Speedo Womens Global Alpha Plus Size Guide

This size guide covers the Speedo Womens Global Alpha Plus Size range. Plus sizes are available in 1X, 2X and 3X, covering a wide range of international size systems including GB, D, FR/ES, I, Lat Am, Aus, USA, CAN and MEX equivalents. Sizing is based on body measurements — use your bust, waist and hip measurements to find the most accurate fit.

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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 plus size.

  • A
    Bust Measure around the fullest part of the bust, keeping the tape parallel to the floor.
  • B
    Waist Measure around the natural waistline at the narrowest point of the torso. Note: waist measurement is an approximate guide only for plus sizing.
  • 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 Plus
Size System 1X 2X 3X
International Size Equivalents
GB Dress Size / GB Size 20–22 / 44–46 24–26 / 48–50 28–30 / 52–54
D 46–48 50–52 54–56
FR / ES 48–50 52–54 56–58
I 52–54 56–58 60–62
Lat Am Talla 44–Talla 46 Talla 48–Talla 50 Talla 52–Talla 54
AUS 22–24 26–28 30–32
USA 16W–18W 20W–22W 24W–26W
CAN 16W–18W 20W–22W 24W–26W
MEX 40–42 44–46 48–50

GB Dress Size / GB Size are shown as two equivalent references. USA and CAN sizes are identical across all three plus sizes.

Measurement 1X 2X 3X
Body Measurements (cm)
Bust (cm) 116–122 123–130 131–137
Waist* (cm) 98–104 105–112 113–119
Hips (cm) 123–130 131–137 138–145

*Waist measurement is an approximate guide. For swimwear, use bust as the primary sizing measurement. All measurements are body measurements, not garment measurements.

Fit Notes : Speedo Womens Global Alpha Plus Size
  • 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.
  • The Global Alpha Plus sizing uses a unified international size system. Use the international equivalents table above to find your size in any regional system.
  • GB Dress Size and GB Size are two different reference formats for the same GB sizing. Both are shown for convenience.
  • Unsure? Contact our team or call +44 1827 330600.
Frequently Asked Questions : Speedo Womens Global Alpha Plus Size

Measure your bust, waist and hips using a soft tape measure and match to the body measurements table above. Use your bust measurement as the primary guide for swimwear. The international equivalents table lets you cross-reference your usual regional dress size as a secondary check.

GB Dress Size uses standard UK dress sizing (20, 22, 24 etc.) while GB Size uses the European-style numeric sizing common in some Speedo product lines (44, 46, 48 etc.). Both refer to the same physical size and are shown together for convenience. Use whichever format matches the label on your current clothing.

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

For a one-piece swimsuit, use your bust measurement as the primary guide since this 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.

Yes. In the Speedo Global Alpha Plus size matrix, USA and CAN (Canadian) sizes are identical across all three plus sizes (1X, 2X and 3X). Both use the W sizing convention common in North American plus sizing (16W, 18W, 20W etc.).

The largest size in the Global Alpha Plus range is 3X, covering a bust of 131 to 137 cm (51½ to 54 inches), a waist of 113 to 119 cm (44½ to 47 inches), and hips of 138 to 145 cm (54½ to 57 inches). This is equivalent to GB Dress Size 28 to 30 / USA 24W to 26W.