I fit the sizing measurements for the Large in the sizing info chart.  I ordered a Large.  This item runs extremely large.  It wasn't merely that the item was baggy and loose; they literally would not stay on my waist or hips as they kept falling down.  If you wear a size 10-12 pant(US); I suggest you order a medium or even a small if you want them to fit snug.  I considered puting them on the sewing machine and taking them up ... but just gave them to a friend that is a size 16.  She has a difficult time finding high-waist leggings that fit.