Micrograms to milligrams
Multiply micrograms by 0.001 to get milligrams.
250 mcg = 0.25 mg
How to convert micrograms to milligrams
The milligram is one thousandth of a gram (10⁻⁶ kg). The microgram is one millionth of a gram (10⁻⁹ kg), written mcg in medicine.
Worked example — 250 mcg: 250 × 0.001 = 0.25 mg.
Micrograms to milligrams table
| Micrograms | Milligrams |
|---|---|
| 1 mcg | 0.001 mg |
| 10 mcg | 0.01 mg |
| 50 mcg | 0.05 mg |
| 100 mcg | 0.1 mg |
| 250 mcg | 0.25 mg |
| 500 mcg | 0.5 mg |
| 1,000 mcg | 1 mg |
| 2,000 mcg | 2 mg |
| 5,000 mcg | 5 mg |
Reverse and related
About micrograms and milligrams
Microgram (mcg)
1 mcg = 0.001 mgDefinition. One millionth of a gram (10⁻⁹ kg), written mcg in medicine
History and origin
The microgram is one millionth of a gram, a thousandth of a milligram. In medicine it is written mcg rather than µg to avoid a handwritten mix-up with mg.
Current use
Micrograms measure very small doses of vitamins and drugs, such as vitamin D, folic acid and thyroid medication.
Source: BIPM, The International System of Units (SI), 9th ed. (2019)
Milligram (mg)
1 mg = 1,000 mcgDefinition. One thousandth of a gram (10⁻⁶ kg)
History and origin
The milligram is one thousandth of a gram, part of the decimal metric system. Its small size suits doses and trace amounts.
Current use
Milligrams are the everyday unit for medication doses and for nutrients on food labels.
Source: BIPM, The International System of Units (SI), 9th ed. (2019)
Where people use this
Micrograms: vitamin and drug doses. Milligrams: medication doses, nutrition labels. 1000 mcg is exactly 1 mg.
Every value is carried to full double precision; the display is rounded.
Both units are defined in BIPM, The International System of Units (SI), 9th ed. (2019).
Questions people ask
How many mg is 1000 mcg?
1000 mcg is exactly 1 mg. To convert micrograms to milligrams, divide by 1000.
How many mcg in a mg?
One milligram is 1000 micrograms.
How many mg is 500 mcg?
500 mcg is 0.5 mg.