# Grains to Centigrams (gr to cg) Source: https://www.unitconvertercalculator.com/weight/grains-to-centigrams/ **1 gr = 6.479891 cg** One grain equals approximately 6.480 centigrams. The grain (64.80 mg) is 6.48 times heavier than a centigram (10 mg). Both units occupy the small-mass end of their respective systems, but the grain remains actively used in ammunition manufacturing while the centigram has been sidelined by the milligram. Their conversion is most relevant when translating grain-based ammunition data to metric scales. ## Formula Apply the conversion factor ## Conversion Table | Grains (gr) | Centigrams (cg) | |---|---| | 1 gr | 6.479891 cg | | 5 gr | 32.399455 cg | | 10 gr | 64.79891 cg | | 15 gr | 97.198365 cg | | 20 gr | 129.59782 cg | | 50 gr | 323.99455 cg | | 100 gr | 647.9891 cg | | 200 gr | 1295.9782 cg | | 437.5 gr | 2834.9523125 cg | | 480 gr | 3110.34768 cg | | 500 gr | 3239.9455 cg | | 1000 gr | 6479.891 cg | | 5000 gr | 32399.455 cg | | 7000 gr | 45359.237 cg | ## Units ### Grain (gr) A grain is a unit of mass equal to exactly 64.79891 milligrams. It is the same in the avoirdupois, troy, and apothecaries' systems, derived from the 1959 international agreement defining the pound as exactly 0.45359237 kilograms. ### 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. ## Background A standard 5-grain aspirin tablet weighs 32.4 centigrams. A 55-grain .223 Remington bullet weighs 356.4 centigrams. When handloaders work with metric-only scales, converting from grain specifications to centigram readings requires this factor. Most reloading manuals specify charges in grains, but some international equipment displays only metric units. ## Good to Know The grain is one of the oldest weight units still in active professional use. Its origins trace to ancient Mesopotamia, where barley grains served as the basis for weight standards. Through Egypt, Greece, Rome, and medieval England, the grain evolved but retained its fundamental nature: the weight of a single seed. Today it measures bullet weights and powder charges, a journey from agriculture to ballistics spanning 5,000 years. ## FAQ ### How many centigrams are in one grain? One grain equals approximately 6.480 centigrams. This comes from 1 grain = 64.80 mg and 1 centigram = 10 mg: 64.80 / 10 = 6.480. ### Is the centigram useful for ammunition work? Not typically. Ammunition specifications use grains, and metric scales display in grams or milligrams. The centigram sits between these in a range nobody targets. Reloaders who need metric conversion go directly from grains to grams or milligrams. ### Is the grain defined exactly in metric terms? Yes. Since 1959, one grain has been defined as exactly 64.79891 milligrams. This makes the grain a precisely metric-derived unit, even though it is used in imperial contexts. ## Non-Frequently Asked Questions ### If a bullet weighs 150 grains, how many centigrams of lead is that? 150 grains equals about 972 centigrams (9.72 grams). But bullets are not pure lead - modern bullets use copper jackets over lead cores, sometimes with steel or other metals. The grain specification refers to total bullet weight regardless of composition. Nobody specifies bullet metallurgy in centigrams. ### Could competitive target shooters tell the difference of one centigram on a bullet? One centigram (10 mg) is about 0.154 grains. Elite competitive shooters sort bullets by weight to within 0.1 to 0.3 grains (roughly 1 to 2 centigrams). So yes, a centigram variation could affect group size at long range. Competitive shooting operates at a level of precision where centigrams actually matter, even if nobody calls them that. ### What weighs exactly one grain in everyday life? One grain (64.8 mg) is roughly the weight of a single dry grain of rice, a small sesame seed, or about 1.3 drops of water. The name 'grain' derives from the weight of a cereal grain - and remarkably, actual wheat and barley grains do weigh roughly 40 to 65 milligrams, so the etymology is surprisingly literal. ## 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 - [Centigrams to Grains](https://www.unitconvertercalculator.com/weight/centigrams-to-grains/)