What Are Ideal Chart Designs for Maximum Conversion on Your Ecommerce Store

Here we share out experience with what we have observed to be good size chart designs on product pages.
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Last updated on September 18, 2022

As we have mentioned in our blog, product sizing is often an overlooked part of an online clothing business. One of the biggest challenges with shopping online is in fact picking the right size, as evident in research where 20-40% of returns are due to fitting problems. Unlike shopping in a physical store, you can’t try on different sizes to see what fits the best. To make the issue more complicated, sizes are not standardized across brands or even within the same brand.

This is why special attention should be put on optimizing product sizing. At the very minimum, shops need to provide accurate size chart information on every product page with a clear how-to-measure guide.

Here we want to share some of our experience on what we think are good size chart designs that can help your customers better pick the right size. Sometimes merchants treat product sizing just as something to check-off the to-do-list and don’t give enough attention. This is a mistake as product sizing should be prioritized and iterated over time.

Ideal Size Chart design

Based on our experience working with thousands of shops over the years, we believe there are certain elements important for an effective size chart. Here are a few things we recommend!

Do not use size chart images

We often encounter clients that use size chart images from their manufacturers or vendors. Like the following:

There are a few issues with using a sizing image directly:

  • Inconsistent design across different products (if you have different vendors)
  • Poor visibility on mobile screens (the text do not dynamically resize themselves)
  • Not including unit conversions

Use size chart table Instead

An ideal size chart should be HTML table so that

  • Designs are consistent on all the product pages
  • Dynamically Resizes according to different screen sizes
  • Include unit conversion between metrics and imperial system
  • May contain other interactive features like row/column highlights

Standardize and be consistent with size chart measurements

  • Body vs Product table: If you show product size charts for one product, you should make sure you are consistent with showing product size charts for all other products. And most importantly, emphasize on the chart whether that is a product table or a body table. Being inconsistent will mislead customers in making the wrong decision. Consistency is key.
  • Full or Half measurements: If in one table, you show chest measurement using the chest width, then make sure you do the same for all tables, and not mix chest width with chest circumference (width multiplied by 2). Being inconsistent here will also mislead customers.

Contains clear how-to-measure section

Having a size chart table alone may leave customers with more questions. It’s important to have a section that instructs the customers what each measurement in the table means and how they can use the number to find out which size they are most suitable with.

Contain international size charts

If the shop sells to an international audience. Having an international conversion chart can help customers have a rough idea of which size they should expect to purchase.

Note that there are no standardized sizes for each country, so international charts are only meant as references but not exact guides.

Prominent display of the size chart info

Experiment with making size chart link obvious to discover on the product page. If you measure how often size charts are opened, it can give you an idea of how obvious the size chart is to the visitors. Experiment with the following:

  • Placements of the size chart link
  • Changing the size chart link font size or color to make it more prominent on the product page.
  • Display in multiple places on the product page: You can display a size chart link and also have a “size & fit” tab on the product page or showing a fixed static size button on the corners of the product page.  Whether this is necessary depends on whether you notice customers not checking the size chart before purchasing.

Additional trust signals on the size chart

There are additional trust signals you can show on size chart to better help customers make their decision. For example:

  • Include model information with their body profiles so people can see how it fit with a real person and can decide on their own relative differences.
  • Include a section for showing fit type & fabric

Other places for fit signals

Additional information regarding fit can be helpful on the product page.

  • For example, as part of the customer reviews, ask the customer for their relevant fit info and how the garment fit for them. Renttherunway does a great job with this.
  • Customer reviews can also show aggregated fit information. This may give buyers more confidence when deciding to pick a size.

Shopping for kids clothes? Don’t forge to check this international size conversion chart for children’s clothing will help you get the perfect fitting clothes.

Common Questions

Should I have generic size charts vs product specific size charts?

