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)10.4.136.0/21

network10.4.136.0/21

broadcast10.4.143.255

first host10.4.136.1

last host10.4.143.254

subnet mask255.255.248.0

wildcard0.0.7.255

addresses2,048

usable hosts2,046

classA

ipcalc 10.4.136.0/21

address00001010.00000100.10001000.00000000

subnet mask11111111.11111111.11111000.00000000

network00001010.00000100.10001000.00000000

broadcast00001010.00000100.10001111.11111111

green = network part, grey = host part

hex0x0a048800

decimal168069120

reverse dns0.136.4.10.in-addr.arpa

ipv4-mapped::ffff:a04:8800

/21 split into /29 · 256 subnets

close ×

#	network	host range	broadcast
1	10.4.136.0/29	10.4.136.1 – 10.4.136.6	10.4.136.7
2	10.4.136.8/29	10.4.136.9 – 10.4.136.14	10.4.136.15
3	10.4.136.16/29	10.4.136.17 – 10.4.136.22	10.4.136.23
4	10.4.136.24/29	10.4.136.25 – 10.4.136.30	10.4.136.31
5	10.4.136.32/29	10.4.136.33 – 10.4.136.38	10.4.136.39
6	10.4.136.40/29	10.4.136.41 – 10.4.136.46	10.4.136.47
7	10.4.136.48/29	10.4.136.49 – 10.4.136.54	10.4.136.55
8	10.4.136.56/29	10.4.136.57 – 10.4.136.62	10.4.136.63
9	10.4.136.64/29	10.4.136.65 – 10.4.136.70	10.4.136.71
10	10.4.136.72/29	10.4.136.73 – 10.4.136.78	10.4.136.79
11	10.4.136.80/29	10.4.136.81 – 10.4.136.86	10.4.136.87
12	10.4.136.88/29	10.4.136.89 – 10.4.136.94	10.4.136.95
13	10.4.136.96/29	10.4.136.97 – 10.4.136.102	10.4.136.103
14	10.4.136.104/29	10.4.136.105 – 10.4.136.110	10.4.136.111
15	10.4.136.112/29	10.4.136.113 – 10.4.136.118	10.4.136.119
16	10.4.136.120/29	10.4.136.121 – 10.4.136.126	10.4.136.127
17	10.4.136.128/29	10.4.136.129 – 10.4.136.134	10.4.136.135
18	10.4.136.136/29	10.4.136.137 – 10.4.136.142	10.4.136.143
19	10.4.136.144/29	10.4.136.145 – 10.4.136.150	10.4.136.151
20	10.4.136.152/29	10.4.136.153 – 10.4.136.158	10.4.136.159
21	10.4.136.160/29	10.4.136.161 – 10.4.136.166	10.4.136.167
22	10.4.136.168/29	10.4.136.169 – 10.4.136.174	10.4.136.175
23	10.4.136.176/29	10.4.136.177 – 10.4.136.182	10.4.136.183
24	10.4.136.184/29	10.4.136.185 – 10.4.136.190	10.4.136.191
25	10.4.136.192/29	10.4.136.193 – 10.4.136.198	10.4.136.199
26	10.4.136.200/29	10.4.136.201 – 10.4.136.206	10.4.136.207
27	10.4.136.208/29	10.4.136.209 – 10.4.136.214	10.4.136.215
28	10.4.136.216/29	10.4.136.217 – 10.4.136.222	10.4.136.223
29	10.4.136.224/29	10.4.136.225 – 10.4.136.230	10.4.136.231
30	10.4.136.232/29	10.4.136.233 – 10.4.136.238	10.4.136.239
31	10.4.136.240/29	10.4.136.241 – 10.4.136.246	10.4.136.247
32	10.4.136.248/29	10.4.136.249 – 10.4.136.254	10.4.136.255
33	10.4.137.0/29	10.4.137.1 – 10.4.137.6	10.4.137.7
34	10.4.137.8/29	10.4.137.9 – 10.4.137.14	10.4.137.15
