At SnapSpreadsheet, we manage thousands of cross-border transactions annually. We have moved beyond simple conversion charts to understand the systemic differences between GB/T (Chinese National Standards) and ASTM (American standards). This guide is designed to bridge that gap, moving from “guessing” to precise engineering.
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The Philosophy of Fit: Metric vs. Imperial Standards
To navigate size conversion China to US accurately, one must understand the underlying philosophy of the two regions. The United States generally relies on the Imperial system (inches), where sizing often accounts for “vanity sizing”—the industry practice of labeling clothes smaller than their actual measurements to flatter the consumer.
Conversely, China strictly adheres to the Metric system (centimeters) and the GB/T National Standards (Guobiao). These standards are less forgiving and more rooted in actual body dimensions. The “average” fit in China is also based on a different anthropometric model:
The US Profile (ASTM)
Typically designed for a frame with broader shoulders, a deeper chest depth, and a higher height-to-weight ratio. Standard fits are often “Boxy” or “Relaxed” to accommodate movement.
The CN Profile (GB/T)
Designed for a leaner frame with narrower shoulders and a shorter torso length. The default fit is “Slim,” often with smaller armholes and tighter sleeves.
When you ignore these nuances, you aren’t just risking a return. You are wasting time. At SnapSpreadsheet, we recommend a general rule: Shift up 2 to 3 sizes when moving from CN to US, but always validate with measurements.
Decoding the Label: What “170/88A” Means
Unlike the abstract “S/M/L” system, the Chinese standard (GB/T 1335 for Men, GB/T 1333 for Women) provides a precise code on the tag. You will often see a tag reading 170/88A. This is the truth of the garment.
Technical Breakdown: 170 / 88 / A
- 170: Represents the recommended Height in centimeters (approx 5’7″).
- 88: Represents the Chest (Men) or Bust (Women) circumference in centimeters (approx 34.6 inches).
- A: Represents the Body Type / Drop.
- Y: Slender/Slim (Large drop between chest and waist).
- A: Standard/Normal (The most common variation).
- B: Slightly Overweight/Stout.
- C: Obese/Broad (Rarely seen in fashion brands).
If you are a US Medium, you likely have a chest measurement of 38-40 inches (96-101cm). Therefore, purchasing a Chinese “M” (often 165/84A or 170/88A) will be physically impossible to button. You would need at least a 175/96A or 180/100A.
Mens Clothing Size Conversion China to US
Men’s fashion in China generally defaults to a “Slim Fit” aesthetic. Even items labeled “Casual” will have higher armholes and narrower sleeves than their American counterparts. For sourcing agents and buyers, the shoulder width is often the critical point of failure. If the shoulders are too narrow, the garment cannot be altered.
Men’s Shirts & Tops Conversion Matrix
Use the following table as a baseline guide. Note that “International Size” refers to the generic tag (S/M/L) sewn onto the garment.
| CN Tag (GB/T) | Approx US Size | Chest (cm) | Chest (inches) | Fit Expectation |
|---|---|---|---|---|
| M (165-170/84-88) | XXS / XS | 84 – 88 | 33″ – 34″ | Very Tight / Youth Fit |
| L (170-175/88-92) | XS / S | 88 – 92 | 35″ – 36″ | Slim / Form Fitting |
| XL (175-180/92-96) | Small (S) | 92 – 96 | 36″ – 38″ | Fitted |
| 2XL (180/100) | Medium (M) | 98 – 102 | 39″ – 40″ | Standard |
| 3XL (185/104) | Large (L) | 104 – 108 | 41″ – 42″ | Comfort |
| 4XL / 5XL | XL | 110 – 116 | 43″ – 45″ | Relaxed |
Expert Sourcing Tip: When purchasing outerwear (Jackets, Coats) from China, check the fabric composition. Non-stretch materials (like 100% cotton canvas or wool) require you to size up more aggressively than knitwear or spandex blends.
