IPv4 Subnet Calculator

Enter an IP with a CIDR prefix or a subnet mask to see its network, broadcast, host range, and host count. You can also split the network into smaller subnets.

Try:192.168.1.10/24 10.0.0.0/8 172.16.5.4/20 203.0.113.9/29

IPv6 calculator →

private IP (RFC 1918)10.2.104.0/21

network10.2.104.0/21

broadcast10.2.111.255

first host10.2.104.1

last host10.2.111.254

subnet mask255.255.248.0

wildcard0.0.7.255

addresses2,048

usable hosts2,046

classA

ipcalc 10.2.104.0/21

address00001010.00000010.01101000.00000000

subnet mask11111111.11111111.11111000.00000000

network00001010.00000010.01101000.00000000

broadcast00001010.00000010.01101111.11111111

green = network part, grey = host part

hex0x0a026800

decimal167929856

reverse dns0.104.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:6800

/21 split into /29 · 256 subnets

close ×

#	network	host range	broadcast
1	10.2.104.0/29	10.2.104.1 – 10.2.104.6	10.2.104.7
2	10.2.104.8/29	10.2.104.9 – 10.2.104.14	10.2.104.15
3	10.2.104.16/29	10.2.104.17 – 10.2.104.22	10.2.104.23
4	10.2.104.24/29	10.2.104.25 – 10.2.104.30	10.2.104.31
5	10.2.104.32/29	10.2.104.33 – 10.2.104.38	10.2.104.39
6	10.2.104.40/29	10.2.104.41 – 10.2.104.46	10.2.104.47
7	10.2.104.48/29	10.2.104.49 – 10.2.104.54	10.2.104.55
8	10.2.104.56/29	10.2.104.57 – 10.2.104.62	10.2.104.63
9	10.2.104.64/29	10.2.104.65 – 10.2.104.70	10.2.104.71
10	10.2.104.72/29	10.2.104.73 – 10.2.104.78	10.2.104.79
11	10.2.104.80/29	10.2.104.81 – 10.2.104.86	10.2.104.87
12	10.2.104.88/29	10.2.104.89 – 10.2.104.94	10.2.104.95
13	10.2.104.96/29	10.2.104.97 – 10.2.104.102	10.2.104.103
14	10.2.104.104/29	10.2.104.105 – 10.2.104.110	10.2.104.111
15	10.2.104.112/29	10.2.104.113 – 10.2.104.118	10.2.104.119
16	10.2.104.120/29	10.2.104.121 – 10.2.104.126	10.2.104.127
17	10.2.104.128/29	10.2.104.129 – 10.2.104.134	10.2.104.135
18	10.2.104.136/29	10.2.104.137 – 10.2.104.142	10.2.104.143
19	10.2.104.144/29	10.2.104.145 – 10.2.104.150	10.2.104.151
20	10.2.104.152/29	10.2.104.153 – 10.2.104.158	10.2.104.159
21	10.2.104.160/29	10.2.104.161 – 10.2.104.166	10.2.104.167
22	10.2.104.168/29	10.2.104.169 – 10.2.104.174	10.2.104.175
23	10.2.104.176/29	10.2.104.177 – 10.2.104.182	10.2.104.183
24	10.2.104.184/29	10.2.104.185 – 10.2.104.190	10.2.104.191
25	10.2.104.192/29	10.2.104.193 – 10.2.104.198	10.2.104.199
26	10.2.104.200/29	10.2.104.201 – 10.2.104.206	10.2.104.207
27	10.2.104.208/29	10.2.104.209 – 10.2.104.214	10.2.104.215
28	10.2.104.216/29	10.2.104.217 – 10.2.104.222	10.2.104.223
29	10.2.104.224/29	10.2.104.225 – 10.2.104.230	10.2.104.231
30	10.2.104.232/29	10.2.104.233 – 10.2.104.238	10.2.104.239
