Molecular Mass Calculator by Christoph Gohlke

Isotopic Composition of the Elements

Element/Isotope Relative mass Abundance
Hydrogen 1.00794000
1H 1.00782503 99.98850000
2H 2.01410178 0.01150000
Helium 4.00260200
3He 3.01602931 0.00013700
4He 4.00260325 99.99986300
Lithium 6.94100000
6Li 6.01512230 7.59000000
7Li 7.01600400 92.41000000
Beryllium 9.01218200
9Be 9.01218210 100.00000000
Boron 10.81100000
10B 10.01293700 19.90000000
11B 11.00930550 80.10000000
Carbon 12.01070000
12C 12.00000000 98.93000000
13C 13.00335484 1.07000000
Nitrogen 14.00670000
14N 14.00307401 99.63200000
15N 15.00010890 0.36800000
Oxygen 15.99940000
16O 15.99491462 99.75700000
17O 16.99913150 0.03800000
18O 17.99916040 0.20500000
Fluorine 18.99840320
19F 18.99840320 100.00000000
Neon 20.17970000
20Ne 19.99244018 90.48000000
21Ne 20.99384674 0.27000000
22Ne 21.99138551 9.25000000
Sodium 22.98977000
23Na 22.98976967 100.00000000
Magnesium 24.30500000
24Mg 23.98504190 78.99000000
25Mg 24.98583702 10.00000000
26Mg 25.98259304 11.01000000
Aluminium 26.98153800
27Al 26.98153844 100.00000000
Silicon 28.08550000
28Si 27.97692653 92.22970000
29Si 28.97649472 4.68320000
30Si 29.97377022 3.08710000
Phosphorus 30.97376100
31P 30.97376151 100.00000000
Sulfur 32.06500000
32S 31.97207069 94.93000000
33S 32.97145850 0.76000000
34S 33.96786683 4.29000000
36S 35.96708088 0.02000000
Chlorine 35.45300000
35Cl 34.96885271 75.78000000
37Cl 36.96590260 24.22000000
Argon 39.94800000
36Ar 35.96754628 0.33650000
38Ar 37.96273220 0.06320000
40Ar 39.96238312 99.60030000
Potassium 39.09830000
39K 38.96370690 93.25810000
40K 39.96399867 0.01170000
41K 40.96182597 6.73020000
Calcium 40.07800000
40Ca 39.96259120 96.94100000
42Ca 41.95861830 0.64700000
43Ca 42.95876680 0.13500000
44Ca 43.95548110 2.08600000
46Ca 45.95369280 0.00400000
48Ca 47.95253400 0.18700000
Scandium 44.95591000
45Sc 44.95591020 100.00000000
Titanium 47.86700000
46Ti 45.95262950 8.25000000
47Ti 46.95176380 7.44000000
48Ti 47.94794710 73.72000000
49Ti 48.94787080 5.41000000
50Ti 49.94479210 5.18000000
Vanadium 50.94150000
50V 49.94716280 0.25000000
51V 50.94396370 99.75000000
Chromium 51.99610000
50Cr 49.94604960 4.34500000
52Cr 51.94051190 83.78900000
53Cr 52.94065380 9.50100000
54Cr 53.93888490 2.36500000
Manganese 54.93804900
55Mn 54.93804960 100.00000000
Iron 55.84500000
54Fe 53.93961480 5.84500000
56Fe 55.93494210 91.75400000
57Fe 56.93539870 2.11900000
58Fe 57.93328050 0.28200000
Cobalt 58.93320000
59Co 58.93320020 100.00000000
Nickel 58.69340000
58Ni 57.93534790 68.07690000
60Ni 59.93079060 26.22310000
61Ni 60.93106040 1.13990000
62Ni 61.92834880 3.63450000
64Ni 63.92796960 0.92560000
Copper 63.54600000
63Cu 62.92960110 69.17000000
65Cu 64.92779370 30.83000000
Zinc 65.40900000
64Zn 63.92914660 48.63000000
66Zn 65.92603680 27.90000000
67Zn 66.92713090 4.10000000
68Zn 67.92484760 18.75000000
70Zn 69.92532500 0.62000000
Gallium 69.72300000
69Ga 68.92558100 60.10800000
