Convert Qirat/Carat to kilograms

From carob seed to metric carat

The word descends from the Greek keration, the carob seed, whose reputation for uniform mass made it a convenient small counterweight around the eastern Mediterranean. Modern seed studies have shown that carob seeds vary about as much as any other seed, so the reputation was folklore rather than fact; what actually stabilised the unit was its definition as one twenty-fourth of a mithqal, an arithmetical relationship rather than a botanical one.

The metric carat of exactly 0.2 grams was agreed internationally in the first decade of the twentieth century and adopted progressively across the gemstone trade. It is a deliberate rounding of the older values rather than a continuation of any one of them, which is why a historical qirat figure and a modern carat figure should never be treated as the same measurement.

The purity scale is not a mass

The second modern descendant of the qirat is the gold purity scale, where 24 carat denotes pure gold and 18 carat denotes eighteen parts gold in twenty-four. This is a ratio, not a weight, and it inherits the twenty-four-part division from the mithqal rather than from the seed. A ring described as 22 carat weighing 8 grams contains about 7.33 grams of gold; the two numbers are doing entirely different jobs.

Confusing them is the single most common error involving this unit. A gemstone described as "two carat" weighs 0.4 grams. A gold chain described as "22 carat" has no implied weight at all. Any conversion interface that accepts the word carat without disambiguating is inviting a wrong answer, which is why this atlas keeps the mass unit and the fineness scale separate.

The Egyptian qirat of land

Egyptian land records use qirat as an area: one feddan divides into twenty-four qirat, and each qirat into twenty-four sahm. A qirat of land is therefore about 175 square metres, derived from a feddan of roughly 4,200 square metres. The twenty-four-fold division is the same arithmetic habit applied to a different dimension.

This matters because Egyptian property deeds, inheritance shares and agricultural leases are still written in feddan, qirat and sahm, and the shares are often fractional. A deed conveying "three qirat" of a plot is conveying an eighth of it. Reading that as a gemstone weight, or converting it with a mass factor, produces nonsense — but the same word appears in both contexts within a single country.

Getting a qirat figure right

Establish the dimension before the value: is the figure describing mass, purity or area? Only then choose a factor. For mass in a modern gemstone context the answer is the metric carat of 0.2 grams and nothing else, because the trade is internationally standardised and certificates are issued against that definition.

For historical and land contexts, the local relationship — twenty-four qirat to the mithqal, or twenty-four qirat to the feddan — is the reliable route, applied once and recorded with the source document. Where an Egyptian deed states both a qirat share and a metric area, the metric area is the registered figure and the qirat share is the ownership fraction; both belong in the record.

Common mistakes to avoid

• Carat as gemstone mass (0.2 g) and carat as gold fineness (parts in 24) are unrelated quantities sharing one word.
• In Egypt a qirat may be land: one twenty-fourth of a feddan, roughly 175 m².
• Historical qirat values are not equal to the metric carat; the 0.2 g figure is a twentieth-century convention.

Questions people ask about the Qirat/Carat

Is a qirat the same as a carat?

The modern metric carat of exactly 0.2 grams descends from the qirat but is a twentieth-century standardisation. Historical qirat values, defined as one twenty-fourth of a local mithqal, differ from it.

How big is a qirat of land in Egypt?

One qirat is one twenty-fourth of a feddan, roughly 175 square metres. It subdivides further into twenty-four sahm, and Egyptian deeds routinely express ownership shares in these terms.

Does carat measure the weight of gold?

No. For gold, carat expresses purity as parts in twenty-four — 18 carat is eighteen parts gold. The mass of the item is quoted separately, usually in grams.