Convert Carat to Pound (ct → lb)

Converting carats to pounds is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.

1. 1
   Take your value in carats

   Start with the number of carats (ct) you want to convert.
2. 2
   Multiply by 0.000441

   The conversion factor from ct to lb is 0.000441. Multiply your value by this number.
3. 3
   Read the result in pounds

   The result is your value in pounds (lb).

Multiply the value in carats by 0.000441. For the reverse direction, multiply by 2,267.9619.

• ✓1 carat = 200 mg = 0.2 g exactly since 1907.
• ✓Carat (gem weight) and karat (gold purity, 24 K = pure) are different words with different meanings.
• ✓A carat is divided into 100 points; a 0.25 ct diamond is called a "25-pointer".

• ✗Confusing carat (mass) with karat (gold purity).
• ✗Assuming a 2-carat diamond is twice the physical size of a 1-carat — volume scales with cube root of mass.
• ✗Using "karat" on gemstone certificates — international standard is "carat" spelled with a C.

What is the Carat?

The carat equals exactly 200 milligrams (0.2 g) and is the universal unit for gemstone and diamond weight in the global jewelry industry. The word derives from the Greek 'keration' and the Arabic 'qīrāṭ,' both referring to carob seeds, which were once used as natural counterweights for weighing gems because they have remarkably uniform mass. The metric carat was standardized in 1907 at exactly 200 mg, replacing dozens of regional carat values that had varied between 188 and 213 mg. A 1-carat diamond is roughly 6.5 mm in diameter, and the famous Hope Diamond weighs 45.52 carats. The carat is distinct from the karat (with a 'k'), which measures gold purity (24-karat = 100% gold). It relates to the gram (5 ct = 1 g) and the milligram (200 mg = 1 ct). Gem dealers commonly use 'points' for fractions (100 points = 1 carat).

• Diamond and gemstone retail and valuation
• Jewellery manufacturing and design
• International gem certification (GIA, IGI)

What is the Pound?

The pound equals exactly 0.45359237 kilograms under the 1959 international yard and pound agreement. The unit's name comes from the Latin 'libra pondo' (a pound by weight), and the abbreviation 'lb' derives from 'libra.' The pound has been the everyday weight unit in English-speaking countries for over a thousand years, with regional variations until 20th-century standardization. Today it remains the primary weight unit in the United States for body weight (a person is '170 lb' rather than 77 kg), groceries, and shipping; in the United Kingdom it persists alongside kilograms, especially for personal weight ('11 stone 4' = 158 lb). The pound relates to the ounce (16 oz = 1 lb), the stone (14 lb = 1 stone), the kilogram (1 lb ≈ 0.454 kg), and the US ton (2,000 lb = 1 ton). The international 'avoirdupois' pound is the common standard, distinct from the troy pound used for precious metals.

• Human body weight in the US and UK
• Grocery and retail food pricing in the US
• Boxing and wrestling weight divisions