Micrograms to Carats
Type a value in either box to convert between micrograms and carats. The factor is 5e-06.
| Micrograms | Carats |
|---|---|
| 1 µg | 5e-06 ct |
| 2 µg | 1e-05 ct |
| 3 µg | 1.5e-05 ct |
| 5 µg | 2.5e-05 ct |
| 10 µg | 5e-05 ct |
| 25 µg | 0.000125 ct |
| 50 µg | 0.00025 ct |
| 100 µg | 0.0005 ct |
How to use
- Enter a value in the Micrograms field.
- The Carats figure appears immediately — no button to press.
- Typing in the Carats field converts back to Micrograms the same way.
- Use the reference table for the values that come up most often.
Micrograms to Carats formula
The factor from micrograms to carats is 5e-06.
ct = µg × 5e-06
Why this factor: the microgram and the carat are both defined against the kilogram, so dividing one definition by the other gives 5e-06 directly. Both definitions are set out in full below.
To go the other way, divide by 5e-06 — or use the Carats to Micrograms converter, which is the same calculation reversed.
Worked example
Start with 2 µg. Multiply by 5e-06 to get 1e-05 ct.
2 µg × 5e-06 = 1e-05 ct
The converter above does this for any value you type, in either direction.
What is a microgram?
A microgram is one millionth of a gram, used where quantities are vanishingly small but still matter.
Definition: Exactly 1×10⁻⁹ kilogram by SI prefix definition. Symbol µg.
Where it is used: Trace nutrients such as vitamin B12 and folate, hormone doses, and air-quality measurements.
Worth knowing: Sometimes abbreviated 'mcg' on labels specifically to avoid µg being misread as mg — a thousandfold dosing error.
What is a carat?
A metric carat is the standard mass unit for gemstones.
Definition: Exactly 200 milligrams — that is, 0.2 gram — standardized internationally in 1907.
Where it is used: Diamond and gemstone weight throughout the jewellery trade.
Worth knowing: Do not confuse the carat (gemstone mass) with the karat (gold purity out of 24). A 1-carat diamond and 24-karat gold measure entirely different things.
Micrograms vs Carats
The microgram is a metric unit while the carat is a specialized unit. That is why the factor between them is not a round number: the two systems were defined independently and only later tied together by exact agreement.
Frequently asked questions
How many carats are in a microgram?
One microgram equals 5e-06 carats.
What is the formula to convert micrograms to carats?
Multiply the number of micrograms by 5e-06. To reverse it, divide by 5e-06 instead.
How do I convert carats back to micrograms?
Divide by 5e-06, which is the same as multiplying by 200000.
How many carats are in 10 micrograms?
10 µg works out to 5e-05 ct.
Is there anything to watch out for with micrograms?
Sometimes abbreviated 'mcg' on labels specifically to avoid µg being misread as mg — a thousandfold dosing error.
How is the microgram defined?
Exactly 1×10⁻⁹ kilogram by SI prefix definition. Symbol µg.