How to Find Your Size

Our period swimwear is designed to fit true to UK dress sizes. Measure yourself using the guide below and compare to our size chart.

Suitable for teens aged 13+ and adults.

Important: Period swimwear needs a snug fit for the absorbent gusset to work effectively. The gusset should sit close to your body for leak-proof protection.

How to Measure Yourself

Bust: Measure around the fullest part of your chest, keeping the tape parallel to the floor.

Waist: Measure around your natural waistline (the narrowest part of your torso, usually just above your belly button).

Hip: Measure around the fullest part of your hips and bottom, keeping the tape parallel to the floor.

Pro tip: Use a soft measuring tape and don't pull it too tight. Measure over underwear only for accuracy. Stand naturally—don't suck in!

Finding Your Perfect Fit

Why Fit Matters for Period Swimwear

Unlike regular swimwear, period swimwear needs to fit snugly—especially around the gusset area. The absorbent layers must sit close to your body to work effectively and prevent leaks.

If You're Between Sizes:

We recommend choosing your usual UK dress size for the most secure, leak-proof fit.

✅ Snug fit = secure protection. The gusset needs to sit flat against your body

✅ Our fabric has 35% Spandex, so it stretches comfortably while staying secure

✅ Adjustable straps on one-pieces let you customize the fit

⚠️ Avoid sizing up unless absolutely necessary. Too loose = potential gaping = compromised protection.

Fit Check:

Good fit indicators:

✅ Swimsuit feels snug but not restrictive

✅ Gusset sits flat against your body with no gaping

✅ Stays in place when you move, swim, or dive

✅ Leg openings fit close to your body

Signs you need a different size:

❌ Gusset area feels loose or pulls away from body

❌ Swimsuit slides around when you move

❌ Excess fabric bunching anywhere

❌ Straps digging in or too loose (one-pieces have adjustable straps!)

Sizing for Teens (Ages 13+)

Our period swimwear is perfect for teens! Swimming lessons, school trips, beach holidays—never miss out again.

Teen Size Guide:

Ages 13-15 (UK 8-10): Usually XS or S

Ages 15-17 (UK 10-14): Usually S, M, or L

Ages 17+ Use adult sizing chart above

Please note: Our smallest size is 2XS (UK 6-8). We recommend our range for teens who typically wear UK size 8 and above. If your teen usually wears UK size 6 or smaller, our swimwear may be too large.

Want smaller sizes for younger teens? We'd love to hear from you! Email us at contact@kikiandgreen.com and let us know - if there's enough demand, we'll make it happen.

For parents: Have your teen measure bust, waist, and hip using our guide above, then use the size chart. Our adjustable straps on one-pieces make it easy to get the perfect fit.

Style-Specific Notes

Classic One-Piece

Best for: All-day wear, full coverage

Fit: True to size with adjustable straps for a customisable fit. Flattering silhouette with moderate coverage. Use bust and hip measurements to choose your size.

Racerback One-Piece

Best for: Active swimming, sports

Fit: Athletic fit with secure straps that stay in place during movement. True to size. Use bust and hip measurements to choose your size.

High-Rise Bottoms

Best for: Extra tummy coverage, vintage-inspired style

Fit: Sits at natural waist. True to size. Use waist and hip measurements to choose your size. Perfect paired with any swim top or crop top.

Classic Rise Bottoms

Best for: Mix-and-match versatility, modern style

Fit: Sits comfortably at hips. True to size. Use hip measurements primarily. Pairs beautifully with crop tops or swim tops.

Sizing Examples

Example 1: Your measurements are Bust 84cm, Waist 66cm, Hip 91cm

→ You fall into UK 8-10 (XS). Order XS.

Example 2: Your measurements are Bust 94cm, Waist 76cm, Hip 101cm

→ You fall into UK 12-14 (M). Order M.

Example 3: Your bust is between S and M, but your hips are M

→ For one-pieces, order M (hips are more important for the gusset fit, and straps are adjustable).

Example 4 (Teen): Age 14, measurements are Bust 86cm, Hip 92cm

→ Falls into UK 8-10 (XS). Order XS.

Still Unsure About Your Size?

We're here to help! Email us at contact@kikiandgreen.com with your measurements (bust, waist, hip) and age (if ordering for a teen), and we'll recommend the perfect size for you.

Remember: Our swimwear is designed with stretch and moulds to your body. When in doubt, stick to your usual UK dress size for the best leak-proof protection.