Speedo Womens Global Alpha Size Guide

This size guide covers the Speedo Womens Global Alpha Size Matrix — a unified international sizing system covering eight sizes from 3XS through to 2XL. International equivalents are provided for GB, D, FR/ES, I, Lat Am, AUS, USA, CAN and MEX size systems. Sizing is based on body measurements — use your bust, waist and hip measurements to find the most accurate fit.

**3XS is a very small size not available in all styles. Always check individual product listings for available sizes.

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Body Measurement Points
Body measurement guide showing bust, waist and hip measurement points
How to Measure

Use a soft tape measure and take all measurements directly against the skin. Body measurements are the most reliable way to find your correct size.

  • A
    Bust Measure around the fullest part of the bust, keeping the tape parallel to the floor. This is the primary sizing measurement for swimwear.
  • B
    Waist Measure around the natural waistline at the narrowest point of the torso. Note: waist is an approximate guide only.
  • C
    Hips Measure around the fullest part of the hips and seat, keeping the tape parallel to the floor.

If measurements fall between sizes, size up. Use bust as the primary guide for swimwear.

Sizing Table : Speedo Womens Global Alpha
Size **3XS 2XS XS S M L XL 2XL
International Size Equivalents
GB Dress Size / GB Size 4 / 28 6 / 30 8 / 32 10 / 34 12 / 36 14 / 38 16 / 40 18 / 42
D 30 32 34 36 38 40 42 44
FR / ES 32 34 36 38 40 42 44 46
I 36 38 40 42 44 46 48 50
Lat Am 3ECH 2ECH ECH CH M G EG EEG
AUS 6 8 10 12 14 16 18 20
USA 3XS 2XS XS S M L XL 2XL
CAN TTTP TTP TP P M G TG TTG
MEX 3ECH 2ECH ECH CH M G EG EEG

**3XS is a very small size not available in all styles. GB Dress Size and GB Size are two equivalent reference formats for the same GB sizing.

Size **3XS 2XS XS S M L XL 2XL
Body Measurements (cm)
Bust (cm) 77–78 80–83 84–87 88–92 93–97 98–102 103–107 108–112
Waist* (cm) 60–61 62–65 66–69 70–74 75–79 80–84 85–89 90–94
Hips (cm) 85–86 88–90 91–94 95–99 100–104 105–109 110–114 116–120

*Waist measurement is an approximate guide. For swimwear, use bust as the primary sizing measurement. All measurements are body measurements, not garment measurements. Scroll horizontally to see all sizes.

Fit Notes : Speedo Womens Global Alpha
  • Use your bust measurement as the primary guide for swimwear sizing. Waist is shown as an approximate reference only.
  • If your measurements fall between two sizes, size up for a more comfortable fit. Speedo swimwear is designed to fit snugly but should not restrict breathing or movement.
  • 3XS is a very small size and is not available in all Speedo styles. Always check the individual product listing for available sizes before ordering.
  • The Global Alpha sizing system is a unified international size matrix. Use the international equivalents table above to cross-reference your usual regional dress size as a secondary check.
  • Unsure? Contact our team or call +44 1827 330600.
Frequently Asked Questions : Speedo Womens Global Alpha

Measure your bust, waist and hips using a soft tape measure and match to the body measurements table above. Use bust as the primary guide for swimwear. You can also use the international equivalents table to cross-reference your usual dress size in GB, AUS, USA or another regional system as a secondary check.

3XS is a very small size at the lower end of the Speedo Global Alpha range, equivalent to GB Dress Size 4 / GB Size 28 and a bust of 77 to 78 cm. It is not available in all Speedo styles. Always check the individual product listing to confirm which sizes are stocked before ordering.

GB Dress Size uses standard UK dress sizing (4, 6, 8, 10 etc.) while GB Size uses the European-style numeric sizing used in some Speedo product lines (28, 30, 32, 34 etc.). Both refer to the same physical size and are shown together for convenience.

For a one-piece swimsuit, use your bust measurement as the primary guide since it determines how the suit fits across the chest and straps. If you regularly find swimsuits too tight across the hips at your bust size, size up. For swim shorts or bottoms worn separately, hip measurement takes priority.

For swimwear, bust and hip measurements are more reliable indicators of fit than waist. Body proportions vary considerably between individuals, so Speedo marks the waist as an approximate guide. If your waist suggests a different size to your bust, size from the bust for swimwear.

The largest size in the Global Alpha range is 2XL, equivalent to GB Dress Size 18 / GB Size 42, AUS 20, and USA/CAN 2XL. Body measurements for 2XL are a bust of 108 to 112 cm (42½ to 44 inches), waist of 90 to 94 cm (35½ to 37 inches), and hips of 116 to 120 cm (45½ to 47 inches).