# Centigrams to Carats (cg to ct) Source: https://www.unitconvertercalculator.com/weight/centigrams-to-carats/ **1 cg = 0.05 ct** One centigram equals exactly 0.05 carats. Since a carat is defined as 200 milligrams (0.2 grams) and a centigram is 10 milligrams (0.01 grams), the ratio is simply 0.01 divided by 0.2, giving a clean 0.05. Put differently, exactly 20 centigrams make one carat - a tidy relationship that comes from the carat being deliberately standardized in metric terms. ## Formula Apply the conversion factor ## Conversion Table | Centigrams (cg) | Carats (ct) | |---|---| | 1 cg | 0.05 ct | | 2 cg | 0.1 ct | | 5 cg | 0.25 ct | | 10 cg | 0.5 ct | | 20 cg | 1 ct | | 50 cg | 2.5 ct | | 100 cg | 5 ct | | 200 cg | 10 ct | | 500 cg | 25 ct | | 1000 cg | 50 ct | | 2000 cg | 100 ct | | 5000 cg | 250 ct | | 10000 cg | 500 ct | | 50000 cg | 2500 ct | | 100000 cg | 5000 ct | ## Units ### Centigram (cg) A centigram is one hundredth of a gram. It is a metric unit rarely used in everyday life but appears in some scientific and educational contexts. ### Carat (ct) A carat is a unit of mass equal to exactly 200 milligrams (0.2 grams), used for measuring gemstones and pearls. Adopted internationally in 1907 by the Fourth General Conference on Weights and Measures. ## Background This conversion is relevant when laboratory instruments display readings in centigrams but the user needs a gemstone weight in carats. Older European analytical balances sometimes defaulted to centigram resolution, and pharmacists in some traditions recorded measurements this way. A typical 1-carat engagement diamond reads as 20 centigrams on such a scale, while a 0.5-carat stone registers as exactly 10 centigrams. ## Good to Know The centigram and the carat share an interesting parallel: both are 'centi-' scale measurements in their respective domains. The centigram is one hundredth of a gram, while the carat's own subdivision - the 'point' - is one hundredth of a carat. This means 1 point equals 0.2 centigrams, creating a nested system of hundredths that the 1907 standardization committee probably did not intend but mathematicians can appreciate. ## FAQ ### How many centigrams are in one carat? One carat equals exactly 20 centigrams. This comes from 1 carat being 0.2 grams (200 milligrams) and 1 centigram being 0.01 grams (10 milligrams): 200 divided by 10 equals 20. ### When would I need to convert centigrams to carats? This conversion arises when using laboratory scales that display in centigrams, reading historical pharmaceutical records that recorded gemstone weights in metric sub-units, or converting between European scientific notation and gemological terminology. ### Is the centigram part of the metric system? Yes. The centigram (cg) is a standard SI-compatible unit equal to one hundredth of a gram. It follows the same prefix logic as centimeter (one hundredth of a meter). However, it is rarely used in practice, with milligrams and grams preferred for most applications. ## Non-Frequently Asked Questions ### If I saved one centigram of gold every day, how long until I have a carat of gold? At one centigram per day, reaching 20 centigrams (1 carat or 0.2 grams) takes exactly 20 days. But gold is priced by troy ounces, not carats, so your 0.2-gram gold stash would be worth about 13 dollars. The patience required vastly exceeds the payoff. ### Could I feel the difference between 19 and 20 centigrams in my palm? Almost certainly not. The difference is 1 centigram (10 milligrams), roughly the weight of two grains of salt. Humans can typically detect weight differences starting at about 1 gram (100 centigrams) when holding small objects. Your palm is a poor substitute for a gem scale. ### Is the centigram-to-carat conversion the neatest in all of gemology? It is impressively clean: multiply by 0.05 or divide by 20. The only conversion that might rival it for neatness is carats to decigrams (multiply by 2). These tidy ratios exist because the metric carat was standardized at exactly 200 milligrams - a number chosen partly for its compatibility with the decimal system. ## Related Articles - [Why We Measure: The Deepest Urge in Human Civilisation](https://www.unitconvertercalculator.com/blog/why-we-measure) - [The Map Is Not the Territory: Why Every Measurement Is Wrong](https://www.unitconvertercalculator.com/blog/the-map-is-not-the-territory) - [Zero: The Most Dangerous Number in Measurement](https://www.unitconvertercalculator.com/blog/zero-the-most-dangerous-number-in-measurement) - [The Kilogram Problem: The Object That Was Its Own Definition](https://www.unitconvertercalculator.com/blog/the-kilogram-problem) - [The Body as a Ruler: Every Measurement Unit That Came From Us](https://www.unitconvertercalculator.com/blog/the-body-as-a-ruler) - [Why Your Recipe Is Lying to You: The Chaos of Cooking Measurements](https://www.unitconvertercalculator.com/blog/why-recipe-measurements-are-unreliable) - [15 Obscure Measurement Units You've Never Heard Of (But Still Need)](https://www.unitconvertercalculator.com/blog/obscure-measurement-units-guide) - [When Measurements Go Wrong - Disasters, Blunders and Happy Accidents](https://www.unitconvertercalculator.com/blog/when-measurements-go-wrong) - [The Surprising Stories Behind Everyday Units of Measurement](https://www.unitconvertercalculator.com/blog/stories-behind-measurement-units) - [Metric vs. Imperial - The Complete Guide to the World's Two Measurement Systems](https://www.unitconvertercalculator.com/blog/metric-vs-imperial-complete-guide) - [Understanding Weight Units - Kilograms, Pounds, Stones & Ounces](https://www.unitconvertercalculator.com/blog/understanding-weight-units) - [Complete Baking Measurement Guide - Cups, Grams, Ounces](https://www.unitconvertercalculator.com/blog/baking-measurement-guide) ## See Also - [Carats to Centigrams](https://www.unitconvertercalculator.com/weight/carats-to-centigrams/)