Sizing Charts: Why They’re Important and How to Create One for Your Retail Business

T-shirt with a green background

Small, medium, and large: These sizes can vary widely when it comes to actual fit, and that can be a significant challenge if you sell clothing.

The problem is that whether you sell apparel with generic sizes or numerical sizes (dress size 2, 4, or 6, size 38 waist, etc.), none of them are completely standardized. Any savvy shopper will tell you that a size 6 dress in one store could fit very differently from a size 6 dress found at a competing shop. This is particularly a problem if you sell exclusively online—your customers don’t have the opportunity to try on items in a physical store.

But you can boost customer confidence, increase sales, and reduce returns by creating a comprehensive size chart—because there’s nothing more frustrating for a consumer than simply hoping something will fit.

“When shoppers have to guess, one of two things happens: They either don’t buy, or they buy two or three sizes and return the ones that don’t fit,” says Morgan Linton, co-founder of Bold Metrics, a company that offers sizing tools for apparel retailers. 

“In fact, the average online apparel retailer experiences a return rate of 28%, and 80% of these returns are due to fit issues,” Linton adds.

Read on to learn what a sizing chart is and why it’s important in retail and ecommerce, as well as five best practices for making size charts.

What is a sizing chart? 

A sizing chart in retail lists apparel product sizes and how they correspond to body measurements to help customers select the right size while shopping online (though they may also be referenced in-store). 

There are two types of size charts: internal and external. 

Internal size chart vs. external size chart

An internal size chart is private and used to develop garments and maintain consistent sizing across all your products. It involves pattern making, grading, fit samples, and more. 

An external size chart is public and is used to help your customers select the right size for their body. It’s displayed online and generally includes four main measurements: bust, waist, hip, and height. But depending on the products you sell, a more detailed sizing chart could be helpful for customers. For example, if you sell jeans, you can include the inseam, thigh circumference, and width of the opening at the bottom.

In this article, we’re focusing on external sizing charts. 

Why are size charts important? 

“Sizing is frequently the number one reason shoppers cite in their decision to shop in-store versus online,” says Dan Weinsoft, ecommerce conversion strategist for conversion optimization advisory firm The Good. “In-store retailers have the advantage of ‘trial-ability’ and ‘observe-ability,’ simply by having a physical product to touch and try on.”

Without these factors, it’s important to get creative when explaining how your apparel fits without overwhelming or confusing the customer. Let’s look at the main benefits of sizing charts: 

  • Helps customers understand what to buy. If it’s a customer’s first interaction with your brand, they have no idea what to expect when it comes to fit. Having a sizing chart on each product page will help them select the right size. And if they’re a repeat customer buying a new arrival, it’s still helpful to make sure they know what size to buy.
  • Reduces returns. Sizing charts give customers a better shot at selecting the right size when they place their order. This way, you don’t have to deal with as many returns due to “wrong size” issues, and customers can enjoy their new purchase right away.
  • Minimizes the need for live chat and email support. The more details you provide on your product pages, the less human intervention you’ll need. If customers can use your sizing charts to figure out which size is best for them, they won’t have to start a live chat or email customer support. 
  • Increases conversions. The faster and easier it is for customers to click “Add to cart,” the more likely they are to convert. If they have to contact support to understand your sizing, it means they’ll deviate away from the product page and may never return to complete their purchase.

An online retailer that does a good job with sizing is Columbia: “Columbia emphasizes the size and fit guide high on their product detail page,” Weinsoft says. “It also designed a prominent on-page size and fit guide with clear, common measurements and a guide to how to measure yourself for the best fit. The brand has done everything but send a tailor out to their customers’ homes to take measurements.”

Columbia sizing guide | Shopify Retail blog

How do I make a clothing brand size chart?

If you design, manufacture, and sell your own apparel products, you’ll want to first create an internal sizing chart, which involves pattern making, fit samples, and other technical steps, to make sure the clothing properly fits a range of sizes. Then you can create an external sizing chart that’s displayed on each of your product pages.

If you stock products from various different brands in your store and online, you’ll only need to focus on the external sizing chart that your customers see. 

The fastest and easiest way to create an external sizing chart that you can add to your product pages is by starting with a spreadsheet (either in Excel or Google Sheets). If you manufacture the products, you already have the measurements, but if you stock other brands, ask for their sizing charts to make sure you’re adding the right information to your website. Your sizing chart should include all the measurements needed to help customers determine the right size for their bodies. 

Here’s an example of a women’s clothing size chart: 

Sizing chart example

💡Quick Tip: You can create a size chart like this in Google Sheets, take a screenshot of it, and add it to the relevant product pages on your website. 

