What is Molar Mass?
New in Dynochem 5.2, Molar Mass calculator opens a task pane in which you can:
- calculate the Molar Mass (Molecular Weight, Relative Molecular Weight) for any given molecule
- format the formula to the Hill order
- determine the mass percent composition.
How can I use it?
Simple and complex formulas can be entered such as:
- Charged molecules (by placing the charge in square brackets)
- Radicals (which are handled using the upper dot button)
- Partial hydrates and/or solvates (e.g. 0.3H2O and/or 2.6HCl)
Examples
Find the (i) Molar Mass, (ii) Hill Formula and (iii) Elemental mass percentage composition for the following molecules:
Formula |
H2O |
Interpreted as |
H₂O |
Molar Mass |
18.015 g/mol |
Hill Formula |
H₂O |
Average Composition |
Symbol |
Atoms |
Mass |
Mass % |
H |
2 |
2.016 |
11.190 % |
O |
1 |
15.999 |
88.810 % |
|
Formula |
CuSO4.5H2O |
Interpreted as |
CuSO₄·5H₂O |
Molar Mass |
220.136 |
Hill Formula |
CuH₁₀O₉S |
Average Composition |
Symbol |
Atoms |
Mass |
Mass % |
Cu |
1 |
63.546 |
25.450 % |
H |
10 |
10.080 |
4.037 % |
O |
9 |
143.995 |
57.670 % |
S |
1 |
32.068 |
12.843 % |
|
Formula |
CH6N3·HCl·0.25H2O |
Interpreted as |
CH₆N₃·HCl·0.25H₂O |
Molar Mass |
101.043 |
Hill Formula |
CH₇.₅ClN₃O₀.₂₅ |
Average Composition |
Symbol |
Atoms |
Mass |
Mass % |
C |
1 |
12.011 |
11.887 % |
H |
7.5 |
7.560 |
7.482 % |
Cl |
1 |
35.452 |
35.086 % |
N |
3 |
42.021 |
41.587 % |
O |
0.25 |
4.000 |
3.959 % |
|
Formula |
C9H18NO˙ |
Interpreted as |
C₉H₁₈NO˙ |
Molar Mass |
156.245 |
Hill Formula |
C₉H₁₈NO |
Average Composition |
Symbol |
Atoms |
Mass |
Mass % |
C |
9 |
108.095 |
69.183 % |
H |
18 |
18.143 |
11.612 % |
N |
1 |
14.007 |
8.965 % |
O |
1 |
15.999 |
10.240 % |
|
All values returned by the Molar Mass calculator can be written back to the document or worksheet by clicking on the button. The number of decimal places displayed and returned in the calculated figures can be altered by using the decimal place roller .
Heading Substitutions
Formulas can also be entered using a number of common substitutions such as Ac for Acetyl and Bu for Butyl. When a substitution is used, the corresponding interpretation shows the elemental breakdown in parentheses. An example is shown below:
Formula |
