Zone3

Zone3

Performance-focused triathlon and swimwear brand designed by athletes

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Zone3 Size Guide

Zone3 designs performance-driven wetsuits and triwear engineered for competitive swimmers, triathletes, and open-water enthusiasts. All sizing is based on real athletes and genuine body types, not simply numerical ranges. Zone3 offers two distinct fit philosophies: Comfort Fit (Advance and Vision wetsuits) with a straighter torso cut prioritising comfort, and Performance Fit (Aspire and Vanquish-X) emphasising speed and racing performance. If you're new to triathlon wetsuits, expect a snug feel on dry land — this is by design. Once horizontal in water, the suit stretches to your shape and becomes significantly more comfortable.

How to Measure

  1. Height: Stand barefoot against a wall and measure from the floor to the top of your head in centimetres.
  2. Weight: Use accurate scales and record your weight in kilograms. Weight is the primary deciding factor when sizing falls between two options.
  3. Chest/Bust: Measure horizontally across the fullest part of your chest or bust, keeping the tape snug but not tight.
  4. Waist: For triwear, measure around your natural waist (where you naturally bend) in centimetres.
  5. Fit assessment: When trying on a wetsuit on dry land, it should feel tight in the shoulders and torso, but you must be able to move your arms comfortably. Excessive tightness restricts swimming; excessive looseness allows water ingress and reduces performance.

Men's Wetsuits Sizing

Size Height (cm) Weight (kg) Chest (cm)
Small 163 – 173 55 – 65 79 – 91
Small Medium 170 – 178 62 – 70 89 – 97
Small Tall 175 – 191 64 – 72 89 – 97
Medium 173 – 183 68 – 74 97 – 102
Medium Tall 175 – 191 68 – 78 97 – 102
Medium Large 173 – 188 75 – 82 102 – 107
Large 178 – 191 82 – 92 107 – 112
X Large 183 – 196 92 – 100 112 – 122
XX Large 183 – 196 97 – 115 117 – 127

Women's Wetsuits Sizing (Agile, Advance, Aspire, Vanquish-X & Vision)

Size Height (cm) Weight (kg) Bust (cm)
X Small 147 – 163 46 – 53 79 – 84
Small 160 – 168 54 – 61 84 – 89
Small Medium 157 – 168 60 – 70 91 – 97
Small Tall 170 – 183 54 – 64 84 – 91
Medium 165 – 178 60 – 67 89 – 94
Medium Large 165 – 178 64 – 73 91 – 96
Large 168 – 183 68 – 78 94 – 99
X Large 168 – 198 73 – 83 99 – 107
XX Large 168 – 198 87 – 93 104 – 109

Women's Active-Flex Wetsuit Sizing

Size Height (cm) Weight (kg) Bust (cm)
Small 147 – 165 46 – 53 79 – 86
Small Medium 147 – 167 54 – 61 81 – 91
Short Large 147 – 167 60 – 73 91 – 96
Short X Large 147 – 167 68 – 78 86 – 102
Medium 160 – 175 58 – 64 81 – 91
Medium Large 160 – 175 60 – 73 86 – 96
Medium X Large 160 – 175 68 – 78 86 – 102
Large 165 – 180 60 – 73 86 – 96
X Large 168 – 183 68 – 78 91 – 102
XX Large 168 – 193 73 – 83 97 – 107

Women's Glide Wetsuit Sizing

Size Height (cm) Weight (kg) Chest (cm)
Small 160 – 170 54 – 61 81 – 86
Medium 163 – 175 60 – 67 86 – 91
Large 165 – 180 68 – 78 91 – 96
X Large 165 – 180 70 – 80 96 – 101
XX Large 168 – 188 73 – 83 101 – 106

Men's Triwear Sizing

Size Height (cm) Weight (kg) Chest (cm) Waist (cm)
Small 168 – 178 62 – 72 86 – 97 71 – 76
Medium 170 – 185 68 – 78 91 – 102 79 – 84
Large 175 – 188 78 – 86 102 – 112 86 – 97
X Large 178 – 196 85 – 96 112 – 122 91 – 102
XX Large 178 – 196 90 – 105 117 – 127 91 – 107