5 sizing chart best practices 

Whether you’re creating a sizing chart from scratch or evaluating the quality of your existing guide, here are five tips to help you move forward with creating an effective size chart for customers:

1. Make sure your sizes are easily understood

“Customers need perspective and scale when shopping online,” says Maria Haggerty, CEO of Dotcom Distribution, a fulfillment provider for ecommerce businesses. “They’re unsure how clothes will fit the first time, and having a reference for comparison to their body type will ensure they can feel confident in their purchase.”

If your clothing comes in small, medium, and large, for example, provide comparable numerical sizes, such as sizes 8 to 10 for medium. You can also include common measurements, such as length, in inches or centimeters. Also know that “one size fits all” isn’t true; it’s more likely “one size fits most.” Spelling out which sizes each product fits can help improve sales. If you offer more than one type of apparel, provide a sizing chart for each product type (i.e., a chart for dress shirt sizes as well as a shoe size chart).

And if you sell clothing for women, men, and children, make sure you create separate sizing charts for each.

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2. Give information that doesn’t require measurements

“Most shoppers don’t know their body measurements offhand, so make sure your sizing chart doesn’t rely solely on that information,” says Linton.

“Very few people have a measuring tape at home, and if they do, the chances they will measure themselves is very low,” he says. “While a size chart is important, it is critical that shoppers can determine their size without requiring a measuring tape.”

Bold Metrics offers software that uses an algorithm to predict a customer’s size by analyzing their height, weight, age, and shoe size. You could include height and weight information on your sizing chart, as well as information about the cut of the item, such as fitted or loose, so customers know how the item is intended to fit and can adjust the size they order for their personal comfort.

3. Include sizing information on each product page 

If a customer is interested in a product, don’t make them search your site for the sizing chart. 

The best way to share a chart is to include it on each product page or have a link that creates a size chart pop-up on the screen. This can help you avoid losing sales due to customers leaving the product page to look up sizing information. 

4. Add a sizing element to customer reviews

Customers who’ve purchased a piece of clothing can help you assist and convert new customers if they can share their experience through a customer review—especially when it comes to fit.

For example, ModCloth offers a customer rating where reviewers rate products as running small, large, or just right. The merchant also allows shoppers to upload photos of themselves wearing that specific item to publish next to their review in order to give other customers an idea of how a piece of clothing fits on a person versus a mannequin or a model.

ModCloth sizing chart | Shopify Retail Blog

These types of thorough reviews can boost a shoppers’ confidence in sizing, helping them make the decision to purchase the item.

5. Be willing to accept returns 

“Although your return policy is a different part of the shopping experience, it will affect how customers feel about finding the right size and making a purchase,” says Haggerty. “Make shipping and returns effortless so that customers know, even if they do get the wrong size, they can easily exchange it for the right one.”

Having a flexible and clear return policy can increase customer confidence. Even if they order a product that doesn’t fit quite right, they can seamlessly get the correct size or their money back.

Accepting in-store returns and exchanges is also a fantastic way to keep consumers confident they’ll end up with the right size at the end of the day. This means making it easy for customers who purchase online to return and exchange their items in your brick-and-mortar store.

Buy online, return in-store (BORIS) is an enticing option for customers who want an immediate refund (versus waiting for returns to be delivered by mail), or who may want to ensure they can exchange an item for the correct size. 

Either way, offering this option can increase consumer confidence—they’ll eventually get the right size for them—even if it doesn’t work out with the first order. And the added benefit for you is increased in-store foot traffic, which can lead to more sales. A customer coming in to return a product may see another item they’d like to buy. 

Create your retail sizing charts

Now that you know what a sizing chart is and why it’s important to include one on each product page, it’s time to get started. Use the above five tips to make your sizing charts and reap the benefits: boosted customer satisfaction, reduced returns, and increased sales and customer lifetime value.

Additional research and content from Alexis Damen.

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Sizing charts FAQ

How does a sizing chart work?

Size charts include body measurements, not garment measurements. Rather than providing specifications for particular designs or garments, a sizing chart shows the general body measurements that correspond to each garment size.

How do you measure sizing?

The most common size chart measurements are bust, waist, and hip, but if you sell apparel that has an intricate design/fit, including more points of measurement on your size charts makes the customer decision-making process easier, and reduces returns.

What is a size run in retail?

A size run in retail is a range of sizes offered for a product. For example, a shoe retailer may offer a size run of 5–10 in a particular style, while a clothing retailer may offer a size run of XS–XL.