Measurement
Only units of measurement used in Westeros are known. Other peoples in the Free Cities, among the Dothraki, or Yi Ti may use other systems.
Contents
Overview
Measurement units in Westeros are non-metric, growing out of customary use and not abstract principles, reflecting their medieval social level. Generally units of measurement in Westeros match the Imperial units used in the contemporary United States - possibly due ton George R.R. Martin's familiarity with them.
There are four basic units of measurement that would apply to Westeros: length, weight, time,and temperature (other basic units wouldn't apply to their technology level, such as "amperes" which measure electrical current). Scales of temperature measurement are are actually a fairly modern development in real life, the first systems only developed during the scientific revolution of the 1600s. No reference to degrees of temperature using any system has been made in the A Song of Ice and Fire novels, but these didn't exist in the real Middle Ages either. Additional units of measure are derived from these basic ones, such as area and volume from length.
Units of plane angle are apparently also the same in Westeros: a circle is divided up into 360 "degrees". Thus, for example, during the Battle of the Blackwater, Tyrion gives the instruction to swing the catapults "30 degrees west".
ACOK Tyrion XIII
Westeros itself seems to have a uniform system of weights and measures, mentioned interchangeably by characters from Oldtown to King's Landing or Winterfell. This may be due to how the legal code was standardized across the Seven Kingdoms soon after the Targaryen Conquest, by King Jaehaerys I Targaryen.
Archaic units encountered in the text
A few more archaic units of measurement are commonly used in the novels to reflect the medieval social level of Westeros,
which are of particular note:
- Atones of weight[1] (about 14 pounds)
- "League"[2] of distance (they define one "league" as equal to three "miles").
Units of Length, Area, and Volume measurement
Units of Length
Units of Area
- Acres - commonly used as a measure of land area [6]
- Hides
When Tyrion promises payment to the captains of the Second Sons his contract mentions "hides" of land, which is actually
an administrative unit for measuring monetary production, not objective land area. One "hide" is enough to support one
household, i.e. if five fertile acres of farmland can produce 1 gold dragon, but ten acres of poor swampland are required to
produce 1 gold dragon, both grouping are considered to be worth one "hide".[7]
Units of Volume
"Barrels" of wine are also frequently mentioned, but it is unclear if this reflects a standardized size and unit of
measurement. Twenty-three barrels of pickled cod, eighteen jars of fish oil, a cask of salt . . ." ACOK Jon I
Very powerful medicines administered by maesters are usually just functionally measured in number of drops diluted into water
or wine - any intervening units between a drop and a full pint, for larger amounts of medicine, haven't been mentioned, and
might just be functionally measured as "a cup" of milk of the poppy.
Units of Weight measurement
Currency in Westeros contains varying amounts of precious metals, specifically gold, silver, and copper. The exact
amounts in each coin are probably measured in the "ounces" mentioned in other contexts (if one coin weighed one pound, it
wouldn't be easy to carry). In Slaver's Bay, Daenerys is offered "marks" of gold, but a "mark" simply refers to a "measure"
of gold, without specifying how they locally define what a mark/measure is.
Units of Time measurement
Scientific definitions
The base units of time measurement generally match those used in real life: seconds, minutes, hours, days, and years. A
"fortnight" is a commonly used term, somewhat outdated in real life, to refer to any given two week long period.
These units seem to broadly match their real-life equivalents: it's tacitly implied that one minute contains 60 seconds
(otherwise Martin would only confuse the reader if one of their "seconds" is really equal to 30 real life seconds). One
"day" apparently contains 24 hours, each one equivalent to a real life "hour" (in contrast to some sort of Jack Vance style
alternate Earth with more hours in a day).
One "year" roughly matches one real-life "year", and is composed of 12 months. Their moon goes through its astronomical
cycle once every month or so, as in real life, so months are alternatively called "moon-turns" - though whether it is exactly
the same as the moon's rotational period in real life is unknown.
One "year" is defined by astronomy, not the passage of their irregular and years-long seasons. The same is actually true of
real life: seasonal weather is always variable, so since ancient times (i.e. Stonehenge), civilizations have defined a new
"year" by the point when the stars in the night sky reset to where they were around 12 months before. Scholars in Westeros
and other lands, through study of astronomy, are aware that their world is in fact a round globe (though it hasn't been
definitively stated if they know that their planet moves around their sun, and not the other way around).[13][14]
Culture-specific definitions
While a Westeros "year" is functionally equivalent to a real-life "year", their exact rotational period is unknown: in real
life one "year" isn't actually 365 days, but a small remainder beyond that, because the rotational period of the Earth around
the Sun doesn't neatly divide into Earth's rotation time on its own axis (days). This necessitated the development of the
Julian, and later Gregorian, calendars which include leap-years to make up the difference.
Specifics about such time-keeping in Westeros cross over into cultural, not scientific definitions. The calendar system
currently used in Westeros uses the date of the Targaryen Conquest as Year 1. Little is known about their calendar system,
such as the exact number of days in it (364 or 365) or whether it includes leap-years (or even, like ancient pre-Julian
societies, if they should have leap years but haven't reformed their calendar yet to reflect this). What points are
known about the culturally-based calendar in Westeros:
- Individual months apparently don't have specific names. They simply refer to dates in the format, "In the twenty-second day
of the fifth month of the year 130 AC".
- This seems to be a literal translation of how the original Roman calendar simply referred to months by ordinal numbers in
Latin, i.e. "Sept-tember" referring to the "seventh month" (September later became the ninth month, as the addition of other
non-ordinal months named after emperors such as "August" pushed it back later in the year).
- No week-day names have ever been mentioned, such as "Sunday" or "Wednesday". Given that "Wednesday" is a culture-specific
name originating from real life ("Odin's Day"), they might use different weekday names, or none at all, like their months.
- Because they don't have mechanical clocks, individual hours have never been referred to bynames such as "eleven o'clock".
They use functional definitions such as dawn, noon, dusk, etc., or "three hours past dawn".
- Individual hours actually have their own names, after animals. "The hour of the wolf" is most frequently encountered, but
The Princess and the Queen introduced several other names, indicating this is an entire naming system (possibly just for
the night hours). These include:
night"[23], coming after the hour of the owl[24]; not to be confused with the period of a few days,
called Hour of the Wolf, immediately after the civil war called the Dance of the Dragons
- The hour of the nightingale, coming after the hour of the wolf[24]
- The hour of the nightingale, coming after the hour of the wolf[24]