71Ga 70.92470500 39.89200000
Germanium 72.64000000
70Ge 69.92425040 20.84000000
72Ge 71.92207620 27.54000000
73Ge 72.92345940 7.73000000
74Ge 73.92117820 36.28000000
76Ge 75.92140270 7.61000000
Arsenic 74.92160000
75As 74.92159640 100.00000000
Selenium 78.96000000
74Se 73.92247660 0.89000000
76Se 75.91921410 9.37000000
77Se 76.91991460 7.63000000
78Se 77.91730950 23.77000000
80Se 79.91652180 49.61000000
82Se 81.91670000 8.73000000
Bromine 79.90400000
79Br 78.91833760 50.69000000
81Br 80.91629100 49.31000000
Krypton 83.79800000
78Kr 77.92038600 0.35000000
80Kr 79.91637800 2.28000000
82Kr 81.91348460 11.58000000
83Kr 82.91413600 11.49000000
84Kr 83.91150700 57.00000000
86Kr 85.91061030 17.30000000
Rubidium 85.46780000
85Rb 84.91178930 72.17000000
87Rb 86.90918350 27.83000000
Strontium 87.62000000
84Sr 83.91342500 0.56000000
86Sr 85.90926240 9.86000000
87Sr 86.90887930 7.00000000
88Sr 87.90561430 82.58000000
Yttrium 88.90585000
89Y 88.90584790 100.00000000
Zirconium 91.22400000
90Zr 89.90470370 51.45000000
91Zr 90.90564500 11.22000000
92Zr 91.90504010 17.15000000
94Zr 93.90631580 17.38000000
96Zr 95.90827600 2.80000000
Niobium 92.90638000
93Nb 92.90637750 100.00000000
Molybdenum 95.94000000
92Mo 91.90681000 14.84000000
94Mo 93.90508760 9.25000000
95Mo 94.90584150 15.92000000
96Mo 95.90467890 16.68000000
97Mo 96.90602100 9.55000000
98Mo 97.90540780 24.13000000
100Mo 99.90747700 9.63000000
Technetium 97.90721600
98Tc 97.90721600 100.00000000
Ruthenium 101.07000000
96Ru 95.90759800 5.54000000
98Ru 97.90528700 1.87000000
99Ru 98.90593930 12.76000000
100Ru 99.90421970 12.60000000
101Ru 100.90558220 17.06000000
102Ru 101.90434950 31.55000000
104Ru 103.90543000 18.62000000
Rhodium 102.90550000
103Rh 102.90550400 100.00000000
Palladium 106.42000000
102Pd 101.90560800 1.02000000
104Pd 103.90403500 11.14000000
105Pd 104.90508400 22.33000000
106Pd 105.90348300 27.33000000
108Pd 107.90389400 26.46000000
110Pd 109.90515200 11.72000000
Silver 107.86820000
107Ag 106.90509300 51.83900000
109Ag 108.90475600 48.16100000
Cadmium 112.41100000
106Cd 105.90645800 1.25000000
108Cd 107.90418300 0.89000000
110Cd 109.90300600 12.49000000
111Cd 110.90418200 12.80000000
112Cd 111.90275720 24.13000000
113Cd 112.90440090 12.22000000
114Cd 113.90335810 28.73000000
116Cd 115.90475500 7.49000000
Indium 114.81800000
113In 112.90406100 4.29000000
115In 114.90387800 95.71000000
Tin 118.71000000
112Sn 111.90482100 0.97000000
114Sn 113.90278200 0.66000000
115Sn 114.90334600 0.34000000
116Sn 115.90174400 14.54000000
117Sn 116.90295400 7.68000000
118Sn 117.90160600 24.22000000
119Sn 118.90330900 8.59000000
120Sn 119.90219660 32.58000000
122Sn 121.90344010 4.63000000
124Sn 123.90527460 5.79000000
Antimony 121.76000000
121Sb 120.90381800 57.21000000
123Sb 122.90421570 42.79000000
Tellurium 127.60000000
120Te 119.90402000 0.09000000
122Te 121.90304710 2.55000000
123Te 122.90427300 0.89000000
124Te 123.90281950 4.74000000
125Te 124.90442470 7.07000000
