Speedo Global Fit Adult Female Swim XXS-XXL

This size guide covers Speedo Global Fit adult women's swimwear in alpha sizes XXS–XXL (equivalent to UK dress sizes 6/30 through to 20–22/44–46). The Global Fit alpha sizing range makes it easy to find your size using the same XXS–XXL system you may already use for other clothing, while still being based on body measurements for accuracy. All measurements are body measurements taken from your own body, not garment measurements. Always use your bust measurement as the primary guide.

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Body Measurement Points

How to Measure

Take all measurements directly against your skin using a soft tape measure. Wear a well-fitting bra or no bra when measuring for the most accurate results. All measurements in the table are body measurements, not garment measurements.

A
BustMeasure around the fullest part of your chest, keeping the tape horizontal and snug but not tight.
B
WaistMeasure at the narrowest part of your natural waist (the narrowest point).
C
HipMeasure around the fullest part of your hips and seat, keeping the tape horizontal.

*Waist is measured at the natural waist at narrowest point.

Sizing Table — Speedo Global Fit Adult Female Swimwear (XXS–XXL)

Sizing	XXS	XS	S	M	L	XL	XXL
Size Equivalents
GB Dress / Numeric	6/30	8/32	10/34	12/36	14–16/38–40	18/42	20–22/44–46
Body Measurements (cm)
Bust	79–83	84–87	88–92	93–98	99–107	108–116	117–125
Waist*	61–65	66–69	70–74	75–80	81–89	90–98	99–106
Hip	86–90	91–94	95–99	100–105	106–114	115–123	124–132
Body Measurements (inches)
Bust	31–32½	33–34	34½–36	36½–38½	39–42	42½–45½	46–49
Waist*	24–25½	26–27	27½–29	29½–31½	32–35	35½–38½	39–42
Hip	34–35½	36–37	37½–39	39½–41½	42–45	45½–48½	49–52

*Waist is natural waist at narrowest point. All measurements are body measurements, not garment measurements. GB dress and numeric size equivalents are shown as a guide only.

Fit Notes — Speedo Global Fit Women's Swimwear (XXS–XXL)

Always use your bust measurement as the primary guide when selecting a Speedo Global Fit alpha size swimsuit.
The XXS–XXL alpha sizing system is designed to align with familiar clothing sizes while still being based on body measurements — always measure to confirm your size rather than relying on your usual clothing size alone.
If your bust and hip measurements suggest different sizes, choose the size that fits your bust. For one-piece swimsuits, the bust is the hardest area to adjust once fitted.
Speedo swimsuits are made from chlorine-resistant fabrics that feel firm when new and ease slightly with wear — do not size up based on initial tightness.
The swimsuit should feel secure across the bust and back with no gaping, pulling, or riding up.
Rinse in cold fresh water immediately after every use. Do not tumble dry, iron, or dry-clean.
Unsure? Contact our team or call +44 1827 330600.

Frequently Asked Questions — Speedo Global Fit Women's Swimwear (XXS–XXL)

Speedo Global Fit alpha sizing (XXS–XXL) maps to body measurements in the same way as numeric sizing, but uses the familiar S/M/L system. Each size covers a range of body measurements — use your bust measurement as the primary guide and refer to the table above. The equivalent GB dress and numeric sizes are shown as a secondary reference.

Both systems use the same body measurements and produce the same garment fit — the only difference is the labelling. XXS–XXL suits the same range of body sizes as the numeric 30–46 range. If you know your numeric Speedo size, use the equivalents row in the table to find your alpha size. If you are new to Speedo, use your bust measurement as the guide.

If your measurements fall between two sizes, use your bust measurement to decide. For most swimsuit styles this gives the best overall fit. If you have a significantly larger hip measurement relative to your bust, you may benefit from trying the next size up. Speak to a member of staff at Allens if you are unsure.

Speedo swimsuits are primarily designed for pool use. While the chlorine-resistant fabrics will withstand occasional use in open water or the sea, prolonged exposure to salt water can accelerate fabric degradation. For open water swimming, rinse the suit thoroughly in fresh water after every use. For dedicated open water or triathlon use, a wetsuit or open water-specific suit is recommended.

Rinse your Speedo swimsuit in cold fresh water immediately after every use to remove chlorine, salt, and sunscreen. Hand wash gently with a mild detergent if needed. Do not machine wash, tumble dry, iron, or dry-clean. Store flat and dry, away from direct sunlight. Avoid sitting on rough surfaces such as pool surrounds in your swimsuit as this can cause premature fabric wear.

Speedo swimsuit sizes do not directly correspond to standard clothing sizes. Always use body measurements (bust, waist, and hip) to select the correct Speedo size. The size tables above show GB dress size equivalents as a secondary reference, but body measurements should always be the primary guide. If you are between two sizes, consider which measurement matters most for the style you are buying.

Speedo offer swimsuits across a wide range of performance levels. Standard Speedo swimsuits are suitable for recreational and fitness swimming. For competitive pool swimming, Speedo's Fastskin racing range (including the LZR Pure Intent 2, LZR Pure Valor 2, and LZR Ignite) are specifically designed and World Aquatics approved for competition use. If you need a suit for competition, speak to a member of staff at Allens for guidance on the right Fastskin product for your level.