35	10.4.137.16/29	10.4.137.17 – 10.4.137.22	10.4.137.23
36	10.4.137.24/29	10.4.137.25 – 10.4.137.30	10.4.137.31
37	10.4.137.32/29	10.4.137.33 – 10.4.137.38	10.4.137.39
38	10.4.137.40/29	10.4.137.41 – 10.4.137.46	10.4.137.47
39	10.4.137.48/29	10.4.137.49 – 10.4.137.54	10.4.137.55
40	10.4.137.56/29	10.4.137.57 – 10.4.137.62	10.4.137.63
41	10.4.137.64/29	10.4.137.65 – 10.4.137.70	10.4.137.71
42	10.4.137.72/29	10.4.137.73 – 10.4.137.78	10.4.137.79
43	10.4.137.80/29	10.4.137.81 – 10.4.137.86	10.4.137.87
44	10.4.137.88/29	10.4.137.89 – 10.4.137.94	10.4.137.95
45	10.4.137.96/29	10.4.137.97 – 10.4.137.102	10.4.137.103
46	10.4.137.104/29	10.4.137.105 – 10.4.137.110	10.4.137.111
47	10.4.137.112/29	10.4.137.113 – 10.4.137.118	10.4.137.119
48	10.4.137.120/29	10.4.137.121 – 10.4.137.126	10.4.137.127
49	10.4.137.128/29	10.4.137.129 – 10.4.137.134	10.4.137.135
50	10.4.137.136/29	10.4.137.137 – 10.4.137.142	10.4.137.143
51	10.4.137.144/29	10.4.137.145 – 10.4.137.150	10.4.137.151
52	10.4.137.152/29	10.4.137.153 – 10.4.137.158	10.4.137.159
53	10.4.137.160/29	10.4.137.161 – 10.4.137.166	10.4.137.167
54	10.4.137.168/29	10.4.137.169 – 10.4.137.174	10.4.137.175
55	10.4.137.176/29	10.4.137.177 – 10.4.137.182	10.4.137.183
56	10.4.137.184/29	10.4.137.185 – 10.4.137.190	10.4.137.191
57	10.4.137.192/29	10.4.137.193 – 10.4.137.198	10.4.137.199
58	10.4.137.200/29	10.4.137.201 – 10.4.137.206	10.4.137.207
59	10.4.137.208/29	10.4.137.209 – 10.4.137.214	10.4.137.215
60	10.4.137.216/29	10.4.137.217 – 10.4.137.222	10.4.137.223
61	10.4.137.224/29	10.4.137.225 – 10.4.137.230	10.4.137.231
62	10.4.137.232/29	10.4.137.233 – 10.4.137.238	10.4.137.239
63	10.4.137.240/29	10.4.137.241 – 10.4.137.246	10.4.137.247
64	10.4.137.248/29	10.4.137.249 – 10.4.137.254	10.4.137.255
65	10.4.138.0/29	10.4.138.1 – 10.4.138.6	10.4.138.7
66	10.4.138.8/29	10.4.138.9 – 10.4.138.14	10.4.138.15
67	10.4.138.16/29	10.4.138.17 – 10.4.138.22	10.4.138.23
68	10.4.138.24/29	10.4.138.25 – 10.4.138.30	10.4.138.31
69	10.4.138.32/29	10.4.138.33 – 10.4.138.38	10.4.138.39
70	10.4.138.40/29	10.4.138.41 – 10.4.138.46	10.4.138.47
71	10.4.138.48/29	10.4.138.49 – 10.4.138.54	10.4.138.55
72	10.4.138.56/29	10.4.138.57 – 10.4.138.62	10.4.138.63
73	10.4.138.64/29	10.4.138.65 – 10.4.138.70	10.4.138.71
74	10.4.138.72/29	10.4.138.73 – 10.4.138.78	10.4.138.79
75	10.4.138.80/29	10.4.138.81 – 10.4.138.86	10.4.138.87
76	10.4.138.88/29	10.4.138.89 – 10.4.138.94	10.4.138.95
77	10.4.138.96/29	10.4.138.97 – 10.4.138.102	10.4.138.103
78	10.4.138.104/29	10.4.138.105 – 10.4.138.110	10.4.138.111
79	10.4.138.112/29	10.4.138.113 – 10.4.138.118	10.4.138.119
