How much bigger is the LG G Watch R than a regular watch?

Not very. Though that depends which regular watch you're looking at.

On the left is what I would consider a large watch – or it sure is compared to others that I own – and on the right of course is the LG G Watch R. The G Watch R is a little bigger and a little thicker, but it's not perhaps quite as big as some images would lead you to believe.

Whether it's your style, that's a different question.

source: androidcentral