Size chart vs size guide: what's the difference?
A size chart is the table of measurements. A size guide is everything that helps a customer choose: the chart, how to measure, fit notes and tips. Here's what to include in each.
People use "size chart" and "size guide" to mean the same thing, and on most stores they appear together. But there's a useful difference, and knowing it helps you build a better product page.
What is a size chart?
A size chart is the table: sizes in one direction, measurements in the other.
| Chest (cm) | Length (cm) | |
|---|---|---|
| S | 96 | 70 |
| M | 102 | 72 |
It answers one question: "What are the numbers for each size?"
A good size chart:
- uses clear column names (chest width, inseam, foot length)
- says which units it uses, or offers a cm/in switch
- says whether the numbers are garment or body measurements
- stays short enough to read on a phone
What is a size guide?
A size guide is everything that helps a customer choose the right size, and the size chart is one part of it. A complete size guide usually has:
- The size chart itself
- How to measure: a labelled diagram and short steps, so customers measure the same way you did
- Fit notes: "runs small", "relaxed fit", "model is 180 cm and wears M"
- Tips for in-between sizes: whether to size up or down
- Size conversions, where relevant, for example US, UK and EU shoe sizes
It answers the bigger question: "Which size should I buy?"
Which one do you need?
Both. A table on its own leaves customers guessing how to measure themselves or what the numbers mean. A guide without a table has nothing concrete to compare against.
The simplest setup that works well is one pop-up with two tabs:
- Size chart: the table, with a cm/in switch
- How to measure: the labelled diagram and steps
Then add a one-line fit note above the table.
Examples by product
| Product | In the size chart | Extra guide content |
|---|---|---|
| T-shirt | Chest width, length, sleeve | Flat-lay diagram, fit note |
| Jeans | Waist, hip, inseam, leg opening | "Measure a pair that fits you" tip |
| Bra | Band and cup sizes | How to measure underbust and bust |
| Shoes | US, UK and EU sizes, foot length | How to measure your foot |
| Ring | Ring size, inner diameter | How to measure a ring you own |
Our free size chart templates are built this way: each one has the table, a labelled how-to-measure drawing and a fit tip.
How to add both in Shopify
Shopify doesn't have a size chart feature, so you'll use either a page in your theme's pop-up block or a size chart app. An app like Jotly lets you build the chart and guide together, with tabs, images, video and a fit scale, and show it on the right products automatically. See How to add a size chart to Shopify for both methods step by step.