FROM LEFT TO RIGHT: Barton, Roy and Ken/Kenneth

This art was originally done by  fextoon

So, here's a size and reference chart for Barton and his two friends; Roy and Ken (Or Kenneth, but he prefers Ken).

To give a size guideline, Barton stands at 4ft11in, being the tallest of the three.
Barton and Roy are also crossbreed Badgers (Both have European Badger farthers, Barton's mother is an American Badger while Roy's is an Asian Badger), while Ken is a purebred European Badger, to give an idea of their heritage.

The clothes shown are what they're usually dressed in. None of them wear any kind of footwear, they are always barepaw. Barton's hands have gloves on, to obscure the partial plush transformation. Full detail for Barton is available on his reference sheet.

Barton has his own reference sheet here: https://www.furaffinity.net/view/29284198/
Roy and Ken both have 'detail' images that, while they're not 'true' reference sheets, give better detail as to how they look.
Roy: https://www.furaffinity.net/view/30046642/
Ken/Kenneth: https://www.furaffinity.net/view/29957923/

Additional: I am giving each of them birthday dates as well:
Barton's birthday: 15th June
Roy's birthday: 9th May
Ken's birthday: 3rd April