Really enjoying retro/vintage boys names at the moment with a good nn if possible.
I think these are my current favs, which do you prefer and why? Thank you 
I prefer [name_m]Arthur[/name_m]. I love the meaning of it (bear) and the nickname [name_m]Art[/name_m]. I like [name_m]Calvin[/name_m] but not the meaning (bald).
I agree with pp, I prefer [name_m]Arthur[/name_m] because of the meaning! The sound is also more appealing to me.
[name_m]Hi[/name_m] there.
I think that they’re both very handsome. Old fashioned, quirky but grow up well. I give the slight edge to [name_m]Calvin[/name_m], because I love love the spunky sporty nn of [name_u]Cal[/name_u]. The most easily come by nn for [name_m]Arthur[/name_m] is [name_m]Art[/name_m] or [name_m]Artie[/name_m], & those aren’t nearly as good as [name_u]Cal[/name_u]. I also hear [name_m]Calvin[/name_m] less these days. I know a handful of little Arthurs in my area.
[name_f]Hope[/name_f] this helps. 
Thank you for your comments!
I’ve always liked [name_m]Arthur[/name_m], [name_m]Calvin[/name_m] is more of a recent discovery. And I agree [name_u]Cal[/name_u] is lovely, and I guess [name_m]Callum[/name_m] would be another way to get there but not sure I like it as much as [name_m]Calvin[/name_m] although it has a much nicer meaning!
I much prefer [name_m]Arthur[/name_m]. [name_m]Just[/name_m] such a classic and, now, lovely vintage quality. I’m not in the US and feel that outside the US [name_m]Calvin[/name_m] as a name has a strong religious overtone, a negative one I’m afraid. I think [name_u]Cal[/name_u] is lovely too but I’d use a different way to get to [name_u]Cal[/name_u].
[name_m]Arthur[/name_m] is a name I’ve always had a soft spot for! The meaning is so sweet, and the name itself looks lovely on paper, has a great history of use, and ages beautifully. So, I just have to go with [name_m]Arthur[/name_m].
[name_m]Calvin[/name_m] is a handsome name as well, and I do love the nickname [name_u]Cal[/name_u], but it just doesn’t seem to have the magic behind it that [name_m]Arthur[/name_m] does. Plus the meaning is really unfortunate, although meaning isn’t everything.
Both of these are great choices, but [name_m]Arthur[/name_m] is definitely my favorite. I’ve always loved [name_m]Arthur[/name_m]. It’s so warm and has a rich history. If I had been naming my child alone, without suggestions, input, or feedback from a partner, he probably would have been an [name_m]Arthur[/name_m].
[name_m]Arthur[/name_m]! Charming, grounded but also adventurous
I’m really loving the feedback on [name_m]Arthur[/name_m]! I might need another post at some stage for mn help but will have a think and come back. Thank you!!
Definitely [name_m]Calvin[/name_m]. I would have it on my list if it didn’t sound horrible with my last name.