A microgram (µg or mcg) is a metric unit of mass or weight in the International System of Units (SI). It represents one millionth of a gram or 10^-6 grams. The metric system is a decimal-based system of measurement used worldwide, and it provides a convenient way to express both large and small quantities of mass.
To provide context for the size of a microgram:
Micrograms are commonly used in scientific and medical contexts, especially when dealing with substances or quantities that are very small. For example:
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.