Women's Triwear Sizing

Size Height (cm) Weight (kg) Chest (cm) Waist (cm)
X Small 152 – 163 45 – 55 71 – 81 61 – 66
Small 157 – 168 50 – 60 76 – 86 66 – 74
Medium 163 – 175 60 – 70 86 – 97 76 – 81
Large 168 – 183 65 – 75 91 – 102 81 – 91
X Large 168 – 183 70 – 80 91 – 107 81 – 97

Product-Specific Guidance

Wetsuits

Zone3 wetsuits are engineered specifically for open-water swimming and triathlon. Sizing differs by model due to variations in neoprene thickness and cut. Always consult the size guide for your specific wetsuit model, as a Medium in one suit may not correspond to a Medium in another. For Performance Fit suits (Aspire, Vanquish-X with thinner, more flexible neoprene), choose the smaller or middle size if you fall between two options. For Comfort Fit suits (Advance, Vision with thicker neoprene), choose the middle or larger size. A properly fitted wetsuit should feel snug on land but allow comfortable arm movement — this ensures minimal water entry and optimal thermal protection underwater.

Triwear (Race Kits & Apparel)

Zone3 triwear is designed with premium aerodynamic fabrics and athlete-tested construction for racing, training, and tough sessions. Triwear sizing includes both chest and waist measurements for optimal fit through the torso. Choose based on your primary measurements; if you fall between sizes, weight is the deciding factor. Triwear should move with your body, not against it, supporting your stride while maintaining comfort across swimming, cycling, and running disciplines.

Changing Robes

The Zone3 Heat-Tech Changing Robe is oversized by design to accommodate post-swim changes in various weather conditions. Sizing is based on front length, back length, sleeve length, chest, waist, and hem measurements. Choose your size based on your height primarily, with chest measurement as a secondary reference.

Sizing Tips

  • Weight is the primary factor: When your height and chest/bust measurements place you between two sizes, use your weight as the deciding criterion for the best fit.
  • Expect initial tightness in wetsuits: A new triathlon wetsuit will feel noticeably tight on dry land. This is intentional. Once you're horizontal in water, the neoprene stretches and molds to your body shape, becoming significantly more comfortable within the first few uses.
  • Suit-specific sizing charts matter: Do not assume your size across Zone3's entire range. The Glide, Active-Flex, and standard wetsuits have different fits. Always check the size guide for the specific product you're purchasing, as fit varies between models.
  • Choose based on fit philosophy: If you prioritise performance and are racing competitively, opt for Performance Fit suits in a smaller size. If comfort and ease of use are your priority, especially as a beginner, select Comfort Fit suits in a middle or larger size.
  • Test arm mobility on dry land: Before committing to a purchase, move your arms in a swimming motion while wearing the suit on land. You should be able to raise your arms overhead and perform a front crawl stroke without strain. If you cannot move your arms comfortably, the suit is too tight.
  • Account for seasonal changes: If you swim across different seasons, remember that body weight and muscle mass can fluctuate. Re-check your measurements annually, especially before purchasing a new suit.
  • Use the no-hassle exchange policy: Zone3 offers straightforward exchanges within their policy, so order with confidence. If a size doesn't feel right after your first swim, contact Zone3 for support.
  • Triwear fit differs from wetsuits: Triwear should feel closer to standard athletic apparel — snug but not restrictive. Unlike wetsuits, triwear does not significantly stretch or conform further after purchase.

Sizing Information

General Fit

Zone3 sizing tends to follow standard UK sizing. However, we recommend checking the specific size chart for each item.

Fit Recommendations

  • Check product-specific size charts when available
  • Read customer reviews for fit feedback
  • Consider the item type (slim fit, regular fit, etc.)
  • When in doubt, contact customer service

Important: This page provides essential and expertly curated size conversion information that should be used in conjunction with the complete interactive tools available at sizechart.uk. For the most accurate size conversions and access to our comprehensive database of brand-specific charts, measurement guides, and real-time conversion tools, please visit the full website. The information presented here represents only a portion of our complete sizing resources and should be evaluated within the context of your specific sizing needs and the brands you're shopping for. It is impossible to determine the anatomical size of a shoe or clothing item without the use of a measuring tape or ruler in conjunction with the size chart.