Pewter measures used in trade for dispensing liquids had to conform to the prescribed capacity standard. As tankards and mugs could sometimes be used for dispensing, they too conformed to the relevant standard. However, there have been many different standards over the years. Here are the main ones you may encounter.

The capacities are given in millilitres (or cc – they're the same thing). Vessel capacities are rarely 100% accurate, but most will be within a tolerance of -2% to +5% of the standard and the ‘range' shows this tolerance.

* In Ireland, often called a noggin or naggin

Because of the tolerances one cannot always determine which capacity standard was used. For example, it is impossible to say whether a measure with a capacity of 580 ml is Imperial, Old English Ale or even Winchester standard. To confuse matters still further, some of the pre-1826 standards varied in different parts of the country, so a measure might have been made to a standard but still fall outside the tolerance ranges indicated above. There were other standards as well, many of them local, but pewter measures using them are rarely encountered.

Here is the same information in fluid ounces.

This table doesn’t include the ranges, but it is important to bear them in mind.