Molecular Mass Calculator

How to calculate the mass of a
particular isotopic composition

Enter the molecular formula of the molecule.
Examples: C6H12O6, PO4H2(CH2)12CH3

Standard Masses

Standard Formula Weight:   12.095280

Mono-isotopic molecular masses:
12C/14N:    84.0939003852
13C/14N:    90.1140294120
12C/15N:    84.0939003852
13C/15N:    90.1140294120

Calculate molecular mass by:

Molecular Mass for C6H12 = 84.159704 Da

Charge = 0

12C	12.000000
13C	13.003355
14C	14.003242

Average mass of this isotopic composition of C: 12.010736 Da

1H	1.007825
2H (D)	2.014102
3H (T)	3.016049

Average mass of this isotopic composition of H: 1.007941 Da

Masses and Isotopic Compositions came from the NIST Physical Reference Data
^*This mass was calculated from the distribution displayed in the text inputs.