pes (Roman foot)
Ancient Greece / Rome · Antiquity
Surviving foot-rules, monuments and planning evidence support this scale.
approx.More from Ancient Greece / Rome →Feeling curious?
foot
Calculating…
Measurement of the day
The biblical ephah was the dry-measure counterpart of the liquid bath.
One Biblical ephah (common scholarly reconstruction) is understood to be about 0.022 cubic metres.
Read the record →Disagreement
A cubit is not a cubit. These records refuse to collapse into one number, so the converter asks you to choose a tradition first.
Early-17th-century wine context: hogshead = 1/4 tun ≈63 old wine gallons.
Early-17th-century wine context: butt/pipe = 1/2 tun = 2 hogsheads ≈126 old wine gallons.
Greek talent was not one universal standard.
UCL records Old/Middle Kingdom gold deben about 12–14 g and copper deben about 27 g; New Kingdom system used a deben about 91 g divided into 10 qedet/kite.
shekel (ancient mass) is a mass measurement concept whose value depends on the named historical, regional, textual, or commodity variant.
mina (Mesopotamian) is a mass measurement concept whose value depends on the named historical, regional, textual, or commodity variant.
Antiquity
Rebuilt from surviving rods, temple walls and market weights — with the uncertainty left in.
Ancient Greece / Rome · Antiquity
Surviving foot-rules, monuments and planning evidence support this scale.
approx.More from Ancient Greece / Rome →Ancient Greece / Rome · Antiquity
Official Olympia and excavation records agree on track length.
approx.More from Ancient Greece / Rome →Ancient Greece / Rome · Antiquity
Strong internal relation; metric value follows reconstructed foot.
approx.More from Ancient Greece / Rome →Ancient Greece / Rome · Antiquity
Greek talent was not one universal standard.
variantMore from Ancient Greece / Rome →Ancient Greece / Rome · Antiquity
Modern scholarship cautions that proposed SI values span roughly 322.56–330 g.
approx.More from Ancient Greece / Rome →Ancient Greece / Rome · Antiquity
Metrological amphora standardized near 26.2 L; real transport amphora vessels varied.
approx.More from Ancient Greece / Rome →Precision
Fixed by international agreement and constants of nature. Exactly exact.
| metre | m | Length | exact |
|---|---|---|---|
| kilometre | km | Length | exact |
| centimetre | cm | Length | exact |
| millimetre | mm | Length | exact |
| gram | g | Mass | exact |
| kilogram | kg | Mass | exact |
Creativity
Units invented by students, engineers, reindeer herders and jokers — recorded here with the same honesty as the metre.
Sheppey comes from Douglas Adams and John Lloyd's The Meaning of Liff: it is the closest distance at which sheep remain picturesque—approximately seven-eighths of a mile.
Invented for a joke. Documented anyway.
approx.informalThe Jargon File notes a delightful coincidence: an attoparsec is about an inch, and one attoparsec per microfortnight is about one inch per second.
Yes, that is really the name.
informalIts name looks singular, but the historically responsible calculator result is plural: users must choose among documented variants rather than receive one universal conversion.
Yes, that is really the name.
variantinformalThe 10 nm beard-second is the Physics Handbook convention cited in University of Leipzig mechanics material.
Yes, that is really the name.
informalAt 5 nm, one metre contains 200 million beard-seconds.
Yes, that is really the name.
informalKnuth later recalled that MAD paid him $25 for the piece.
Invented for a joke. Documented anyway.
reference-onlyThis record is included as a lesson in measurement history: a claim can be historically interesting without being scientifically valid.
Invented for a joke. Documented anyway.
discreditedEvery measurement humans have agreed on — and the ones they never did.
196 approved records and 21 documented ambiguities. Where the evidence is a range, a reconstruction or a disagreement, Scaleidoscope says so instead of rounding history into a single number.
The whole library
196
measurements, sorted by what they physically measure — length, mass, time, and everything humans argued about in between.
Occasional dispatches
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