A supplement label gives you two different numbers and rarely explains which
is which: the mass of the compound, and the mass of the mineral inside it.
This works out the second from the first, and tells you when a label is
claiming something the chemistry does not allow.
Compound in, mineral out
Hydrates welcome: MgCl2·6H2O or MgCl2.6H2O
Filled from the formula
The raw material, not the mineral
Load a common compound
Or work backwards
Does this label add up?
Bisglycinate by default
Load a common compound
Elemental content of common supplement compounds
Compound
Formula
Molar mass
Elemental
Every percentage here is computed from the formula and standard atomic
weights, not copied from a marketing page. Hydrated forms carry water,
which is why they look weaker per milligram.