Why Size Guides Reduce Returns
Size and fit is the number one reason for clothing returns in the UK, accounting for around 40% of all fashion returns. A customer who buys the wrong size is guaranteed to return the product, costing you postage both ways and processing time.
A well-designed size guide does more than list measurements. It helps customers understand how your sizing compares to other brands they know, explains fit variations (slim fit vs relaxed fit), and provides guidance on how to measure themselves correctly.
Creating Size Guide Content
For each product category, create a size chart with specific measurements (chest, waist, hip, inseam) in centimetres and inches for each size. Include a "how to measure" diagram showing where to take each measurement.
Note whether your sizing runs true to size, small, or large. Include customer notes like "most customers size up in this style" if your data supports it. This kind of specific guidance significantly reduces sizing uncertainty.
Adding to Product Pages
There are several ways to add a size guide to product pages. The simplest is a link in the product description to a dedicated /pages/size-guide page. More effective is a size guide directly on the product page, either inline below the size selector or in a popup modal triggered by a "Size Guide" link near the size selector.
Popup vs Inline
Popup size guides keep the product page clean and allow detailed size information without taking up space. They are easy to implement using Shopify's native popup functionality or a simple app like Kiwi Size Chart and Recommender.
Inline size guides are always visible without requiring an interaction. They work well for simpler sizing (S, M, L, XL) where a small table fits naturally on the page. For complex sizing with many measurements, a popup is usually cleaner.
International Sizing
If you sell internationally, include sizing conversions for UK, EU, US, and AUS sizes. UK size 10 women's clothing is EU 38, US 6, AUS 10. These conversions vary by product type and brand, so always base them on your actual garment measurements rather than generic conversion charts.
Keeping Guides Updated
Size guides must be updated whenever you change your sizing or introduce new products with different specifications. Outdated size information is worse than no size information, as it creates false confidence and guaranteed returns.
