From embedded news reporters in Iraq, I’ve heard expressions like, “We moved our position a few clicks,” in the context of what appears to be a distance. How far is a click? I can’t find an online source that defines a click in terms of distance.
I believe it’s a kilometer.
Previous threads on the exact same subject-
http://boards.straightdope.com/sdmb/showthread.php?threadid=73860&highlight=CLICK
http://boards.straightdope.com/sdmb/showthread.php?threadid=27038&highlight=CLICK
Yep, it’s a kilometer. I believe they spell it “klick”, but I’m not positive.
1,000 metres, or 0.62137 miles. I believe it was coined during the Vietnam war, and is now in common usage in Australia (?).
I’d not say common usage, but I’ve certainly heard it used.
Having said that, I’m big city (for Australia) born and bred, perhaps it’s used more out in the country.
I haven’t heard it used here, but then I’ve only been here 3 years.
Is the origin related to adjusting the sights on a gun for distance - one “click” per kilometer?
A klick is a kilometer - it’s in fairly common usage in Canada - most people will know what you’re talking about if you say “I can go 1,000 klicks on a tank of gas.”
According to my parents, “klick” is representative of the sound that the odometer makes when it rolls over a new kilometer - “click”. (Obviously, this would be in an older model car that had a mechanical odometer).
Really? That’s odd, because I’ve a great cite for it: “bloke down the pub”. Bloke down the pub told me, so it must be true (he’s related to “they”).
In my experience, it’s definitely a rural thing here in Australia, along with its cousin term “kay”, also meaning kilometre. Also I’ve noticed it tends to be used by older folks who would probably much rather be saying “miles” anyway, and don’t like saying “kilometres”.
It is commonly used in Science Fiction for a Kilometre , wherever SI units are used in colloquial speech.
Nope, not quite that big an adjustment. It is commonplace in US military talk.
I hear and use "K"s a lot but not so much with the klicks. I most frequently come across it in science fiction novels.
You may well be right with it being rural. I’m not (and don’t want to be) any more rural than Darwin in this country. 
Yeah, you all city folks need to come out here to the bush more often. We’re only a few kays down the road ya know. We have a fine old time out here, drinkin’ billy tea and swatting away the bunyips down by the billabong, and mostly we talk about how many klicks away the nearest town is - when we need beer.
Well, maybe that’s just older folk like me.
I’m just posting because klicks and kays are common terms to me, and I didn’t realise how rural we must be in this area. If’n a big city like Darwin doesn’t use those quaint country terms, well we must be hicks!