SuperBuy Sizing Guide: How to Pick the Right Fit Every Time

Across every product category in the SuperBuy spreadsheet ecosystem, sizing mistakes account for more returns and exchanges than quality issues, shipping damage, and wrong items combined. The reason is straightforward: the sizing systems used by factories and sellers in the spreadsheet supply chain are not aligned with the sizing expectations of US buyers. An item labeled "Large" in a factory size chart might correspond to a US Medium, or even a Small, depending on the factory's target market and production standards. In 2026, some curators have started including detailed sizing notes in their spreadsheets, but the majority still rely on generic size labels that require interpretation. The problem is compounded by factory variance. Even within the same batch, two "Large" hoodies might measure slightly differently because the cutting and sewing process has natural tolerances. A one-centimeter difference in chest width is enough to change whether a hoodie fits comfortably or feels tight across the shoulders. For shoes, the issue is even more acute because lasts — the molds around which shoes are constructed — vary between factories. A size 10 from one factory might fit like a 10.5 from another. The only reliable way to avoid sizing errors is to stop trusting size labels and start trusting measurements. This requires a small investment of time — measuring your own body or your best-fitting clothes — but it eliminates the vast majority of fit-related disappointment.

The fundamental difference between Asian and US sizing is not just a linear offset where every size runs one step smaller. It is a structural difference in proportions. Asian sizing is designed for average East Asian body proportions, which tend to have narrower shoulders, shorter torsos, and slimmer arm lengths relative to chest width than the average US wearer. This means that simply sizing up one full size does not always solve the problem. A US buyer who normally wears a Medium might find that an Asian Large fits the chest but has sleeves that are too short, or that the shoulders are still narrow despite the overall width increase. For tops and outerwear, the most important measurements are shoulder width, chest circumference, sleeve length, and overall length. For bottoms, the critical numbers are waist circumference, hip circumference, inseam length, and thigh width. Shoes require a different approach: instead of relying on size labels, you need the insole length in centimeters or millimeters. A US men's size 10 typically corresponds to an insole length of approximately 28 centimeters, but factory charts sometimes use 27.5 or 28.5 depending on their last. The spreadsheet notes column sometimes includes these measurements, but when it does not, you should ask the community or measure based on the seller's size chart. The golden rule for 2026 is this: never order based on a size label alone. Always cross-reference the factory size chart against your own measurements, and when in doubt, size up rather than down. A slightly loose item can be tailored or worn oversized. A too-tight item is unusable.

Factory size charts are your most accurate source of fit information, but they require careful reading. First, verify what unit of measurement the chart uses. Most Chinese factories use centimeters, but some use inches, and occasional charts mix the two in confusing ways. Second, understand whether the chart shows garment measurements or body measurements. Garment measurements are the actual dimensions of the finished item laid flat. Body measurements are the recommended wearer dimensions. A size Large with a 110-centimeter chest in garment measurement might only fit a 100-centimeter chest body comfortably because of the need for ease and movement. Third, check whether the chart is flat-lay or circumference. A flat-lay chest measurement of 55 centimeters means the full circumference is 110 centimeters. Beginners sometimes misread flat-lay charts and order items that are half the size they expected. Fourth, look for notes about stretch, shrinkage, or fit. A chart for a cotton t-shirt might note that the fabric shrinks 3 to 5 percent after the first wash, which means you should size up if you are on the borderline. A chart for a stretchy knit might show unstretched measurements, which will expand significantly when worn. Fifth, compare the chart against an item you already own that fits well. Lay your favorite hoodie flat, measure its chest, length, and sleeves, and compare those numbers directly against the factory chart. This comparison is the single most reliable method because it translates abstract numbers into a known fit reference. In 2026, some spreadsheet curators have started including flat-lay measurement photos from actual items, which is even more valuable than text charts because it shows you the real garment rather than the factory's ideal specifications.

Different product categories have different sizing behaviors, and understanding these category norms prevents generic sizing mistakes. For t-shirts and hoodies, the most reliable approach is to measure your best-fitting equivalent item and compare directly against the factory chart. If the chart shows shorter sleeves or a narrower shoulder than your reference, expect a tighter fit. For jackets and outerwear, pay special attention to layering ease. If you plan to wear a hoodie under a jacket, the jacket chest measurement needs to be at least 8 to 12 centimeters larger than the hoodie's chest measurement to allow comfortable movement. For bottoms like pants and shorts, the waist measurement is critical but not sufficient. Hip and thigh measurements determine whether the fit is comfortable in the seat, which is where most pants fail for buyers who size up only by waist. For jeans and rigid fabrics, there is little give, so being precise matters more than with stretch fabrics. For shoes, always prioritize insole length over size label. Measure the insole of a shoe that fits you perfectly, then compare that millimeter measurement against the factory chart. If the factory chart does not list insole length, ask the seller or search Reddit for a QC thread where someone photographed the insole with a ruler. For headwear like caps, the adjustable strap range matters more than the labeled size because most caps fit a range of head sizes. Beanies and fitted caps require actual circumference measurement. For accessories like belts, measure where you wear your belt on your waist or hips, then add 10 to 15 centimeters to account for the tail that hangs past the buckle.

The sizing decision ultimately depends on three factors: the item category, the intended fit, and the factory's specific size chart. For oversized streetwear styles, staying true to your usual label might already produce the intended loose fit because the garment is designed oversized. For fitted or tailored styles, sizing up one is almost always necessary when buying from Asian factories. For slim or skinny cuts, sizing up one or even two may be required depending on your build. Shoes are the most variable category because factory lasts differ so significantly. As a general framework for 2026: for hoodies and loose-fit tops, size up one from your US size if you want a standard fit, or stay TTS if you want a slightly fitted look. For t-shirts, size up one for a standard fit, or stay TTS if the fabric is stretchy and the cut is already relaxed. For jackets, size up one to allow layering, or size up two if you plan to wear thick hoodies underneath. For pants, measure your waist and hips and compare against the chart rather than using any rule of thumb. For shoes, use insole length and consider whether the silhouette is narrow or wide — runners usually fit TTS by length, while high-tops and luxury trainers may require half-size adjustments based on last shape. The safest universal rule is: when your measurement falls on the borderline between two sizes, always choose the larger size. The cost of a slightly loose garment is negligible. The cost of a garment that does not fit is a return, an exchange, or an unwearable purchase.