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)10.2.136.0/21

network10.2.136.0/21

broadcast10.2.143.255

first host10.2.136.1

last host10.2.143.254

subnet mask255.255.248.0

wildcard0.0.7.255

addresses2,048

usable hosts2,046

classA

ipcalc 10.2.136.0/21

address00001010.00000010.10001000.00000000

subnet mask11111111.11111111.11111000.00000000

network00001010.00000010.10001000.00000000

broadcast00001010.00000010.10001111.11111111

green = network part, grey = host part

hex0x0a028800

decimal167938048

reverse dns0.136.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:8800

/21 split into /29 · 256 subnets

close ×

#	network	host range	broadcast
1	10.2.136.0/29	10.2.136.1 – 10.2.136.6	10.2.136.7
2	10.2.136.8/29	10.2.136.9 – 10.2.136.14	10.2.136.15
3	10.2.136.16/29	10.2.136.17 – 10.2.136.22	10.2.136.23
4	10.2.136.24/29	10.2.136.25 – 10.2.136.30	10.2.136.31
5	10.2.136.32/29	10.2.136.33 – 10.2.136.38	10.2.136.39
6	10.2.136.40/29	10.2.136.41 – 10.2.136.46	10.2.136.47
7	10.2.136.48/29	10.2.136.49 – 10.2.136.54	10.2.136.55
8	10.2.136.56/29	10.2.136.57 – 10.2.136.62	10.2.136.63
9	10.2.136.64/29	10.2.136.65 – 10.2.136.70	10.2.136.71
10	10.2.136.72/29	10.2.136.73 – 10.2.136.78	10.2.136.79
11	10.2.136.80/29	10.2.136.81 – 10.2.136.86	10.2.136.87
12	10.2.136.88/29	10.2.136.89 – 10.2.136.94	10.2.136.95
13	10.2.136.96/29	10.2.136.97 – 10.2.136.102	10.2.136.103
14	10.2.136.104/29	10.2.136.105 – 10.2.136.110	10.2.136.111
15	10.2.136.112/29	10.2.136.113 – 10.2.136.118	10.2.136.119
16	10.2.136.120/29	10.2.136.121 – 10.2.136.126	10.2.136.127
17	10.2.136.128/29	10.2.136.129 – 10.2.136.134	10.2.136.135
18	10.2.136.136/29	10.2.136.137 – 10.2.136.142	10.2.136.143
19	10.2.136.144/29	10.2.136.145 – 10.2.136.150	10.2.136.151
20	10.2.136.152/29	10.2.136.153 – 10.2.136.158	10.2.136.159
21	10.2.136.160/29	10.2.136.161 – 10.2.136.166	10.2.136.167
22	10.2.136.168/29	10.2.136.169 – 10.2.136.174	10.2.136.175
23	10.2.136.176/29	10.2.136.177 – 10.2.136.182	10.2.136.183
24	10.2.136.184/29	10.2.136.185 – 10.2.136.190	10.2.136.191
25	10.2.136.192/29	10.2.136.193 – 10.2.136.198	10.2.136.199
26	10.2.136.200/29	10.2.136.201 – 10.2.136.206	10.2.136.207
27	10.2.136.208/29	10.2.136.209 – 10.2.136.214	10.2.136.215
28	10.2.136.216/29	10.2.136.217 – 10.2.136.222	10.2.136.223
29	10.2.136.224/29	10.2.136.225 – 10.2.136.230	10.2.136.231
30	10.2.136.232/29	10.2.136.233 – 10.2.136.238	10.2.136.239
31	10.2.136.240/29	10.2.136.241 – 10.2.136.246	10.2.136.247
32	10.2.136.248/29	10.2.136.249 – 10.2.136.254	10.2.136.255
33	10.2.137.0/29	10.2.137.1 – 10.2.137.6	10.2.137.7
34	10.2.137.8/29	10.2.137.9 – 10.2.137.14	10.2.137.15
