Why Size Labels Are Meaningless Across Borders
The most expensive mistake a new buyer makes is ordering their usual Western size on a Chinese marketplace. A Chinese large is closer to a Western medium or even small, depending on the brand and item type. Size labels are not standardized across countries, manufacturers, or even product categories within the same factory.
Vanity sizing in Western markets has made the problem worse. Over the past two decades, American and European brands have gradually inflated their size labels to make customers feel better about their measurements. A size medium t-shirt today is closer to what was labeled large in the year 2000. Chinese producers generally do not engage in vanity sizing, which means their labels map to actual measurements more honestly.
The solution is to abandon size labels entirely and work with centimeter measurements. Every serious Chinese seller provides a size chart with actual garment dimensions. Your job is to measure a well-fitting equivalent garment from your own closet and match those numbers to the chart. This method eliminates guesswork and works across every category.
The OOPBUY Spreadsheet includes fit notes for many items, but the ultimate responsibility falls on you as the buyer. Measure carefully, compare diligently, and size up if you are between measurements. It is far easier to tailor a slightly large garment than to stretch one that is too small.
How to Measure Yourself and Your Clothes
You need two basic tools: a flexible measuring tape and a well-fitting garment to use as a reference. For tops, lay the garment flat on a hard surface and measure shoulder width, chest, length, and sleeve. For bottoms, measure waist, hip, inseam, thigh, and rise. Record every number in both centimeters and inches.
Shoulder width is measured across the back from seam to seam. Chest is measured pit to pit and then doubled for full circumference. Length runs from the highest point of the shoulder to the hem. Sleeve length goes from shoulder seam to cuff. For bottoms, waist is measured across the top edge. Hip is the widest point of the seat.
Inseam is the inside leg measurement from crotch to hem. Thigh is measured across the leg at its widest point. Rise is from the waistband to the crotch seam. These five measurements for bottoms tell you almost everything you need to know about fit. Compare each to the seller size chart and choose the size where most measurements align.
If your measurements fall between two sizes, consider the garment type and your fit preference. For slim or skinny cuts, size up. For oversized or relaxed cuts, you may size down. Stretch fabrics allow more forgiveness than rigid fabrics. Woven fabrics like dress shirts have less give than knit fabrics like t-shirts.
Pre-Order Measurement Routine
Category-Specific Sizing Rules
T-shirts and casual tops generally run one size smaller than Western labels. If you normally wear a medium, order a large on Chinese marketplaces. Hoodies and sweatshirts often run true to size or slightly small depending on the intended fit. Oversized hoodies should be ordered true to size because the cut is already generous.
Jackets and outerwear require extra room for layering. Measure over a typical layer you would wear underneath, like a hoodie or sweater. Add 2-4 centimeters to your chest measurement for comfort. Chinese jackets are sometimes cut shorter in the body than Western styles, so check the length measurement carefully if you are tall.
Pants are the most inconsistent category. Chinese pants often have a lower rise and narrower thigh than Western equivalents. If you have muscular thighs or prefer a relaxed fit, size up and check the thigh measurement specifically. Selvedge denim rarely stretches significantly, so err on the side of slightly loose rather than tight.
Shoes are measured by insole length in centimeters. Place a ruler inside your best-fitting shoe and note the length from heel to toe. Compare this to the seller size chart rather than using your normal shoe size. Chinese shoes often run narrow, so width matters if you have broad feet. Some sellers offer wide options; otherwise, sizing up half a size adds slight width.
Vanity Sizing Trap: Western brands have inflated size labels by up to two sizes since 2000. A Chinese "Large" is often closer to an American "Medium" from 15 years ago. Always trust centimeters over letter sizes.