Convert Milligram to Microgram
Convert milligrams to micrograms instantly. 1 milligram = 1000 microgram — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Microgram to Milligram converter for the reverse conversion.
Units explained
Milligram
A milligram (mg) equals one-millionth of a kilogram, or 0.001 gram.
From the SI prefix 'milli-' (from Latin 'mille', thousand).
Standard for medicine dosing, nutrition labels, and fine jewelry.
Part of the original metric system of 1795.
Microgram
A microgram (ug) equals 10^-9 kilogram, or one-millionth of a gram.
From the SI prefix 'micro-' (from Greek 'mikros', small).
Trace nutrients, potent drug doses, and environmental contaminant levels.
The micro- prefix was incorporated into the SI in 1960.
Milligram to Microgram conversion formula
The relationship between milligrams and micrograms:
To convert milligrams to micrograms, multiply the value in milligrams by 1000. To reverse, multiply micrograms by 0.001.
How to use this converter
Type a value into the calculator. The result in micrograms updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Microgram to Milligram converter for the reverse direction.
Step-by-step: convert milligrams to micrograms
- Write down the value in milligrams (mg).
- Multiply that value by the factor 1000.
- The product is the equivalent value in micrograms (µg).
- To reverse, multiply the microgram value by 0.001.
Worked examples
Example 1 — Convert 1 mg to µg:
1 × 1000 = 1000 µg
Example 2 — Convert 100 mg to µg:
100 × 1000 = 100000 µg
Real-world example — Mid-micron to nanometer
3 milligrams equals 3,000 micrograms — useful when relating mid-infrared wavelengths (typically quoted in microns) to nanometer-scale visible-light wavelength tables.
3 mg × 1000 = 3000 µg
Real-world example — From microns to sub-micron features
One milligram equals one thousand micrograms — the conversion semiconductor designers do constantly when comparing mask feature dimensions to actual transistor gate lengths.
1 mg × 1000 = 1000 µg
Real-world example — Infrared to visible-spectrum mapping
A 10-milligram thermal infrared wavelength corresponds to a much larger number in micrograms, the unit favoured for ultraviolet and visible-light specifications.
10 mg × 1000 = 10000 µg
Milligram to Microgram conversion table
Standard reference values for converting milligrams to micrograms:
| Milligram [mg] | Microgram [µg] |
|---|---|
| 0.01 | 10 |
| 0.1 | 100 |
| 1 | 1000 |
| 2 | 2000 |
| 3 | 3000 |
| 4 | 4000 |
| 5 | 5000 |
| 10 | 10000 |
| 20 | 20000 |
| 30 | 30000 |
| 40 | 40000 |
| 50 | 50000 |
| 100 | 100000 |
| 500 | 499999.9999999999 |
| 1000 | 999999.9999999999 |
Frequently asked questions
How many micrograms is 1 milligram?
How do I convert milligrams to micrograms?
How do I convert micrograms back to milligrams?
How many micrograms is 100 milligrams?
Popular weight unit conversions
Convert Milligram to other weight units
Show all Milligram conversions
Metric / SI (17 units)
Avoirdupois (15 units)
Troy & Apothecary (10 units)
Indian / South Asian (6 units)
Scientific / Atomic (9 units)
Astronomical (4 units)
Biblical / Ancient (14 units)
Sources & references
Conversion factor (1 mg = 1000 µg) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.