Atlas Size Guide

All measurements are in centimetres (CM). Measure your body and compare with the size chart below.

Atlas Sports Bra

Size Bust (CM) UK Size US Size
XS 86 4-6 2
S 91 8-10 4-6
M 97 12-14 8-10
L 102 16-18 12-14
XL 107 20-22 16-18

Atlas Halter Neck Top

Size Bust (CM) UK Size US Size
XS 86 4-6 2
S 91 8-10 4-6
M 97 12-14 8-10
L 102 16-18 12-14
XL 107 20-22 16-18

Atlas Shorts

Size Waist (CM) Hips (CM) Inside Leg (CM) UK Size US Size
XS 64 89 76 4-6 2
S 70 97 76 8-10 4-6
M 76 104 79 12-10 8-10
L 84 110 79 16-18 12-14
XL 93 118 81 20-22 16-18

Atlas Leggings

Size Waist (CM) Hips (CM) Inside Leg (CM) UK Size US Size
XS 64 89 76 4-6 2
S 70 97 76 8-10 4-6
M 76 104 79 12-10 8-10
L 84 110 79 16-18 12-14
XL 93 118 81 20-22 16-18

How to measure: Use a soft measuring tape. For bust, measure around the fullest part. For waist, measure around the narrowest part. For hips, measure around the fullest part. For inside leg, measure from the crotch to the ankle. If you're between sizes, we recommend sizing up.

OBSYRN | Own the Fit

OBSYRN was created to bring the feel of luxury activewear to everyday life.


Every piece is designed with intention. Elevated materials, precise fits, and a restrained aesthetic built for movement, presence, and repeat wear. This isn’t performance for the spotlight. It’s performance for real life.


Our mailer bags are made from recycled plastic, because responsibility should feel natural, not performative.


OBSYRN is for those who move quietly. Those who don’t chase attention, but understand its weight. Once you step into OBSYRN, you don’t go back.