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What are micrograms?

Micrograms (ug or mcg) are a unit of measurement. One microgram is equivalent to one millionth of a gram. In nutrition, micrograms are used for measuring nutrients that we need very small amounts of. You may see micrograms used for measuring nutritional values for nutrients like folate and vitamin B12.

How many micrograms are in one milligram?

Whether you’re looking at your nutritional needs, a food label, or making very precise measurements, you may need to know how to convert micrograms to milligrams. The conversion may seem confusing because the names micrograms and milligrams sound similar. There are 1,000 micrograms (mcg) for every 1 milligram (mg). This means 1 mcg is equal to 1/1,000 mg or 0.001 mg. 

How many micrograms are in one milligram, one gram and in one kilogram?

1 milligram = 1,000 micrograms
1 gram = 1,000,000 micrograms
1 kilogram = 1,000,000,000 micrograms=

When converting micrograms to grams, or vice versa, you need to know how many micrograms are in 1 gram. There are 1,000,000 micrograms in 1 gram. This means 1 microgram is equal to 1/1,000,000 grams or 0.000001. To convert micrograms to kilograms, you need to know that there are 1,000,000,000 micrograms for every 1 kilogram. One microgram is equal to 1/1,000,000,000 kilograms or 0.000000001. 

Why is the measurement microgram used?

Since micrograms are a very small unit of measurement, micrograms are used to measure very precise amounts. Micrograms are often used for medications and prescription drugs, as well as certain vitamins and minerals. Micrograms may be used for nutrients and medications we need very small amounts of or that are not safe when taken at a high dosage.

Related Terms

Milligrams Grams

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Photo of Kristin Ricklefs-Johnson

Medically reviewed by:

Kristin Ricklefs-Johnson, Ph.D., RD

Kristin is an RDN who also earned her Ph.D. in Nutrition from Arizona State University with an emphasis on insulin resistance, lipid metabolism disorders, and obesity. She completed her post-doctoral fellowship at Mayo Clinic where she focused on nutrition-related proteomic and metabolic research. Her interests include understanding the exact mechanism of action of various genetic variations underlying individual predispositions to nutrition-related health outcomes. Her goal is to help all individuals prevent chronic diseases and achieve long, healthy lives through eating well.

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