µmol to µg Converter
To convert µmol to µg, multiply the value in micromoles by the molecular weight (g/mol).
How to Convert µmol to µg
Use this µmol to µg converter to change micromoles into micrograms. Enter µmol and the molecular weight.
Because both units use the micro- prefix, the rule is simply µg = µmol × molecular weight.
For example, 2 µmol of ATP (free acid, MW 507.182 g/mol) is 2 × 507.182 = 1,014.36 µg.
µg = µmol × MWMultiply the micromoles by the molecular weight (g/mol) to get micrograms.Conversion Formula
The formula to convert µmol to µg is:
Where:
- µmol = amount in micromoles (10⁻⁶ mol)
- µg = mass in micrograms (10⁻⁶ g)
- MW = molecular weight (molar mass) in g/mol
Conversion Table
Common µmol to µg conversions are shown below. The last column uses ATP (MW 507.182 g/mol) as an example.
| µmol | µg (formula) | µg for ATP |
|---|---|---|
| 0.01 | 0.01 × MW | 5.07182 |
| 0.1 | 0.1 × MW | 50.7182 |
| 0.33 | 0.33 × MW | 167.37006 |
| 0.5 | 0.5 × MW | 253.591 |
| 1 | 1 × MW | 507.182 |
| 2.5 | 2.5 × MW | 1,267.955 |
| 5 | 5 × MW | 2,535.91 |
| 10 | 10 × MW | 5,071.82 |
| 33 | 33 × MW | 16,737.006 |
| 50 | 50 × MW | 25,359.1 |
| 100 | 100 × MW | 50,718.2 |
| 250 | 250 × MW | 126,795.5 |
| 500 | 500 × MW | 253,591 |
| 1,000 | 1,000 × MW | 507,182 |
Worked Examples
Here are some common examples of µmol to µg conversion, using ATP (MW 507.182 g/mol):
- 507.182 µg = 1 µmol
- 2,535.91 µg = 5 µmol
- 16,737.006 µg = 33 µmol
- 50,718.2 µg = 100 µmol
Unit Definitions
What is a micromole (µmol)?
A micromole (µmol) is a unit of amount of substance equal to 10⁻⁶ mole.
The prefix micro- (µ) means 10⁻⁶, or one millionth. So 1 µmol = 0.000001 mol.
It is often typed as “umol” when the µ symbol is not available.
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.
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 µmol to µg, you multiply by MW. Both units use the same prefix size, so no extra step is needed.
Uses and Importance of µmol and µg
µmol and µg are a natural pair for small-scale biochemistry, where reagents are used in micro amounts.
Nucleotide stocks
ATP and other nucleotides are often weighed in mg and used in µmol. Converting helps prepare exact stocks.
Enzyme assays
Substrates are dosed in µmol per reaction. Converting to µg gives the mass to add.
Microscale synthesis
Small reactions use a few µmol of each reagent, which is often only hundreds of µg.
Frequently Asked Questions (FAQ)
Why is µmol to µg just × MW?
Both units carry the same prefix, so the powers of ten cancel.
How many µg are in 1 µmol of ATP?
About 507.182 µg for the free acid form.
Does the salt form of ATP matter?
Yes. ATP is often sold as a sodium salt, which is heavier than the free acid. Use the molecular weight on your product label.
Is the same rule true for mmol to mg?
Yes. mmol × MW = mg and nmol × MW = ng, because the prefixes match.
Can I use this for proteins?
Yes. Enter the protein's molecular weight. A large protein weighs many µg per µmol.
Other Related Tools
Accuracy and Scope
The example uses the free acid form of ATP (C₁₀H₁₆N₅O₁₃P₃). Commercial ATP is often a salt or hydrate with a higher molecular weight.
The result depends on the molecular weight you enter.
Sources