31	10.2.104.240/29	10.2.104.241 – 10.2.104.246	10.2.104.247
32	10.2.104.248/29	10.2.104.249 – 10.2.104.254	10.2.104.255
33	10.2.105.0/29	10.2.105.1 – 10.2.105.6	10.2.105.7
34	10.2.105.8/29	10.2.105.9 – 10.2.105.14	10.2.105.15
35	10.2.105.16/29	10.2.105.17 – 10.2.105.22	10.2.105.23
36	10.2.105.24/29	10.2.105.25 – 10.2.105.30	10.2.105.31
37	10.2.105.32/29	10.2.105.33 – 10.2.105.38	10.2.105.39
38	10.2.105.40/29	10.2.105.41 – 10.2.105.46	10.2.105.47
39	10.2.105.48/29	10.2.105.49 – 10.2.105.54	10.2.105.55
40	10.2.105.56/29	10.2.105.57 – 10.2.105.62	10.2.105.63
41	10.2.105.64/29	10.2.105.65 – 10.2.105.70	10.2.105.71
42	10.2.105.72/29	10.2.105.73 – 10.2.105.78	10.2.105.79
43	10.2.105.80/29	10.2.105.81 – 10.2.105.86	10.2.105.87
44	10.2.105.88/29	10.2.105.89 – 10.2.105.94	10.2.105.95
45	10.2.105.96/29	10.2.105.97 – 10.2.105.102	10.2.105.103
46	10.2.105.104/29	10.2.105.105 – 10.2.105.110	10.2.105.111
47	10.2.105.112/29	10.2.105.113 – 10.2.105.118	10.2.105.119
48	10.2.105.120/29	10.2.105.121 – 10.2.105.126	10.2.105.127
49	10.2.105.128/29	10.2.105.129 – 10.2.105.134	10.2.105.135
50	10.2.105.136/29	10.2.105.137 – 10.2.105.142	10.2.105.143
51	10.2.105.144/29	10.2.105.145 – 10.2.105.150	10.2.105.151
52	10.2.105.152/29	10.2.105.153 – 10.2.105.158	10.2.105.159
53	10.2.105.160/29	10.2.105.161 – 10.2.105.166	10.2.105.167
54	10.2.105.168/29	10.2.105.169 – 10.2.105.174	10.2.105.175
55	10.2.105.176/29	10.2.105.177 – 10.2.105.182	10.2.105.183
56	10.2.105.184/29	10.2.105.185 – 10.2.105.190	10.2.105.191
57	10.2.105.192/29	10.2.105.193 – 10.2.105.198	10.2.105.199
58	10.2.105.200/29	10.2.105.201 – 10.2.105.206	10.2.105.207
59	10.2.105.208/29	10.2.105.209 – 10.2.105.214	10.2.105.215
60	10.2.105.216/29	10.2.105.217 – 10.2.105.222	10.2.105.223
61	10.2.105.224/29	10.2.105.225 – 10.2.105.230	10.2.105.231
62	10.2.105.232/29	10.2.105.233 – 10.2.105.238	10.2.105.239
63	10.2.105.240/29	10.2.105.241 – 10.2.105.246	10.2.105.247
64	10.2.105.248/29	10.2.105.249 – 10.2.105.254	10.2.105.255
65	10.2.106.0/29	10.2.106.1 – 10.2.106.6	10.2.106.7
66	10.2.106.8/29	10.2.106.9 – 10.2.106.14	10.2.106.15
67	10.2.106.16/29	10.2.106.17 – 10.2.106.22	10.2.106.23
68	10.2.106.24/29	10.2.106.25 – 10.2.106.30	10.2.106.31
69	10.2.106.32/29	10.2.106.33 – 10.2.106.38	10.2.106.39
70	10.2.106.40/29	10.2.106.41 – 10.2.106.46	10.2.106.47
71	10.2.106.48/29	10.2.106.49 – 10.2.106.54	10.2.106.55
72	10.2.106.56/29	10.2.106.57 – 10.2.106.62	10.2.106.63
73	10.2.106.64/29	10.2.106.65 – 10.2.106.70	10.2.106.71
74	10.2.106.72/29	10.2.106.73 – 10.2.106.78	10.2.106.79
75	10.2.106.80/29	10.2.106.81 – 10.2.106.86	10.2.106.87
76	10.2.106.88/29	10.2.106.89 – 10.2.106.94	10.2.106.95
77	10.2.106.96/29	10.2.106.97 – 10.2.106.102	10.2.106.103