BuCl |
Interpreted as |
(C₄H₉)Cl |
Molar Mass |
92.566 |
Hill Formula |
C₄H₉Cl |
Average Composition |
Symbol |
Atoms |
Mass |
Mass % |
C |
4 |
48.042 |
51.901 % |
H |
9 |
9.072 |
9.800 % |
Cl |
1 |
35.452 |
38.299 % |
|
A full list of substitutions is shown below:
Token |
Interpretation |
|
Token |
Interpretation |
|
Token |
Interpretation |
Ac |
acetyl (COCH₃) |
|
Gln |
glutamine (C₅H₈N₂O₂) |
|
Pht |
Phthaldehydic acid (C₈H₅O₃) |
Ad |
adamantyl (C₁₀H₁₅) |
|
Glu |
glutamic acid (C₅H₇NO₃) |
|
Piv |
Phthaldehydic acidPivaloyl (C₅H₉O) |
Ala |
alanine (C₃H₅NO) |
|
Gly |
glycine (C₂H₃NO) |
|
PMB |
para-methoxybenzyl (C₈H₉O) |
Alloc |
Alloxycarbonyl (C₄H₅O₂) |
|
His |
histidine (C₆H₇N₃O) |
|
PMBM |
para-methoxybenoxymethyl (C₉H₁₁O₂) |
Allyl |
Allyl (C₃H₅) |
|
Hp |
heptyl (C₇H₁₅) |
|
Pn |
phenylene (C₆H₄) |
Am |
amyl (C₅H₁₁) |
|
Hpc |
heptacosanyl (C₂₇H₅₅) |
|
PNB |
para-nitrobenzyl (C₇H₄NO₃) |
Ant |
anthracenyl (C₁₄H₉) |
|
Hpd |
heptadecyl (C₁₇H₃₅) |
|
p-Phenylene |
p-Phenylene (C₆H₄) |
Arg |
arginine (C₆H₁₂N₄O) |
|
Hx |
hexyl (C₆H₁₃) |
|
PPi |
Pyrophosphate (P₂O₆³⁻) |
Asn |
asparagine (C₄H₆N₂O₂) |
|
Hxc |
hexacosanyl (C₂₆H₅₃) |
|
Pr |
propyl (C₃H₇) |
Asp |
aspartic acid (C₄H₅NO₃) |
|
Hxd |
hexadecyl (C₁₆H₃₃) |
|
Pro |
proline (C₅H₇NO) |
Ay |
allyl (CH₂CHCH₂) |
|
i-Am |
Isoamyl (C₅H₁₁) |
|
p-Tolyl |
p-Tolyl (C₇H₇) |
Benzoyl |
Benzoyl (C₇H₅O) |
|
i-Bu |
Isobutyl (C₄H₉) |
|
Pv |
Pivaloyl (C₅H₉O) |
Benzyl |
Benzyl (C₇H₇) |
|
i-C3H7 |
Isopropyl (C₃H₇) |
|
Py |
pyridyl (C₅H₄N) |
Bn |
benzyl (C₆H₅CH₂) |
|
i-C4H9 |
Isobutyl (C₄H₉) |
|
s-Am |
sec-amyl (C₅H₁₁) |
Boc |
tert-butyloxycarbonyl (C₅H₉O₂) |
|
i-C5H11 |
Isopentyl (C₅H₁₁) |
|
s-Bu |
sec-butyl (C₄H₉) |
BOM |
Benzyloxymethyl acetal (C₈H₉O) |
|
Ile |
isoleucine (C₆H₁₁NO) |
|
s-Butyl |
sec-butyl (C₄H₉) |
Bs |
brosyl (C₆H₄BrO₂S) |
|
i-Pr |
Isopropyl (C₃H₇) |
|
s-C4H9 |
sec-butyl (C₄H₉) |
Bt |
benzotriazol-1-yl (C₆H₄N₃) |
|
Leu |
leucine (C₆H₁₁NO) |
|
s-C5H11 |
sec-amyl (C₅H₁₁) |
Btm |
benzylsulfanylmethyl (C₇H₇S) |
|
Lys |
lysine (C₆H₁₂N₂O) |
|
Sec |
Selenocysteine (C₃H₅NOSe) |
Bu |
butyl (C₄H₉) |
|
m-C6H4 |
m-C6H4 (C₆H₄) |
|
SEM |
2-Trimethylsilylethoxymethoxy (C₆H₁₅OSi) |
Bz |
benzoyl (C₆H₅CO) |
|
MDIPS |
Methyl diisopropylsilyl (C₇H₁₇Si) |
|
Ser |
serine (C₃H₅NO₂) |