126Te 125.90330550 18.84000000
128Te 127.90446140 31.74000000
130Te 129.90622280 34.08000000
Iodine 126.90447000
127I 126.90446800 100.00000000
Xenon 131.29300000
124Xe 123.90589580 0.09000000
126Xe 125.90426900 0.09000000
128Xe 127.90353040 1.92000000
129Xe 128.90477950 26.44000000
130Xe 129.90350790 4.08000000
131Xe 130.90508190 21.18000000
132Xe 131.90415450 26.89000000
134Xe 133.90539450 10.44000000
136Xe 135.90722000 8.87000000
Caesium 132.90545000
133Cs 132.90544700 100.00000000
Barium 137.32700000
130Ba 129.90631000 0.10600000
132Ba 131.90505600 0.10100000
134Ba 133.90450300 2.41700000
135Ba 134.90568300 6.59200000
136Ba 135.90457000 7.85400000
137Ba 136.90582100 11.23200000
138Ba 137.90524100 71.69800000
Lanthanum 138.90550000
138La 137.90710700 0.09000000
139La 138.90634800 99.91000000
Cerium 140.11600000
136Ce 135.90714000 0.18500000
138Ce 137.90598600 0.25100000
140Ce 139.90543400 88.45000000
142Ce 141.90924000 11.11400000
Praseodymium 140.90765000
141Pr 140.90764800 100.00000000
Neodymium 144.24000000
142Nd 141.90771900 27.20000000
143Nd 142.90981000 12.20000000
144Nd 143.91008300 23.80000000
145Nd 144.91256900 8.30000000
146Nd 145.91311200 17.20000000
148Nd 147.91688900 5.70000000
150Nd 149.92088700 5.60000000
Promethium 144.91274400
145Pm 144.91274400 100.00000000
Samarium 150.36000000
144Sm 143.91199500 3.07000000
147Sm 146.91489300 14.99000000
148Sm 147.91481800 11.24000000
149Sm 148.91718000 13.82000000
150Sm 149.91727100 7.38000000
152Sm 151.91972800 26.75000000
154Sm 153.92220500 22.75000000
Europium 151.96400000
151Eu 150.91984600 47.81000000
153Eu 152.92122600 52.19000000
Gadolinium 157.25000000
152Gd 151.91978800 0.20000000
154Gd 153.92086200 2.18000000
155Gd 154.92261900 14.80000000
156Gd 155.92212000 20.47000000
157Gd 156.92395700 15.65000000
158Gd 157.92410100 24.84000000
160Gd 159.92705100 21.86000000
Terbium 158.92534000
159Tb 158.92534300 100.00000000
Dysprosium 162.50000000
156Dy 155.92427800 0.06000000
158Dy 157.92440500 0.10000000
160Dy 159.92519400 2.34000000
161Dy 160.92693000 18.91000000
162Dy 161.92679500 25.51000000
163Dy 162.92872800 24.90000000
164Dy 163.92917100 28.18000000
Holmium 164.93032000
165Ho 164.93031900 100.00000000
Erbium 167.25900000
162Er 161.92877500 0.14000000
164Er 163.92919700 1.61000000
166Er 165.93029000 33.61000000
167Er 166.93204500 22.93000000
168Er 167.93236800 26.78000000
170Er 169.93546000 14.93000000
Thulium 168.93421000
169Tm 168.93421100 100.00000000
Ytterbium 173.04000000
168Yb 167.93389400 0.13000000
170Yb 169.93475900 3.04000000
171Yb 170.93632200 14.28000000
172Yb 171.93637770 21.83000000
173Yb 172.93820680 16.13000000
174Yb 173.93885810 31.83000000
176Yb 175.94256800 12.76000000
Lutetium 174.96700000
175Lu 174.94076790 97.41000000
176Lu 175.94268240 2.59000000
Hafnium 178.49000000
174Hf 173.94004000 0.16000000
176Hf 175.94140180 5.26000000
177Hf 176.94322000 18.60000000
178Hf 177.94369770 27.28000000
