After browsing Facebook recently when looking for a second-hand car, I came across the curious term ‘NaN miles’ for the vehicle’s mileage but didn’t have a clue what it meant. The thought flitted through my mind to contact the seller and ask them directly but, at the risk of appearing to be a dimwit, I decided not to and just to research it quickly online. Surely it would pop up right there at the top of the search results and it would be job done. With this flawless logic, I thought, the easiest solution would simply be to either choose the search query “what are nan miles” or the other obvious alternative “what do nan miles mean”.

Although I thought ‘Nan’ may be an acronym, I couldn’t figure out what it meant simply by guessing so thought perhaps that it might be something a little more obvious. Now, in the UK, a “nan” is a colloquial term for a grandmother so I reasoned that Nan miles might mean that the car had been driven very carefully and slowly since many older people don’t tend to fit the typical “boy racer” profile. A boy racer btw is another slang term for a younger person who likes to drives fast and furiously. Therefore nan miles would surely mean the same as ‘carefully driven’.

Of course not… what on earth was I thinking?!

The actual meaning of NaN miles – Not a Number

Surprisingly, it took a bit of hunting online before I tracked down the actual answer. The “nan” part of NaN miles is an acronym and stands for Not a Number. With this in mind, why would anyone advertise their car with NaN as the mileage? Upon further investigation, it turns out that if you don’t enter the mileage correctly, Facebook returns NaN (not a number) in the listing, telling the advertiser there’s been a typo. This clearly leaves the rest of us scratching our heads wondering what on earth it could mean.

NaN is already a geeky acronym

If you look at this forum post, you’ll see a similar question posted by someone who came across Nan miles in the geo-location sense. When the ‘from’ and ‘destination’ locations were the same, he/she also came across NaN miles as the result, rather than a big fat zero. Again, NaN is used in the world of coding as Not a Number as well. Similarly, you’ll find the same question being asked on the Fitbit forum.

Anyway, so now you know and you’re no longer a dimwit like me.