UK Trainer Size Guide: Nike, Asics & Saucony Sizing Explained
UK Trainer Size Guide: Nike, Asics & Saucony Sizing Explained
Buying trainers online means you can't try before you buy — so getting the size right the first time matters. Here's everything you need to convert your size correctly and know what to expect from each brand we stock.
UK to EU to US size conversion
Sizes are labelled slightly differently depending on where a shoe is made, so here's a general men's conversion chart to work from:
| UK | EU | US (Men's) | Foot length (cm) |
|---|---|---|---|
| 5 | 38 | 6 | 23.5 |
| 5.5 | 38.5 | 6.5 | 24 |
| 6 | 39.5 | 7 | 24.5 |
| 6.5 | 40 | 7.5 | 25 |
| 7 | 41 | 8 | 25.5 |
| 7.5 | 41.5 | 8.5 | 26 |
| 8 | 42 | 9 | 26.5 |
| 8.5 | 43 | 9.5 | 27 |
| 9 | 43.5 | 10 | 27.5 |
| 9.5 | 44 | 10.5 | 28 |
| 10 | 44.5 | 11 | 28.5 |
| 10.5 | 45 | 11.5 | 29 |
| 11 | 46 | 12 | 29.5 |
This is a standard guide — exact conversions can shift slightly from brand to brand, which is why the notes below matter just as much as the chart.
How to measure your foot at home
If you're not sure what size you currently wear, this takes two minutes:
- Stand on a piece of paper with your full weight on your foot
- Trace around the outline, keeping the pen upright
- Measure the longest point from heel to toe in centimetres
- Match that measurement to the table above
Measure both feet — most people have one slightly larger than the other — and size for the bigger one.
Brand-by-brand fit notes
Asics — Generally true to size, and one of the more forgiving brands if you have wider feet. The Gel Kayano 14 has a noticeably wider toe box than most retro trainers on the market, so most people can order their usual size with confidence. The Gel 1130 fits true to size too, though a few wearers find the panel near the little toe slightly snug — if you're between sizes or have wider feet, sizing up half a size is worth considering.
Nike — Mostly true to size across the range, including P-6000 and Vomero styles. Some running-focused models fit a touch roomier through the forefoot, which most people find comfortable rather than loose.
Saucony — The ProGrid Omni 9 fits true to size for most people, with a comfortable amount of room in the toe box. If you have wider feet, the overlays around the midfoot can feel a little snug, so it's worth trying a half size up if you're in doubt.
Still not sure? Go with your usual size
If you already own trainers from one of these brands and they fit well, that's your best reference point. If this is your first pair from a brand, order true to size — it's the right call for the vast majority of people, and our 14-day hassle-free returns policy means you're covered if it's not quite right.
Browse the full range of Asics, Nike and footwear at Sourcedinuk, with free UK delivery on orders over £200.