ON RUNNING Cloud Monster Hyper Women's US Size 8 B (regular width) IMO, size runs big. I am usually a true 8 and these were a little big on me, not enough to annoy me while walking around but felt too big for running. Perfect for someone who is 8 or 8.5. Running Shoes High Cushion White and Green Great deal since this is a current model and they are originally $220!