Mass and Weight · Unit Converter

Convert Carat (metric) to Microgram

Convert carats (metric) to micrograms instantly. 1 carat (metric) = 200000 microgram — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Microgram to Carat (metric) converter for the reverse conversion.

Written by Sunith Babu L, Ph.D., Lead Engineer Reviewed by Dr. Ashok Kumar K, Ph.D.

Mass and Weight category 2 min read Published June 10, 2026 Last reviewed June 10, 2026 Updated June 10, 2026

Units explained

Troy & Apothecary

Carat (metric)

What is a carat (metric)?

The metric carat (ct) equals exactly 200 milligrams (0.0002 kg).

Origin of the carat (metric)

From Arabic 'qirat' and Greek 'keration', the carob seed once used as a counterweight.

Where it is used

The worldwide standard for gemstone and diamond mass.

When and where it was developed

The metric carat was fixed at 200 mg internationally in 1907.

Metric / SI

Microgram

What is a microgram?

A microgram (ug) equals 10^-9 kilogram, or one-millionth of a gram.

Origin of the microgram

From the SI prefix 'micro-' (from Greek 'mikros', small).

Where it is used

Trace nutrients, potent drug doses, and environmental contaminant levels.

When and where it was developed

The micro- prefix was incorporated into the SI in 1960.

Carat (metric) to Microgram conversion formula

The relationship between carats (metric) and micrograms:

1 ct = 200000 µg

1 µg = 5e-6 ct

To convert carats (metric) to micrograms, multiply the value in carats (metric) by 200000. To reverse, multiply micrograms by 5e-6.

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 Carat (metric) converter for the reverse direction.

Step-by-step: convert carats (metric) to micrograms

Write down the value in carats (metric) (ct).
Multiply that value by the factor 200000.
The product is the equivalent value in micrograms (µg).
To reverse, multiply the microgram value by 5e-6.

Worked examples

Example 1 — Convert 1 ct to µg:
1 × 200000 = 200000 µg

Example 2 — Convert 100 ct to µg:
100 × 200000 = 2e+7 µg

Real-world example — From microns to sub-micron features

One carat (metric) equals one thousand micrograms — the conversion semiconductor designers do constantly when comparing mask feature dimensions to actual transistor gate lengths.

1 ct × 200000 = 200000 µg

Real-world example — Infrared to visible-spectrum mapping

A 10-carat (metric) thermal infrared wavelength corresponds to a much larger number in micrograms, the unit favoured for ultraviolet and visible-light specifications.

10 ct × 200000 = 2000000 µg

Real-world example — Mid-micron to nanometer

3 carats (metric) equals 3,000 micrograms — useful when relating mid-infrared wavelengths (typically quoted in microns) to nanometer-scale visible-light wavelength tables.

3 ct × 200000 = 600000 µg

Carat (metric) to Microgram conversion table

Standard reference values for converting carats (metric) to micrograms:

Carat (metric) [ct]	Microgram [µg]
0.01	2000
0.1	20000
1	200000
2	400000
3	600000
4	800000
5	1000000
10	2000000
20	4000000
30	6000000
40	8000000
50	1e+7
100	2e+7
500	1e+8
1000	2e+8

Frequently asked questions

How many micrograms is 1 carat (metric)?

1 carat (metric) equals 200000 microgram.

How do I convert carats (metric) to micrograms?

Multiply the value in carats (metric) by 200000 to get micrograms.

How do I convert micrograms back to carats (metric)?

Multiply the value in micrograms by 5e-6, or use the Microgram to Carat (metric) converter.

How many micrograms is 100 carats (metric)?

100 carats (metric) equals 2e+7 micrograms, because 100 × 200000 = 2e+7.

Convert Carat (metric) to other weight units

Show all Carat (metric) conversions

Metric / SI (18 units)

Avoirdupois (15 units)

Troy & Apothecary (9 units)

Carat (metric) to Point (1/100 carat) (pt) Carat (metric) to Scruple (apothecary) (s ap) Carat (metric) to Pennyweight (dwt) Carat (metric) to Momme (mom) Carat (metric) to Mace (mace) Carat (metric) to Dram (apothecary/troy) (dr ap) Carat (metric) to Troy Ounce (oz t) Carat (metric) to Tael (tael) Carat (metric) to Pound (troy/apothecary) (lb t)

Indian / South Asian (6 units)

Carat (metric) to Ratti (ratti) Carat (metric) to Masha (masha) Carat (metric) to Tola (tola) Carat (metric) to Chittack (Chatank) (chittack) Carat (metric) to Seer (Ser) (seer) Carat (metric) to Maund (Mann) (maund)

Scientific / Atomic (9 units)

Carat (metric) to Electron Mass (rest) (me) Carat (metric) to MeV/c2 (MeV/c²) Carat (metric) to Muon Mass (mµ) Carat (metric) to Atomic Mass Unit (u) Carat (metric) to Proton Mass (mp) Carat (metric) to Neutron Mass (mn) Carat (metric) to Deuteron Mass (md) Carat (metric) to Carbon-12 Atom Mass (C-12) Carat (metric) to Planck Mass (mP)

Astronomical (4 units)

Carat (metric) to Lunar Mass (Moon) (M☾) Carat (metric) to Earth's Mass (M⊕) Carat (metric) to Jupiter Mass (MJ) Carat (metric) to Sun's Mass (M☉)

Biblical / Ancient (14 units)

Carat (metric) to Lepton (Biblical Roman) (lepton) Carat (metric) to Quadrans (Biblical Roman) (quadrans) Carat (metric) to Assarion (Biblical Roman) (assarion) Carat (metric) to Gerah (Biblical Hebrew) (gerah) Carat (metric) to Drachma (Biblical Greek) (drachma) Carat (metric) to Denarius (Biblical Roman) (denarius) Carat (metric) to Bekan (Biblical Hebrew) (bekah) Carat (metric) to Didrachma (Biblical Greek) (didrachma) Carat (metric) to Shekel (Biblical Hebrew) (shekel) Carat (metric) to Tetradrachma (Biblical Greek) (tetra) Carat (metric) to Mina (Biblical Greek) (mina) Carat (metric) to Mina (Biblical Hebrew) (mina) Carat (metric) to Talent (Biblical Greek) (talent) Carat (metric) to Talent (Biblical Hebrew) (talent)

Force / Engineering (5 units)

Carat (metric) to Poundal (pdl) Carat (metric) to Ton (assay) (US) (AT) Carat (metric) to Ton (assay) (UK) (AT) Carat (metric) to Kilogram-force square second/meter (hyl) Carat (metric) to Slug (slug)

Sources & references

Conversion factor (1 ct = 200000 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 Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.

Results are provided for general reference. Verify critical measurements against an authoritative standard.