35	10.2.137.16/29	10.2.137.17 – 10.2.137.22	10.2.137.23
36	10.2.137.24/29	10.2.137.25 – 10.2.137.30	10.2.137.31
37	10.2.137.32/29	10.2.137.33 – 10.2.137.38	10.2.137.39
38	10.2.137.40/29	10.2.137.41 – 10.2.137.46	10.2.137.47
39	10.2.137.48/29	10.2.137.49 – 10.2.137.54	10.2.137.55
40	10.2.137.56/29	10.2.137.57 – 10.2.137.62	10.2.137.63
41	10.2.137.64/29	10.2.137.65 – 10.2.137.70	10.2.137.71
42	10.2.137.72/29	10.2.137.73 – 10.2.137.78	10.2.137.79
43	10.2.137.80/29	10.2.137.81 – 10.2.137.86	10.2.137.87
44	10.2.137.88/29	10.2.137.89 – 10.2.137.94	10.2.137.95
45	10.2.137.96/29	10.2.137.97 – 10.2.137.102	10.2.137.103
46	10.2.137.104/29	10.2.137.105 – 10.2.137.110	10.2.137.111
47	10.2.137.112/29	10.2.137.113 – 10.2.137.118	10.2.137.119
48	10.2.137.120/29	10.2.137.121 – 10.2.137.126	10.2.137.127
49	10.2.137.128/29	10.2.137.129 – 10.2.137.134	10.2.137.135
50	10.2.137.136/29	10.2.137.137 – 10.2.137.142	10.2.137.143
51	10.2.137.144/29	10.2.137.145 – 10.2.137.150	10.2.137.151
52	10.2.137.152/29	10.2.137.153 – 10.2.137.158	10.2.137.159
53	10.2.137.160/29	10.2.137.161 – 10.2.137.166	10.2.137.167
54	10.2.137.168/29	10.2.137.169 – 10.2.137.174	10.2.137.175
55	10.2.137.176/29	10.2.137.177 – 10.2.137.182	10.2.137.183
56	10.2.137.184/29	10.2.137.185 – 10.2.137.190	10.2.137.191
57	10.2.137.192/29	10.2.137.193 – 10.2.137.198	10.2.137.199
58	10.2.137.200/29	10.2.137.201 – 10.2.137.206	10.2.137.207
59	10.2.137.208/29	10.2.137.209 – 10.2.137.214	10.2.137.215
60	10.2.137.216/29	10.2.137.217 – 10.2.137.222	10.2.137.223
61	10.2.137.224/29	10.2.137.225 – 10.2.137.230	10.2.137.231
62	10.2.137.232/29	10.2.137.233 – 10.2.137.238	10.2.137.239
63	10.2.137.240/29	10.2.137.241 – 10.2.137.246	10.2.137.247
64	10.2.137.248/29	10.2.137.249 – 10.2.137.254	10.2.137.255
65	10.2.138.0/29	10.2.138.1 – 10.2.138.6	10.2.138.7
66	10.2.138.8/29	10.2.138.9 – 10.2.138.14	10.2.138.15
67	10.2.138.16/29	10.2.138.17 – 10.2.138.22	10.2.138.23
68	10.2.138.24/29	10.2.138.25 – 10.2.138.30	10.2.138.31
69	10.2.138.32/29	10.2.138.33 – 10.2.138.38	10.2.138.39
70	10.2.138.40/29	10.2.138.41 – 10.2.138.46	10.2.138.47
71	10.2.138.48/29	10.2.138.49 – 10.2.138.54	10.2.138.55
72	10.2.138.56/29	10.2.138.57 – 10.2.138.62	10.2.138.63
73	10.2.138.64/29	10.2.138.65 – 10.2.138.70	10.2.138.71
74	10.2.138.72/29	10.2.138.73 – 10.2.138.78	10.2.138.79
75	10.2.138.80/29	10.2.138.81 – 10.2.138.86	10.2.138.87
76	10.2.138.88/29	10.2.138.89 – 10.2.138.94	10.2.138.95
77	10.2.138.96/29	10.2.138.97 – 10.2.138.102	10.2.138.103
78	10.2.138.104/29	10.2.138.105 – 10.2.138.110	10.2.138.111
79	10.2.138.112/29	10.2.138.113 – 10.2.138.118	10.2.138.119
