If you sell clothing items that require customers to know their size before they make a purchase, you can add a custom size chart to your product page. This instruction shows you how to setup the size chart.
On this page
Size chart eligibility
All products that are eligible for this size chart function must have a Size option.
In your Themes admin, navigate to your theme and click Edit languages under Actions menu:
Under Products tab, navigate to the Size chart trigger and change it to the name you want for validation:
Click Save to confirm your changes.
Enable size chart
First you need to create a page for your size chart content. From your Shopify admin, go to Online Store > Pages then click Add page. Please check out official Shopify document in case of need.
You can enable size chart on product page, featured product section or product modal by navigating to Variant picker block.
There is an option named Size chart page, and here's to choose the page that you just created. If a product is eligible, a size chart button should display below the size options. When clicked, it opens a popup that represents the page's content: