That is not new though? I am fairly certain I bought both sizes at various places all over Europe. I guess the 440 is meant for the british market while the 500 is intended for civilised countries.
Yeah, this is not new and not shrinkflation… here in Canada the 440ml has been around for over 20 years in multi-packs, and the 500ml is available as individual cans.
In Britain lots of beers come on both sizes, and it makes comparing prices #mildlyinfuriating. Is 6x500ml at £7.99 better than 4x440ml at £4.50? What if there's an 12 pack of 330ml stubbies for £15, but it's Buy One Get One Free?
440ml is a UK variant. No one has a confirmed explanation for its existence alongside 500ml.
However 440ml of water would be 0.44kg which is just under one pound imperial weight (0.45kg). Presumably the fluid plus the aluminium can would weight about 1lb which may explain the odd volume measure (given transport costs and possibly even how customs costs may have used to work?).
I always thought it was because 440ml is a round number when you convert it from metric to medieval units (not a pint though, which is 568ml), but a quick google shows me there's another reason:
One reason for the popularity of the 440ml size is its convenience for calculating alcohol units. A 440ml can at 4.5% alcohol by volume (ABV) equates to exactly 2 units of alcohol, making it easier for consumers to track their alcohol consumption
The UK measures alcohol in units to track total amount consumption, as it's not easy to track with percentage in volume. A unit is 10 ml of pure alcohol, and cans/bottles/etc have the total units printed. That way it's supposed to be easier to track how much alcohol you drink e.g. if you drink a beer, then a wine - now that's 4 units.
I'm not British so I'm not used to units, but at least that's the theory.
A non-standardized amount of grams of alcohol in a standard drink.
Each country have their own definitions, usually between 8-14g somewhere, and then each country use that to create their own health rules of how many standard units of alcohol can be part of a healthy nutrition guidelines / low-risk consumption guidelines.
I guess it translates to one of those units used in the US and UK, that you divide by twentyeleven, then multiply by two large fries, and you get the result in football (which is actually hand-egg ball) fields.
Edit: the extra 30ml might be accounted for with the patented Guinness widget, a little ball of nitrogen gas that ruptures and forms a foamy head when the can is cracked.