80	10.2.138.120/29	10.2.138.121 – 10.2.138.126	10.2.138.127
81	10.2.138.128/29	10.2.138.129 – 10.2.138.134	10.2.138.135
82	10.2.138.136/29	10.2.138.137 – 10.2.138.142	10.2.138.143
83	10.2.138.144/29	10.2.138.145 – 10.2.138.150	10.2.138.151
84	10.2.138.152/29	10.2.138.153 – 10.2.138.158	10.2.138.159
85	10.2.138.160/29	10.2.138.161 – 10.2.138.166	10.2.138.167
86	10.2.138.168/29	10.2.138.169 – 10.2.138.174	10.2.138.175
87	10.2.138.176/29	10.2.138.177 – 10.2.138.182	10.2.138.183
88	10.2.138.184/29	10.2.138.185 – 10.2.138.190	10.2.138.191
89	10.2.138.192/29	10.2.138.193 – 10.2.138.198	10.2.138.199
90	10.2.138.200/29	10.2.138.201 – 10.2.138.206	10.2.138.207
91	10.2.138.208/29	10.2.138.209 – 10.2.138.214	10.2.138.215
92	10.2.138.216/29	10.2.138.217 – 10.2.138.222	10.2.138.223
93	10.2.138.224/29	10.2.138.225 – 10.2.138.230	10.2.138.231
94	10.2.138.232/29	10.2.138.233 – 10.2.138.238	10.2.138.239
95	10.2.138.240/29	10.2.138.241 – 10.2.138.246	10.2.138.247
96	10.2.138.248/29	10.2.138.249 – 10.2.138.254	10.2.138.255
97	10.2.139.0/29	10.2.139.1 – 10.2.139.6	10.2.139.7
98	10.2.139.8/29	10.2.139.9 – 10.2.139.14	10.2.139.15
99	10.2.139.16/29	10.2.139.17 – 10.2.139.22	10.2.139.23
100	10.2.139.24/29	10.2.139.25 – 10.2.139.30	10.2.139.31
101	10.2.139.32/29	10.2.139.33 – 10.2.139.38	10.2.139.39
102	10.2.139.40/29	10.2.139.41 – 10.2.139.46	10.2.139.47
103	10.2.139.48/29	10.2.139.49 – 10.2.139.54	10.2.139.55
104	10.2.139.56/29	10.2.139.57 – 10.2.139.62	10.2.139.63
105	10.2.139.64/29	10.2.139.65 – 10.2.139.70	10.2.139.71
106	10.2.139.72/29	10.2.139.73 – 10.2.139.78	10.2.139.79
107	10.2.139.80/29	10.2.139.81 – 10.2.139.86	10.2.139.87
108	10.2.139.88/29	10.2.139.89 – 10.2.139.94	10.2.139.95
109	10.2.139.96/29	10.2.139.97 – 10.2.139.102	10.2.139.103
110	10.2.139.104/29	10.2.139.105 – 10.2.139.110	10.2.139.111
111	10.2.139.112/29	10.2.139.113 – 10.2.139.118	10.2.139.119
112	10.2.139.120/29	10.2.139.121 – 10.2.139.126	10.2.139.127
113	10.2.139.128/29	10.2.139.129 – 10.2.139.134	10.2.139.135
114	10.2.139.136/29	10.2.139.137 – 10.2.139.142	10.2.139.143
115	10.2.139.144/29	10.2.139.145 – 10.2.139.150	10.2.139.151
116	10.2.139.152/29	10.2.139.153 – 10.2.139.158	10.2.139.159
117	10.2.139.160/29	10.2.139.161 – 10.2.139.166	10.2.139.167
118	10.2.139.168/29	10.2.139.169 – 10.2.139.174	10.2.139.175
119	10.2.139.176/29	10.2.139.177 – 10.2.139.182	10.2.139.183
120	10.2.139.184/29	10.2.139.185 – 10.2.139.190	10.2.139.191
121	10.2.139.192/29	10.2.139.193 – 10.2.139.198	10.2.139.199
122	10.2.139.200/29	10.2.139.201 – 10.2.139.206	10.2.139.207
123	10.2.139.208/29	10.2.139.209 – 10.2.139.214	10.2.139.215
124	10.2.139.216/29	10.2.139.217 – 10.2.139.222	10.2.139.223
