If you change your mind, you can return full-price items for an exchange, online store credit or refund when they are returned in saleable condition within 7 days of receiving your order.
Sale items can be returned for an exchange or online store credit only unless purchasing to try on for size. Learn more at unepiece.com/returns.
Our first model wears size AU 8 (US 4). She is 179cm (5'10.5") tall with an 84cm (33") bust, a 69cm (27") waist and 94cm (37") hips.
We follow standard sizing guidelines and make our products true to size.
Our swimsuits are constructed with a firm fit to flatter your shape. If you are between sizes, we recommend choosing the larger of the two sizes. For example, if you wear a size 10 in the top but a size 12 on the bottom (or vice versa) we recommend you purchase a size 12.
Find size measurements and international size conversions at unepiece.com/sizing.
To keep your UNE PIECE looking beautiful, please carefully follow our care instructions:
Cold hand wash
Do not soak, bleach or dry clean
Do not spin or tumble dry
Do not iron
Line dry out of direct sunlight
Do not pack or store when wet
Remove any excess water and dry without delay
Separate light colours from dark before washing
Size Guide
CMIN
AU/UK
Bust
Underbust
Waist
Hips
US
Bust
Underbust
Waist
Hips
6 (XS)
76 - 80
64 - 68
59 - 63
86 - 90
8 (S)
81 - 85
69 - 73
64 - 68
91 - 95
10 (S)
86 - 90
74 - 78
69 - 73
96 - 100
12 (M)
91 - 95
79 - 83
74 - 78
101 - 105
14 (M)
96 - 100
84 - 88
79 - 83
106 - 110
16 (L)
101 - 105
89 - 93
84 - 88
111 - 115
18 (L)
106 - 110
94 - 98
89 - 93
116 - 120
20 (XL)
111 - 115
99 - 103
94 - 98
121 - 125
22 (XL)
116 - 120
104 - 108
99 - 103
126 - 130
24 (XXL)
121 - 125
109 - 113
104 - 108
131 - 135
2 (XS)
29.9 - 31.5
25.2 - 26.8
23.2 - 24.8
33.9 - 35.4
4 (S)
31.9 - 33.5
27.2 - 28.7
25.2 - 26.8
35.8 - 37.4
6 (S)
33.9 - 35.4
29.1 - 30.7
27.2 - 28.7
37.8 - 39.4
8 (M)
35.8 - 37.4
31.1 - 32.7
29.1 - 30.7
39.8 - 41.3
10 (M)
37.8 - 39.4
33.1 - 34.6
31.1 - 32.7
41.7 - 43.3
12 (L)
39.8 - 41.3
35 - 36.6
33.1 - 34.6
43.7 - 45.3
14 (L)
41.7 - 43.3
37 - 38.6
35 - 36.6
45.7 - 47.2
16 (XL)
43.7 - 45.3
39 - 40.6
37 - 38.6
47.6 - 49.2
18 (XL)
45.7 - 47.2
40.9 - 42.5
39 - 40.6
49.6 - 51.2
20 (XXL)
47.6 - 49.2
42.9 - 44.5
40.9 - 42.5
51.6 - 53.1
Size
AU/UK
US
EU/FR ES/PT
DE
IT
JP
XS
6
2
34
36
38
5
S
8
4
36
38
40
7
S
10
6
38
40
42
9
M
12
8
40
42
44
11
M
14
10
42
44
46
13
L
16
12
44
46
48
15
L
18
14
46
48
50
17
XL
20
16
48
50
52
19
XL
22
18
50
52
54
21
XXL
24
20
52
54
56
23
Our swimwear is designed for a firm, flattering fit. If you find yourself between sizes, we recommend selecting the larger size for optimal comfort.
How to measure
Bust: Using a flexible tape measure, measure across the fullest part of your chest, ensuring the tape measure is straight across your back.
Underbust: Measure directly under your bust, where the band of a bra would sit.
Waist: Measure around your natural waistline — this is the narrowest part of your torso, usually right above your belly button.
Hips: Stand with your heels together and measure around the fullest part of your hips and bottom.
Frequently Asked Questions
What size should I select in the Classic Square Neck one piece?
This style runs true to size with a firm, sculpting fit. If you’re between sizes or have a long torso or curvier hips, go up one size. Suits A–J cup sizes. See the women’s swimwear size guide for measurements when selecting your size.
What size bust is this swimsuit best for?
This style has been designed to support A–J cup sizes with many fuller-busted women reporting excellent support.
Is the Classic Square Neck one piece see-through when wet?
No, this is a fully lined swimsuit is made with recycled lining for reliable coverage in and out of water. The panelled bodice also keeps the fabric flat so it doesn’t go sheer when wet.
Is this a supportive one piece swimsuit for bigger busts without underwire?
Yes. The InvisiBust Support Technology uses a panelled, fully lined bodice to lift and hold without bulky cups or underwire. It’s designed for A–J cup sizes and is praised for how comfortable it is to wear.
Is the fabric UPF50+ and chlorine resistant for pool use?
Yes. The recycled fabric is UPF50+ (blocks 98% of UV rays) and ultra chlorine resistant. Rinse after every swim and line dry out of direct sun to keep colour and elasticity strong.
Will the Classic Square Neck work for a long torso?
Yes! Thanks to the firm stretch and panelled construction. If you usually need extra length, size up for more torso room without losing support.
A modern square neckline one piece with removable bows and a panelled, fully lined bodice make this a flattering, wear-anywhere swimsuit. Crafted from recycled, UPF50+ fabric that blocks 98% of UV rays and holds its shape swim after swim.
Why you’ll love it
Excellent bust support with InvisiBust Support Technology for a firm, supportive fit without bulky cups
Designed to support A–J cup sizes
Good bottom coverage
Ultra chlorine resistant to help maintain colour and elasticity
Pilling and sun-cream resistant fabric for longer wear
Fully lined with recycled and sustainable fabrics for a soft, comfortable feel against the skin
Removable bows to switch between minimal and playful looks