Bzh |
Benzhydryl (C₁₃H₁₁) |
|
MDPS |
Methyl diphenylsilyl (C₁₃H₁₃Si) |
|
SES |
(2-trimethylsilyl)ethanesulfonyl (C₅H₁₃O₂SSi) |
Bzl |
Benzoyl (C₇H₅O) |
|
Me |
methyl (CH₃) |
|
t-Am |
tert-amyl (C₅H₁₁) |
BzOM |
Benzyloxymethyl (C₈H₉O) |
|
MEM |
2-Methoxyethoxymethyl (C₄H₉O₂) |
|
TBDMS |
tert-butyldimethylsilyl (C₆H₁₅Si) |
Cbz |
methylenedioxybenzyl (C₈H₇O₂) |
|
Mes |
Mesitylene (C₉H₁₁) |
|
TBDPS |
tert-butyldiphenylsilyl (C₁₆H₁₉Si) |
c-C3H5 |
cyclopropyl (C₃H₅) |
|
Met |
methionine (C₅H₉NOS) |
|
TBMPS |
bis(tert-butyl)-1-pyrenylmethyl-silyl (C₁₁H₁₇OSi) |
c-C4H7 |
cyclobutyl (C₄H₇) |
|
MMTr |
4-Methoxytriphenylmethyl (C₂₀H₁₇O) |
|
t-BOC |
tert-butyl carbonate (C₅H₉O₂) |
c-C5H9 |
cyclopentyl (C₅H₉) |
|
MOM |
Methoxymethyl (C₂H₅O) |
|
TBS |
tert-butyldimethylsilyl (C₆H₁₅Si) |
c-C6H11 |
cyclohexyl (C₆H₁₁) |
|
m-Phenylene |
m-Phenylene (C₆H₄) |
|
t-Bu |
tert-butyl (C₄H₉) |
c-C7H13 |
cycloheptyl (C₇H₁₃) |
|
MPM |
p-Methoxybenzyl (C₈H₉O) |
|
t-Butyl |
tert-butyl (C₄H₉) |
c-C8H15 |
cyclooctyl (C₈H₁₅) |
|
Ms |
mesyl (CH₃SO₃) |
|
t-C4H9 |
tert-butyl (C₄H₉) |
cHex |
cyclohexyl (C₆H₁₁) |
|
MTM |
Methylthiomethyl (C₂H₅S) |
|
t-C5H11 |
tert-amyl (C₅H₁₁) |
c-Hx |
cyclohexyl (C₆H₁₁) |
|
n-Am |
n-Amyl (C₅H₁₁) |
|
TDS |
Dimethylthexylsilyl (C₈H₁₉Si) |
CoA |
CoenzymeA (C₂₁H₃₁N₇O₁₆P₃) |
|
n-Bu |
n-Butyl (C₄H₉) |
|
Tec |
tetracosanyl (C₂₄H₄₉) |
Cy |
cyclohexyl (C₆H₁₁) |
|
n-C3H7 |
n-C3H7 (C₃H₇) |
|
Ted |
tetradecyl (C₁₄H₂₉) |
cyclobutyl |
cyclobutyl (C₄H₇) |
|
n-C4H9 |
n-C4H9 (C₄H₉) |
|
TES |
triethylsilane (C₆H₁₅Si) |
cycloheptyl |
cycloheptyl (C₇H₁₃) |
|
n-C5H11 |
n-C5H11 (C₅H₁₁) |
|
Tf |
triflyl (CF₃O₂S) |
cyclooctyl |
cyclooctyl (C₈H₁₅) |
|
Ndc |
nonadecyl (C₁₉H₃₉) |
|
TfO |
triflate (CF₃SO₃) |
cyclopentyl |
cyclopentyl (C₅H₉) |
|
neo-Am |
neo-Amyl (C₅H₁₁) |
|
Thexyl |
Thexyl (C₆H₁₃) |
cyclopropyl |
cyclopropyl (C₃H₅) |
|
neo-C5H11 |
neo-pentyl (C₅H₁₁) |
|
Thr |
threonine (C₄H₇NO₂) |
Cys |
cysteine (C₃H₅NOS) |
|
Nh |
naphthyl (C₁₀H₇) |
|
TIPDS |
Tetraisopropyldisiloxane-1,3-diyl (C₁₂H₂₈OSi₂) |
Dan |
Dansyl (C₁₂H₁₂NO₂S) |
|
Nn |
nonyl (C₉H₁₉) |
|
TIPS |
triisopropylsilyl (C₉H₂₁Si) |
Dc |
decyl (C₁₀H₂₁) |
|
Noc |
nonacosanyl (C₂₉H₅₉) |
|
TMS |
trimethylsilane (C₃H₉Si) |
Dd |
dodecyl (C₁₂H₂₅) |
|
Nos |
nosyl (C₆H₄NO₄S) |
|
Tos |
