Purchased a big kids size 7 (which I suspected was the same as a ladies size 7) for my 12 yr old daughter who happens to wear a womens size 6.5.  When she tried this shoe on, it was very big on her.  I tried on the shoe and am a wonens Size 9 and this shoe in big kids size 7 is roomy on me.  It feels super comfortable and airy.  I like that my foot doesnt sweat in it.  Im keeping this for sure since I can wear it or my daughter can grow into it.