**In kilograms, the mass of a hydrogen atom is 1.67 times 10 to the power of negative 27 or 1.67 x 10 ^{-24} grams.** That conversion is based on one atomic measurement unit of atomic mass for an atom of hydrogen.

In grams, the mass of an atom of hydrogen is expressed as 1.67 x 10^{-24}. The mass of an atom of hydrogen can also be expressed in molar mass units as one gram per mole. In kilograms, the molar mass of a hydrogen atom can be written as 0.001 kilograms per mole. An amu is equivalent to one dalton unit.