80	10.4.138.120/29	10.4.138.121 – 10.4.138.126	10.4.138.127
81	10.4.138.128/29	10.4.138.129 – 10.4.138.134	10.4.138.135
82	10.4.138.136/29	10.4.138.137 – 10.4.138.142	10.4.138.143
83	10.4.138.144/29	10.4.138.145 – 10.4.138.150	10.4.138.151
84	10.4.138.152/29	10.4.138.153 – 10.4.138.158	10.4.138.159
85	10.4.138.160/29	10.4.138.161 – 10.4.138.166	10.4.138.167
86	10.4.138.168/29	10.4.138.169 – 10.4.138.174	10.4.138.175
87	10.4.138.176/29	10.4.138.177 – 10.4.138.182	10.4.138.183
88	10.4.138.184/29	10.4.138.185 – 10.4.138.190	10.4.138.191
89	10.4.138.192/29	10.4.138.193 – 10.4.138.198	10.4.138.199
90	10.4.138.200/29	10.4.138.201 – 10.4.138.206	10.4.138.207
91	10.4.138.208/29	10.4.138.209 – 10.4.138.214	10.4.138.215
92	10.4.138.216/29	10.4.138.217 – 10.4.138.222	10.4.138.223
93	10.4.138.224/29	10.4.138.225 – 10.4.138.230	10.4.138.231
94	10.4.138.232/29	10.4.138.233 – 10.4.138.238	10.4.138.239
95	10.4.138.240/29	10.4.138.241 – 10.4.138.246	10.4.138.247
96	10.4.138.248/29	10.4.138.249 – 10.4.138.254	10.4.138.255
97	10.4.139.0/29	10.4.139.1 – 10.4.139.6	10.4.139.7
98	10.4.139.8/29	10.4.139.9 – 10.4.139.14	10.4.139.15
99	10.4.139.16/29	10.4.139.17 – 10.4.139.22	10.4.139.23
100	10.4.139.24/29	10.4.139.25 – 10.4.139.30	10.4.139.31
101	10.4.139.32/29	10.4.139.33 – 10.4.139.38	10.4.139.39
102	10.4.139.40/29	10.4.139.41 – 10.4.139.46	10.4.139.47
103	10.4.139.48/29	10.4.139.49 – 10.4.139.54	10.4.139.55
104	10.4.139.56/29	10.4.139.57 – 10.4.139.62	10.4.139.63
105	10.4.139.64/29	10.4.139.65 – 10.4.139.70	10.4.139.71
106	10.4.139.72/29	10.4.139.73 – 10.4.139.78	10.4.139.79
107	10.4.139.80/29	10.4.139.81 – 10.4.139.86	10.4.139.87
108	10.4.139.88/29	10.4.139.89 – 10.4.139.94	10.4.139.95
109	10.4.139.96/29	10.4.139.97 – 10.4.139.102	10.4.139.103
110	10.4.139.104/29	10.4.139.105 – 10.4.139.110	10.4.139.111
111	10.4.139.112/29	10.4.139.113 – 10.4.139.118	10.4.139.119
112	10.4.139.120/29	10.4.139.121 – 10.4.139.126	10.4.139.127
113	10.4.139.128/29	10.4.139.129 – 10.4.139.134	10.4.139.135
114	10.4.139.136/29	10.4.139.137 – 10.4.139.142	10.4.139.143
115	10.4.139.144/29	10.4.139.145 – 10.4.139.150	10.4.139.151
116	10.4.139.152/29	10.4.139.153 – 10.4.139.158	10.4.139.159
117	10.4.139.160/29	10.4.139.161 – 10.4.139.166	10.4.139.167
118	10.4.139.168/29	10.4.139.169 – 10.4.139.174	10.4.139.175
119	10.4.139.176/29	10.4.139.177 – 10.4.139.182	10.4.139.183
120	10.4.139.184/29	10.4.139.185 – 10.4.139.190	10.4.139.191
121	10.4.139.192/29	10.4.139.193 – 10.4.139.198	10.4.139.199
122	10.4.139.200/29	10.4.139.201 – 10.4.139.206	10.4.139.207
123	10.4.139.208/29	10.4.139.209 – 10.4.139.214	10.4.139.215
