Size guide block

The Size guide is a Product template block, not a template. Fit Check can power that block with a Shopify Size Chart metaobject and a product metafield named custom.size_chart.

Use this setup when products need different charts but the same Product page layout. One Product template can keep the same Size guide block while tops, jeans, shoes, accessories, and one-off products each use their own Size Chart entry. Create separate Product templates only when the page layout itself needs to change.

For a screenshot-led workflow from Shopify Admin to the Theme editor, use the Size guide setup guide.

Setup Order

Create the Size Chart metaobjectIn Shopify admin, create a Size Chart metaobject definition with the exact fields Fit Check reads.
Create the product metafieldCreate a Product metafield named Size chart with namespace and key custom.size_chart, using a metaobject reference to Size Chart.
Add chart entriesCreate one Size Chart entry for each sizing system, garment category, or product-specific chart.
Assign the chart to productsOpen each product and select the matching Size Chart entry in the Size chart metafield.
Enable the Product template blockIn the theme editor, set the Size guide table block to use Product size chart metaobject.

Create the Metaobject Definition

In Shopify admin, go to Settings > Custom data > Metaobjects, then create a metaobject definition named Size Chart.

Add these fields:

Field name	Field key	Type	Required	What to enter
Title	`title`	Single line text	Yes	The chart name shown in the Size guide drawer, such as `Jeans size chart`.
Source unit	`source_unit`	Single line text	Yes	Enter `inches` or `centimeters`.
Headers	`headers`	Single line text	Yes	Pipe-separated column labels, without units, such as `Size
Rows	`rows`	Multi-line text	Yes	One pipe-separated row per line. The first value is the size label.
Fit note	`fit_note`	Multi-line text	No	Optional fit guidance shown below the table.
Measurement note	`measurement_note`	Multi-line text	No	Optional measuring guidance shown below the table.

Set Title as the display name field if Shopify asks which field should identify entries.

If Shopify shows storefront or access options for the definition, keep the Size Chart available to the storefront so the theme can read the assigned entry.

Create the Product Metafield

Go to Settings > Custom data > Products, then add a product metafield definition.

Use these values:

Setting	Value
Name	`Size chart`
Namespace and key	`custom.size_chart`
Type	Metaobject reference
Reference	Size Chart

Pin the metafield if your team edits size charts often. Pinning is optional, but it makes the field easier to find on product pages in Shopify admin.

Add a Jeans Chart Entry

Go to Content > Metaobjects, open Size Chart, and add an entry.

Example jeans entry:

Field	Example value
Title	`Jeans size chart`
Source unit	`centimeters`
Headers	`Size
Rows	`24
Fit note	`Runs true to size.`
Measurement note	`Measurements are body measurements in centimeters.`

Because source_unit is centimeters, Fit Check displays the source table in centimeters and automatically creates the inches table. The size label column stays unchanged, while measurement columns are converted.

For example, the first jeans row displays:

Table	Size	Waist	Hip	Inseam	Rise
Source	`24`	`61 cm`	`86 cm`	`76 cm`	`24 cm`
Converted	`24`	`24 in`	`33.9 in`	`29.9 in`	`9.4 in`

Add a Tops Chart Entry

Use the same definition for tops. Only the entry content changes.

Example tops entry:

Field	Example value
Title	`Tops size chart`
Source unit	`inches`
Headers	`Size
Rows	`XS
Fit note	`Choose your usual size for a close fit.`
Measurement note	`Measure around the fullest part of the chest.`

Because source_unit is inches, Fit Check displays the source table in inches and automatically creates the centimeters table.

Assign the Chart to Products

Open each product in Shopify admin, then find the Size chart metafield.

Choose the matching Size Chart entry:

Product type	Suggested entry
Jeans	`Jeans size chart`
T-shirts, shirts, jackets	`Tops size chart` or a more specific tops chart
Shoes	A shoe-size chart entry
One product with unique measurements	A product-specific chart entry

Save the product.

Enable the Theme Block

In the theme editor:

Open Products and choose the Product template that includes the Size guide drawer.
Open the Size guide drawer content.
Select the Size guide table block.
Set Size guide data source to Product size chart metaobject.
Choose what should happen when a product has no chart:
- Show manual table keeps the block’s manual fallback table visible.
- Hide size guide hides the table when no product chart is assigned.
Save the theme.

The default Product template can keep its manual fallback table. Once a product has custom.size_chart assigned, the metaobject content takes over for that product.

How Unit Conversion Works

Fit Check reads the source_unit field from the Size Chart entry:

Source unit	Source table	Converted table
`inches`	Inches	Centimeters
`centimeters`	Centimeters	Inches

The toggle in the Size guide drawer switches between the source and converted tables. Ranges are supported, including values like 32-34, 32–34, and 32 to 34.

Use only measurements in the measurement columns. Put text labels, such as XS, S, 24, or 30 Short, in the first column.

Troubleshooting

Issue	Check
The manual table still appears	Confirm the product has a value in `custom.size_chart`, and the Size guide table block is set to Product size chart metaobject.
The chart is missing	Confirm the product metafield references a Size Chart entry, not plain text.
Values are not converting as expected	Confirm `source_unit` is exactly `inches` or `centimeters`, and measurement cells contain numbers or number ranges.
Header units look wrong	Enter headers without units. Fit Check adds `(in)` or `(cm)` based on the selected unit.
Different categories need different columns	Create separate Size Chart entries with different `headers` and `rows`. You do not need separate Product templates unless the page layout changes.