I do care, though, and use ISO 8601 almost exclusively in writing. And I do know a few others. Perhaps things will change eventually.
[1]: https://fr.wikipedia.org/wiki/A4_(format)#/media/Fichier:Pre...
Some places even mix metric, imperial, and some traditional pre-imperial system.
Several countries (e.g. France) use the word pound (livre) to mean 500g, which could confuse visitors into thinking something non-metric is being used. I noticed that in south America.
[0] These days, and selling butter in 200g packages to keep the prices seemingly low.
And that's why i do my shopping now based on €/kg. There are some very telling differences between even the same manufacturer: last thing i was looking at was gin [the drink] € per litre. Just a visually minor difference in bottle size was a substantial difference in a) cost and perceived value and b) cost and actual value.
Also in Italy, when dealing with agricolture, forestry, and related services, non-SI surface units are still commonly used, at leat in the north:
https://it.wikipedia.org/wiki/Pertica_(unit%C3%A0_di_misura)...
Note that nobody I know below the age of 70 uses the "livre" unit in France. It's something you see pretty much only in old recipes
These are basically “sizes” that are imperial by tradition/accident more than people using them as measurement. If I wear size 32 waist jeans is that imperial? Maybe. I’m not measuring I’m just using it as a known size. Might be inches.
Same for wheels, rifle ammunition, …
I use inches for TVs/monitors and although I’m as metric as they get, I have a 55” TV and my car has 20” rims and so on. Everything has cm, kW instead of horsepower etc listed as well for a TV of course.
As far as I know only a few countries - presumably because of regulation - have switched for absolutely everything. Australia is an example of a country where you can get a 100cm TV.
"But being (as?) this is a .44 Magnum, the most powerful handgun in the world, and would blow your head clean off, you've got to ask yourself one question ..."
(Which totally illustrates your point because it's not really 0.44 inches.)
On the other hand:
"Seven-six-two millimeter. Full metal jacket."
295mm tyre width, sidewall height is 30% of the width and the wheel it fits in is 20 inches (can't recall whether it's 20 inch radius or diameter).
(Is there anywhere that doesn't use this mix of measures for tire sizes [tyre syzes]?)
But here in Finland (a completely metric country) things like televisions are still marketed/sold as 44" etc where the cm value could very easily be used.
E.g TV sizes are mainly compared with each other, and so the unit used doesn't really matter, and if you want to know the external dimensions it'll typically be given in metric in countries which uses it.
This leads to two interesting consequences for aircraft that perform international flights from/to China: [1]
- they need to be equipped with two altimetry systems;
- they need to perform small climbs or descents when entering or leaving Chinese airspace, as metric flight levels do not usually match Imperial ones (flight levels are defined by round numbers).
[0] https://en.wikipedia.org/wiki/Flight_level#Metric_flight_lev...
[1] https://skybrary.aero/articles/china-reduced-vertical-separa...
I'm not saying I agree with it, but it is at least understandable!
Notice that before the end of WW2, continental European aviation was metric too. For this reason, the instrument panel from a Messerschmidt BF-109 is almost readable for a layperson: https://live.staticflickr.com/3746/14275081012_1f74be13b4_4k...
Also naval folks are stubborn too. Own miles, knots as speed, craaazy! : )
Instead of DPI, one could use µm per px, or px per (c)m if you want something easier to work with at very high DPI.
I know what DPI and points are, but just because I know a few values and can say "that one's large", "this one is small", with no idea how much they act iually measure. With other units I could approximate the viewing distance much better.
Easy halving, the same reason why A4 has been extolled.
Normal text would be 40mpt = 4mm = 11.33pt.
But there are already metric point definitions: https://en.wikipedia.org/wiki/Point_(typography)
Other examples are screen sizes: I have no intuition at all about how big 5.5" actually are, but I know where in the current phone market 5.5" would fall (awesomely non-huge!), whereas to my mind, the metric equivalent would carry no information at all ("bigger than a stamp, smaller than a TV"). And for sensor sizes you even have the situation where the imperial number is a "size class" with very little relation to actual size, whereas the metric number usually describes actual size. Completely different numbers. All countries use a combination of metric and some other system.
> Other examples are screen sizes
that's common, but not as units of measure, but as marketing.
Same as megapixels in photo cameras.