179Hf 178.94581510 13.62000000
180Hf 179.94654880 35.08000000
Tantalum 180.94790000
180Ta 179.94746600 0.01200000
181Ta 180.94799600 99.98800000
Tungsten 183.84000000
180W 179.94670600 0.12000000
182W 181.94820600 26.50000000
183W 182.95022450 14.31000000
184W 183.95093260 30.64000000
186W 185.95436200 28.43000000
Rhenium 186.20700000
185Re 184.95295570 37.40000000
187Re 186.95575080 62.60000000
Osmium 190.23000000
184Os 183.95249100 0.02000000
186Os 185.95383800 1.59000000
187Os 186.95574790 1.96000000
188Os 187.95583600 13.24000000
189Os 188.95814490 16.15000000
190Os 189.95844500 26.26000000
192Os 191.96147900 40.78000000
Iridium 192.21700000
191Ir 190.96059100 37.30000000
193Ir 192.96292400 62.70000000
Platinum 195.07800000
190Pt 189.95993000 0.01400000
192Pt 191.96103500 0.78200000
194Pt 193.96266400 32.96700000
195Pt 194.96477400 33.83200000
196Pt 195.96493500 25.24200000
198Pt 197.96787600 7.16300000
Gold 196.96655000
197Au 196.96655200 100.00000000
Mercury 200.59000000
196Hg 195.96581500 0.15000000
198Hg 197.96675200 9.97000000
199Hg 198.96826200 16.87000000
200Hg 199.96830900 23.10000000
201Hg 200.97028500 13.18000000
202Hg 201.97062600 29.86000000
204Hg 203.97347600 6.87000000
Thallium 204.38330000
203Tl 202.97232900 29.52400000
205Tl 204.97441200 70.47600000
Lead 207.20000000
204Pb 203.97302900 1.40000000
206Pb 205.97444900 24.10000000
207Pb 206.97588100 22.10000000
208Pb 207.97663600 52.40000000
Bismuth 208.98038000
209Bi 208.98038300 100.00000000
Polonium 208.98241600
209Po 208.98241600 100.00000000
Astatine 209.98710000
210At 209.98713100 100.00000000
Radon 222.01760000
222Rn 222.01757050 100.00000000
Francium 223.01973070
223Fr 223.01973070 100.00000000
Radium 226.02540300
226Ra 226.02540260 100.00000000
Actinium 227.02774700
227Ac 227.02774700 100.00000000
Thorium 232.03810000
232Th 232.03805040 100.00000000
Protactinium 231.03588000
231Pa 231.03587890 100.00000000
Uranium 238.02891000
234U 234.04094560 0.00550000
235U 235.04392310 0.72000000
238U 238.05078260 99.27450000
Neptunium 237.04816700
237Np 237.04816730 100.00000000
Plutonium 244.06419800
244Pu 244.06419800 100.00000000
Americium 243.06137300
243Am 243.06137270 100.00000000
Curium 247.07034700
247Cm 247.07034700 100.00000000
Berkelium 247.07029900
247Bk 247.07029900 100.00000000
Californium 251.07958000
251Cf 251.07958000 100.00000000
Einsteinium 252.08297000
252Es 252.08297000 100.00000000
Fermium 257.09509900
257Fm 257.09509900 100.00000000
Mendelevium 258.09842500
258Md 258.09842500 100.00000000
Nobelium 259.10102000
259No 259.10102000 100.00000000
Lawrencium 262.10969000
262Lr 262.10969000 100.00000000
Rutherfordium 261.10875000
261Rf 261.10875000 100.00000000
Dubnium 262.11415000
262Db 262.11415000 100.00000000
Seaborgium 266.12193000
266Sg 266.12193000 100.00000000
Bohrium 264.12473000
264Bh 264.12473000 100.00000000
Hassium 269.13411000
269Hs 269.13411000 100.00000000
Meitnerium 268.13882000
268Mt 268.13882000 100.00000000