I'm 174cm tall, around 63 kg, waist 66cm, hips 91cm and wearing size S. they are very stretchy and tight, but not in the uncomfortable way. Like!
Purchased size small and medium and only tried on the medium and it fits exactly like the Gymshark size small! Same exact leggings (material, quality and design) but with a much more affordable price tag and minus the logo. Shipping took a little over 2 weeks. Highly recommend !