tosyl (CH₃C₆H₄SO₂) |
DEAE |
2-(diethylamino)ethanol (C₆H₁₄N) |
|
Np |
p-nitrophenyl (C₆H₄NO₂) |
|
trans-Cinnamyl |
trans-Cinnamyl (C₉H₉) |
DEIPS |
Diethylisopropylsilyl (C₇H₁₇Si) |
|
n-Pr |
n-propyl (C₃H₇) |
|
Trc |
tricosanyl (C₂₃H₄₇) |
DMIPS |
Dimethylisopropylsilyl (C₅H₁₃Si) |
|
Ns |
nosyl (C₆H₄NO₄S) |
|
Trd |
tridecyl (C₁₃H₂₇) |
DMPM |
3,4-Dimethoxybenzyl (C₉H₁₁O₂) |
|
Oc |
octyl (C₈H₁₇) |
|
Troc |
2,2,2-Trichloroethoxycarbonyl (C₃H₂Cl₃O₂) |
DMPS |
Dimethylphenyl silyl (C₈H₁₁Si) |
|
o-C6H4 |
o-C6H4 (C₆H₄) |
|
Trp |
tryptophan (C₁₁H₁₀N₂O) |
DMTr |
Dimethoxytrityl (C₂₁H₁₉O₂) |
|
Occ |
octacosanyl (C₂₈H₅₇) |
|
Trt |
Trityl (C₁₉H₁₅) |
DNS |
Dansyl (C₁₂H₁₂NO₂S) |
|
Ocd |
octadecyl (C₁₈H₃₇) |
|
Ts |
tosyl (CH₃C₆H₄SO₂) |
Doc |
docosanyl (C₂₂H₄₅) |
|
o-Phenylene |
o-Phenylene (C₆H₄) |
|
Tyr |
tyrosine (C₉H₉NO₂) |
Dod |
dodecyl (C₁₂H₂₅) |
|
OTf |
triflate (CF₃SO₃) |
|
Ud |
undecyl (C₁₁H₂₃) |
DPIPS |
Diphenyl isopropoxy silyl (C₁₅H₁₇OSi) |
|
o-Tolyl |
o-Tolyl (C₇H₇) |
|
Udc |
undecyl (C₁₁H₂₃) |
DPTBS |
Diphenyl tert-butoxy silyl (C₁₆H₁₉OSi) |
|
p-C6H4 |
p-C6H4 (C₆H₄) |
|
Unc |
heneicosanyl (C₂₁H₄₃) |
Ds |
dansyl (C₁₂H₁₂NO₂S) |
|
Pdc |
pentadecyl (C₁₅H₃₁) |
|
Val |
valine (C₅H₉NO) |
DTBMS |
di-tert-butylmethylsilyl (C₉H₂₁Si) |
|
Pe |
pentyl (C₅H₁₁) |
|
Vi |
vinyl (C₂H₃) |
DTBS |
di-tert-butylsilylene (C₈H₁₈Si) |
|
Pec |
pentacosanyl (C₂₅H₅₁) |
|
Vn |
vinylene (C₂H₂) |
Ec |
eicosanyl (C₂₀H₄₁) |
|
Ph |
phenyl (C₆H₅) |
|
Xyl |
(Xyl) (C₈H₉O) |
Et |
ethyl (C₂H₅) |
|
Phe |
phenylalanine (C₉H₉NO) |
|
Z |
methylenedioxybenzyl (C₈H₇O₂) |
Fmoc |
fluorenylmethyloxycarbonyl (C₁₅H₁₁O₂) |
|
Phenyl |
Phenyl (C₆H₅) |
|
|
|
Special Cases
There are a small number of common abbreviations whose use raises potential conflicts with the symbols for elements.
Symbol |
Element Name |
Dynochem Substution |
Interpretation |
Am |
Americium |
Amyl |
(C5H11) |
Np |
Neptumium |
p-nitrophenyl |
(C6H4NO2) |
Ac |
Actinium |
Acetyl |
(COCH3) |
Pr |
Praseodymium |
Propyl |
(C3H7) |
If the Molar Mass of one of the relevant elements is required, then the whole element name needs to be included in the Formula. For example Praseodymium(III) Sulfate would need to be entered as Praseodymium2(SO4)3 in order to get the correct molar mass of 570.011 for Pr₂(SO₄)₃.