125	10.2.139.224/29	10.2.139.225 – 10.2.139.230	10.2.139.231
126	10.2.139.232/29	10.2.139.233 – 10.2.139.238	10.2.139.239
127	10.2.139.240/29	10.2.139.241 – 10.2.139.246	10.2.139.247
128	10.2.139.248/29	10.2.139.249 – 10.2.139.254	10.2.139.255
129	10.2.140.0/29	10.2.140.1 – 10.2.140.6	10.2.140.7
130	10.2.140.8/29	10.2.140.9 – 10.2.140.14	10.2.140.15
131	10.2.140.16/29	10.2.140.17 – 10.2.140.22	10.2.140.23
132	10.2.140.24/29	10.2.140.25 – 10.2.140.30	10.2.140.31
133	10.2.140.32/29	10.2.140.33 – 10.2.140.38	10.2.140.39
134	10.2.140.40/29	10.2.140.41 – 10.2.140.46	10.2.140.47
135	10.2.140.48/29	10.2.140.49 – 10.2.140.54	10.2.140.55
136	10.2.140.56/29	10.2.140.57 – 10.2.140.62	10.2.140.63
137	10.2.140.64/29	10.2.140.65 – 10.2.140.70	10.2.140.71
138	10.2.140.72/29	10.2.140.73 – 10.2.140.78	10.2.140.79
139	10.2.140.80/29	10.2.140.81 – 10.2.140.86	10.2.140.87
140	10.2.140.88/29	10.2.140.89 – 10.2.140.94	10.2.140.95
141	10.2.140.96/29	10.2.140.97 – 10.2.140.102	10.2.140.103
142	10.2.140.104/29	10.2.140.105 – 10.2.140.110	10.2.140.111
143	10.2.140.112/29	10.2.140.113 – 10.2.140.118	10.2.140.119
144	10.2.140.120/29	10.2.140.121 – 10.2.140.126	10.2.140.127
145	10.2.140.128/29	10.2.140.129 – 10.2.140.134	10.2.140.135
146	10.2.140.136/29	10.2.140.137 – 10.2.140.142	10.2.140.143
147	10.2.140.144/29	10.2.140.145 – 10.2.140.150	10.2.140.151
148	10.2.140.152/29	10.2.140.153 – 10.2.140.158	10.2.140.159
149	10.2.140.160/29	10.2.140.161 – 10.2.140.166	10.2.140.167
150	10.2.140.168/29	10.2.140.169 – 10.2.140.174	10.2.140.175
151	10.2.140.176/29	10.2.140.177 – 10.2.140.182	10.2.140.183
152	10.2.140.184/29	10.2.140.185 – 10.2.140.190	10.2.140.191
153	10.2.140.192/29	10.2.140.193 – 10.2.140.198	10.2.140.199
154	10.2.140.200/29	10.2.140.201 – 10.2.140.206	10.2.140.207
155	10.2.140.208/29	10.2.140.209 – 10.2.140.214	10.2.140.215
156	10.2.140.216/29	10.2.140.217 – 10.2.140.222	10.2.140.223
157	10.2.140.224/29	10.2.140.225 – 10.2.140.230	10.2.140.231
158	10.2.140.232/29	10.2.140.233 – 10.2.140.238	10.2.140.239
159	10.2.140.240/29	10.2.140.241 – 10.2.140.246	10.2.140.247
160	10.2.140.248/29	10.2.140.249 – 10.2.140.254	10.2.140.255
161	10.2.141.0/29	10.2.141.1 – 10.2.141.6	10.2.141.7
162	10.2.141.8/29	10.2.141.9 – 10.2.141.14	10.2.141.15
163	10.2.141.16/29	10.2.141.17 – 10.2.141.22	10.2.141.23
164	10.2.141.24/29	10.2.141.25 – 10.2.141.30	10.2.141.31
165	10.2.141.32/29	10.2.141.33 – 10.2.141.38	10.2.141.39
166	10.2.141.40/29	10.2.141.41 – 10.2.141.46	10.2.141.47
167	10.2.141.48/29	10.2.141.49 – 10.2.141.54	10.2.141.55
168	10.2.141.56/29	10.2.141.57 – 10.2.141.62	10.2.141.63
169	10.2.141.64/29	10.2.141.65 – 10.2.141.70	10.2.141.71