Nobody measure power in HP, we say "that car has 85 HP" only in speech, but when it matters (for example on car papers) power is express in KW and screens are measured in cm that are also written on the package, they are only marketed in inches.
You would be correct if people had an idea of how much power 1 HP is or the surface of 1 MP camera shot, but they don't know, they only know that 16 MP > 12 MP and 300 HP > 100 HP, they (we) ignore what it actually means.
It is also perceived completely differently depending on context.
A 120HP tractor is not the same thing than a 120HP car or a 120HP motorbike.
According to US measures I'm 5'11, which means nothing to me, while it's obvious to them, because they actually use foot and inches all the time and do math using them.
Also 90F means nothing to me.
It's actually a pretty convenient unit, as long as you're familiar with how large tatami mats are.
Note that this unit isn't used for measuring an entire apartment's floor area though, that's done in meters.
The whole thing is absolutely mad and most efforts to standardise the systems historically lead to the adoption of the SI unit system for "important" things, as well as a few good intentioned bits of legislation, like the International Yard and Pound agreement [1] which standardised those measures between the US and other former imperial users. Don't get me started on the survey foot, or the hell that arose when the units of classical mechanics, electromagnetism or similar scientific systems had to meet imperial or US customary units...
[1] https://en.wikipedia.org/wiki/International_yard_and_pound
Well, in the middle ages, the furlong was important, because it was the standard size for farmers' fields (based on how long a furrow an ox could plow without resting). But 8 furlongs didn't fit neatly into a mile, so to make things easier for everybody, the mile got expanded to a nice round 5280 feet, or exactly 8 furlongs.
The numbers don’t work out too, “litres per 100km”. Why not millilitres per km (or litres per gigametre)
I drive X miles (or X km), I then fill up with Y litres (or Y gallons)
If I put 40 litres in my car and do 16 km per litre that’s 640km of range, simple calculation of 40x16
If I need to travel 260km at 20km/litre I need to but 260/20 litres or about 13 litres.
If I put 40 litres in my 3.6 litre per 100 km my range is 40/3.6 = 11 x 100 = 1100km.
If I need to do 260km at 3.6l/100km I need to do 260/100 = 2.6, times 3.6 = 9 litres.
With the “metric” way you need to do two calculations.
if you insist on using volume per length, I’d personally prefer 36ml/km, then I know I need 36x260 ml of fuel to go 260km, or my 40,000ml tank will take me 40000/36 = 1100km.
> I drive X miles (or X km), I then fill up with Y litres (or Y gallons)
This isn't what most use the liters per 100km for though. People just fill up whenever the light on the car tells them to. Mainly the number is used to compare cars when buying a new one. Some keep track of the actual consumption to notice if something is wrong with their car (just write down the current number on the odometer and how many liters you put in on some paper/app/whatever. you can do the actual calculations later)
At least this has been my experience here in Finland.
> With the “metric” way you need to do two calculations.
That's really an absurd way of looking at it, because one of those calculations is a division or multiplication by 100, and 100km happens to be a typical distance someone might be interested into finding fuel efficiency.
So the answer to me is an immediate mental computation, 2.6 x 5l = 13, you never ever need to compute consumption per km, express things in ml etc.
Your own "easy" examples look to me very intuitive and convoluted, so I guess the systems are 100% comparable, the only difference is the power of habit.
Measures are much more common in inches, foot and miles than metric. Volumes are much more common in cups, gallons, pints than metric. Weights are more common in pounds and ounces than metric.
That's in almost all domains, not just "a few high-profile holdouts" (even cooking, where it kills me that quantities of solids are in "cups" rather than grams...)
I think this is partially true, particularly with the older generation. People often talk about their height in feet and inches, and their weight in stone and pounds.
> Volumes are much more common in cups, gallons, pints than metric. Weights are more common in pounds and ounces than metric.
Your experience seems to be very different to mine. To be honest I have no idea what a gallon even is, and no intuitive concept of an ounce. The only place I have ever seen measurements in "cups" is one chicken biryani recipe I found on an American website. (I agree it's bizarre: half a cup of mint leaves - wtf?!). Any recipe published in the UK in the last couple of decades tends to be in grams and millilitres. Example picked at random: https://www.bbcgoodfood.com/recipes/chocolate-courgette-cake
I rarely see/hear/use imperial outside pints and road signs, or for “sizes” like screen or clothing waist sizes, unless I’m talking to people a generation older than me (I’m 40).
