pes (Roman foot)
Ancient Greece / Rome · Antiquity
Surviving foot-rules, monuments and planning evidence support this scale.
approx.More from Ancient Greece / Rome →Scaleidoscope
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Biblical ephah (common scholarly reconstruction)
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 →- Dimension
- volume
- Region
- Mesopotamia / Levant
- Era
- Antiquity
- Certainty
- Historically reconstructed
approx.
Disagreement
Where humans could not agree
A cubit is not a cubit. These records refuse to collapse into one number, so the converter asks you to choose a tradition first.
- hogshead1 documented definitionsvariant
Early-17th-century wine context: hogshead = 1/4 tun ≈63 old wine gallons.
- English wine hogshead (early 17th c. nominal)England / Britain · Medieval / Early modern
- butt1 documented definitionsvariant
Early-17th-century wine context: butt/pipe = 1/2 tun = 2 hogsheads ≈126 old wine gallons.
- English wine butt / pipe (early 17th c. nominal)England / Britain · Medieval / Early modern
- Greek talent1 documented definitionsvariant
Greek talent was not one universal standard.
- Attic talentAncient Athens / Attic standard · Classical–Hellenistic
- deben3 documented definitionsvariant
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.
- Egyptian deben (New Kingdom standard)Ancient Egypt · Ancient
- Egyptian gold deben (Old/Middle Kingdom range)Ancient Egypt · Ancient
- Egyptian copper deben (Old/Middle Kingdom reference)Ancient Egypt · Ancient
- shekel (ancient mass)1 documented definitionsvariant
shekel (ancient mass) is a mass measurement concept whose value depends on the named historical, regional, textual, or commodity variant.
- mina (Mesopotamian)Mesopotamia / Levant · Antiquity
- mina (Mesopotamian)2 documented definitionsvariant
mina (Mesopotamian) is a mass measurement concept whose value depends on the named historical, regional, textual, or commodity variant.
- Mesopotamian mina (later reference standard)Mesopotamia / Levant · Antiquity
- Early Dynastic Mesopotamian mina (range)Mesopotamia / Levant · Antiquity
Antiquity
Measured before there were standards
Rebuilt from surviving rods, temple walls and market weights — with the uncertainty left in.
stadion (Olympia)
Ancient Greece / Rome · Antiquity
Official Olympia and excavation records agree on track length.
approx.More from Ancient Greece / Rome →Roman mile (mille passus)
Ancient Greece / Rome · Antiquity
Strong internal relation; metric value follows reconstructed foot.
approx.More from Ancient Greece / Rome →Greek talent
Ancient Greece / Rome · Antiquity
Greek talent was not one universal standard.
variantMore from Ancient Greece / Rome →Roman libra
Ancient Greece / Rome · Antiquity
Modern scholarship cautions that proposed SI values span roughly 322.56–330 g.
approx.More from Ancient Greece / Rome →amphora quadrantal
Ancient Greece / Rome · Antiquity
Metrological amphora standardized near 26.2 L; real transport amphora vessels varied.
approx.More from Ancient Greece / Rome →Precision
The measurements we stopped arguing about
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
Strange & wonderful
Units invented by students, engineers, reindeer herders and jokers — recorded here with the same honesty as the metre.
Sheppey
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.informalmicromort
Micromorts make very different hazards comparable on the same one-in-a-million risk scale.
Someone actually measured this.
informalattoparsec
The 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.
informalbarn
Despite the comic-sounding name, the barn is a real scientific unit with an exact SI conversion.
beard-second
Its 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.
variantinformalBeard-second (10 nm convention)
The 10 nm beard-second is the Physics Handbook convention cited in University of Leipzig mechanics material.
Yes, that is really the name.
informalBeard-second (5 nm convention)
At 5 nm, one metre contains 200 million beard-seconds.
Yes, that is really the name.
informalEvery 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.