Sizing Charts: How to Make a Size Chart for your Retail Business

Small, medium, and large: these sizes can vary widely in terms of actual fit, which can be a challenge if you sell clothing.

A Size 6 dress can fit snugly in one store and hang loose in the next, because apparel sizing is anything but standardized. The stakes climb online, where shoppers can’t step into a fitting room and often abandon carts, or buy multiples to hedge their bets.

That uncertainty is costly. In fact, a 2025 survey of 6,000 global consumers found 61% returned apparel because it didn’t fit. For retailers, those returns eat into margins and chip away at customer loyalty. 

A clear sizing chart removes the guesswork, enabling buyers to choose the right size the first time—while reducing returns. In this guide, you’ll learn what a sizing chart is and the exact steps to create one. 

What is a sizing chart? 

A sizing chart lists your product’s sizes alongside the body dimensions each size is designed to fit. Shoppers use it to choose the right option both online and in-store. 

For retailers, sizing charts serve two purposes: internally, they guide product development and ensure consistency; externally, they help customers select with confidence and reduce costly returns.

Body measurement vs. garment measurement

There are two main approaches to sizing charts. Many brands use one or both depending on their products:

• Body measurement charts match each size to key body dimensions—like bust, waist, hip, height, and shoulder—so shoppers can compare the numbers to their own shape. This format is most helpful for first-time buyers and aligns with global sizing standards such as ISO 8559.
• Garment measurement charts list the finished specs of the item itself (e.g., chest width, outseam, leg opening). They’re useful for styles where drape or ease matters, such as oversized sweaters, tailored jackets, or denim. Experienced shoppers can decide how much room they want.

Many brands now provide both. Indian clothing retailer Lashkaraa, for example, shows both formats on one page.

• Body Measurements are listed first, specifying the wearer’s dimensions that each size is designed to fit (e.g., Size M chest = 40 inches).
• Garment Measurements appear below and show the finished dimensions of the clothing itself (Size M chest = 44 inches), building in the extra “ease” needed for comfort and drape.

Because both tables use the same measurement points, shoppers can first match their own body numbers, then confirm how the garment will fit when worn.

Why accurate sizing charts are critical for ecommerce

Online shoppers can’t zip, button, or twirl before they buy, so your size chart has to do the convincing. Here are two key reasons why: 

In-store confidence vs. online uncertainty

“Sizing is frequently the number one reason shoppers cite in their decision to shop in-store versus online,” says Dan Weinsoft, ecommerce conversion strategist at The Good.

“In-store retailers have the advantage of ‘trial-ability’ and observability, simply by having a physical product to touch and try on,” Dan continues. 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 helps them select the right size. 

Columbia is one online retailer that gets it right: “Columbia emphasizes the size and fit guide high on their product detail page,” Dan 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.”

Fit issues drive expensive returns

“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, cofounder of Bold Metrics. 

“In fact, the average online apparel retailer experiences a return rate of 28%, and 80% of these returns are due to fit issues,” Morgan adds. A Coresight Research survey backs this up. The survey found that size and fit are the top reasons for 53% of returns, contributing to a 24.4% online apparel return rate.

A clear sizing chart gives customers a better shot at selecting the right size on the first try. For your business, that means fewer costly returns due to “wrong size” issues, higher conversion rates, and stronger customer loyalty over time.

How to create a size chart in four steps

1. Determine your key measurements
2. Document your measurement in a template
3. Add a “how to measure” guide on your product page
4. Include international size conversions

1. Determine your key measurements

Start by listing every body point that influences how the garment fits. At minimum, capture:

• T-shirts and knit tops: Chest/bust width, shoulder width, body length, sleeve length
• Dresses: Bust, waist, hip, garment length (shoulder to hem), sleeve length, sometimes shoulder breadth for tailored styles
• Pants and jeans: Natural waist, high hip, low hip, front rise, thigh circumference, inseam, leg opening

If you manufacture the products, you already have the measurements. If you stock other brands, ask for their sizing charts to make sure your site includes accurate information. The more precise your measurements, the fewer returns you’ll face from customers ordering the wrong size.

2. Document your measurements in a template

Transfer the numbers into a spreadsheet and keep units (inches or centimeters) consistent. Lock the top row so every column label stays visible as you scroll.

Here are a few templates to use when building out your spreadsheet.

