Wine Bottles

 In case you ever wondered why wine bottles are exactly 750 ml. and not, for example, 1 liter (1000 milliliters).

In the 19th century, the main customer of the French wine producers was England. The English unit of measurement for liquid volume is imperial gallon, which is equal to 4.54609 liters. To simplify the calculations when converting units of measurement, the French transported wine from Bordeaux in 225 liter barrels or exactly 50 gallons, corresponding to 300 bottles of 750 ml.  To make it easier for them, they assumed that 50 gallons = 300 bottles.

So, one gallon corresponds to 6 bottles. In fact, this is the reason why even today, wine cases often contain 6 bottles.