Ancient Measures

Darius the Great built the first truly imperial metrology. The Achaemenid administration took Babylonian and Egyptian measures, fixed their ratios — 5 fingers (angosht) to the hand, 3 hands to the foot, 5 feet to the pace — and ran a continent on them. The karsha (83 g) is stamped on surviving bronze lion-weights; the gold daric weighed exactly one shekel (8.33 g) and became the ancient Near East’s dollar for two centuries. Distances on the Royal Road were posted in parasangs (~6 km, an hour’s march), and Herodotus — our best witness — describes the whole tribute of the empire in talents (3.89–96).

Try the Persian length, weight, and volume converters.

Greece is Rome’s photographic negative: brilliant, and never standardized. Every polis kept its own foot — Athens 30.8 cm, Samos ~34, Pergamon ~33 — its own drachma (Athens 4.32 g of silver, Aegina 6.1 g, Corinth 2.9 g), its own stadion (177–192 m). The money-changer’s table, the trapeza — root of “bank” — existed to bridge the gaps. What the Greeks shared was the shape of the system: 16 daktyloi to the pous, 6 obols to the drachma, 60 minae to the talent — and a genius for exporting it, from the Olympic stadion to the parasang borrowed from Persia.

Try the Greek length, weight, and volume converters.

Rome did what no one before it had done: it made one foot rule an empire. The pes (29.6 cm) was cast in bronze and distributed from Britain to Syria; surviving foot-rules cluster so tightly that archaeologists can spot a provincial copy. The system was ruthlessly decimal-adjacent: 16 digiti to the foot, 12 unciae to the libra (whence our ounce and “lb”), 5 feet to the passus — the legionary’s double step — and 1,000 passus to the mille passus, the mile that outlived the empire by two millennia. Grain moved in modii (8.73 L), wine in amphorae (26.2 L); the emperor’s largesse was literally measured by the congius.

Try the Roman length, weight, and volume converters.

The units of the Hebrew Bible grew out of the body and the harvest: the etzba (fingerbreadth), the tefach (handbreadth), the amah (cubit, forearm to fingertip). They measure Noah’s ark (Gen 6:15), the Tabernacle, and Solomon’s Temple — and they never went away. Rabbinic literature systematized them into a precise instrument of law: the Mishnah and Talmud fixed the relationships (4 etzbaot to the tefach, 6 tefachim to the amah, 2000 amot to the mil) because real commandments depend on them — the height of a sukkah, the volume of a mikveh (40 seahs), the distance one may walk on Shabbat.

That living legal use is exactly why the values are disputed. A thumb’s width is not a constant of nature, and the great modern authorities measured different thumbs: R. Chaim Naeh’s etzba is 2.0 cm, the Chazon Ish’s 2.4 cm. Our Jewish length converter lets you choose the opinion; the notes say plainly where each figure comes from.

Japan borrowed its measures from Tang China — the shaku is the Tang chi, frozen in time — and then made them unmistakably its own. The 1891 Weights and Measures Act fixed the shaku at exactly 10/33 m (30.303 cm); the ken (6 shaku) became the module of all Japanese architecture, the koku (180 L of rice, one person’s yearly food) became the unit of wealth itself — daimyo domains were rated in koku, not acres. The monme (3.75 g) survives as the world’s pearl weight, and sake is still sold by the sho.

Try the Japanese length, weight, and volume converters.

No unit on earth has been re-measured as often as the Chinese chi. It ran ~23 cm under the Zhou and Han, ~30 cm under the Tang, ~32 cm under the Ming and Qing — every dynasty literally redefined the foot — until the 1929 reform fixed it at exactly one-third of a meter. The system’s logic is decimal and ancient: 10 cun to the chi, 10 chi to the zhang; 16 liang to the jin (the catty); 10 sheng to the dou, 10 dou to the dan — the porter’s full load of rice, 50 kg. Qin Shi Huang’s bronze standard weights (221 BC) are the oldest state metrology you can hold in your hand.

Try the Chinese length, weight, and volume converters.

Old Russia measured the same way everyone did — with the body. The vershok (“tip,” of a finger), the pyad (hand-span), the arshin (the arm, from a Persian word for elbow), the sazhen (fathom, what a man can reach). In 1068 Prince Gleb had the frozen Kerch Strait measured and carved the result into marble: 14,000 sazhens — the famous Tmutarakan stone, our oldest Russian measurement record.

What makes the Russian story distinctive is its ending: Peter the Great, frustrated by cheating cloth-merchants, fixed the arshin at exactly 28 English inches (71.12 cm) and issued iron-bound state rulers to every market town. Two centuries later Dmitri Mendeleev — of the periodic table — oversaw Russia’s conversion to the metric system (1899). The units died officially but live on in proverbs and kettlebells: every Russian strongman still lifts a pud.