170	10.2.141.72/29	10.2.141.73 – 10.2.141.78	10.2.141.79
171	10.2.141.80/29	10.2.141.81 – 10.2.141.86	10.2.141.87
172	10.2.141.88/29	10.2.141.89 – 10.2.141.94	10.2.141.95
173	10.2.141.96/29	10.2.141.97 – 10.2.141.102	10.2.141.103
174	10.2.141.104/29	10.2.141.105 – 10.2.141.110	10.2.141.111
175	10.2.141.112/29	10.2.141.113 – 10.2.141.118	10.2.141.119
176	10.2.141.120/29	10.2.141.121 – 10.2.141.126	10.2.141.127
177	10.2.141.128/29	10.2.141.129 – 10.2.141.134	10.2.141.135
178	10.2.141.136/29	10.2.141.137 – 10.2.141.142	10.2.141.143
179	10.2.141.144/29	10.2.141.145 – 10.2.141.150	10.2.141.151
180	10.2.141.152/29	10.2.141.153 – 10.2.141.158	10.2.141.159
181	10.2.141.160/29	10.2.141.161 – 10.2.141.166	10.2.141.167
182	10.2.141.168/29	10.2.141.169 – 10.2.141.174	10.2.141.175
183	10.2.141.176/29	10.2.141.177 – 10.2.141.182	10.2.141.183
184	10.2.141.184/29	10.2.141.185 – 10.2.141.190	10.2.141.191
185	10.2.141.192/29	10.2.141.193 – 10.2.141.198	10.2.141.199
186	10.2.141.200/29	10.2.141.201 – 10.2.141.206	10.2.141.207
187	10.2.141.208/29	10.2.141.209 – 10.2.141.214	10.2.141.215
188	10.2.141.216/29	10.2.141.217 – 10.2.141.222	10.2.141.223
189	10.2.141.224/29	10.2.141.225 – 10.2.141.230	10.2.141.231
190	10.2.141.232/29	10.2.141.233 – 10.2.141.238	10.2.141.239
191	10.2.141.240/29	10.2.141.241 – 10.2.141.246	10.2.141.247
192	10.2.141.248/29	10.2.141.249 – 10.2.141.254	10.2.141.255
193	10.2.142.0/29	10.2.142.1 – 10.2.142.6	10.2.142.7
194	10.2.142.8/29	10.2.142.9 – 10.2.142.14	10.2.142.15
195	10.2.142.16/29	10.2.142.17 – 10.2.142.22	10.2.142.23
196	10.2.142.24/29	10.2.142.25 – 10.2.142.30	10.2.142.31
197	10.2.142.32/29	10.2.142.33 – 10.2.142.38	10.2.142.39
198	10.2.142.40/29	10.2.142.41 – 10.2.142.46	10.2.142.47
199	10.2.142.48/29	10.2.142.49 – 10.2.142.54	10.2.142.55
200	10.2.142.56/29	10.2.142.57 – 10.2.142.62	10.2.142.63
201	10.2.142.64/29	10.2.142.65 – 10.2.142.70	10.2.142.71
202	10.2.142.72/29	10.2.142.73 – 10.2.142.78	10.2.142.79
203	10.2.142.80/29	10.2.142.81 – 10.2.142.86	10.2.142.87
204	10.2.142.88/29	10.2.142.89 – 10.2.142.94	10.2.142.95
205	10.2.142.96/29	10.2.142.97 – 10.2.142.102	10.2.142.103
206	10.2.142.104/29	10.2.142.105 – 10.2.142.110	10.2.142.111
207	10.2.142.112/29	10.2.142.113 – 10.2.142.118	10.2.142.119
208	10.2.142.120/29	10.2.142.121 – 10.2.142.126	10.2.142.127
209	10.2.142.128/29	10.2.142.129 – 10.2.142.134	10.2.142.135
210	10.2.142.136/29	10.2.142.137 – 10.2.142.142	10.2.142.143
211	10.2.142.144/29	10.2.142.145 – 10.2.142.150	10.2.142.151
212	10.2.142.152/29	10.2.142.153 – 10.2.142.158	10.2.142.159
213	10.2.142.160/29	10.2.142.161 – 10.2.142.166	10.2.142.167
