Ancient Greek units of measurement facts for kids

Ancient Greeks used different ways to measure things, and these measurements often changed depending on where you were and when. Over time, as people traded more across the Mediterranean Sea, some units became more common. The tools they used for measuring also got better. By around 500 BC, the city of Athens even had a special place called the Tholos where merchants had to check their measuring tools against official standards.

How Ancient Greeks Measured Length

Some Greek length measurements were named after body parts. For example, the δάκτυλος (daktylos) was like the size of a finger, and the πούς (pous) was like the size of a foot. The exact size of these units could be different in various cities. For instance, a pous in Aegina was about 333 mm (13.1 in), but in Athens (Attica), it was about 296 mm (11.7 in). However, the way these units related to each other (like how many fingers made a foot) usually stayed the same.

How Ancient Greeks Measured Area

When measuring land, the Ancient Greeks used specific units. These units were often based on their length measurements, like the "pous" (foot), but squared to cover an area.

How Ancient Greeks Measured Volume

Greeks measured volume differently for solids (like grain) and liquids (like wine). A common unit for both was the cotyle or cotyla. Its exact size varied, but it was usually between 210 ml and 330 ml. The smallest basic unit for both was the κύαθος (kyathos).

Here are the Attic (Athenian) measures for liquids:

An illustration of the Third Horseman of the Apocalypse holding scales. This image relates to a time of high food prices, where a choinix of wheat cost a denarius.

Here are the Attic dry measures (for things like grain):

Ancient Greek Currency

The main unit of money in Athens was the obol. It was a small silver coin, weighing about 0.72 grams.

An obol from Attica, Athens, weighing 0.69g, made after 449 BC.

How Ancient Greeks Measured Mass

Mass (or weight) was often linked to currency because coins were made of specific amounts of metal. For example, the English pound was once both a unit of weight and money!

There were two main weight systems in the eastern Mediterranean: one from Euboea (later used in Attica by Solon), and another from Aegina. The Attic/Euboean system was supposedly based on barley grains, with twelve barley corns making one obol. However, actual weights found by historians often vary a bit from these perfect numbers.

Here's a table of these theoretical weight standards:

How Ancient Greeks Measured Time

Athenians used sundials to tell time during the day. For measuring periods at night or when the sun wasn't out, they used a water clock (called a clepsydra). This clock worked by water dripping at a steady speed.

Unlike our modern calendar where the day starts at midnight, the Greek day began after sunset. Athenians named each year after a special leader called the Archon Eponymous. Later, during the Hellenistic period, years were counted in four-year cycles based on the Olympiad (the Olympic Games).

This part of a frieze from the Elgin Marbles shows a cavalry parade that was part of the Greater Panathenaic festival, held every four years in the month of Hekatombion.

In early Greek times, months followed the Moon's cycle. This meant they didn't perfectly match the solar year, so the months would slowly shift into different seasons. The Athenian year had 12 months. To try and keep the calendar in line with the seasons, they added an extra month (called Poseidon deuterons) every second year. Even with this extra month, the Athenian calendar wasn't always accurate, and sometimes extra days had to be added by a leader called the Archon Basileus. The year started around the summer solstice (the longest day of the year), and months were named after Athenian religious festivals.

See Also

• Ancient Roman units of measurement
• Byzantine units of measurement
• Level staff