JV PRO LABS GUIDE · UPDATED OCTOBER 6, 2026
Add a Shopify size chart shoppers can actually use
Choose the right measurements, assign your products, and test a size chart in your Shopify theme before publishing it.
Start with accurate measurements
Use measurements for the actual product or product family. Explain whether your table describes the garment itself or the body it is intended to fit. A chest measurement taken across a flat garment is different from a full chest circumference; label it clearly.
Choose one unit for each clearly labeled table, such as centimeters or inches, and explain where to measure. Choose the original measurement unit in Fit; shoppers can switch the displayed table between centimeters and inches. Fit converts those numeric values, but it does not measure shoppers or recommend a size. Avoid importing another brand’s chart unless it accurately describes the products you sell and you have permission to use it.
Create a small, readable chart
Install Fit from the Shopify App Store and create a chart. Give it a descriptive name, select the original unit, and enter the measurement table as CSV. The first column is Size; the remaining columns are measurement names. Start with the measurements that actually affect fit, rather than adding every possible dimension.
For a fictional shirt, headings might be Size, Chest circumference, and Body length, with Centimeters selected as the original unit. Fit adds the displayed unit to measurement headings. Enter your own verified values for each size. Do not treat sample measurements as a production sizing recommendation.
Assign products and add the theme block
Assign the chart to the relevant products, save it and publish it in Fit. Use a duplicate Online Store 2.0 theme for the first check. In the theme editor, open the appropriate product template and add Fit’s size-chart app block near the product information.
Check a product assigned to the chart and one that is not. If an expected chart is missing, confirm its assignments, published state, storefront setting and app block in the template that product actually uses. Save the theme changes before checking the storefront preview.
Check the chart on a phone before going live
Open the product preview on desktop and mobile. Read the longest heading and the largest size row; make sure the table can be used without losing the size label. Check that the chart’s units agree with your measurement instructions and product description.
When the preview is correct, publish the intended theme through Shopify. Recheck the actual product page. Review sizing questions and returns with your own store data; a chart does not guarantee fewer returns or more sales.
Choose a plan that matches the catalog
Fit’s Free plan supports one chart assigned to up to 50 products. Growth is $7 USD per 30 days for up to 100 charts, with up to 50 product assignments per chart. There is no percentage-of-sales fee.
Use one chart for products with the same sizing, and separate charts when their measurements differ. Shopify shows the applicable plan terms before you approve a subscription. Fit is available now on the Shopify App Store.