Women’s apparel

Columns: Size (XS–XXL) | Bust | Waist | Hip | Garment length | Sleeve length

Men’s apparel

Columns: Size (S–XXXL) | Chest | Neck | Natural waist | Hip | Inseam | Sleeve length

Unisex T-shirt

Columns: Size (XS–5XL) | Chest width (flat) | Body length (shoulder-to-hem) | Sleeve length (center-back)

3. Add a "how to measure" guide

Once you’ve documented your measurements, help your customers use them correctly. Adding a clear “how to measure” guide shows shoppers exactly how to take their own measurements and compare them to your chart.

The easiest way to add this to your site is with a Shopify app like Mageplaza’s Size Chart & Size Guide. You can import a CSV, or start with one of the 23 industry-specific templates provided. 

Customize every detail with a built-in editor. Tweak colors, fonts, layouts, and add images or videos without touching code. 

You can also activate the smart size recommender, so shoppers get a personalized fit suggestion from their own measurements. The charts you make can also show up anywhere (inline, popup, or floating icon) and are optimized for mobile, tablet, and desktop. 

For example, motorcycle apparel brand Bohn Body Armor embeds a sizing popup alongside illustrated body shapes and fit notes. Scroll down and you’ll find measurement charts as well.

4. Include international size conversions

If you sell internationally, add a second tab or toggle in every chart that maps your core sizes to global standards. Consider the US, UK, EU, Australia, and Japan at minimum, and give shoppers the option to switch between inches and centimeters. 

Start with your SKUs (e.g., a US women’s Size 8 ≈ UK 12 ≈ EU 40), then add footwear or lettered equivalents as needed.

Online fashion marketplace Farfetch nails this with a conversion-chart popup that defaults to UK/US sizing, then lets shoppers pick Italy/France, Japan, Brazil, and more from a single dropdown.

Five sizing chart best practices 

Whether you’re creating a sizing chart from scratch or improving an existing one, these best practices will help ensure your sizing information builds customer trust and reduces returns:

1. Make sure your sizes are easily understood

“Customers need perspective and scale when shopping online,” says Maria Haggerty, CEO of Dotcom Distribution (recently acquired by Ryder System, Inc.). “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, pair those labels with equivalent numerical sizes (e.g., Medium = sizes 8–10). 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.” 

If you sell multiple apparel types or categories—like shirts, shoes, or kidswear—create separate sizing charts for each to avoid confusion.

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 Morgan from Bold Metrics.

“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.”

Including details like height, weight, or cut notes (e.g., fitted vs. relaxed) helps customers choose if they don’t have a tape measure handy. Tools like Bold Metrics use this data to predict size. In-store teams can pull the same data through retail clienteling apps, using a shopper’s past purchases and ideal size to speed up fittings on the sales floor.

3. Include sizing information on each product page 

Make it easy for customers to get the information they need. Place a sizing chart on each product page or have a link that creates a size chart popup on the screen. This can help you avoid losing sales due to customers leaving the product page to look up sizing information. 

💡Tip: Pair a size chart with virtual fitting rooms so shoppers can spin a 3D avatar and see how fabric drapes before they click “Add to Cart.”

4. Add a sizing element to customer reviews

Customers who’ve purchased a piece of clothing can help convert new shoppers by sharing their experience through customer reviews—especially when it comes to fit.

Let reviewers rate products as running small, large, or just right. You can also allow shoppers to upload photos of themselves wearing the item. This gives future buyers a real comparison of how a garment fits on different body types versus a mannequin or a model.

These types of reviews don’t replace your sizing chart, but can reinforce it. They boost a shopper’s 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 customer experience, it will affect how customers feel about finding the right size and making a purchase,” says Maria from Dotcom Distribution. “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. Your sizing chart should prevent most issues with fit, but a strong return policy reassures shoppers that they won’t be stuck if something doesn’t work out.

Accepting retail returns and exchanges keeps consumers confident they’ll end up with the right size in the end. Make 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 want to leave with the correct size the same day. 

Either way, offering this option boosts confidence in your sizing guidance and drives in-store foot traffic, which can lead to more sales.

Create your retail sizing charts

Now that you know what a sizing chart is, why it’s important for your clothing store, and how to build one, it’s time to get started. A clear, accurate chart is one of the simplest ways to boost customer satisfaction, reduce returns, and increase sales. Done well, your sizing guide becomes more than a reference tool—it’s a driver of customer lifetime value and long-term growth.