How to Add a Size Chart in Shopify (With or Without an App)

Adding a size chart to your Shopify store is the cheapest way to answer the one question that decides most apparel sales: “what size should I buy?” Get it right and shoppers buy with confidence. Get it wrong — or leave it out — and you pay twice: once in carts abandoned by unsure shoppers, and again in returns when the ones who guessed got it wrong. Fit and sizing are consistently the number-one reason online clothing comes back, by some estimates close to 38% of apparel returns.

This guide covers every realistic way to add a size chart in Shopify — including how to do it without an app, and the faster no-code app method most stores end up using. We’ll be honest about the trade-offs of each so you can pick the right one.

The four ways to add a size chart in Shopify

There are four common methods, from the quickest-but-most-limited to the most capable:

1. Add a size chart image to the product description — no app, but static and clunky on mobile.
2. Create a size guide page and link to it — no app, but it pulls shoppers away from the product.
3. Use metafields or theme code — no app, but needs a developer and breaks on theme updates.
4. Use a size chart app — no code, mobile-friendly, per-product charts, and optional AI size recommendations.

Let’s walk through each.

Method 1: Add a size chart image to the product description (no app)

The fastest way to get something live. Create your chart in a spreadsheet or design tool, export it as an image, and insert it into the product description.

1. Open Products in your Shopify admin and select a product.
2. In the Description rich-text editor, click the Insert image button.
3. Upload your size chart image and save.

Good for: a single product, or testing whether a chart helps at all.

The catch: images don’t scale well on phones (where most shopping happens), the text often becomes unreadable, there’s no unit switching (cm ↔ in), and you have to paste the same image into every product by hand. Update one measurement and you’re re-exporting and re-uploading everywhere.

Method 2: Create a size guide page and link to it (no app)

Instead of repeating an image on every product, build one size guide page and link to it from your products.

1. Go to Online Store → Pages → Add page and build your chart (the page editor supports a basic table).
2. Save and note the page URL, e.g. /pages/size-guide.
3. In each product description, add a link such as “View our size guide.”

Good for: stores where one chart covers most products.

The catch: the link navigates shoppers away from the product page at the exact moment they’re deciding to buy — a conversion leak. It’s also still one chart for everything, which rarely matches reality when you sell multiple brands or categories.

Method 3: Use metafields or theme code (no app, for developers)

For full control without an app, you can store chart data in metafields and render it in your theme with Liquid, or hard-code a chart block into your product template.

1. Define a metafield (e.g. custom.size_chart) under Settings → Custom data.
2. Edit your theme’s product template to display the metafield in a popup or section.
3. Repeat the wiring for each template that needs it.

Good for: developers who want a bespoke result and are comfortable in Liquid.

The catch: it requires code, every theme update risks breaking it, and you’re rebuilding from scratch the things an app gives you for free — mobile layout, unit conversion, multi-language, and per-product targeting. For most merchants this is more maintenance than it’s worth.

Method 4: Use a size chart app (the no-code way)

This is what most stores land on, because it removes every “catch” above at once. A good size chart app adds a Size Chart button right next to the size selector, opens a clean popup without leaving the page, and lets you assign different charts to different products — all without touching code.

SmartSize does this and adds the parts the manual methods can’t:

• AI builds the chart for you — upload a size chart image, screenshot, or spreadsheet and AI fills in every row and column automatically.
• Mobile-friendly by default, with automatic unit conversion (cm ↔ in, kg ↔ lbs) and international size mappings (US / EU / UK / JP).
• One-click AI translation into every storefront language.
• An optional AI fit quiz (a “find my size” recommender) that tells each shopper a single, confident size — turning the chart from a passive reference into an active recommendation.

It installs via Shopify’s theme app extensions, so there’s no code and nothing to re-fix when your theme updates. There’s a free plan to start, with paid tiers on the pricing page .

Which method should you use?

If you only sell one product, Method 1 is fine for now. For everyone else — multiple products, multiple categories, or shoppers on phones — a size chart app is the method that actually scales and protects your conversion rate.

How to add a size chart with SmartSize in 3 steps

1. Install SmartSize from the Shopify App Store and enable the app embed in your theme editor (one click).
2. Upload your existing size chart image or spreadsheet — AI turns it into an editable chart in seconds.
3. Publish. The Size Chart button appears automatically next to your size selector. Optionally turn on the AI fit quiz to recommend a size to every shopper.

Frequently asked questions

Ready to stop shoppers from guessing? Add a professional size chart — and an optional AI fit finder — to your store in minutes.