78	10.2.106.104/29	10.2.106.105 – 10.2.106.110	10.2.106.111
79	10.2.106.112/29	10.2.106.113 – 10.2.106.118	10.2.106.119
80	10.2.106.120/29	10.2.106.121 – 10.2.106.126	10.2.106.127
81	10.2.106.128/29	10.2.106.129 – 10.2.106.134	10.2.106.135
82	10.2.106.136/29	10.2.106.137 – 10.2.106.142	10.2.106.143
83	10.2.106.144/29	10.2.106.145 – 10.2.106.150	10.2.106.151
84	10.2.106.152/29	10.2.106.153 – 10.2.106.158	10.2.106.159
85	10.2.106.160/29	10.2.106.161 – 10.2.106.166	10.2.106.167
86	10.2.106.168/29	10.2.106.169 – 10.2.106.174	10.2.106.175
87	10.2.106.176/29	10.2.106.177 – 10.2.106.182	10.2.106.183
88	10.2.106.184/29	10.2.106.185 – 10.2.106.190	10.2.106.191
89	10.2.106.192/29	10.2.106.193 – 10.2.106.198	10.2.106.199
90	10.2.106.200/29	10.2.106.201 – 10.2.106.206	10.2.106.207
91	10.2.106.208/29	10.2.106.209 – 10.2.106.214	10.2.106.215
92	10.2.106.216/29	10.2.106.217 – 10.2.106.222	10.2.106.223
93	10.2.106.224/29	10.2.106.225 – 10.2.106.230	10.2.106.231
94	10.2.106.232/29	10.2.106.233 – 10.2.106.238	10.2.106.239
95	10.2.106.240/29	10.2.106.241 – 10.2.106.246	10.2.106.247
96	10.2.106.248/29	10.2.106.249 – 10.2.106.254	10.2.106.255
97	10.2.107.0/29	10.2.107.1 – 10.2.107.6	10.2.107.7
98	10.2.107.8/29	10.2.107.9 – 10.2.107.14	10.2.107.15
99	10.2.107.16/29	10.2.107.17 – 10.2.107.22	10.2.107.23
100	10.2.107.24/29	10.2.107.25 – 10.2.107.30	10.2.107.31
101	10.2.107.32/29	10.2.107.33 – 10.2.107.38	10.2.107.39
102	10.2.107.40/29	10.2.107.41 – 10.2.107.46	10.2.107.47
103	10.2.107.48/29	10.2.107.49 – 10.2.107.54	10.2.107.55
104	10.2.107.56/29	10.2.107.57 – 10.2.107.62	10.2.107.63
105	10.2.107.64/29	10.2.107.65 – 10.2.107.70	10.2.107.71
106	10.2.107.72/29	10.2.107.73 – 10.2.107.78	10.2.107.79
107	10.2.107.80/29	10.2.107.81 – 10.2.107.86	10.2.107.87
108	10.2.107.88/29	10.2.107.89 – 10.2.107.94	10.2.107.95
109	10.2.107.96/29	10.2.107.97 – 10.2.107.102	10.2.107.103
110	10.2.107.104/29	10.2.107.105 – 10.2.107.110	10.2.107.111
111	10.2.107.112/29	10.2.107.113 – 10.2.107.118	10.2.107.119
112	10.2.107.120/29	10.2.107.121 – 10.2.107.126	10.2.107.127
113	10.2.107.128/29	10.2.107.129 – 10.2.107.134	10.2.107.135
114	10.2.107.136/29	10.2.107.137 – 10.2.107.142	10.2.107.143
115	10.2.107.144/29	10.2.107.145 – 10.2.107.150	10.2.107.151
116	10.2.107.152/29	10.2.107.153 – 10.2.107.158	10.2.107.159
117	10.2.107.160/29	10.2.107.161 – 10.2.107.166	10.2.107.167
118	10.2.107.168/29	10.2.107.169 – 10.2.107.174	10.2.107.175
119	10.2.107.176/29	10.2.107.177 – 10.2.107.182	10.2.107.183
120	10.2.107.184/29	10.2.107.185 – 10.2.107.190	10.2.107.191
121	10.2.107.192/29	10.2.107.193 – 10.2.107.198	10.2.107.199
