The imperial pint is a unit of volume in the imperial unit system with the symbol pt.
1 imperial pint is equal to 1/8 of an imperial gallon. This is equal to 1/2 imperial quart, 4 imperial gills or 20 imperial fluid ounces. In SI / metric this equates to 568.26125 ml.
In Britain, all beer, ales and stout must be served in pubs by the pint (or half pint). Every single glass, despite being a 'pint' must have the numbers 568 ml printed on the side - and because of this, is likely the most commonly known conversion factor amongst the British population.