UK Clothing Size Guide: Nike, Asics, Under Armour, Berghaus, Elude & Trailberg
UK Clothing Size Guide: Nike, Asics, Under Armour, Berghaus, Elude & Trailberg
Trainers aren't the only thing worth double-checking before you order — tracksuits, jackets, and tees vary just as much from brand to brand. Here's a full breakdown of standard UK sizing plus how each brand we stock actually fits.
Standard UK clothing size chart
Most of our activewear brands use the same S–XXL scale, based on chest and waist measurement in inches:
| Size | Chest (in) | Chest (cm) | Waist (in) | Waist (cm) |
|---|---|---|---|---|
| XS | 33–35 | 84–89 | 27–29 | 69–74 |
| S | 36–38 | 91–97 | 30–32 | 76–81 |
| M | 39–41 | 99–104 | 33–35 | 84–89 |
| L | 42–44 | 106–112 | 36–38 | 91–97 |
| XL | 45–47 | 114–120 | 39–41 | 99–104 |
| XXL | 48–50 | 122–127 | 42–44 | 106–112 |
Use this as your starting point, then check the brand notes below — the same size letter doesn't always mean the same fit.
How to measure yourself
- Chest — wrap a soft tape around the fullest part of your chest, under your arms, keeping it level
- Waist — measure around your natural waistline, usually just above the belly button
- Compare both to the chart above, and size up if you fall between two sizes
Brand-by-brand fit notes
Nike — True to size across most of the range, with a standard athletic cut. Nike tracksuits and tees fit as expected without needing to size up or down.
Asics — Also true to size generally. Asics' activewear follows the same sizing logic as its footwear — reliable and consistent across tees, shorts, and 1/4 zips.
Under Armour — True to size for most styles, but fit depends heavily on the category. Compression pieces are designed to sit close to the body — that's intentional, not a sizing issue. Looser, relaxed-fit styles like tracksuits run roomier by design. If you're between sizes, size up for a relaxed fit, or stay true to size for a snugger one.
Berghaus — The one brand on this list where fit genuinely varies by product line, since Berghaus builds for outdoor performance first. Look out for three fit categories on the product description:
- Technical — closest to the body, built for freedom of movement during activity
- Active — a balanced, not-too-close not-too-baggy fit
- Relaxed — roomier, with space to layer underneath
Check which fit applies before you order — a Technical jacket and a Relaxed jacket in the same labelled size can feel noticeably different.
Elude — True to size, with a standard, comfortable athletic fit across the tracksuit range — no notable surprises reported either way.
Trailberg — True to size, cut consistently with the rest of the trail and running-inspired pieces in the range.
Still unsure? Go with what you know
If you already own something from one of these brands, that's the most reliable size reference you have. If it's your first time trying a brand, true to size is the right call in almost every case above — and our 14-day hassle-free returns policy means an exchange is simple if it's not quite right.
Looking for footwear too? Check our UK trainer size guide for Nike, Asics and Saucony shoe sizing.
Browse the full range at Sourcedinuk — Nike, Asics, Under Armour, Berghaus and Trailberg — with free UK delivery on orders over £200.