124	10.4.139.216/29	10.4.139.217 – 10.4.139.222	10.4.139.223
125	10.4.139.224/29	10.4.139.225 – 10.4.139.230	10.4.139.231
126	10.4.139.232/29	10.4.139.233 – 10.4.139.238	10.4.139.239
127	10.4.139.240/29	10.4.139.241 – 10.4.139.246	10.4.139.247
128	10.4.139.248/29	10.4.139.249 – 10.4.139.254	10.4.139.255
129	10.4.140.0/29	10.4.140.1 – 10.4.140.6	10.4.140.7
130	10.4.140.8/29	10.4.140.9 – 10.4.140.14	10.4.140.15
131	10.4.140.16/29	10.4.140.17 – 10.4.140.22	10.4.140.23
132	10.4.140.24/29	10.4.140.25 – 10.4.140.30	10.4.140.31
133	10.4.140.32/29	10.4.140.33 – 10.4.140.38	10.4.140.39
134	10.4.140.40/29	10.4.140.41 – 10.4.140.46	10.4.140.47
135	10.4.140.48/29	10.4.140.49 – 10.4.140.54	10.4.140.55
136	10.4.140.56/29	10.4.140.57 – 10.4.140.62	10.4.140.63
137	10.4.140.64/29	10.4.140.65 – 10.4.140.70	10.4.140.71
138	10.4.140.72/29	10.4.140.73 – 10.4.140.78	10.4.140.79
139	10.4.140.80/29	10.4.140.81 – 10.4.140.86	10.4.140.87
140	10.4.140.88/29	10.4.140.89 – 10.4.140.94	10.4.140.95
141	10.4.140.96/29	10.4.140.97 – 10.4.140.102	10.4.140.103
142	10.4.140.104/29	10.4.140.105 – 10.4.140.110	10.4.140.111
143	10.4.140.112/29	10.4.140.113 – 10.4.140.118	10.4.140.119
144	10.4.140.120/29	10.4.140.121 – 10.4.140.126	10.4.140.127
145	10.4.140.128/29	10.4.140.129 – 10.4.140.134	10.4.140.135
146	10.4.140.136/29	10.4.140.137 – 10.4.140.142	10.4.140.143
147	10.4.140.144/29	10.4.140.145 – 10.4.140.150	10.4.140.151
148	10.4.140.152/29	10.4.140.153 – 10.4.140.158	10.4.140.159
149	10.4.140.160/29	10.4.140.161 – 10.4.140.166	10.4.140.167
150	10.4.140.168/29	10.4.140.169 – 10.4.140.174	10.4.140.175
151	10.4.140.176/29	10.4.140.177 – 10.4.140.182	10.4.140.183
152	10.4.140.184/29	10.4.140.185 – 10.4.140.190	10.4.140.191
153	10.4.140.192/29	10.4.140.193 – 10.4.140.198	10.4.140.199
154	10.4.140.200/29	10.4.140.201 – 10.4.140.206	10.4.140.207
155	10.4.140.208/29	10.4.140.209 – 10.4.140.214	10.4.140.215
156	10.4.140.216/29	10.4.140.217 – 10.4.140.222	10.4.140.223
157	10.4.140.224/29	10.4.140.225 – 10.4.140.230	10.4.140.231
158	10.4.140.232/29	10.4.140.233 – 10.4.140.238	10.4.140.239
159	10.4.140.240/29	10.4.140.241 – 10.4.140.246	10.4.140.247
160	10.4.140.248/29	10.4.140.249 – 10.4.140.254	10.4.140.255
161	10.4.141.0/29	10.4.141.1 – 10.4.141.6	10.4.141.7
162	10.4.141.8/29	10.4.141.9 – 10.4.141.14	10.4.141.15
163	10.4.141.16/29	10.4.141.17 – 10.4.141.22	10.4.141.23
164	10.4.141.24/29	10.4.141.25 – 10.4.141.30	10.4.141.31
165	10.4.141.32/29	10.4.141.33 – 10.4.141.38	10.4.141.39
166	10.4.141.40/29	10.4.141.41 – 10.4.141.46	10.4.141.47
167	10.4.141.48/29	10.4.141.49 – 10.4.141.54	10.4.141.55
