In 1 micrograms there are 0.001 milligrams. Meanwhile in 1 milligrams there are 1,000 micrograms. Keep reading to learn more about each unit of measure and how they are calculated. Or just use the Milligrams to Micrograms calculator above to convert any number.
* Values rounded to 6 decimal places for readability
To convert micrograms (mcg or µg) to milligrams (mg), use the fact that 1 mg = 1,000 mcg. This means micrograms are smaller than milligrams.
Conversion formula (micrograms to milligrams):
Quick examples:
Tip: Move the decimal three places left when converting mcg to mg.
To convert micrograms (mcg) to milligrams (mg), divide by 1,000.
Formula: mg = mcg ÷ 1,000
The conversion factor is 1,000 micrograms per 1 milligram.
That means 1 mcg = 0.001 mg and 1 mg = 1,000 mcg.
1 microgram = 0.001 milligrams.
This is one-thousandth of a milligram.
1 milligram = 1,000 micrograms.
This is a common dose unit switch on labels.
To convert milligrams to micrograms, multiply by 1,000.
Formula: mcg = mg × 1,000
Both are metric units for mass, often used for vitamins and medicine.
Micrograms are used when the amount is very small. This helps avoid decimals and makes labels easier to read, like 400 mcg instead of 0.4 mg.
Here are quick examples people often need:
Move the decimal three places left.
No. mcg and mg measure mass. mL measures volume.
You can’t convert mg to mL without knowing the substance and its strength (like mg per mL).
Yes, they mean the same unit.
Double-check the unit and the decimal place. Many errors happen by mixing up mcg and mg, which changes the amount by 1,000 times. Writing the formula helps: mg = mcg ÷ 1,000.
The Calculate Box tool to convert micrograms to milligrams uses the open source script Convert.js to convert units of measurement. To use this tool, simply type a micrograms value in the box and have it instantly converted to milligrams.