I had tried a pair of Privos on in a store (different style than the Kosmo) and they ran big.  So when I ordered the Kosmo online I ordered a 7.5 even though I normally wear an 8.  The 7.5 in the Kosmo were too small.  I returned them for an 8 and the 8 fits perfectly.  I would say these are true to size.  They are so comfortable and very cute!  I purchased the sage green ones, which is a very light green and a low-key color (I'm not a fan of green normally, but these are almost a 'neutral' green).