Sometimes for simplicity, merchants only show generic size charts for all the shirts in the store. This may be okay if all of your shirts follow the same fit model. But if they vary and are from different vendors, it is absolutely critical to display accurate sizing for each product. This is extra work but will avoid confusion and help lower chances of unhappy customers returning the wrong size.

Should I display body size charts or product size charts?

What are the differences?

  • Many customers and even merchants don’t know the difference between the two. Often time manufacturers and vendors provide product size charts, which are physical measurements of the garments. Displaying those tables on the product pages is good, but it is important to emphasize on the table and the “how-to-measure” section that the measurements numbers are for the product.
  • Body size charts are essentially the product size charts adding the intended easing. Easing is the amount of “spaces” needed for each body part. For example, a standard fit t-shirt may need chest easing of 10-12cm for comfort. This “easing” will vary depending on the product type, style and intended fit. For example, leggings may prefer negative easing because it is meant to be worn tight on the skin while jackets will need bigger easing as they are often worn after multiple layers.

Potential problem with only showing product size chart

  • Customers cannot simply measure their body and check against the numbers of product measurements directly. If a chest for size M is 110cm, and the customer measures his chest to be 108cm, size M will actually be too tight. There is some mental math that needs to be done, and that is often too cumbersome for potential shoppers.

Potential problem with only showing the body size chart

  • Customers can check their body measurements with the numbers in the table. But if they want to know the actual measurements to compare with another clothing they already wear frequently, they won’t be able to do that. Sometimes customers may have their own fit preferences and the implicit easing the brand added does not fit their needs.

This is why we suggest showing BOTH product & body size charts if possible. This is extra work but will provide customers with the maximum amount of information they care about when picking size.

Should I bump Asian sizes to US sizes?

Many stores source their products from vendors in Asia and Asian sizes are generally smaller than sizes in North America and Europe. Generally, an Asian size label is 1 or 2 sizes smaller than the same label in US sizes. For example, a typical L in Asian size is similar to a S in US sizes. Of course, again, there is no universal standard here, but it’s a rule of thumb many people use.

Ultimately, because of how misleading the size label (i.e. S, M, L, etc) is, we recommend merchants to urge customers to check the actual measurements (i.e. chest, waist, hip) instead.

Sometimes merchants may want to bump the labeling on the website to be more consistent with the labels the target customers are more used to. This has its own benefits but the issues could be confusion when customers receive the garment with a different size tag than what they see on the invoice. We don’t recommend one way or another, and merchants should weigh their own pros and cons.

How much can I trust size charts from vendors?

Not always. We have seen countless examples of size charts from manufacturers being slightly off or outright incorrect. When possible, we always urge merchants to measure the garments themselves to verify the accuracy of the size tables. No design or fit recommender is gonna help when your size table is not accurate.

To conclude, there are many things to consider when setting up size charts for your products pages. We strongly encourage merchants to spend more time thinking of how to better optimize this.

Related information:

  • Kiwi Sizing was launched in mid/late 2015. The idea was motivated by Sam, the founder’s personal experience running a dog fashion store on Shopify. He realized how much of a pain managing size charts is on the platform when selling over 100 different skus from different vendors.
  • Kiwi Sizing has over 10,000 active users and integrates with over 10 e-commerce platforms.
  • Over 400,000 size charts have been created on the platform.
  • Future direction: Kiwi Sizing is dedicated to continuously improve its fit recommendation model by including more data like third party clothing brands.

Kiwi Sizing is an e-commerce plugin to help solve the sizing problems for online shopping. Over 40% of online clothing returns are due to sizes. Kiwi Sizing is designed to make sizing easy by offering stylish size charts and easy-to-use fit recommenders that let shoppers know what is the best size to purchase. We help improve conversions, cut down on returns, and lower the needs for customer support.

We are trusted by thousands of Shopify stores with over 400 5-star reviews. Try it now for free and start reducing unnecessary returns.

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Personalized Size Recommendations on your Shopify Stores