A microgram (mcg) is a metric unit of mass equal to one-millionth of a gram. It’s one of the smallest standard units of mass, commonly used in medical, nutritional, and scientific settings where extremely small quantities matter.
The term comes from the Greek word mikros meaning “small” and “gram,” the base metric unit for mass. Its official SI symbol is µg. However, in medical practice especially in the U.S. mcg is used to prevent confusion with mg (milligram), which is 1,000 times larger.
How Is Microgram Used?
A milligram (mg) is a unit of mass in the metric system, equal to one-thousandth of a gram (1 mg = 0.001 g). It's one of the smallest standard units used in everyday measurements and is essential when dealing with very light weights. Milligrams are especially useful for measuring things that are too small to be weighed in grams—like medication doses, vitamins, or trace ingredients in scientific experiments.
The word "milligram" is derived from Latin roots: milli-, meaning "one-thousandth," and gramma meaning "a small weight." It became part of the International System of Units (SI) as countries adopted metric standards for more precise and consistent measurements.
How is the Milligram Used: The milligram plays a vital role in fields where accuracy matters most. Because it's a tiny measurement, even slight errors can affect results—especially in health and science.
1 µg = 0.001 mg
Let’s say you want to convert 1,000,000 µg to mg.
Using the formula:
1,000,000 × 0.001 = 1,000 mg
So, 1,000,000 µg is approximately 1,000 mg.
| Microgram (µg) | Milligram (mg) |
|---|---|
| 1 µg | 0.001 mg |
| 2 µg | 0.002 mg |
| 3 µg | 0.003 mg |
| 4 µg | 0.004 mg |
| 5 µg | 0.005 mg |
| 6 µg | 0.006 mg |
| 7 µg | 0.007 mg |
| 8 µg | 0.008 mg |
| 9 µg | 0.009 mg |
| 10 µg | 0.01 mg |
| 11 µg | 0.011 mg |
| 12 µg | 0.012 mg |
| 13 µg | 0.013 mg |
| 14 µg | 0.014 mg |
| 15 µg | 0.015 mg |