Looking for the right Arena Powerfin Pro II size. Use our UK-based size chart, easy women→men conversion (subtract 1.5 sizes), and quick fit checks to choose with confidence. Plus tips for half sizes, socks, and foot shape, so you train longer with zero rub. See the full Arena Powerfin Pro II size guide and shop at Ness Swimwear.
Start with your men’s UK shoe size. Women: subtract 1.5 from your UK size (e.g. W7.5 → M6), then choose the matching Arena fin. If you’re between sizes or wearing fin socks, go up.
Find Your Fit: Arena Powerfin Pro II
| Arena size (EU) | UK Men’s | UK Women’s (approx.)* |
|---|---|---|
| 36–37 | 3.5–4 | 5–5.5 |
| 38–39 | 5–6 | 6.5–7.5 |
| 40–41 | 6.5–7.5 | 8–9 |
| 42–43 | 8–9 | 9.5–10.5 |
| 44–45 | 10–10.5 | 11.5–12 |
| 46–47 | 11.5–12 | 13–13.5 |
*Women’s column shown for conversion only. Order by men’s UK size after subtracting 1.5 from your UK women’s size.
Between sizes? Use this rule
- Half size or using neoprene fin socks → size up.
- Narrow feet & no socks → some swimmers stay with the lower of the two.
- High instep / wide forefoot → size up to avoid rub.
30-second home fit check
- Snug, not painful. Toes close but not curled.
- Heel sits flush with the back rim — no big gap or bulge.
- Flex your ankle: open heel shouldn’t dig in.
Common mistakes
- Using women’s UK size directly (don’t forget: W→M minus 1.5).
- Mixing up EU and UK numbers.
- Assuming silicone will “stretch a lot” — it won’t.
Helpful add-ons
- Thin neoprene fin socks (warmth & anti-rub)
- Mesh equipment bag to drain/dry
- Anti-chafe balm for long kick sets
Quick how-to
1) Find your men’s UK shoe size. 2) If you usually buy women’s shoes, subtract 1.5 (e.g. W7.5 → M6). 3) Use the chart above to pick your Arena fin. If you’re on a half size or plan to wear socks, go up.
Why fit matters
Powerfin Pro II is designed for a faster kick and ankle mobility. A correct fit reduces hotspots and helps you hold pace over longer kick sets.
