Ecommerce · THE NO-PANIC PLAN
Build and publish a verified Shopify product size chart
For a Shopify merchant or catalog editor preparing a size chart for one apparel product or a clearly defined product family. The chart is only as reliable as the measurements and fit notes supplied by the brand or manufacturer: Shopify does not determine your garment measurements or guarantee that letter sizes are equivalent across brands or countries. Keep body measurements distinct from finished-garment measurements, state units and fit assumptions, and confirm every value against a current sample or approved supplier specification before publishing. Shopify's documented pop-up method uses a page-reference product metafield and a compatible product template; themes that do not support dynamic sources may require code or partner help.
MISSION Create an accurate, accessible size chart for a Shopify product and connect it to the right product page.
Build a product size chartTHE REAL-WORLD BIT
What happens outside this browser tab?
Confirm the product and authoritative measurement source, define measurement labels and units, turn verified values into a clear table, connect that content to the correct Shopify product template, then test the live chart against actual variants and accessibility requirements.
YOUR CHECKLIST, WITH FEWER DRAMATIC SIGHES
One step at a time.
Follow the order below. If a step names a Nirmion tool, its link is right there with it.
- 01
Set the product scope and verify the source measurements
Choose one product or a genuinely shared-fit product family and identify the source of truth for its sizing: an approved production sample measured by your team, a current supplier specification, or a fit guide signed off by the product owner. Record the source, version or date, applicable color/style variants and who approved the figures. Decide whether the numbers describe the wearer's body or the finished garment; these are different things and must not be mixed in one grid. Check the measuring method, points, tolerances and ease/fit notes with the supplier or fit specialist, especially for stretch fabrics, relaxed fits and styles whose measurements change by size. Do not fill gaps by interpolating values or copying a generic chart from another brand. If different products use different cuts or size runs, give them separate charts. Shopify's product variants represent real combinations such as size and color, so the chart scope should match the product and variants customers can actually select. (Sources 1, 2)
- 02
Define size labels, units and measurement notes
Create a short data dictionary before laying out the chart. List each displayed size exactly as it appears in the product's size option, then define each measurement column in plain language (for example, garment chest width measured flat, or body chest circumference). Set one consistent unit system for the chart and show it in the column headings or an immediately adjacent note; never leave values unitless. If you need another market's size labels, obtain and approve a separate conversion source for this garment rather than assuming that S/M/L or numeric labels map universally. Add a concise method note explaining where or how the measurement is taken and whether the number is a body or garment measurement. Include a fit note only if the product team has approved it. Check that every variant customers can buy has a corresponding row and that unavailable sizes are handled honestly rather than left as ambiguous blank cells. Keep a version/date with your internal source record so later supplier changes can be traced. (Sources 1, 2, 3)
- 03
Build the chart from approved values
Lay out the approved data with one row per selectable size and clearly named columns for the measurements that help customers choose this product. Add a descriptive title, measurement units and the body-versus-garment note in text that remains visible with the chart; do not rely on color, an image, or a hover hint to explain a column. Use CSV to HTML Table (Nirmion tool 7518) only to format a reviewed, non-confidential sample into table markup. Inspect and correct the generated output before using it: a converter does not validate fit, units, numerical accuracy, Shopify compatibility or accessibility semantics. Preserve the approved source file separately so the page can be rebuilt if supplier values change. Keep the chart concise on narrow screens, but do not remove labels or measurement context to make it fit. W3C guidance requires programmatic relationships between table header and data cells; simple charts need correctly marked header cells, and more complex tables may need explicit row/column scope. (Sources 3, 4)
- 04
Connect the chart to the right Shopify product page
Follow Shopify's documented page-reference pattern if your theme supports dynamic sources: create a product metafield definition for the size-chart page reference; create a product page template with the appropriate block or link; make a Shopify page containing the finished chart and notes; then open each in-scope product, select that page in its Size chart metafield, assign the size-chart template and save. Shopify specifically warns that the link can still appear when its page reference is empty, leaving a blank pop-up, so check every assigned product. Use distinct templates or metafield references when products need different charts, rather than attaching one chart to the entire catalog by default. If the theme lacks dynamic-source support, Shopify says theme-code changes or a Shopify Partner may be needed; do not assume the workflow will work unchanged on a vintage or custom theme. (Sources 1, 2)
- 05
Test the live chart against variants and assistive technology
Preview the published product page on a phone and desktop, open the chart link, and test each assigned product rather than checking only the template preview. Confirm the chart appears once, opens and closes correctly, identifies the product/style and units, contains all purchasable size values, and agrees with the latest approved measurement sheet. Check that the size option values match Shopify's actual variants and that no product with an empty page reference displays a dead chart link. Run the chart markup through Accessible Table Checker (Nirmion tool 30031) as an additional review, then inspect the underlying result: a checker cannot certify all assistive-technology behavior or replace keyboard and screen-reader checks. Ensure header cells are identified and related to their data cells, labels remain understandable when the layout wraps or scrolls, and text is not conveyed by color alone. Have the product owner approve the final numbers and record the source version/date; when supplier specs, fit, or variants change, update and retest the chart. (Sources 2, 3, 4)
THE HELPER CREW
Tools for the fiddly bits.
These are the currently published Nirmion tools matched to this guide. Open a tool page for its accepted inputs and limits.
RECEIPTS, PLEASE
Sources & review notes
Each source is linked to the steps it supports. Open it to check its scope and current guidance.
Source checked 2026-10-06