微克，质量单位，符号μg或者mcg（英语：microgram）。

1微克等于一百万分之一克（10克）

1 微克 = 1000 奈克

1,000 微克 = 1毫克

1,000,000 微克 = 1克

1,000,000,000 微克 = 1千克

In the metric system, a microgram or microgramme (μg; while the recommended symbol in the United States when communicating medical information is mcg) is a unit of mass equal to one billionth (6991100000000000000♠1×10) of a kilogram, one millionth (6994100000000000000♠1×10) of a gram, or one thousandth (6997100000000000000♠1×10) of a milligram. The unit symbol is μg according to the International System of Units. In µg the prefix symbol for micro- is the Greek letter μ (Mu).