NAIA Beach

NAIA Beach Size Guide

Sizing Philosophy

NAIA Beach swimwear fits true to size. The brand uses UK sizing across all collections, but provides international conversion charts for customers shopping in US, European, French, Italian, and Australian sizes. If you find yourself between sizes, NAIA recommends sizing up in all styles to ensure comfortable wear throughout the day. Each style may vary slightly, so checking individual product recommendations is advised.

How to Measure

To find your perfect NAIA Beach size, follow these measurement steps. Use a soft measuring tape and wear minimal or no clothing for accuracy. Measure yourself in the evening when your body is at its typical size, as measurements can vary throughout the day.

1. Bust Measurement: Measure around the fullest part of your bust, keeping the tape parallel to the ground and ensuring it passes under your arms and across your shoulder blades. Keep the tape snug but not tight.
2. Waist Measurement: Measure around the slimmest part of your natural waistline, typically where your body creases when you bend slightly forwards or where you find it most comfortable to wear your waistband. Avoid pulling the tape too tightly.
3. Hip Measurement: Measure around the fullest part of your hips and bottom, keeping the tape parallel to the ground. This measurement is particularly important for bikini briefs and one-piece swimsuits.
4. Cup Size (for Bikini Tops): To determine your cup size, subtract your underbust measurement (just below your bust) from your full bust measurement. Each inch of difference equals one cup size (A, B, C, D, DD, E, F, FF, etc.).
5. Reference Your Measurements: Once you have all three measurements, cross-reference them with the appropriate size chart below to find your UK size, then use the international sizing guide to convert to your preferred sizing system.
6. Consider Coverage and Support: Different NAIA styles offer varying levels of coverage and support. Review individual product descriptions to determine which features best suit your preferences, such as Subtle Sculpt technology, removable pads, or hidden shelf support.

Women's Bikini Tops Size Chart

NAIA Beach bikini tops are available in UK sizes 6 through 18. The chart below shows bust measurements and cup size ranges for each size. Note that cup sizes vary within each UK size depending on band size.

UK Size	Bust (inches)	Bust (cm)	Cup Size Range	US Size	EU Size
6	30–32	76–82	A–B	2	34
8	32–34	82–86	B–C	4	36
10	34–36	86–91	C–D	6	38
12	36–38	91–96	D–DD	8	40
14	38–40	96–102	DD–E	10	42
16	40–42	102–107	E–F	12	44
18	42–44	107–112	F–FF	14	46

Women's Bikini Briefs & Bottoms Size Chart

Bikini bottoms are sized independently, allowing you to pair any top size with any bottom size. This chart shows waist and hip measurements for each bottom size.

UK Size	Waist (inches)	Waist (cm)	Hips (inches)	Hips (cm)	US Size	EU Size
6	24–26	60–66	33–35	83.5–88.5	2	34
8	26–28	66–71	35–37	88.5–93.5	4	36
10	28–30	71–76	37–39	93.5–99	6	38
12	30–32	76–81	39–41	99–104	8	40
14	32–34	81–86	41–43	104–109	10	42
16	34–36	86–91	43–45	109–114	12	44
18	36–38	91–96	45–47	114–119	14	46

Women's One-Piece Swimsuit Size Chart

One-piece swimsuits combine bust, waist, and hip measurements. NAIA one-pieces are designed to provide sleek coverage with optional Subtle Sculpt technology for gentle stomach control.

UK Size	Waist (inches)	Bust (inches)	Hips (inches)	Hips (cm)	US Size	EU Size
6	24–26	30–32	33–35	83.5–88.5	2	34
8	26–28	32–34	35–37	88.5–93.5	4	36
10	28–30	34–36	37–39	93.5–99	6	38
12	30–32	36	39–41	99–104	8	40
14	32–34	36–38	41–43	104–108	10	42
16	34–36	38–40	43–45	109–114	12	44
18	36–38	42	45–47	114–119	14	46

Women's Resort Wear Size Chart

NAIA's resort wear collection uses standard clothing sizing and is sized in XS through XL. Use this chart to find your resort wear size.

