Womens Swimwear UK Size 18 & 20

Browse women's swimwear in UK sizes 18–20 at Allens Swimwear. Our range includes training swimsuits, kneesuits and competition suits from Speedo, Arena, Funkita, Amanzi and more - all available in UK sizes 18–20. Browse other sizes using our swimwear by UK size page, or switch to swimwear by chest size...

Browse women's swimwear in UK sizes 18–20 at Allens Swimwear. Our range includes training swimsuits, kneesuits and competition suits from Speedo, Arena, Funkita, Amanzi and more - all available in UK sizes 18–20.

Browse other sizes using our swimwear by UK size page, or switch to swimwear by chest size if that's a better guide for you.

  • About Womens Swimwear UK Size 18 & 20

  • Why Allens Of Kingsbury?

Womens Swimwear UK Size 18 & 20

Finding swimwear that fits well in UK size 18 & 20 makes a genuine difference to your training experience. Our collection brings together training suits, kneesuits, and racing designs from Speedo, Arena, Amanzi, TYR, Zoggs, and Funkita. Whether you're building a rotation of training suits, preparing for racing, or advancing through swimming lessons, having swimwear that actually fits properly means you can focus entirely on your swimming instead of adjusting your kit in the water.

Proper fit changes how you feel and perform

Why fit matters more than brand

A suit that fits your size 18 & 20 frame stays in place during active swimming, supports your natural body position, and avoids pressure points that pull your attention away from technique. Loose suits create drag and shift around during turns and tumble rolls. Too-tight suits restrict your shoulders and make every stroke feel uncomfortable. Good fit means you can move freely through all four strokes, focus on building fitness, and actually enjoy your time in the water.

The foundation of most swimmers' wardrobes

What to expect from training suits

Quality training suits prioritise durability and comfort for the real demands of regular pool sessions. These are designed to handle chlorine exposure, multiple swims per week, and intensive training without falling apart. The fabrics resist chlorine degradation, seams are reinforced in stress areas, and the fit stays responsive through extended use. A training suit should feel secure without restricting movement, letting you complete your sets and build your fitness without distraction.

When you're ready to race

Racing kneesuits for competition preparation

Kneesuits offer streamlined support and compression designed to reduce drag in the water while providing targeted support to key muscle groups. The fit matters significantly on race day. A suit that actually fits your size means the compression works as designed without creating pressure points that distract you from your race strategy. Many swimmers find that having the right fit in a racing suit is as important as the suit's technical features.

Speedo, Arena, Amanzi, TYR, Zoggs, and Funkita

Different brands, different approaches

Speedo is known for straightforward durability and technical features that work consistently through regular training. Arena brings advanced compression technology and responsive fabric that appeals to swimmers who value a more reactive feel. Amanzi balances high performance with genuine comfort, which matters when you're spending an hour in the pool most days. TYR brings their competitive racing heritage even to training suits. Zoggs focuses on accessibility and good value. Funkita combines high-performance materials with expressive design for swimmers who want their kit to reflect their personality. Trying a few helps you find what genuinely works for your body and your swimming style.

Simple routines extend the life of your suits

Looking after your investment

Fresh water rinse immediately after every session is the single most important thing you can do. Chlorine breaks down the fabric and elastic gradually over time, but rinsing stops that process in its tracks. Air dry completely before storing to prevent mildew and elastic degradation. Avoid direct sun which fades colour and degrades materials faster than most swimmers realise. With this simple routine, a quality training suit stays in good condition for 60 to 100 hours of pool time.

Get more life from your investment

Why rotating suits makes practical sense

Most swimmers who commit to regular training find that rotating between two or three training suits in size 18 & 20 dramatically extends how long each one lasts. Every time you finish a session, you rinse, wring out, and hang your suit to dry completely before storing it. When you rotate suits, each piece gets more drying time between uses. This means the elastic stays responsive longer, the fabric holds up better, and you'll notice a significant difference in how your suits perform over months of training.

Understanding your options

Our collection includes traditional one-piece swimsuits, racerback designs, and cross-back styles. One-piece suits offer comprehensive coverage and support. Racerback designs provide excellent shoulder freedom and work well for swimmers with wider shoulders or those who prefer less strap tension. Cross-back designs combine shoulder mobility with additional support at the middle back. All styles come in multiple colours and designs. Finding the right cut for your body shape and swimming style, combined with the right size fit, means you're set up for comfortable training. Many swimmers find that trying a couple of styles helps them discover their preference, and then they can build their rotation around what genuinely works for them.

Seasonal training considerations

Whether you're training year-round or adjusting your schedule through seasons, having appropriate swimwear for your training goals matters. Summer training with high-frequency sessions might mean you rotate more frequently to keep suits dry between sessions. Winter training with lower water temperatures might mean preferring more substantial coverage. Spring racing preparation might mean introducing kneesuits or compression options. Autumn might be when you build your rotation for the winter training months ahead. Thinking seasonally about your swimwear needs helps you build a wardrobe that supports your swimming all year.

Starting your size specific journey

Whether you're new to finding proper fitting swimwear or you've been swimming for years, our size 2 & 4, 6 & 8, 10 & 12, 14 & 16, 18 & 20, and 22 & 24 options give you genuine choices at every size. Many swimmers find that having swimwear that actually fits transforms their training experience. No adjusting between lengths, no pressure points, no dragging fabric. Just the right support, right coverage, right comfort. Starting with quality swimwear in your correct size sets you up for genuinely enjoying your swimming, whether that's three sessions a week or a casual swim now and then.

Explore other sizes and collections

Check out Womens Swimwear UK Size 22 & 24 and Womens Swimwear UK Size 14 & 16 and Womens Clothing & Cover-Ups. Free UK delivery on orders over £20.

Related Collections: Womens Swimwear UK Size 2 & 4, Womens Swimwear UK Size 6 & 8, Womens Swimwear UK Size 10 & 12

Allens Swimwear is a family-run business established in 1976. For 50 years, we have supplied competitive, leisure and open water swimmers with the right kit. From jammers and briefs to swimsuits, racing and competition swimwear, kneesuits, bikinis and tankinis, aquashorts, drag shorts, kids swimwear and open water wetsuits, Allens has been there for it all.

We are an authorised UK stockist for every brand we sell, including Arena, Speedo, TYR, Funkita, Funky Trunks, Nike, Adidas and more. That means every product is authentic and supplied through authorised channels.

Brand size guides are available on site for brands we stock. If you need help with sizing or fit before you buy, our team is available to help. You can also visit us in person at our store in Dordon, Tamworth, where we have been fitting swimmers in store for many years.

After purchase, our product aftercare guidance is available on site to help you get the most from your swimwear.

With over 1 million orders served to 500,000+ customers and 2,400+ five-star Google reviews, we have a long record of getting swimmers into the right kit.

Free UK delivery on all orders over £20. Price match may be available, please see our terms and conditions.

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