122	10.2.107.200/29	10.2.107.201 – 10.2.107.206	10.2.107.207
123	10.2.107.208/29	10.2.107.209 – 10.2.107.214	10.2.107.215
124	10.2.107.216/29	10.2.107.217 – 10.2.107.222	10.2.107.223
125	10.2.107.224/29	10.2.107.225 – 10.2.107.230	10.2.107.231
126	10.2.107.232/29	10.2.107.233 – 10.2.107.238	10.2.107.239
127	10.2.107.240/29	10.2.107.241 – 10.2.107.246	10.2.107.247
128	10.2.107.248/29	10.2.107.249 – 10.2.107.254	10.2.107.255
129	10.2.108.0/29	10.2.108.1 – 10.2.108.6	10.2.108.7
130	10.2.108.8/29	10.2.108.9 – 10.2.108.14	10.2.108.15
131	10.2.108.16/29	10.2.108.17 – 10.2.108.22	10.2.108.23
132	10.2.108.24/29	10.2.108.25 – 10.2.108.30	10.2.108.31
133	10.2.108.32/29	10.2.108.33 – 10.2.108.38	10.2.108.39
134	10.2.108.40/29	10.2.108.41 – 10.2.108.46	10.2.108.47
135	10.2.108.48/29	10.2.108.49 – 10.2.108.54	10.2.108.55
136	10.2.108.56/29	10.2.108.57 – 10.2.108.62	10.2.108.63
137	10.2.108.64/29	10.2.108.65 – 10.2.108.70	10.2.108.71
138	10.2.108.72/29	10.2.108.73 – 10.2.108.78	10.2.108.79
139	10.2.108.80/29	10.2.108.81 – 10.2.108.86	10.2.108.87
140	10.2.108.88/29	10.2.108.89 – 10.2.108.94	10.2.108.95
141	10.2.108.96/29	10.2.108.97 – 10.2.108.102	10.2.108.103
142	10.2.108.104/29	10.2.108.105 – 10.2.108.110	10.2.108.111
143	10.2.108.112/29	10.2.108.113 – 10.2.108.118	10.2.108.119
144	10.2.108.120/29	10.2.108.121 – 10.2.108.126	10.2.108.127
145	10.2.108.128/29	10.2.108.129 – 10.2.108.134	10.2.108.135
146	10.2.108.136/29	10.2.108.137 – 10.2.108.142	10.2.108.143
147	10.2.108.144/29	10.2.108.145 – 10.2.108.150	10.2.108.151
148	10.2.108.152/29	10.2.108.153 – 10.2.108.158	10.2.108.159
149	10.2.108.160/29	10.2.108.161 – 10.2.108.166	10.2.108.167
150	10.2.108.168/29	10.2.108.169 – 10.2.108.174	10.2.108.175
151	10.2.108.176/29	10.2.108.177 – 10.2.108.182	10.2.108.183
152	10.2.108.184/29	10.2.108.185 – 10.2.108.190	10.2.108.191
153	10.2.108.192/29	10.2.108.193 – 10.2.108.198	10.2.108.199
154	10.2.108.200/29	10.2.108.201 – 10.2.108.206	10.2.108.207
155	10.2.108.208/29	10.2.108.209 – 10.2.108.214	10.2.108.215
156	10.2.108.216/29	10.2.108.217 – 10.2.108.222	10.2.108.223
157	10.2.108.224/29	10.2.108.225 – 10.2.108.230	10.2.108.231
158	10.2.108.232/29	10.2.108.233 – 10.2.108.238	10.2.108.239
159	10.2.108.240/29	10.2.108.241 – 10.2.108.246	10.2.108.247
160	10.2.108.248/29	10.2.108.249 – 10.2.108.254	10.2.108.255
161	10.2.109.0/29	10.2.109.1 – 10.2.109.6	10.2.109.7
162	10.2.109.8/29	10.2.109.9 – 10.2.109.14	10.2.109.15
163	10.2.109.16/29	10.2.109.17 – 10.2.109.22	10.2.109.23
164	10.2.109.24/29	10.2.109.25 – 10.2.109.30	10.2.109.31
165	10.2.109.32/29	10.2.109.33 – 10.2.109.38	10.2.109.39
166	10.2.109.40/29	10.2.109.41 – 10.2.109.46	10.2.109.47
167	10.2.109.48/29	10.2.109.49 – 10.2.109.54	10.2.109.55
