Wetsuit Thickness Calculator

Wetsuit thickness is measured in millimetres of neoprene and is usually expressed as two numbers (e.g. 3/2 mm) where the first number is the torso thickness and the second is the arm/leg thickness. Some suits add a third number for the hood panel.

Water temperature — not air temperature — determines what wetsuit you need. Water conducts heat away from the body approximately 25 times faster than air at the same temperature.

Standard thickness guide (water temperature):

• Above 24 C / 75 F: Board shorts or 1mm rash guard — no wetsuit needed
• 21–24 C / 70–75 F: 1mm or 2mm shorty / spring suit
• 18–21 C / 64–70 F: 2mm or 3/2mm full suit
• 14–18 C / 57–64 F: 3/2mm or 4/3mm full suit (consider gloves)
• 10–14 C / 50–57 F: 4/3mm or 5/4mm with hood, boots, and gloves
• 7–10 C / 44–50 F: 5/4mm or 6/5mm with hood, boots, and gloves
• Below 7 C / 44 F: 6/5mm or drysuit — full hood, 5mm boots, 5mm gloves

Cold adjustment factors:

• Prone to feeling cold: choose the next warmer option
• Surfing for more than 2 hours: choose the next warmer option (exhaustion reduces core temperature)
• Strong wind and air temperature below 10 C / 50 F: consider a windproof layer over a standard suit

Neoprene quality matters as much as thickness. A premium 3/2mm suit from a quality brand is warmer than a budget 4/3mm suit, due to better seam taping, higher-quality neoprene, and superior fit.