I’ve heard lots of British army and air force people use it. It never occurred to me until now that it might be an Americanism.
Kays or K for distance or speed.
Singular ‘K’ only for money (‘it costs 5k’).
But, yes - just as likely to use time units to express distance. (‘How far?’ ‘About an hour, hour-ten’).
It might be a universal militarism, *I *just associate it with (specifically Vietnam) war movies, for some reason. Maybe because that was the first big war where the US had to work with kilometre-using allied forces? Or do they use kilometres as standard now anyway?
Also, IIRC it’s often spelt “klicks” not “clicks”.
Izzit?
I’m a Kiwi, (kissing cousins for them funny blokes across the ditch)…
I basically never heard “K” in connection with money until I came to Singapore …
we always called 1K “a grand” —
Likewise $2,000 would be “2 grand”
Does this still apply?
My old bastard is around 70 and he uses km exclusively - he never talks in miles anymore (anecdote is not data and all that)
I’d always imagined “grand” was purely an Americanism. Interesting to know it’s more widespread.
Maybe my North Queensland heritage is showing. 
Yes, the majority of even old timers would use kays, but it wouldn’t surprise me to hear an older person from rural Qld use miles.
I am in BC Canada and around here we say “kliks”. I have never heard anyone say “kay”. And most people I have heard using the whole word pronounce it as “kill AW mitter” rather than “KEE lo meeter”. What is odd is that they will then use “KEE lo gram”, “KEE lo leeter”, etc for other types of measurement. I just go with “KEE lo <everything>”.
And I spell the word as “kilometer” rather than “kilometre”.
Aw, but you’re Canadian, almost half a Yank! ( 
)
It’s certainly true that kill-AW-meter is a pronunciation outlier, as everything is is “KEEL-oh-x” or “KILL-oh-x.” KILL-oh-liter, KILL-oh-ton, etc. And when the prefix is used by itself, it turns into “KEEL.” Two KEELOs of drugs, man…
A Commonwealthism I had trouble with was “Recce” for “Reconnaissance.” I had wanted to pronounce it “REE-see” but found out later that it’s “Recky.” Embarrassing, as I’d been saying it the first way aloud.
K’s mostly, sometimes clicks, but yeah I grew up in the bush and distance was measured in either units of time or how many stubby’s back in the old days when drink driving was compulsory.
eg, Q. how far to the next town?
A. 2 stubbies north (20km or 10-12 minutes)
Never once in my life have I heard ‘clicks’ as a placeholder for kilometres in an actual conversation between Australians of any state. To me it has always been k’s, pronounced kayes.
" It’s twenty K’s to the shop, then you hang a left just after the servo".
I’ve never in my 50 years heard any Australian use “clicks” for kilometres either. Always K or kays.
In writing, though, it’s almost always written as km. “It’s about 10 km from here.” You’d say K but write km.
ETA: And km is the correct way of abbreviating kilometres, BTW. Recognised by my Australian spell-check, too.
km would be the appropriate scientific notation also…
So, in dialogue, the guy would say “Kays.” Keen! Thanks again! I wish all my problems were as easily solved! Y’all’s great!
Clicks is for old people. Very old people. Or wankers, I guess.
Definitely k’s (pronounced “kays”). Miles can be used for generic mentions e.g “it’s miles away”, but for specifics, it’s always k’s.