I got these for my husband.He normally wears 10.5 so I got him size 11 but they were too small. I sent them back for an exchange to size 12 and they fit perfect now.
My husband did not even realize he was still wearing his Ugg Slippers into the car, so comfortable and yet durable! I have a similar pair and they still look good 3 years later- so I hope for the same with his!
I wear this with sweatpants in my house or out in public. They are perfect for any situation where you want to be comfy. If you are a half size (which they don't have), I would go up in sizing instead of down.