There was considerable flexibility about these matters in the ancient world. What follows is just one system.
Measuring Distance
In addition, Herodotus uses a square measure: 1 aroura (‘field’) is defined at 2.168 as 100 square cubits.
In modern absolute terms, 1 foot, on the Attic scale which Herodotus was using, has been estimated to be 29.6cm. (11.65 in.). Therefore:
Money, or Measuring Weight
Greek coinage was not on the whole fiduciary, but was worth its weight. Hence the measures of weight are at the same time financial measures.
This is the scale for the Euboïc-Attic talent (see 3.89); Herodotus there also talks about a Babylonian talent, which is worth 70 Euboïc minas, or 30.324 kg. (66.86lb).
There was also in circulation in the east, at any rate, a stater (or ‘standard’, also sometimes called a daric, after Darius), which Herodotus occasionally mentions, whose weight on the Attic scale was 4 drachmas, or almost 18 g. (0.63 oz.). But it is not absolutely clear, when Herodotus is talking about eastern staters (as at 7.28–9), that he is thinking in terms of the Attic scale.
Measuring Capacity
Liquid measures: 1 amphora (‘jar’) = 12 choes (‘pitchers’) = 144 cotylae (‘cups’) = 864 cyathi (‘spoons’). Since 1 amphora = about 39 litres (68.64pints, 8.58 gallons), then 1 chous = 3.25 litres (5.72 pints), 1 cotyle = 270ml. (0.48 pint), and 1 cyathus = 45 ml. (0.079 pint, 1.58 fl. oz.). Herodotus refers only to the amphora (1.51, 70, 4.81) and cotyle (6.57). In this latter passage he also refers to a liquid measure he calls the ‘Laconian fourth’, which F. Hultsch (Griechische und Römische Metrologie (Berlin, 1882), 500) says is ‘obviously’ a quarter of a metretes or amphora—i.e. (on the Laconian scale) about 14 litres (24.64 pints). The ‘arister’ mentioned at 2.168 was apparently the same as a cotyle.
Dry measures: 1 medimnus = 48 choenixes = 192 cotylae. Since 1 cotyle = 270ml. (0.48 pint), then 1 choenix = 1.08 litres (1.90 pints), and 1 medimnus = 51.84 litres (91.24 pints, 11.40 gallons).