The Molar Mass Calculator 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
What is Molar Mass Calculator?
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:
- H2O
| Formula | H2O | ||||||||||||
| Interpreted as | H₂O | ||||||||||||
| Molar Mass | 18.015 g/mol | ||||||||||||
| Hill Formula | H₂O | ||||||||||||
| Average Composition | |||||||||||||
|
|||||||||||||
- CuSO4.5H2O
| Formula | CuSO4.5H2O | ||||||||||||||||||||
| Interpreted as | CuSO₄·5H₂O | ||||||||||||||||||||
| Molar Mass | 220.136 | ||||||||||||||||||||
| Hill Formula | CuH₁₀O₉S | ||||||||||||||||||||
| Average Composition | |||||||||||||||||||||
|
|||||||||||||||||||||
- CH6N3·HCl·0.25H2O
| Formula | CH6N3·HCl·0.25H2O | ||||||||||||||||||||||||
| Interpreted as | CH₆N₃·HCl·0.25H₂O | ||||||||||||||||||||||||
| Molar Mass | 101.043 | ||||||||||||||||||||||||
| Hill Formula | CH₇.₅ClN₃O₀.₂₅ | ||||||||||||||||||||||||
| Average Composition |
|
- C9H18NO˙
| Formula | C9H18NO˙ | ||||||||||||||||||||
| Interpreted as | C₉H₁₈NO˙ | ||||||||||||||||||||
| Molar Mass | 156.245 | ||||||||||||||||||||
| Hill Formula | C₉H₁₈NO | ||||||||||||||||||||
| Average Composition |
|
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.