Magnesium oxide molar mass
Molar mass of MgO = 40.3044 g/mol
Molecular weight calculation:
24.3050 + 15.9994
Element  Symbol  Atomic Mass  # of Atoms  Mass Percent 
Mg  24.3050  60.304%  
15.9994  39.696% 
In chemistry, the formula weight is a quantity computed by multiplying the atomic weight (in atomic mass units) of each element in a chemical formula by the number of atoms of that element present in the formula, then adding all of these products together.
Using the chemical formula of the compound and the periodic table of elements, we can add up the atomic weights and calculate molecular weight of the substance.
If the formula used in calculating molar mass is the molecular formula, the formula weight computed is the molecular weight. The percentage by weight of any atom or group of atoms in a compound can be computed by dividing the total weight of the atom (or group of atoms) in the formula by the formula weight and multiplying by 100.
Formula weights are especially useful in determining the relative weights of reagents and products in a chemical reaction. These relative weights computed from the chemical equation are sometimes called equation weights.
A common request on this site is to convert grams to moles. To complete this calculation, you have to know what substance you are trying to convert. The reason is that the molar mass of the substance affects the conversion. This site explains how to find molar mass.
The atomic weights used on this site come from NIST, the National Institute of Standards and Technology. We use the most common isotopes. This is how to calculate molar mass (average molecular weight), which is based on isotropically weighted averages. This is not the same as molecular mass, which is the mass of a single molecule of welldefined isotopes. For bulk stoichiometric calculations, we are usually determining molar mass, which may also be called standard atomic weight or average atomic mass.
Finding molar mass starts with units of grams per mole (g/mol). When calculating molecular weight of a chemical compound, it tells us how many grams are in one mole of that substance. The formula weight is simply the weight in atomic mass units of all the atoms in a given formula.
PacificCoast NutriLabs 500mg Magnesium Citrate, 1000mg Calcium, Free eBook, 120 Vegetarian Tablets Health and Beauty (PacificCoast NutriLabs)

MAGNESIUM CITRATE  250 SMALL & EASY TO SWALLOW Tablets  includes FREE DOSAGE GUIDE. Highly Absorbable Supplement. Helps with Sleep, Anxiety, Migraines, and Leg Cramps.* Satisfaction Guaranteed. Health and Beauty (Nuvari LIfe)

Generic OTC Magnesium Oxide Tablets  3 Bottles Health and Beauty (Generic OTC)


Young PHorever pHLush Powder 200g Beauty (Young Phorever)


Medline Magnesium Oxide Tablets, 400 gm Bottle (2 Case) BISS (Medline)
