Size charts that reduce returns

In a shop you'd take the piece to the fitting room. Online you can't, so your size guide has to do that job. That's why I think it's one of the most useful things to get right in ecommerce.

We're Design by Karina, a strategy-first boutique Shopify agency in Rotterdam for premium fashion and beauty brands, and we design and build Shopify stores for brands across the Netherlands and Belgium, turning what makes your brand different into a reason to choose you. We build product pages around the doubts your buyer has, and for clothing, size is the big one. This guide goes with our UX checklist for fashion and beauty webshops.

Why do size charts cut returns?

Think about what someone does when they aren't sure about their size. They might leave. They might guess. Or they might order two sizes and send one back. The last two turn into returns, and the first is a sale you never see. A size chart that's easy to find and easy to use helps them make that decision on the page, before they order.

It won't stop every return, because people also just change their minds, so you still need an honest returns policy. What the chart does is help the first order be the right one more often.

What belongs on a size chart?

Keep your usual sizes, like XS to XL or 34 to 42, in the size selector. Then put the body measurements in the chart next to them, so someone with a tape measure can match their own numbers to a size.

Where should the size chart sit?

Next to the size selector and the buy button. Not in the footer, and not behind a "size guide" link three scrolls down.

Picture someone on your product page trying to decide between M and L. That's the moment they want the numbers. If they have to go looking for them, they might guess, or get distracted and not come back.

VYOLA is a good example. It's a Belgian atelier for made-to-measure body jewelry. At events, people fall for a piece the moment they try it on. Online they can't, so ordering had to feel safe. On the product page we put a size chart in centimeters (underbust, waist and hip, from XS-S up to 5XL-6XL), a field for your own measurements and a fit guarantee with free adjustments, all next to "add to cart". And because someone buying a gift often doesn't know the size, there's a gift card as the easy way out. These pieces are worn on the body, so it's the same question a clothing buyer asks. You can read more in the VYOLA case.

How do fit notes and model info help?

A size chart tells people what their measurements are. Fit notes tell them how this particular piece behaves: tight through the waist, long in the body, meant to sit cropped. Model info gives them a second reference, because seeing that someone 1.75 m tall wears an S helps you picture it on yourself.

Write both the way you'd say it to a customer in your shop. One honest line does more than a paragraph of fashion copy.

What about filters and variants?

Size charts work together with how Shopify keeps track of stock. Every size and every color is a variant with its own inventory, so your collection pages can filter by size and color, and people only see what they can buy. When a size sells out, the selector can show it.

That's why we plan variants before we design, because changing them later means doing the same work twice.

Returns, said plainly

Even with a great size chart, some pieces will come back. So say how long people have, how to start a return and who pays for the return shipping, in one line under the button.

In the EU, consumers who buy online have at least 14 days to change their mind, without giving a reason, and those days start when the order arrives. So you might as well say it before anyone has to look for it.

Made to measure works differently, and that matters for this article. Someone who orders a piece made to their own specifications, like a tailor-made suit, doesn't have that right. But you have to tell them before they order, so put it on the product page, close to the measurement field. This exception doesn't stretch far, so ask someone who knows the rules before you use it for pieces in your regular sizes.

A clear return line helps people feel safe placing a first order with a brand they don't know yet.

Good to know in the Netherlands

The Dutch rules follow the EU ones, and the ACM is the regulator that checks them. When a customer cancels, you refund them within 14 days, including the standard delivery cost, and you can wait until you have the piece back or proof that it was sent. The customer only pays the return postage if you told them that before the sale. If you don't explain the bedenktijd, the Dutch word for this cooling-off period, it can run up to a year longer. And since June 2026, a webshop that sells to consumers needs a clear button or link to undo a purchase online, the herroepingsknop, which has to stay easy to find for the whole period.

A short checklist for your next drop

• Chart in centimeters next to the size selector.

• A fit note for every piece.

• Model height and size worn.

• How to measure, in one short line.

• Stock visible per size.

• Returns in one line under the button.

• Size filters on every collection.