Sizing Chart Optimization Experiment

What We Tested

Test Hypothesis:
To make it easy for the users to select size, as choosing size is one of the major concerns while buying clothes online. By improving the sizing chart, we were able to optimize the sizing chart which in turn increased the conversion rate on the desktop displays. (Mobile sizing optimization gave us different results which we will discuss at a later time).

What We Tested:
3 variations were created and tested and against control.

Variation 1: All the sizes were opened by default and sizing guide opened in a pop up (This variation has turned out to be a winner). If you wanted to see the size chart, you would have to click the link. No hover capability over the link.

Variation 2: All the sizes were opened by default and and a tool tip was added on hover of sizing chart link. In the Variation 2 picture below, the mouse is hovering over the “sizing chart” link. The visitor could also make the size chart bigger by magnifying the chart.

Variation 3: Same as Variation 2, all the sizes were opened by default but the visitor could also select the size from the size chart pop up.


VISITORS TO CART – we measured the number of visitors actually reaching the shopping cart in this experiment. See Exhibit A below:

A 12% increase in visitors reaching the cart page in Variation 1 with 98% confidence. A 98% confidence means the variation will outperform the original version 98 times out of 100 chances.

Whereas, a 6% increase in visitors reaching cart page in Variation 3

As per sessions tracked in Google Analytics (see Exhibit B below), a 27% uplift in eCommerce conversion rate in variation 1 in comparison to control.

244 transactions completed for Variation 1 vs. 195 transactions in control, with $4000 more in revenue!


The sizing chart optimization test ran from October 13th, 2917 to October 21st, 2017.
The main goal of running this test was to increase clarity regarding size, so more visitors can move forward with confidence to complete the purchase.
Variation 1 turned out to be a clear winner with massive increase in transactions completed.
Changes of Variation 1 must be implemented on the live website.