168	10.2.109.56/29	10.2.109.57 – 10.2.109.62	10.2.109.63
169	10.2.109.64/29	10.2.109.65 – 10.2.109.70	10.2.109.71
170	10.2.109.72/29	10.2.109.73 – 10.2.109.78	10.2.109.79
171	10.2.109.80/29	10.2.109.81 – 10.2.109.86	10.2.109.87
172	10.2.109.88/29	10.2.109.89 – 10.2.109.94	10.2.109.95
173	10.2.109.96/29	10.2.109.97 – 10.2.109.102	10.2.109.103
174	10.2.109.104/29	10.2.109.105 – 10.2.109.110	10.2.109.111
175	10.2.109.112/29	10.2.109.113 – 10.2.109.118	10.2.109.119
176	10.2.109.120/29	10.2.109.121 – 10.2.109.126	10.2.109.127
177	10.2.109.128/29	10.2.109.129 – 10.2.109.134	10.2.109.135
178	10.2.109.136/29	10.2.109.137 – 10.2.109.142	10.2.109.143
179	10.2.109.144/29	10.2.109.145 – 10.2.109.150	10.2.109.151
180	10.2.109.152/29	10.2.109.153 – 10.2.109.158	10.2.109.159
181	10.2.109.160/29	10.2.109.161 – 10.2.109.166	10.2.109.167
182	10.2.109.168/29	10.2.109.169 – 10.2.109.174	10.2.109.175
183	10.2.109.176/29	10.2.109.177 – 10.2.109.182	10.2.109.183
184	10.2.109.184/29	10.2.109.185 – 10.2.109.190	10.2.109.191
185	10.2.109.192/29	10.2.109.193 – 10.2.109.198	10.2.109.199
186	10.2.109.200/29	10.2.109.201 – 10.2.109.206	10.2.109.207
187	10.2.109.208/29	10.2.109.209 – 10.2.109.214	10.2.109.215
188	10.2.109.216/29	10.2.109.217 – 10.2.109.222	10.2.109.223
189	10.2.109.224/29	10.2.109.225 – 10.2.109.230	10.2.109.231
190	10.2.109.232/29	10.2.109.233 – 10.2.109.238	10.2.109.239
191	10.2.109.240/29	10.2.109.241 – 10.2.109.246	10.2.109.247
192	10.2.109.248/29	10.2.109.249 – 10.2.109.254	10.2.109.255
193	10.2.110.0/29	10.2.110.1 – 10.2.110.6	10.2.110.7
194	10.2.110.8/29	10.2.110.9 – 10.2.110.14	10.2.110.15
195	10.2.110.16/29	10.2.110.17 – 10.2.110.22	10.2.110.23
196	10.2.110.24/29	10.2.110.25 – 10.2.110.30	10.2.110.31
197	10.2.110.32/29	10.2.110.33 – 10.2.110.38	10.2.110.39
198	10.2.110.40/29	10.2.110.41 – 10.2.110.46	10.2.110.47
199	10.2.110.48/29	10.2.110.49 – 10.2.110.54	10.2.110.55
200	10.2.110.56/29	10.2.110.57 – 10.2.110.62	10.2.110.63
201	10.2.110.64/29	10.2.110.65 – 10.2.110.70	10.2.110.71
202	10.2.110.72/29	10.2.110.73 – 10.2.110.78	10.2.110.79
203	10.2.110.80/29	10.2.110.81 – 10.2.110.86	10.2.110.87
204	10.2.110.88/29	10.2.110.89 – 10.2.110.94	10.2.110.95
205	10.2.110.96/29	10.2.110.97 – 10.2.110.102	10.2.110.103
206	10.2.110.104/29	10.2.110.105 – 10.2.110.110	10.2.110.111
207	10.2.110.112/29	10.2.110.113 – 10.2.110.118	10.2.110.119
208	10.2.110.120/29	10.2.110.121 – 10.2.110.126	10.2.110.127
209	10.2.110.128/29	10.2.110.129 – 10.2.110.134	10.2.110.135
210	10.2.110.136/29	10.2.110.137 – 10.2.110.142	10.2.110.143
211	10.2.110.144/29	10.2.110.145 – 10.2.110.150	10.2.110.151
