pg to mol Converter
To convert pg to mol, divide the value in picograms by the molecular weight (g/mol), then divide by 10¹².
How to Convert pg to mol
This pg to mol converter changes a mass in picograms into moles. Enter the mass in pg and the molecular weight.
Divide picograms by 1012 to get grams, then divide by the molecular weight: mol = pg ÷ MW ÷ 1012.
For example, 800 pg of cortisol (MW 362.466 g/mol) ≈ 2.207 × 10−12 mol.
mol = pg ÷ MW ÷ 10¹²Divide the mass in pg by the molecular weight (g/mol), then divide by 10¹² to get moles.Conversion Formula
The formula to convert pg to mol is:
Where:
- pg = mass in picograms (10⁻¹² g)
- mol = amount in moles
- MW = molecular weight (molar mass) in g/mol
Conversion Table
Common pg to mol conversions are shown below. The last column uses cortisol (MW 362.466 g/mol) as an example.
| pg | mol (formula) | mol for cortisol |
|---|---|---|
| 0.01 | 1 × 10⁻¹⁴ ÷ MW | 2.758879454 × 10⁻¹⁷ |
| 0.1 | 1 × 10⁻¹³ ÷ MW | 2.758879454 × 10⁻¹⁶ |
| 0.33 | 3.3 × 10⁻¹³ ÷ MW | 9.104302197 × 10⁻¹⁶ |
| 0.5 | 5 × 10⁻¹³ ÷ MW | 1.379439727 × 10⁻¹⁵ |
| 1 | 1 × 10⁻¹² ÷ MW | 2.758879454 × 10⁻¹⁵ |
| 2.5 | 2.5 × 10⁻¹² ÷ MW | 6.897198634 × 10⁻¹⁵ |
| 5 | 5 × 10⁻¹² ÷ MW | 1.379439727 × 10⁻¹⁴ |
| 10 | 1 × 10⁻¹¹ ÷ MW | 2.758879454 × 10⁻¹⁴ |
| 33 | 3.3 × 10⁻¹¹ ÷ MW | 9.104302197 × 10⁻¹⁴ |
| 50 | 5 × 10⁻¹¹ ÷ MW | 1.379439727 × 10⁻¹³ |
| 100 | 1 × 10⁻¹⁰ ÷ MW | 2.758879454 × 10⁻¹³ |
| 250 | 2.5 × 10⁻¹⁰ ÷ MW | 6.897198634 × 10⁻¹³ |
| 500 | 5 × 10⁻¹⁰ ÷ MW | 1.379439727 × 10⁻¹² |
| 1,000 | 1 × 10⁻⁹ ÷ MW | 2.758879454 × 10⁻¹² |
Worked Examples
Here are some common examples of pg to mol conversion, using cortisol (MW 362.466 g/mol):
- 2.758879454 × 10⁻¹⁵ mol = 1 pg
- 1.379439727 × 10⁻¹⁴ mol = 5 pg
- 9.104302197 × 10⁻¹⁴ mol = 33 pg
- 2.758879454 × 10⁻¹³ mol = 100 pg
Unit Definitions
What is a picogram (pg)?
A picogram (pg) is a unit of mass equal to 10⁻¹² gram.
The prefix pico- (p) means 10⁻¹², or one trillionth. So 1 pg = 0.000000000001 g.
What is a mole (mol)?
The mole (mol) is the SI base unit for amount of substance. It counts particles, such as atoms, molecules or ions.
Since 2019, one mole contains exactly 6.02214076 × 1023 particles. This number is the Avogadro constant.
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 pg to mol, you divide by MW, then divide by 10¹². The extra step (÷ 10¹²) only adjusts for the different sizes of the two units.
Uses and Importance of pg and mol
Picogram results are sometimes converted to moles to compare them with other molecules or to use them in binding and kinetic formulas.
Comparing hormones
Cortisol and other steroids have different molecular weights. Converting pg to moles lets you compare them by number of molecules.
Receptor occupancy
Receptors bind molecules, not mass. Converting to moles is the first step in occupancy calculations.
Checking assay units
Converting a pg result to pmol and back helps find unit mistakes in reports.
Frequently Asked Questions (FAQ)
What is 1 pg of cortisol in mol?
1 ÷ 362.466 ÷ 1012 ≈ 2.759 × 10−15 mol.
Is there a simpler unit for the answer?
Yes. pg ÷ MW gives pmol directly. 800 pg of cortisol is about 2.207 pmol.
How is cortisol usually reported?
In mass units such as µg/dL, or in molar units such as nmol/L. Labcorp lists a factor of 27.6 to go from µg/dL to nmol/L for blood cortisol.
Why must I know the molecular weight?
A picogram of a light molecule contains more molecules than a picogram of a heavy one. The molecular weight accounts for this.
Can I use a rounded molecular weight?
For most purposes, yes. Rounding 362.466 to 362.5 changes the result by only about 0.01%.
Other Related Tools
Accuracy and Scope
The result depends on the molecular weight you enter.
This page converts units and does not interpret cortisol or other hormone results.
Sources