Arena 3D Soft Swimming Cap

This size guide covers the Arena 3D Soft Cap. The Arena 3D Soft cap is a premium silicone swimming cap designed for comfort and performance. Its soft, skin-friendly silicone construction stretches to fit a wide range of head shapes without pulling hair, while the 3D moulded design provides a wrinkle-free fit that reduces drag in the water. Available in three sizes — M, L, and XL — with XL specifically designed to accommodate voluminous or thick hair.

Select your size using your head circumference (A) measured around the widest part of your head, just above the eyebrow.

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How to Measure
Arena 3D Soft Cap head circumference measurement diagram
Measurement Guide

Use a soft tape measure to measure your head circumference. This is the only measurement needed to select the correct Arena 3D Soft Cap size.

  • A
    Circumference of the HeadMeasure around the widest part of the head, just above the eyebrow, keeping the tape horizontal and level all the way around.

If you have voluminous or thick hair that you will be wearing inside the cap, select the XL size regardless of your head circumference measurement.

Sizing Table — Arena 3D Soft Cap
Measurement M L XL
Body Measurements (cm)
A — Head Circumference 56–57 58–59 58–59*

*XL is designed for voluminous or thick hair worn inside the cap. If your head circumference measures 58–59 cm and you have thick or voluminous hair, select XL.

Fit Notes — Arena 3D Soft Cap
  • Measure your head circumference just above the eyebrow at the widest point. This is the only measurement needed to select the correct size.
  • If you have voluminous or thick hair that you will be wearing inside the cap, select XL regardless of your head circumference measurement.
  • The cap should feel snug but not tight — it should sit flat on the head with no wrinkles or air pockets, and should not pull at the hairline or ears.
  • The 3D moulded construction means the cap retains its shape and provides a streamlined, wrinkle-free fit that reduces drag in the water.
  • The soft silicone material is gentle on hair and will not pull or snag. Wet your hair before putting the cap on to make it easier to wear.
  • Rinse in fresh water after every use and allow to dry naturally. Store away from direct sunlight and sharp objects. Dust lightly with talc if the cap sticks together when stored.
  • Unsure? Contact our team or call +44 1827 330600. Speak to a member of staff at Allens if you are unsure.
Frequently Asked Questions — Arena 3D Soft Cap

Measure around the widest part of your head, just above the eyebrow, using a soft tape measure. Compare your measurement to the sizing table above. If you have voluminous or thick hair that you will wear inside the cap, select XL regardless of your head circumference. Speak to a member of staff at Allens if you are unsure.

The XL size of the Arena 3D Soft Cap is specifically designed to accommodate voluminous or thick hair worn inside the cap. It has the same head circumference measurement range as the L (58–59 cm) but provides more internal volume. If your head measures 58–59 cm and you have thick or voluminous hair, select XL for a more comfortable fit.

The Arena 3D Soft Cap is moulded in three dimensions to follow the natural shape of the head, creating a wrinkle-free fit that reduces drag in the water. Standard flat silicone caps can bunch or wrinkle when worn, increasing surface drag. The 3D construction also means the cap is more comfortable to wear over longer training sessions and is gentler on hair than non-moulded alternatives.

Yes. The Arena 3D Soft Cap can accommodate long hair, particularly in the XL size which is designed for voluminous or thick hair. For very long or thick hair, tie hair up before putting the cap on to reduce bulk. The soft silicone material is gentle on hair and will not pull or snag. Wet your hair before putting the cap on to make it easier to wear.

A swimming cap should sit snugly on the head with no wrinkles, air pockets, or gaps at the hairline or ears. It should feel secure but not cause discomfort or headaches. The cap should not slip during swimming. If the cap feels uncomfortably tight or causes pain, speak to a member of staff at Allens who can advise on the best size.

Yes. The Arena 3D Soft Cap is designed to be worn with swimming goggles. For competitive swimming, the cap is typically worn over the goggle strap to keep the straps in place and reduce drag. For training use, the goggle strap can be worn over or under the cap according to personal preference.

Rinse the cap in cold fresh water after every use to remove chlorine and salt. Allow to dry naturally away from direct sunlight — UV exposure can degrade the silicone over time. Store in a cool, dry place away from sharp objects. If the cap sticks to itself when stored, dust lightly with talcum powder to prevent sticking. Do not fold or crease the cap when storing.

Yes. The Arena 3D Soft Cap is suitable for competitive swimming. Its 3D moulded construction provides a wrinkle-free, streamlined fit that minimises drag in the water. For competition use, ensure the cap sits flat with no wrinkles and is pulled down firmly over the ears. Check with your event organiser for any specific cap rules that may apply at your competition.