X-BIONIC Size Chart
Note: Current X-BIONIC functional apparel and base layers mainly use single sizes. Older collections may still use combined sizes such as S/M or L/XL. The size chart shown directly on the individual product page always takes priority.
Men's Tops and Base Layers
Current Single-Size System
| Size | Chest Circumference (cm) |
| S | 90–96 |
| M | 96–102 |
| L | 102–108 |
| XL | 108–114 |
| XXL | 114–120 |
Men's Pants and Base-Layer Bottoms
| Size | Waist Circumference (cm) |
| S | 77–83 |
| M | 83–89 |
| L | 89–95 |
| XL | 95–101 |
| XXL | 101–107 |
Women's Tops and Base Layers
| Size | Chest Circumference (cm) |
| XS | 77–83 |
| S | 83–89 |
| M | 89–95 |
| L | 95–101 |
| XL | 101–107 |
Women's Pants and Base-Layer Bottoms
| Size | Hip Circumference (cm) |
| XS | 85–91 |
| S | 91–97 |
| M | 97–103 |
| L | 103–109 |
| XL | 109–115 |
Converting Older Combined Sizes to Current Single Sizes
Men's Tops – Based on Chest Circumference
| Old Size | Old Measurement Range (cm) | Current Size | Current Measurement Range (cm) |
| S/M | 86–97 | S | 90–96 |
| L/XL | 98–109 | M or L | 96–108 |
| XXL | 110–122 | XL or XXL | 108–120 |
Men's Bottoms – Based on Waist Circumference
| Old Size | Old Measurement Range (cm) | Current Size | Current Measurement Range (cm) |
| S/M | 74–85 | S | 77–83 |
| L/XL | 86–99 | M, L or XL | 83–101 |
| XXL | 100–115 | XXL | 101–107 |
Women's Tops – Based on Chest Circumference
| Old Size | Old Measurement Range (cm) | Current Size | Current Measurement Range (cm) |
| XS | 78–89 | XS or S | 77–89 |
| S/M | 90–102 | M or L | 89–101 |
| L/XL | 103–119 | XL | 101–107 |
Women's Bottoms – Based on Hip Circumference
| Old Size | Old Measurement Range (cm) | Current Size | Current Measurement Range (cm) |
| XS | 88–98 | XS or S | 85–97 |
| S/M | 99–108 | M | 97–103 |
| L/XL | 109–121 | L or XL | 103–115 |
Important for older combined sizes: The measurement ranges of the old and current systems do not always overlap exactly. Always select the size using the actual body measurement rather than relying only on the old size label.
Junior Apparel
| Size | Age | Height (cm) | Weight (kg) | Chest (cm) | Waist (cm) | Hips (cm) |
| 6/7 | 6–7 years | 118–125 | 22–25 | 59–62 | 56–58 | 69–71 |
| 8/9 | 8–9 years | 126–137 | 25–30 | 62–68 | 58–62 | 71–76 |
| 10/11 | 10–11 years | 138–143 | 30–35 | 68–74 | 62–66 | 76–82 |
| 12/13 | 12–13 years | 144–158 | 35–42 | 74–80 | 66–70 | 82–87 |
X-SOCKS Men and Unisex
| EU Shoe Size | UK | US | Manufacturer Size |
| 35–38 | 3–5.5 | 3.5–6 | 1 |
| 39–41 | 6–7.5 | 6.5–8.5 | 2 |
| 42–44 | 8–9.5 | 9–11 | 3 |
| 45–47 | 10–12 | 11.5–13 | 4 |
X-SOCKS Women
| EU Shoe Size | UK | US Women | Manufacturer Size |
| 35/36 | 2.5–3.5 | 4.5–5.5 | 1 |
| 37/38 | 4–5 | 6–7 | 2 |
| 39/40 | 5.5–6.5 | 7.5–9 | 3 |
| 41/42 | 7–8 | 9.5–10.5 | 4 |
X-SOCKS Junior
| EU Shoe Size | Category |
| 24–26 | Junior / Kids |
| 27–30 | Junior / Kids |
| 31–34 | Junior / Kids |
| 35–38 | Junior / Youth |
Accessories
| Product Category | Size | Measurement Range |
| Calf Compression / Calf Sleeves | S/M | 34–38 cm calf circumference |
| Calf Compression / Calf Sleeves | L/XL | 39–43 cm calf circumference |
| Beanie | 1 | 54–58 cm head circumference |
| Beanie | 2 | 59–63 cm head circumference |
TerraSkin Trail Running Shoes
| Product Category | UK Sizes | EU Range | Note |
| TerraSkin Trail Running Shoes | UK 4–12.5 | EU approx. 36 2/3–48 | Model-specific; use the product size chart |
How to measure: Measure the chest horizontally around the fullest point. Measure the waist at the natural waistline or around navel height. Measure the hips around the fullest point. The tape should sit close to the body without digging in.
Fit: X-BIONIC base layers are designed for a close fit. The functional zones should remain close to the body without restricting movement or circulation. If you are between sizes, check the product-specific fit information.
Selected outerwear, cycling, triathlon, footwear and special-edition collections may use their own sizing systems. Always also check the information shown directly on the product page.