About

In quantitative chemistry and biological research, converting mass (mcg) to amount of substance (nmol) is critical for preparing molar solutions. Unlike simple unit conversions, this process is dependent on the specific Molecular Weight (MW) of the compound in question.

This tool is designed for laboratory use, offering a streamlined interface to calculate nanomoles based on micrograms and Dalton/MW. It includes an integrated database of common biological and chemical compounds, allowing users to auto-fill molecular weights for rapid calculation. This ensures accuracy in workflows such as PCR primer dilution, peptide reconstitution, and drug dosing studies.

Formulas

The calculation utilizes the molar mass formula, adjusting for the micro- and nano- scales.

n_(nmol) = m_(mcg) × 1,000MW_(g/mol)

Alternatively, since 1 g/mol is equivalent to 1 ng/nmol:

n_(nmol) = m_(ng)MW

Reference Data

Compound	Molecular Weight (g/mol)	100 mcg to nmol
Water (H2O)	18.015	5,550.9
Glucose	180.16	555.06
ATP	507.18	197.16
Cholesterol	386.65	258.63
Testosterone	288.42	346.71
Caffeine	194.19	514.96
NaCl	58.44	1,711.1
Ethanol	46.07	2,170.6

Frequently Asked Questions

MW stands for Molecular Weight (often expressed in g/mol or Daltons). It is a constant property of a molecule determined by the sum of the atomic weights of its constituent atoms. You can find it on the product datasheet, MSDS, or by using the search feature in this tool.

Yes, if you know the average molecular weight. For example, the average MW of a DNA base pair is ~650 g/mol, and a single nucleotide is ~330 g/mol. Enter this value into the MW field.

The database uses standard atomic weights. However, for critical analytical chemistry, always verify the specific molecular weight of your reagent batch, as salt forms (e.g., HCl salts) or hydration states (monohydrate vs. anhydrous) significantly alter the MW.