Periodic table of atomic radius

Interactive periodic table of atomic radius in picometers. ElementWorks is a free interactive periodic table: hover an element to preview it, click it for its full card, or pick another view from the Show menu.

Periodic table of atomic radius explained

Atomic radius describes the size of an atom. This table uses covalent radius in picometers (pm). Radius decreases from left to right across a period, because more protons pull the same shell closer, and increases down a group, because each row adds a new electron shell.

Highest values

Francium (Fr): 260 pm
Cesium (Cs): 244 pm
Radium (Ra): 221 pm
Rubidium (Rb): 220 pm
Actinium (Ac): 215 pm

Lowest values

Helium (He): 28 pm
Hydrogen (H): 31 pm
Fluorine (F): 57 pm
Neon (Ne): 58 pm
Oxygen (O): 66 pm

Data table

Show the full data table (all 118 elements)

Atomic radius (pm) of all 118 elements
No.	Symbol	Element	Atomic radius (pm)
1	H	Hydrogen	31 pm
2	He	Helium	28 pm
3	Li	Lithium	128 pm
4	Be	Beryllium	96 pm
5	B	Boron	84 pm
6	C	Carbon	76 pm
7	N	Nitrogen	71 pm
8	O	Oxygen	66 pm
9	F	Fluorine	57 pm
10	Ne	Neon	58 pm
11	Na	Sodium	166 pm
12	Mg	Magnesium	141 pm
13	Al	Aluminium	121 pm
14	Si	Silicon	111 pm
15	P	Phosphorus	107 pm
16	S	Sulfur	105 pm
17	Cl	Chlorine	102 pm
18	Ar	Argon	106 pm
19	K	Potassium	203 pm
20	Ca	Calcium	176 pm
21	Sc	Scandium	170 pm
22	Ti	Titanium	160 pm
23	V	Vanadium	153 pm
24	Cr	Chromium	139 pm
25	Mn	Manganese	139 pm
26	Fe	Iron	132 pm
27	Co	Cobalt	126 pm
28	Ni	Nickel	124 pm
29	Cu	Copper	132 pm
30	Zn	Zinc	122 pm
31	Ga	Gallium	122 pm
32	Ge	Germanium	120 pm
33	As	Arsenic	119 pm
34	Se	Selenium	120 pm
35	Br	Bromine	120 pm
36	Kr	Krypton	116 pm
37	Rb	Rubidium	220 pm
38	Sr	Strontium	195 pm
39	Y	Yttrium	190 pm
40	Zr	Zirconium	175 pm
41	Nb	Niobium	164 pm
42	Mo	Molybdenum	154 pm
43	Tc	Technetium	147 pm
44	Ru	Ruthenium	146 pm
45	Rh	Rhodium	142 pm
46	Pd	Palladium	139 pm
47	Ag	Silver	145 pm
48	Cd	Cadmium	144 pm
49	In	Indium	142 pm
50	Sn	Tin	139 pm
51	Sb	Antimony	139 pm
52	Te	Tellurium	138 pm
53	I	Iodine	139 pm
54	Xe	Xenon	140 pm
55	Cs	Cesium	244 pm
56	Ba	Barium	215 pm
57	La	Lanthanum	207 pm
58	Ce	Cerium	204 pm
59	Pr	Praseodymium	203 pm
60	Nd	Neodymium	201 pm
61	Pm	Promethium	199 pm
62	Sm	Samarium	198 pm
63	Eu	Europium	198 pm
64	Gd	Gadolinium	196 pm
65	Tb	Terbium	194 pm
66	Dy	Dysprosium	192 pm
67	Ho	Holmium	192 pm
68	Er	Erbium	189 pm
69	Tm	Thulium	190 pm
70	Yb	Ytterbium	187 pm
71	Lu	Lutetium	187 pm
72	Hf	Hafnium	175 pm
73	Ta	Tantalum	170 pm
74	W	Tungsten	162 pm
75	Re	Rhenium	151 pm
76	Os	Osmium	144 pm
77	Ir	Iridium	141 pm
78	Pt	Platinum	136 pm
79	Au	Gold	136 pm
80	Hg	Mercury	132 pm
81	Tl	Thallium	145 pm
82	Pb	Lead	146 pm
83	Bi	Bismuth	148 pm
84	Po	Polonium	140 pm
85	At	Astatine	150 pm
86	Rn	Radon	150 pm
87	Fr	Francium	260 pm
88	Ra	Radium	221 pm
89	Ac	Actinium	215 pm
90	Th	Thorium	206 pm
91	Pa	Protactinium	200 pm
92	U	Uranium	196 pm
93	Np	Neptunium	190 pm
94	Pu	Plutonium	187 pm
95	Am	Americium	180 pm
96	Cm	Curium	169 pm
97	Bk	Berkelium	—
98	Cf	Californium	—
99	Es	Einsteinium	—
100	Fm	Fermium	—
101	Md	Mendelevium	—
102	No	Nobelium	—
103	Lr	Lawrencium	—
104	Rf	Rutherfordium	—
105	Db	Dubnium	—
106	Sg	Seaborgium	—
107	Bh	Bohrium	—
108	Hs	Hassium	—
109	Mt	Meitnerium	—
110	Ds	Darmstadtium	—
111	Rg	Roentgenium	—
112	Cn	Copernicium	—
113	Nh	Nihonium	—
114	Fl	Flerovium	—
115	Mc	Moscovium	—
116	Lv	Livermorium	—
117	Ts	Tennessine	—
118	Og	Oganesson	—

Frequently asked questions

Why does atomic radius decrease across a period?

Each step to the right adds one proton and one electron in the same shell. The extra nuclear charge pulls the electrons in more tightly, so the atom gets smaller.

Why does atomic radius increase down a group?

Each new row adds an electron shell that sits farther from the nucleus, and inner electrons shield the outer ones, so the atom gets larger.

Which element has the largest atomic radius in this table?

Francium (about 260 pm) in this data set, followed by cesium (about 244 pm) and rubidium (about 220 pm).