How many micrograms are in a milligram?

There are exactly 1,000 micrograms (mcg or µg) in one milligram (mg). To convert mg to mcg, multiply by 1,000. To convert mcg back to mg, divide by 1,000.

What is the difference between mg and mcg?

"mg" stands for milligram (10⁻³ grams) and "mcg" or "µg" stands for microgram (10⁻⁶ grams). A milligram is 1,000 times heavier than a microgram.

Why do some labels use mcg and others use µg?

"mcg" is the informal abbreviation used most commonly on food and drug labels to avoid confusion with the Greek letter µ. "µg" is the official SI notation. Both mean exactly the same thing.

Can I convert decimal milligram values?

Yes. For example, 0.5 mg = 500 mcg. This converter accepts any positive decimal number, so fractional doses and precise lab weights all work correctly.

Is this converter accurate for medical dosing?

The math is exact (multiplication by 1,000), but always cross-check critical medical or pharmaceutical calculations with a licensed professional. Use this tool as a convenience aid, not a clinical decision tool.

Milligrams to Micrograms Converter

Name: Milligrams to Micrograms Converter
Availability: InStock
Author: Nham Vu

Type a value in milligrams and instantly see the equivalent in micrograms — no sign-up, no server.

Enter Value

Milligrams (mg)

Micrograms (mcg / µg)

Result

Milligrams → Micrograms

— mcg

Micrograms → Milligrams

— mg

Quick Reference — Common Conversions

Milligrams (mg)	Micrograms (mcg)
0.001 mg	1 mcg
0.01 mg	10 mcg
0.1 mg	100 mcg
0.25 mg	250 mcg
0.5 mg	500 mcg
1 mg	1,000 mcg
5 mg	5,000 mcg
10 mg	10,000 mcg
100 mg	100,000 mcg
1,000 mg	1,000,000 mcg

Summary

Type a value in milligrams and instantly see the equivalent in micrograms — no sign-up, no server.

How it works

Enter a value in milligrams in the input field.
The converter multiplies your value by 1,000.
The result in micrograms appears instantly below.
Use the swap button to convert micrograms back to milligrams.
Copy the result with one click.

Use cases

Convert medication doses listed in mg to mcg for prescription accuracy.
Cross-check supplement label amounts when switching between units.
Verify laboratory sample weights during chemistry or biology work.
Convert nutritional values from mg to mcg for dietary tracking.
Help students understand SI unit prefixes (milli vs. micro).
Double-check dosage calculations in pharmaceutical or clinical settings.

Frequently Asked Questions

Last updated: 2026-06-10 · Reviewed by Nham Vu