212	10.2.110.152/29	10.2.110.153 – 10.2.110.158	10.2.110.159
213	10.2.110.160/29	10.2.110.161 – 10.2.110.166	10.2.110.167
214	10.2.110.168/29	10.2.110.169 – 10.2.110.174	10.2.110.175
215	10.2.110.176/29	10.2.110.177 – 10.2.110.182	10.2.110.183
216	10.2.110.184/29	10.2.110.185 – 10.2.110.190	10.2.110.191
217	10.2.110.192/29	10.2.110.193 – 10.2.110.198	10.2.110.199
218	10.2.110.200/29	10.2.110.201 – 10.2.110.206	10.2.110.207
219	10.2.110.208/29	10.2.110.209 – 10.2.110.214	10.2.110.215
220	10.2.110.216/29	10.2.110.217 – 10.2.110.222	10.2.110.223
221	10.2.110.224/29	10.2.110.225 – 10.2.110.230	10.2.110.231
222	10.2.110.232/29	10.2.110.233 – 10.2.110.238	10.2.110.239
223	10.2.110.240/29	10.2.110.241 – 10.2.110.246	10.2.110.247
224	10.2.110.248/29	10.2.110.249 – 10.2.110.254	10.2.110.255
225	10.2.111.0/29	10.2.111.1 – 10.2.111.6	10.2.111.7
226	10.2.111.8/29	10.2.111.9 – 10.2.111.14	10.2.111.15
227	10.2.111.16/29	10.2.111.17 – 10.2.111.22	10.2.111.23
228	10.2.111.24/29	10.2.111.25 – 10.2.111.30	10.2.111.31
229	10.2.111.32/29	10.2.111.33 – 10.2.111.38	10.2.111.39
230	10.2.111.40/29	10.2.111.41 – 10.2.111.46	10.2.111.47
231	10.2.111.48/29	10.2.111.49 – 10.2.111.54	10.2.111.55
232	10.2.111.56/29	10.2.111.57 – 10.2.111.62	10.2.111.63
233	10.2.111.64/29	10.2.111.65 – 10.2.111.70	10.2.111.71
234	10.2.111.72/29	10.2.111.73 – 10.2.111.78	10.2.111.79
235	10.2.111.80/29	10.2.111.81 – 10.2.111.86	10.2.111.87
236	10.2.111.88/29	10.2.111.89 – 10.2.111.94	10.2.111.95
237	10.2.111.96/29	10.2.111.97 – 10.2.111.102	10.2.111.103
238	10.2.111.104/29	10.2.111.105 – 10.2.111.110	10.2.111.111
239	10.2.111.112/29	10.2.111.113 – 10.2.111.118	10.2.111.119
240	10.2.111.120/29	10.2.111.121 – 10.2.111.126	10.2.111.127
241	10.2.111.128/29	10.2.111.129 – 10.2.111.134	10.2.111.135
242	10.2.111.136/29	10.2.111.137 – 10.2.111.142	10.2.111.143
243	10.2.111.144/29	10.2.111.145 – 10.2.111.150	10.2.111.151
244	10.2.111.152/29	10.2.111.153 – 10.2.111.158	10.2.111.159
245	10.2.111.160/29	10.2.111.161 – 10.2.111.166	10.2.111.167
246	10.2.111.168/29	10.2.111.169 – 10.2.111.174	10.2.111.175
247	10.2.111.176/29	10.2.111.177 – 10.2.111.182	10.2.111.183
248	10.2.111.184/29	10.2.111.185 – 10.2.111.190	10.2.111.191
249	10.2.111.192/29	10.2.111.193 – 10.2.111.198	10.2.111.199
250	10.2.111.200/29	10.2.111.201 – 10.2.111.206	10.2.111.207
251	10.2.111.208/29	10.2.111.209 – 10.2.111.214	10.2.111.215
252	10.2.111.216/29	10.2.111.217 – 10.2.111.222	10.2.111.223
253	10.2.111.224/29	10.2.111.225 – 10.2.111.230	10.2.111.231
254	10.2.111.232/29	10.2.111.233 – 10.2.111.238	10.2.111.239
255	10.2.111.240/29	10.2.111.241 – 10.2.111.246	10.2.111.247
256	10.2.111.248/29	10.2.111.249 – 10.2.111.254	10.2.111.255

