These are gorgeous and so comfy and warm.
They mould to your feet over a few days of wear. The fur inside pads down a bit giving a bit more room.
I'm a size 7.5 and bought the 7.
The box says 7.5 as do all UGG boots, this doesn't mean it's a size 7.5.
There's just some technical reason for it to do with international sizing.
So don't think they've sent you the wrong boots, they haven't.
The 7 fits me perfectly, so they're definitely roomy, as a 7 in any other shoe would not fit me.
I have skinny long feet, so going down to a 7 works for me. But if you have fuller feet, I'd go up to the 8.
If you are unsure of what size to buy?
Go to the Ugg Australia website and measure your foot.
There is a difference between measurements for the mens boots and womens boots.
So make sure you use the right size chart.