Size Label	UK	US	EU	France	Italy
XS	6–8	2–4	34–36	34–36	38–40
S	8–10	4–6	36–38	36–38	40–42
M	10–12	6–8	38–40	38–40	42–44
L	14–16	10–12	42–44	42–44	46–48
XL	18	14	46	46	50

International Size Conversions

NAIA Beach uses UK sizing as its primary system. If you typically shop in other countries' sizes, use this conversion chart to determine your equivalent UK size.

UK / Australia	US	France	Italy	Denmark / Germany
6	2	34	38	32
8	4	36	40	34
10	6	38	42	36
12	8	40	44	38
14	10	42	46	40
16	12	44	48	42
18	14	46	50	44

Understanding Cup Sizes in NAIA Bikini Tops

NAIA Beach offers extensive cup size options across multiple sizing systems. Cup sizes can be confusing because the same cup size corresponds to different band sizes. For example, a UK 30D is equivalent to a US 30D or EU 65D, while a UK 34B is equivalent to a US 34B or EU 75B. The size charts below show available cup sizes by NAIA band size.

NAIA UK Size	UK Cup Sizes	US Equivalent	EU Equivalent
6	30C, 32B	30C, 32B	65C, 70B
8	30D, 32C, 34B	30D, 32C, 34B	65D, 70C, 75B
10	30DD, 32D, 34C, 36B	30DD/E, 32D, 34C, 36B	65E, 70D, 75C, 80B
12	30E, 32DD, 34D, 36C, 38B	30DDD/F, 32DD/E, 34D, 36C, 38B	65F, 70E, 75D, 80C, 85B
14	30F, 32E, 34DD, 36D, 38C, 40B	30G, 32DDD/F, 34DD/E, 36D, 38C, 40B	65G, 70F, 75E, 80D, 85C, 90B
16	30FF, 32F, 34E, 36DD, 38D, 40C, 42B	30H, 32G, 34DDD/F, 36DD/E, 38D, 40C, 42B	65H, 70G, 75F, 80E, 85D, 90C, 95B
18	30G, 32FF, 34F, 36E, 38DD, 40D, 42C, 44B	30I, 32H, 34G, 36DDD/F, 38DD/E, 40D, 42C, 44B	65J, 70H, 75G, 80F, 85E, 90D, 95C, 100B

NAIA Swimwear Features & Technology

NAIA Beach swimwear incorporates several design features to enhance comfort and fit:

• Subtle Sculpt: Selected styles feature NAIA's proprietary Subtle Sculpt technology, which provides comfortable stomach control without feeling restrictive. This feature is ideal for customers seeking gentle shaping.
• Separable Bikinis: Tops and bottoms are sold separately, allowing complete customisation. You can pair any top size with any bottom size to achieve your perfect fit.
• Support Options: Different styles offer varying levels of support. Some feature removable pads for customizable coverage, others include built-in cups for structured support, and select styles incorporate hidden shelf support for enhanced lift and shape.
• Coverage Varieties: NAIA offers multiple styles with different coverage levels. Whether you prefer minimal coverage or more comprehensive designs, there's a NAIA style to suit your preference.
• Premium Construction: All NAIA pieces undergo rigorous fitting and testing (a minimum of 5 times) to ensure quality and perfect fit before reaching customers.

Sizing Tips

General Swimwear Fit Guidance

When trying on NAIA Beach swimwear, keep these fit checks in mind:

• Bikini tops should provide comfortable support without gapping at the sides or spillage over the cups.
• Bikini bottoms should sit comfortably on your hips without riding up, sliding down, or creating visible panty lines.
• One-piece swimsuits should provide comfortable coverage through the torso with straps that sit properly on your shoulders without slipping.