Im in UK and tried this on at size 10, small, what would this be from the US?

Tech Specs:

Material:

[Shell] HyVent 2L, quilted taffeta; [Shell lining] mesh body, taffeta sleeves 

Insulation:

[Snap-in liner] 100g Heetseaker 

Waterproof Rating:

[Shell] not specified 

Breathable Rating:

[Shell] not specified 

Core Venting:

[Shell] Underarm zips 

Pockets:

[Shell] 2 front, 1 wrist with goggle cloth, 1 internal media, 1 internal goggle; [Liner] 2 front, 1 internal media 

Seam Taped:

[Shell] yes, fully 

Powder Skirt:

Yes 

Hood:

Yes, removable 

Zip-in Compatibility:

Yes, snap-in liner included 

Recommended Use:

Skiing 

Manufacturer Warranty:

Lifetime