Use measurements, not a familiar letter alone
A medium on one source listing may not match another seller's medium. For a candidate such as the graphic T-shirt and shorts set (7819865565) or the hoodie set (7819033111), open the current seller page and locate the actual size chart.
- Lay a garment you already like flat. Measure chest width, shoulder width, body length and sleeve length where relevant.
- Write down whether the seller chart uses garment measurements or body measurements. They are not interchangeable.
- Compare each dimension in the same unit; if needed, convert inches to centimeters using 1 inch = 2.54 cm.
- Check whether the selected listing is a set. Top and bottom pieces may have separate measurements or a shared size option.
- If the chart is missing or ambiguous, ask the seller or purchasing service for clarification before ordering.
Keep your size note attached to the item ID
Save the exact source ID and date with the chart you consulted. A screenshot without the listing identity can become misleading when the seller edits a product page. Warehouse photos may show a label, but they cannot guarantee fit. See the QC checklist for what photos can and cannot confirm.
Measure the same way the chart does
For a flat garment, record whether the chest value is a width across the front or a full circumference. A width of 50 cm and a circumference of 50 cm describe very different garments. The seller's chart may use either convention, so read its diagram or labels before comparing numbers. For pants, waist, rise and inseam can be more useful than a letter size.
Do not choose a larger size automatically because a listing is from China. Compare actual measurements for the specific product and decide how much ease you want for layering or movement. Save the chart alongside the selected item ID in case the seller edits the page before checkout.