Size chart vs size guide: what's the difference

A size chart is a table: sizes on one side, measurements on the other, so a shopper can match their numbers to a size. A size guide is the chart plus everything that makes it usable: how to measure, how the item fits, what to do between two sizes, and ideally a way to get a size straight from the shopper's measurements.

The two words are used for the same thing all the time, on product pages and in apps. The difference still matters, because a chart on its own leaves the shopper to do half the work.

The size chart: the table

Here is a size chart, the body measurements of Ruban Size's men's shirts template:

It answers one question well: which size goes with which numbers. A good chart gets a few things right on top of that: ranges rather than single values, the unit in every header, body or garment measurements said plainly, and other size systems (US, UK, EU) on their own rows when shoppers come from several countries.

What it doesn't answer is everything around the numbers. Where does the tape go for a neck? Does this shirt run small? What if the neck says M and the chest says L?

A shopper who guesses any of those can end up with the wrong size, even with a perfect table.

The size guide: the chart and what makes it usable

The men's shirts template answers those three questions next to its table. Its how to measure step for the neck: "Around the base of your neck, one finger under the tape." Its fit: true to size. Its note: "Choose your collar size first, then check the chest." That is the difference between a chart and a guide, in three lines.

A full size guide has six parts:

Not every product needs all six. A belt chart doesn't need a gallery. But every product with sizes needs the first three, and the size finder is what turns a table into an answer.

Here is the women's tops template as a full guide: body and garment measurements in two tabs, US, UK and EU rows, a how to measure figure, the fit scale set to true to size with its note, and Find my size. Switch the units, then try it with your own numbers.

Why the difference matters for a store

Every part of the guide removes a guess. The how to measure steps stop shoppers measuring over a sweater or around the wrong part of the waist. The fit scale tells them a pair of jeans runs slightly small before they order, not after. A size finder settles the case where two measurements point to two sizes, which a table can't do by itself.

A size chart pasted as an image does even less: it can't switch units, it is hard to read on a phone, and nothing on the page can use its numbers. A guide built from real values can do all three.

What a size guide looks like in Ruban Size

The link. A "Size guide" link sits next to the size option. The app embed places it there by itself on 25 of the 26 themes most used by stores with size charts, or you drag the app block where you want it in the theme editor. The link text is yours to change, chart by chart. Where to put the size chart compares the spots on a product page.

The window. The guide opens as a popup that slides up from the bottom on phones (on every plan), or as a side drawer, inline on the page, in an accordion, from a floating button, or in a quick view. There is also a size guide page that lists every chart, with search and categories. Fonts and colors follow your theme by default; the design page shows the rest.

The blocks. The size chart editor builds a guide from blocks: size table, text, image, video, how to measure, tabs, columns, accordion, divider, image and text, and gallery. A shared section, such as a measuring guide or a returns note, is written once and used in as many charts as you like.

The finder. Find my size asks for the measurements the chart uses and answers with one size, how sure it is, and one line per measurement. It works on 37 of the 39 templates; the two others, necklaces and socks, are conversion tables.

A checklist for your own size guide

1. One table per kind of product, in centimeters and inches.
2. A header that says body or garment measurements.
3. How to measure, one step for each measurement in the table.
4. A fit scale and a one-line fit note.
5. What to do between two sizes.
6. A size finder that works from the shopper's own measurements.

How to add a size chart to Shopify takes you through setting one up, from template to product page.

Questions

Is a size chart the same as a size guide?

People use the two words for the same thing. Strictly, the chart is the table of sizes and measurements, and the guide is the chart plus how to measure, fit information and help choosing a size.

What should a size guide include?

At least the size table with units, how to measure each row, and how the item fits. A note for shoppers between two sizes and a size finder that works from measurements make it complete.

Should the link say "size chart" or "size guide"?

Shoppers understand both. Ruban Size's link says "Size guide" by default, and you can change the text for each chart.

Do I need a separate size guide page?

It is optional but useful for shoppers who want to check sizes before choosing a product. Ruban Size can add a page that lists every chart, with search and categories.