01 / table

IPv4 CIDR prefix table.

Click a prefix longer than your network to split it into subnets.

prefix	subnet mask	addresses	hosts	in your /21
/0	0.0.0.0	4,294,967,296	4,294,967,294	-
/1	128.0.0.0	2,147,483,648	2,147,483,646	-
/2	192.0.0.0	1,073,741,824	1,073,741,822	-
/3	224.0.0.0	536,870,912	536,870,910	-
/4	240.0.0.0	268,435,456	268,435,454	-
/5	248.0.0.0	134,217,728	134,217,726	-
/6	252.0.0.0	67,108,864	67,108,862	-
/7	254.0.0.0	33,554,432	33,554,430	-
/8	255.0.0.0	16,777,216	16,777,214	-
/9	255.128.0.0	8,388,608	8,388,606	-
/10	255.192.0.0	4,194,304	4,194,302	-
/11	255.224.0.0	2,097,152	2,097,150	-
/12	255.240.0.0	1,048,576	1,048,574	-
/13	255.248.0.0	524,288	524,286	-
/14	255.252.0.0	262,144	262,142	-
/15	255.254.0.0	131,072	131,070	-
/16	255.255.0.0	65,536	65,534	-
/17	255.255.128.0	32,768	32,766	-
/18	255.255.192.0	16,384	16,382	-
/19	255.255.224.0	8,192	8,190	-
/20	255.255.240.0	4,096	4,094	-
/21	255.255.248.0	2,048	2,046	1
/22	255.255.252.0	1,024	1,022	2 split →
/23	255.255.254.0	512	510	4 split →
/24	255.255.255.0	256	254	8 split →
/25	255.255.255.128	128	126	16 split →
/26	255.255.255.192	64	62	32 split →
/27	255.255.255.224	32	30	64 split →
/28	255.255.255.240	16	14	128 split →
/29	255.255.255.248	8	6	256 split →
/30	255.255.255.252	4	2	512 split →
/31	255.255.255.254	2	2	1,024 split →
/32	255.255.255.255	1	1	2,048 split →

02 / faq

About this calculator.

How do I use this subnet calculator?

▼

Type an IP address followed by a prefix, like 192.168.1.10/24, or by a subnet mask, like 192.168.1.10 255.255.255.0. Without a prefix it uses /24. Click a row in the table to split the network into smaller subnets.

Why are usable hosts always 2 fewer?

▼

The first address in a subnet is the network address and the last is the broadcast address, so neither can go to a device. The exceptions are /31 (point-to-point links, RFC 3021) and /32 (a single address), which use every address.

Can I use it from a terminal?

▼

Yes. curl 'ipku.in/en/tools/ipv4-subnet-calculator?q=192.168.1.10/24' returns the result as plain text.

Learn how to work it out →