I only buy when I have to, but that might be more often than many - I replace most clothes when they start to show wear, not wear thru. I give jeans a pass as far as looking worn, and I’m okay with my shoes looking broken in, but nothing with holes or frayed threads stays around.
Whenever go up to town for a few days, about every three months or so, one day is set aside for clothes-shopping safari mode.
I prefer hitting up the second hand couture shops, though, so it takes a while. I also find it entertaining to try on crazy, expensive stuff I can’t afford, especially when I’m up there and it’s raining. The museums are packed, the high street chains are packed, but there’s hardly anyone else in the dark shops and corners except other die-hards. 
I’ve found some pretty neat items that way.
I also tend to sell or trade in clothes around the same time that I shop, so I can still shut my closet door.
Pretty much never. About the only thing I buy for myself are new t-shirts, and those I get on-line. Everything else is usually my wife’s purchase for me, since (as anyone who has met me can tell you) her taste in clothing is far superior to mine.
I voted “only when I have to” which is true. I go through my closet and get rid of stuff that’s no longer wearable and then go buy new. Except for shirts. I will go and buy shirts anytime. I am a shirtaholic.
Once a year. I go to Lands End and look for knit tee shirts on sale and choose some short sleeved and some long sleeved. They last forever, don’t shrink or fade, and the only reason I even shop once a year is because the rotation gets boring.
My jeans last forever – haven’t bought a new pair since 2009. Same for shoes, and my winter coat was purchased in 2005.
Nobody can accuse me of being a style maven!
When I put a hole through my pants then I go to the store and replace them. Ditto with everything else. I buy underwear on line since no store has what I like - I’m quite peculiar. It is not something I enjoy.
We can add Stanley Kubrick to the “only when I have to list.” During the shooting of 2001 his wife and staff convinced him he needed some new suits. They made an appointment at a famous clothing store, where the tailors stood waiting to fit him. On the way in he stopped at a rack - pointed to a suit, said “I’ll take three of those” and turned around and left.
My hero!
I don’t shop every month. I have made a separate account for my shopping and also keeps the list of things i intend to buy and then i shop one month all the things. This keep checks if i am not overspending. Sometimes when some things are hard to resist i buy them rarely.
“Only when I need to” ends up being about twice a year, so I just went with the less-traveled option and picked twice a year. Usually once for undergarments and summer items and once for winter items. I actually bought a coat this year. Nice sale. Replaced a coat I’d been wearing for fourteen years. Figure that’s a pretty good run for a coat, eh?
For some reason my pants wear out fast compared to other people’s. Not sure why exactly. Maybe I just need more in rotation. Hmm.
Count me as twice a year, and only what is needed. I am frugal by nature, and when I do buy I go for quality at a deep discount.
Now, the spouse, on the other hand, regarding their clothes buying habits…let’s just say that we (and by that I mean me) have had occasion to actually utter the word “Yikes!”
Do you mean go in person to a store? If so, a few times a year for underwear but it would be part of a routine trip for various things.
On line, seasonally for a set of shirt and pants.
Not often. I’m in the process of losing weight. Doing great thus far and I can’t weight to buy no clothes.
I’ve had to go more shopping lately since losing weight. I try to stay in clothes as long as possible, but they get baggy and look really bad so I have to buy more. I hate shopping, even for a smaller size. Since moving down from women’s/plus sizes to the regular department, there is so much more choice in what to buy, but that makes it all the more complicated.
I haunt eBay for high quality mens clothes, such as Orvis, which I can often buy unworn. Also better quality Thrift stores, etc. Thus I checked “other” since few of my clothes (other than sox or underwear) are bought “new” from store.
I probably buy a pack of socks yearly, otherwise I would say half of my clothes are stuff my mom bought me when I was still living at home, or, nowadays, when I sometimes go visit my parents. And the other half are second hand clothes from friends.