If a user can convert each time they visit the site:
Imagine we own an ecommerce site — Roger's Robotics. A user could make a new purchase each session. We want to optimize so they make as many purchases as possible. If a user visited the site three times, that would be three sessions — and three opportunities to convert.
Let's closer at our user's three sessions and how they behaved:
Session 1: No conversion — user was familiarizing themselves with the site and poking around.
Session 2: User bought a shiny new antenna. This is a conversion!
Session 3: User came back and bought a new set of gears and a blinking light — another conversion! Even though they bought two items, this is a single unique order and thus counts as a single conversion.
To figure out our conversion rate, we would take the number of unique purchase orders and divide it by the total number of sessions.
For our imaginary user, they converted two out of three times they came to the site:
user a unique orders sessions
2 3
(2orders/3sessions)=66% conversion rate
To find out the conversion rate for your site, you'll look at all unique orders divided the total number of sessions.
Calculating Conversion Rate by Sessions:
unique orders sessions
500 5000
(500orders/5000sessions)=10% conversion rate