Usually wear a 5, but the size 7 fit perfectly.  These appear to be the same sizing scheme as the first Spitfire.  Can't beat the quality for around $10.  Ordered these with https://www.amazon.com/dp/B0081MSXSU/ref=cm_cr_ryp_prd_ttl_sol_48 after the https://www.amazon.com/dp/B000M504J0/ref=cm_cr_ryp_prd_ttl_sol_46 didn't fit in size 6.5.