Sizing errors are the single most common reason for buyer dissatisfaction in the USFans ecosystem. An otherwise perfect item becomes unwearable when it arrives two sizes too small or fits in the chest but drapes like a tent over the shoulders. The root cause is almost never the product itself — it is the gap between how buyers think about size and how manufacturers actually construct garments. This guide teaches you how to measure your body correctly, read spreadsheet size charts accurately, convert between regional sizing conventions, and match items to your actual dimensions rather than the size tag you usually wear.
Why Sizing Is the #1 Return Reason
Most sizing failures happen because buyers order based on habit rather than measurement. You might wear a Medium in one brand and a Large in another even at the same domestic retailer. International manufacturing adds another layer of complexity: Asian sizing conventions typically run one to two sizes smaller than US equivalents, and factory-to-factory variation within the same nominal size can be dramatic. The spreadsheet size charts exist for a reason, but they only help if you use them correctly.
How to Measure Your Body
Chest / Bust
Measure around the fullest part of your chest, keeping the tape level and snug but not tight. Exhale normally.
Shoulder Width
Measure from the edge of one shoulder bone to the other across your upper back. This determines fit in structured garments.
Waist
Measure at your natural waistline — typically the narrowest point of your torso, usually near the navel.
Hip
Measure around the fullest part of your hips and seat, usually 7-9 inches below your waistline.
Inseam
Measure from the crotch seam down to where you want the hem to fall. Use a favorite pair of pants as a reference.
Reading USFans Size Charts
Size charts in the USFans spreadsheet typically list flat measurements in centimeters. A flat measurement means the garment is laid on a surface and measured across, not wrapped around the body. To estimate your needed size, add 2-4cm of ease to your body measurement for a fitted look, or 6-10cm for a relaxed or oversized fit. Compare this target number to the flat chart measurement multiplied by two (since flat measurement is half the circumference).
| Your Chest | Fitted Target | Relaxed Target | Likely Flat Chart |
|---|---|---|---|
| 96cm (38in) | 100-102cm | 106-110cm | 50-55cm flat |
| 102cm (40in) | 106-108cm | 112-116cm | 53-58cm flat |
| 108cm (42in) | 112-114cm | 118-122cm | 56-61cm flat |
| 114cm (45in) | 118-120cm | 124-128cm | 59-64cm flat |
Regional Sizing Differences
Asian Sizing Quick Rule
As a general rule, add one full size to Asian sizing when comparing to US retail. If you normally wear a US Medium, start with Asian Large. For shoes, add 0.5 to 1 size. Always verify with the actual flat measurements rather than relying on this rule alone.