Conversion rate (CR for short) is one of the most important metrics in online marketing. It tells us what share of visitors to a site complete a desired action — a purchase, a form submission, or a newsletter sign-up.
Definition and formula
Conversion rate = (number of conversions / number of sessions or users) × 100%
Example: an online store was visited by 10,000 users in a month, of whom 200 made a purchase. The conversion rate is 2%.
How to calculate conversion rate? The method matters
Before you start interpreting the results, it’s worth knowing that conversion rate can be calculated in several ways — and each of them gives a different result.
Conversions / sessions — the most common method in Google Analytics. One session is one visit to the site, and the same user can have many of them. If someone visits a store five times and buys once, we count one conversion per five sessions.
Converters / users — we divide the number of users who converted by the total number of users. This way we measure only unique conversions — each user counts once, regardless of how many times they visited the site.
Google Ads: one-per-click vs. every conversion — this is a separate logic. With the one conversion per click setting, the system counts at most one conversion per ad click. However, if the same user clicks the ad twice and makes a purchase each time, two conversions will be recorded — because those are two separate clicks. This differs from measuring unique conversions per user.
When looking at a conversion rate, it’s worth checking exactly how it is calculated — the differences described above can make the same data look completely different depending on the method used.
What does conversion rate depend on?
Conversion rate depends on many factors at once — the type of conversion, the industry, the product price, and traffic quality. Leads (sign-ups, forms) usually have a higher CR than sales, because it’s an easier decision for the user. More expensive products convert less often than cheap ones. Traffic from well-targeted campaigns converts better than random traffic.
For this reason it’s hard to define a universal expected conversion rate — a number that is good in one industry may be poor in another. We cover this topic in detail in a separate article: [What is a good conversion rate? Benchmarks for e-commerce and leads] ← link will appear here.
What affects conversion rate?
- Site UX — intuitive navigation, fast loading, a clear form
- Offer and price — competitiveness, a clear product value
- Trust — customer reviews, certificates, a return policy
- Ad-to-landing-page match — the ad promises what the user actually finds after clicking
How to improve conversion rate?
Conversion Rate Optimization (CRO) is a separate marketing discipline. The most effective actions are:
- A/B testing — comparing two versions of a page or an element
- simplifying the contact form or the checkout process
- improving page load speed
- adding social proof (reviews, number of customers)
- retargeting users who did not convert
Summary
Conversion rate is the percentage of visitors who complete a desired action. Before you interpret it, check how it is calculated, because the methods (sessions, users, clicks) give different results. CR depends on the type of conversion, the product price, the industry, and traffic quality. What matters most is tracking your own trend over time and optimizing based on data.
