µg to mmol Converter
To convert µg to mmol, divide the value in micrograms by the molecular weight (g/mol), then divide by 1,000.
How to Convert µg to mmol
This µg to mmol converter changes micrograms into millimoles. Enter the mass in µg and the molecular weight.
Divide µg by the molecular weight to get µmol, then divide by 1,000 to get mmol: mmol = µg ÷ MW ÷ 1,000.
For example, 200 µg of caffeine (MW 194.194 g/mol) ≈ 0.00103 mmol.
mmol = µg ÷ MW ÷ 1,000Divide the mass in µg by the molecular weight (g/mol), then divide by 1,000 to get millimoles.Conversion Formula
The formula to convert µg to mmol is:
Where:
- µg = mass in micrograms (10⁻⁶ g)
- mmol = amount in millimoles (10⁻³ mol)
- MW = molecular weight (molar mass) in g/mol
Conversion Table
Common µg to mmol conversions are shown below. The last column uses caffeine (MW 194.194 g/mol) as an example.
| µg | mmol (formula) | mmol for caffeine |
|---|---|---|
| 0.01 | 0.00001 ÷ MW | 5.149489686 × 10⁻⁸ |
| 0.1 | 0.0001 ÷ MW | 5.149489686 × 10⁻⁷ |
| 0.33 | 0.00033 ÷ MW | 0.000001699331596 |
| 0.5 | 0.0005 ÷ MW | 0.000002574744843 |
| 1 | 0.001 ÷ MW | 0.000005149489686 |
| 2.5 | 0.0025 ÷ MW | 0.00001287372421 |
| 5 | 0.005 ÷ MW | 0.00002574744843 |
| 10 | 0.01 ÷ MW | 0.00005149489686 |
| 33 | 0.033 ÷ MW | 0.0001699331596 |
| 50 | 0.05 ÷ MW | 0.0002574744843 |
| 100 | 0.1 ÷ MW | 0.0005149489686 |
| 250 | 0.25 ÷ MW | 0.001287372421 |
| 500 | 0.5 ÷ MW | 0.002574744843 |
| 1,000 | 1 ÷ MW | 0.005149489686 |
Worked Examples
Here are some common examples of µg to mmol conversion, using caffeine (MW 194.194 g/mol):
- 0.000005149489686 mmol = 1 µg
- 0.00002574744843 mmol = 5 µg
- 0.0001699331596 mmol = 33 µg
- 0.0005149489686 mmol = 100 µg
Unit Definitions
What is a microgram (µg)?
A microgram (µg) is a unit of mass equal to 10⁻⁶ gram.
The prefix micro- (µ) means 10⁻⁶, or one millionth. So 1 µg = 0.000001 g.
It is often written as “mcg” on labels, to avoid confusing µg with mg.
What is a millimole (mmol)?
A millimole (mmol) is a unit of amount of substance equal to 10⁻³ mole.
The prefix milli- (m) means 10⁻³, or one thousandth. So 1 mmol = 0.001 mol.
Why Is Molecular Weight Needed?
Moles count particles. Grams measure mass. One particle of each substance has its own mass, so the link between them is the molecular weight (MW), also called molar mass.
MW tells you how many grams one mole of a substance weighs. For example, one mole of water weighs about 18.015 g, while one mole of glucose weighs about 180.16 g.
Therefore, to convert µg to mmol, you divide by MW, then divide by 1,000. The extra step (÷ 1,000) only adjusts for the different sizes of the two units.
Uses and Importance of µg and mmol
Converting µg to mmol is useful when a trace mass must be compared with larger amounts listed in mmol.
Comparing with recipes
If a protocol lists a component in mmol but you have it weighed in µg, converting shows whether you have enough.
Food and drink testing
Caffeine and other small molecules are often measured in µg. Converting to mmol links them to molar concentrations.
Unit checks
Converting between these units helps catch a misplaced factor of 1,000.
Frequently Asked Questions (FAQ)
What is 1,000 µg of caffeine in mmol?
1,000 µg = 1 mg. 1 ÷ 194.194 ≈ 0.005149 mmol.
Would µmol be a better unit?
Often yes. µg ÷ MW gives µmol directly. 200 µg of caffeine is about 1.03 µmol.
What is caffeine's molecular weight?
Caffeine is C₈H₁₀N₄O₂, about 194.194 g/mol.
Why is my answer so small?
A millimole of caffeine weighs about 194 mg, which is 194,000 µg. So a few hundred µg is only a tiny part of a millimole.
Is µg the same as mcg?
Yes. mcg is another way to write µg, used on labels.
Other Related Tools
Accuracy and Scope
The result depends on the molecular weight you enter.
Example values are rounded to four significant figures.
Sources