Women’s Sizing: A Revolution in Accuracy
Women’s sizing presents higher variance due to the complexity of silhouette and drape. In the Chinese domestic market, the “A-shape” silhouette is less common than the “H-shape” or “Straight” silhouette. This means garments may not accommodate wider hips as generously as Western brands.
The “Free Size” (Jun Ma) Caveat
You will frequently encounter a size labeled “F” or “Free Size” (均码). In the US, “One Size Fits All” usually implies a loose, oversized garment. In China, “Free Size” is specific: it generally targets a height of 155-165cm and a weight of 45-55kg.
Women’s Dresses and Tops Conversion
| CN Size | US Size | UK Size | Bust (cm) | Waist (cm) |
|---|---|---|---|---|
| S | 0 – 2 (XS) | 4 – 6 | 80 – 84 | 60 – 64 |
| M | 4 (S) | 8 | 84 – 88 | 64 – 68 |
| L | 6 – 8 (M) | 10 | 88 – 92 | 68 – 72 |
| XL | 10 (L) | 12 | 92 – 96 | 72 – 76 |
| 2XL | 12 (XL) | 14 | 98 – 102 | 78 – 82 |
Convert Chinese Shoe Size to US: The Millimeter Rule
Footwear is the foundation of comfort. The Chinese shoe sizing system (Mondopoint based) is actually more logical than the US system—it is based directly on the length of the foot in millimeters (mm).
In China, a size “250” means the shoe is designed for a foot that is 250mm long. This is often abbreviated to “40” (Euro sizing). The US system, however, is abstract. When you convert, you are translating a physical measurement into an arbitrary integer.
Chinese Baby Clothes Size to US Conversion
Children grow rapidly, and their clothing sizing should reflect their physical stature, not just their age. The Chinese system for children is superior in this regard, as it relies on the child’s height in centimeters (e.g., 90cm, 100cm) rather than the ambiguous “Age” system (2T, 3T) used in the US.
A tall 2-year-old might not fit a US 2T, but they will perfectly fit a Chinese Size 100 if they are 95-100cm tall. It removes the guesswork.
| CN Size (Height cm) | US Size (Age/Type) | Weight Guidelines (lbs) |
|---|---|---|
| 52 / 59 | 0-3 Months | Up to 12 lbs |
| 66 | 3-6 Months | 12-17 lbs |
| 73 | 6-12 Months | 17-22 lbs |
| 80 | 12-18 Months | 22-27 lbs |
| 90 | 2T | 27-30 lbs |
| 100 | 3T | 30-33 lbs |
| 110 | 4T | 33-36 lbs |
| 120 | 5 | 36-40 lbs |
A Word from Our Founder, Shengbin Lin
“Hello, I’m Shengbin Lin. For over 15 years, my passion has been to connect the world to the incredible variety of goods China has to offer. I’ve seen firsthand the challenges international buyers face—particularly with sizing—and I built CNSNAP.CLUB and SnapSpreadsheet to be the solution. My team leverages years of experience in supply chain management and quality control to ensure your cross-border shopping is simple, secure, and successful.”
Direct Contact: [email protected]
Frequently Asked Questions (FAQ)
What is Chinese size XL in US size?
Generally, a Chinese XL equates to a US Medium. However, this depends on the body type cut (A or Y). A “Slim Fit” Chinese XL may feel tighter than a standard US Small in the shoulders.
Is a Chinese size 40 shoes in US a size 8?
For Men, a CN 40 is roughly a US 7. For Women, a CN 40 is roughly a US 9. Always check if the shoe is sized for men or women, as the numbering system (Euro) is unisex but the conversion to US sizes is not.
Why are Chinese sizes generally smaller?
They are designed based on the GB/T National Standard, which uses the average anthropometric data of the East Asian population. This demographic historically has a smaller average frame and height compared to the North American average used for ASTM standards.
Don’t Settle for the Wrong Fit
Size conversion shouldn’t be a gamble. At CNSNAP, we believe in removing the friction of international logistics. Whether you are buying one shirt or stocking a warehouse, let us handle the details.
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