pay off later. That is why it pays to analyze organic traffic by the search intent behind each keyword.
- Paid: in Google Ads you choose the keywords and the landing page, so you can focus on searches with buying intent. On social media, by contrast, you interrupt someone who was not looking for anything.
- Email: reaches people who already know you and gave you their address, so it starts from a relationship the other channels do not have.
Be wary of generic benchmark figures: ranges vary enormously by industry, price and offer. The only benchmark that matters is your own history, channel by channel. If your organic rate drops while organic traffic grows, you may simply be winning informational visits in the SERP, not converting worse.
How to measure conversion rate in GA4
In Google Analytics 4, conversions are now called key events, as Google explains in its comparison of conversions and key events. The process is:
- Make sure every important action sends an event (purchase, generate_lead, a tap on the phone number).
- Mark it as a key event under Admin, Data display, Events, following Google's guide to marking events as key events.
- Look at the session key event rate and user key event rate metrics in the traffic acquisition report, filtered by the event you care about and split by channel.
If event tracking is not set up properly from the start, none of these numbers can be trusted. That is exactly what a solid analytics implementation fixes.
Common measurement errors
- Mixing sessions and users: comparing one month's per-session rate with another month's per-user rate leads to false conclusions.
- Missing events: forms inside iframes, calls from mobile or bookings on an external platform that never get recorded. Your rate comes out lower than it really is.
- Duplicate events: a purchase counted twice when someone reloads the confirmation page inflates the rate.
- "Unassigned" traffic: if your UTM parameters are tagged badly (for example, a utm_medium GA4 does not recognize), a campaign's visits and conversions end up with no channel and your per-channel rates stop adding up.
- Cookie consent: users who reject cookies are not measured the same way, so always compare periods with the same setup.
How to improve conversion rate
Improving conversion rate systematically is the job of CRO (conversion rate optimization). The basic steps:
- Find pages with plenty of traffic and a low rate compared with similar pages.
- Check that the landing page answers what its visitors were looking for.
- Remove friction: long forms, surprise costs at checkout, slow loading on mobile.
- Add trust signals: reviews, guarantees, visible contact details.
- Test changes with A/B tests and keep only what improves the numbers.
If you want a full testing and prioritization plan, that is what our CRO strategy service covers.
From traffic to revenue
Conversion rate is the piece that turns visits into money: revenue = visits × conversion rate × value per customer.
For example, if an SEO improvement brings you 3,000 extra organic visits a month, your organic conversion rate is 1.5% and the average order is worth €80, those visits are worth 3,000 × 1.5% × €80 = €3,600 a month in sales. If you convert leads rather than orders, add your sales close rate: 3,000 × 2% lead rate × 25% close rate × €1,500 per customer = €22,500.
This is the same calculation the SEO forecasting tool uses to estimate what additional organic traffic is worth. Subtract your costs and you have the ROI of the investment. And note this: lifting conversion rate from 1.5% to 2% has the same effect on revenue as growing traffic by 33%, often at a lower cost.
Frequently Asked Questions
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It is the percentage of visits (or users) that complete the action you want on your site: a purchase, a form, a call or a booking. If 1,000 sessions produce 20 orders, the conversion rate is 2%.
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Divide conversions by visits for the same period and multiply by 100: conversion rate = conversions / sessions × 100. Keep the same denominator (sessions or users) whenever you compare periods or channels.
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There is no universal number. It varies widely by industry, price point, type of conversion and channel, so a low-cost online store and a B2B consultancy cannot be compared. The useful reference is your own history, split by channel and by page type.
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It depends on the question. Per session measures how effective each visit is; per user measures how many people end up converting, even if they need several visits. GA4 gives you both: session key event rate and user key event rate. Just never mix them.