214	10.2.142.168/29	10.2.142.169 – 10.2.142.174	10.2.142.175
215	10.2.142.176/29	10.2.142.177 – 10.2.142.182	10.2.142.183
216	10.2.142.184/29	10.2.142.185 – 10.2.142.190	10.2.142.191
217	10.2.142.192/29	10.2.142.193 – 10.2.142.198	10.2.142.199
218	10.2.142.200/29	10.2.142.201 – 10.2.142.206	10.2.142.207
219	10.2.142.208/29	10.2.142.209 – 10.2.142.214	10.2.142.215
220	10.2.142.216/29	10.2.142.217 – 10.2.142.222	10.2.142.223
221	10.2.142.224/29	10.2.142.225 – 10.2.142.230	10.2.142.231
222	10.2.142.232/29	10.2.142.233 – 10.2.142.238	10.2.142.239
223	10.2.142.240/29	10.2.142.241 – 10.2.142.246	10.2.142.247
224	10.2.142.248/29	10.2.142.249 – 10.2.142.254	10.2.142.255
225	10.2.143.0/29	10.2.143.1 – 10.2.143.6	10.2.143.7
226	10.2.143.8/29	10.2.143.9 – 10.2.143.14	10.2.143.15
227	10.2.143.16/29	10.2.143.17 – 10.2.143.22	10.2.143.23
228	10.2.143.24/29	10.2.143.25 – 10.2.143.30	10.2.143.31
229	10.2.143.32/29	10.2.143.33 – 10.2.143.38	10.2.143.39
230	10.2.143.40/29	10.2.143.41 – 10.2.143.46	10.2.143.47
231	10.2.143.48/29	10.2.143.49 – 10.2.143.54	10.2.143.55
232	10.2.143.56/29	10.2.143.57 – 10.2.143.62	10.2.143.63
233	10.2.143.64/29	10.2.143.65 – 10.2.143.70	10.2.143.71
234	10.2.143.72/29	10.2.143.73 – 10.2.143.78	10.2.143.79
235	10.2.143.80/29	10.2.143.81 – 10.2.143.86	10.2.143.87
236	10.2.143.88/29	10.2.143.89 – 10.2.143.94	10.2.143.95
237	10.2.143.96/29	10.2.143.97 – 10.2.143.102	10.2.143.103
238	10.2.143.104/29	10.2.143.105 – 10.2.143.110	10.2.143.111
239	10.2.143.112/29	10.2.143.113 – 10.2.143.118	10.2.143.119
240	10.2.143.120/29	10.2.143.121 – 10.2.143.126	10.2.143.127
241	10.2.143.128/29	10.2.143.129 – 10.2.143.134	10.2.143.135
242	10.2.143.136/29	10.2.143.137 – 10.2.143.142	10.2.143.143
243	10.2.143.144/29	10.2.143.145 – 10.2.143.150	10.2.143.151
244	10.2.143.152/29	10.2.143.153 – 10.2.143.158	10.2.143.159
245	10.2.143.160/29	10.2.143.161 – 10.2.143.166	10.2.143.167
246	10.2.143.168/29	10.2.143.169 – 10.2.143.174	10.2.143.175
247	10.2.143.176/29	10.2.143.177 – 10.2.143.182	10.2.143.183
248	10.2.143.184/29	10.2.143.185 – 10.2.143.190	10.2.143.191
249	10.2.143.192/29	10.2.143.193 – 10.2.143.198	10.2.143.199
250	10.2.143.200/29	10.2.143.201 – 10.2.143.206	10.2.143.207
251	10.2.143.208/29	10.2.143.209 – 10.2.143.214	10.2.143.215
252	10.2.143.216/29	10.2.143.217 – 10.2.143.222	10.2.143.223
253	10.2.143.224/29	10.2.143.225 – 10.2.143.230	10.2.143.231
254	10.2.143.232/29	10.2.143.233 – 10.2.143.238	10.2.143.239
255	10.2.143.240/29	10.2.143.241 – 10.2.143.246	10.2.143.247
256	10.2.143.248/29	10.2.143.249 – 10.2.143.254	10.2.143.255

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 →