cubit (biblical)
Mesopotamia / Levant · Antiquity
cubit (biblical) is a length measurement concept whose value depends on the named historical, regional, textual, or commodity variant.
variantMore from Mesopotamia / Levant →Convert familiar measurements into the historical, scientific and unusual
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Measurement of the day
pascal
A pascal is a very small pressure in everyday terms, so kilopascals and megapascals are commonly convenient.
SI derived unit of pressure and stress; 1 Pa = 1 N/m² = 1 kg·m⁻¹·s⁻².
Read the record →- Dimension
- pressure
- Region
- International
- Era
- Modern
- Certainty
- Standardized
exact
What's the top of a mountain?
What counts as the top of a mountain?
Denali's official height includes the ice on top.
Surveyors estimated about 13.6 ft of ice beneath the summit.
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.
- tokooGold Coast / Akan-European trade · historicalvariant
Historical museum sources record eight tokoo to one ackie in Gold Coast gold/currency reckoning.
Why historians disagree → - angula1 documented definitionsvariant
Texts define finger-based aṅgula systems, but ASI explicitly found bodily aṅgula/hasta measurements vary; architectural sources distinguish multiple aṅgula sizes.
- South Asian aṅgula (24-aṅgula hasta reference)South Asia · Historical textual reference
- old carat / pre-metric caratHistorical gemstone trade · Pre-20th-century; locality-dependentvariant
Historical carats were not globally uniform. U.S. NBS material gives one old-carats conversion basis of 205.3 mg; French and other historical standards differed.
Why historians disagree → - drachma (mass)Ancient Greek · Classical/Hellenisticvariant
Attic representative ≈4.3 g; other Greek standards differed
Why historians disagree → - Fournier pointLengthvariant
A 1908 technical reference gives the Fournier point as 0.34875 mm and notes that the system had largely been superseded by Didot; treat the value as a historical convention rather than an exact universal modern standard.
Why historians disagree → - cable lengthMaritime historical family · Historical-modernvariant
Cable length is a nautical distance term whose numerical value has varied by country, navy and period.
Why historians disagree →
Antiquity
Measured before there were standards
Rebuilt from surviving rods, temple walls and market weights — with the uncertainty left in.
deben
Ancient Egypt · Antiquity
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.
variantMore from Ancient Egypt →Egyptian copper deben (Old/Middle Kingdom reference)
Ancient Egypt · Ancient
One Egyptian copper deben (Old/Middle Kingdom reference) is understood to be about 0.027 kilograms.
approx.More from Ancient Egypt →Roman mile (mille passus)
Ancient Greece / Rome · Antiquity
One Roman mile (mille passus) is understood to be about 1,480 metres.
approx.More from Ancient Greece / Rome →vitasti
South Asian traditional · Ancient/medieval textual traditions
1 vitasti = 12 aṅgulas; a universal centimetre value should not be assigned without choosing an underlying aṅgula reconstruction.
variantMore from South Asian traditional →ephah
Mesopotamia / Levant · Antiquity
ephah is a volume measurement concept whose value depends on the named historical, regional, textual, or commodity variant.
variantMore from Mesopotamia / Levant →Precision
The measurements we stopped arguing about
Fixed by international agreement and constants of nature. Exactly exact.
| light-year | ly | Length | exact |
|---|---|---|---|
| electronvolt | eV | Energy | exact |
| millimetre of mercury (conventional) | — | Pressure | exact |
| volt | V | Electric potential | exact |
| mass concentration | — | Mass concentration | reference-only |
| kos | — | Length | variant |
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.
informalBeard-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.
informalknot
A knot is a speed, not a distance; saying 'knots per hour' for ordinary speed is dimensionally wrong.
Yes, that is really the name.
informalSagan
Despite later jokes that try to assign it a number, the hacker Jargon File defines a sagan simply as 'a large quantity of anything'—a deliberately fuzzy tribute to Carl Sagan's cosmic-scale rhetoric.
Yes, that is really the name.
informalreference-onlysmoot
MIT commemorates the bridge as 364.4 Smoots, plus or minus one ear.
Yes, that is really the name.
approx.informalpotrzebie
Knuth later recalled that MAD paid him $25 for the piece.
Invented for a joke. Documented anyway.
reference-onlyEvery measurement humans have agreed on — and the ones they never did.
392 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
392
measurements, sorted by what they physically measure — length, mass, time, and everything humans argued about in between.
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