Grain: The grain is a unit of mass primarily used for measuring the weight of small objects or quantities, especially in the context of bullets, ammunition, and some food products. One grain is approximately equal to 0.0648 grams.
A milligram (mg) is a unit of mass in the metric system and the International System of Units (SI). It is equal to one one-thousandth of a gram, which means that 1 milligram is equivalent to 0.001 grams. The milligram is a small unit of mass commonly used for measuring very small quantities of substances, especially in scientific, medical, and pharmaceutical contexts.
For example, when you see the dosage of a medication listed on a prescription or on over-the-counter drugs, it is often measured in milligrams. Additionally, in laboratory settings, chemicals and substances are frequently measured in milligrams due to its precision in measuring small quantities.