Every recipe site I use either has both or is entirely metric, and I only ever use metric. I’d probably look elsewhere if a search turned up a recipe in imperial only.
Even distances are in KM outside of driving (because of the road signs).
Pretty much everyone I know talks about their weight in KG. Heights do seem pretty split between cm and ft/inches but everyone understands both.
Most liquids except beer and cider (including other alcohol like wine and spirits) are in litres and ml.
It’s very obvious to me how metric-first life is for me because visiting America involves constant conversion and thinking whereas everything in other European countries (which are generally entirely metric) comes easily.
Ask an average American to give you the length of their car, size of their kitchen or weight of a brick in metric and they'll have no clue. The average British person can do this, because education has been metric for 50+ years and the least-technical industry (e.g. construction, DIY) is metric.
(See e.g. https://www.diy.com/, the largest consumer-facing DIY shop in Britain. It's 20kg of 10mm gravel, doors in millimetres, paint in litres. I can't even see a button offering an imperial conversion.)
The USA only uses metric in some important industries.
Britain uses it for lots of "unimportant" things, like construction/DIY, medicine, health care, cooking, sport/fitness.
We're still a bit of a mishmash, but it's not as bad as it might seem from outside.
The government proposed a consultation on doing so, mostly as a distraction.
I'd eat my hat if anything actually changes, the UK was (partially) metricated over 50 years ago, there's zero appetite for reversing it among people of working age and business concerns will dominate any serious consultation around changing legislation.
For example: https://www.builderdepot.co.uk/timber-sheets/carcassing-timb...
Note the listing is primarily in mm with the imperial measure along side.
So of course the actual size is still equivalent to the old imperial size because of the history, from a legal perspective it's metric.
We (Canada) partially transitioned too, but didn't complete the building supplies part of it.
So food is all metric, roads, speed limits, distances, weights, yet wood is imperial, and tools are metric and imperial.
This makes sense, because with the US so close, and the largest trading partner, imperial cannot fully vanish in some repects, until they get rid of it too.
It doesn't mention one product that is very much in the news at the moment: energy. I'm fairly sure they still sell it by the kWh rather than the MJ.
Colloquially, people still talk about calories rather than kJ in food. (And they do that even in Germany, I think, one of the few places where they measure font sizes in mm rather than points, or so I've heard.)
EDIT: Perhaps kWh counts as metric, even though it's not SI?
Watts are a metric unit, as are seconds. Hours are not formally an SI unit, but at least according to Wikipedia [0] are "officially accepted for use with the SI".
[0] https://en.m.wikipedia.org/wiki/Non-SI_units_mentioned_in_th...
EDIT: According to Wikipedia [0], the Imperial unit of energy is ft⋅lbf.
The kcal (kilocalorie) is what most people mean when they refer to calories in food, and that's just the energy needed to heat 1 kg of water by 1 deg C.
Since a person is mostly water this means that, say if you weigh 100 kg, and eat 1000 kcal of food, that food contains (theoretically) enough energy to heat your body mass by 10 deg C. The units do give a kind of intuitive understanding of the energy in food, while also being based on metric quantities.
It's sold in MWh in the rest of Europe.
No need for perhaps, unless it's btu (or some horse power/hour) it's metric.
On the other hand if nobody over 65 voted every vote would be different.
Business interests align with hard cash. That's going to lean towards metric.
Over 65s don't "vote" much in businesses, they're retired.
If you only buy milk in multiples of 500mL, you're buying a luxury brand or from a corner shop -- both situations use the slightly smaller (vs 568mL) size to make the price seem lower.
You can see at Tesco [1] that Yeo Valley, Arla, Cravendale, Finest, Tesco Filtered are all 1 or 2 litres. "Normal" milk is 2 or 4 pints.
(The EU used to have regulations around this sort of thing, but I think they've unfortunately been repealed for most products. It's why bread was only sold in multiples of 400g -- it meant the merchant couldn't discreetly reduce the size of some/all products.)
[1] https://www.tesco.com/groceries/en-GB/shop/fresh-food/milk-b...
The dairy that delivers here does 500ml, 1l, and 2l, as does the one I bought milk from before I moved, and the one before I moved the time before that.
The normal milk is all in pints.
Distance on road signs, car speed, engine fuel efficiency, beer pints (though I don't mind this since it means our average drink is larger, easier to say than 568ml as well), and that's it as far as I can recall