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:   79.997000

Mono-isotopic molecular masses:
12C/14N:    150.0528234315
13C/14N:    155.0695976205
12C/15N:    150.0528234315
13C/15N:    155.0695976205

Calculate molecular mass by:

Molecular Mass for C5H10O5 = 150.130112 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

16O    15.994915
17O    16.999132
18O    17.999160

Average mass of this isotopic composition of O: 15.999405 Da



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