168	10.4.141.56/29	10.4.141.57 – 10.4.141.62	10.4.141.63
169	10.4.141.64/29	10.4.141.65 – 10.4.141.70	10.4.141.71
170	10.4.141.72/29	10.4.141.73 – 10.4.141.78	10.4.141.79
171	10.4.141.80/29	10.4.141.81 – 10.4.141.86	10.4.141.87
172	10.4.141.88/29	10.4.141.89 – 10.4.141.94	10.4.141.95
173	10.4.141.96/29	10.4.141.97 – 10.4.141.102	10.4.141.103
174	10.4.141.104/29	10.4.141.105 – 10.4.141.110	10.4.141.111
175	10.4.141.112/29	10.4.141.113 – 10.4.141.118	10.4.141.119
176	10.4.141.120/29	10.4.141.121 – 10.4.141.126	10.4.141.127
177	10.4.141.128/29	10.4.141.129 – 10.4.141.134	10.4.141.135
178	10.4.141.136/29	10.4.141.137 – 10.4.141.142	10.4.141.143
179	10.4.141.144/29	10.4.141.145 – 10.4.141.150	10.4.141.151
180	10.4.141.152/29	10.4.141.153 – 10.4.141.158	10.4.141.159
181	10.4.141.160/29	10.4.141.161 – 10.4.141.166	10.4.141.167
182	10.4.141.168/29	10.4.141.169 – 10.4.141.174	10.4.141.175
183	10.4.141.176/29	10.4.141.177 – 10.4.141.182	10.4.141.183
184	10.4.141.184/29	10.4.141.185 – 10.4.141.190	10.4.141.191
185	10.4.141.192/29	10.4.141.193 – 10.4.141.198	10.4.141.199
186	10.4.141.200/29	10.4.141.201 – 10.4.141.206	10.4.141.207
187	10.4.141.208/29	10.4.141.209 – 10.4.141.214	10.4.141.215
188	10.4.141.216/29	10.4.141.217 – 10.4.141.222	10.4.141.223
189	10.4.141.224/29	10.4.141.225 – 10.4.141.230	10.4.141.231
190	10.4.141.232/29	10.4.141.233 – 10.4.141.238	10.4.141.239
191	10.4.141.240/29	10.4.141.241 – 10.4.141.246	10.4.141.247
192	10.4.141.248/29	10.4.141.249 – 10.4.141.254	10.4.141.255
193	10.4.142.0/29	10.4.142.1 – 10.4.142.6	10.4.142.7
194	10.4.142.8/29	10.4.142.9 – 10.4.142.14	10.4.142.15
195	10.4.142.16/29	10.4.142.17 – 10.4.142.22	10.4.142.23
196	10.4.142.24/29	10.4.142.25 – 10.4.142.30	10.4.142.31
197	10.4.142.32/29	10.4.142.33 – 10.4.142.38	10.4.142.39
198	10.4.142.40/29	10.4.142.41 – 10.4.142.46	10.4.142.47
199	10.4.142.48/29	10.4.142.49 – 10.4.142.54	10.4.142.55
200	10.4.142.56/29	10.4.142.57 – 10.4.142.62	10.4.142.63
201	10.4.142.64/29	10.4.142.65 – 10.4.142.70	10.4.142.71
202	10.4.142.72/29	10.4.142.73 – 10.4.142.78	10.4.142.79
203	10.4.142.80/29	10.4.142.81 – 10.4.142.86	10.4.142.87
204	10.4.142.88/29	10.4.142.89 – 10.4.142.94	10.4.142.95
205	10.4.142.96/29	10.4.142.97 – 10.4.142.102	10.4.142.103
206	10.4.142.104/29	10.4.142.105 – 10.4.142.110	10.4.142.111
207	10.4.142.112/29	10.4.142.113 – 10.4.142.118	10.4.142.119
208	10.4.142.120/29	10.4.142.121 – 10.4.142.126	10.4.142.127
209	10.4.142.128/29	10.4.142.129 – 10.4.142.134	10.4.142.135
210	10.4.142.136/29	10.4.142.137 – 10.4.142.142	10.4.142.143
211	10.4.142.144/29	10.4.142.145 – 10.4.142.150	10.4.142.151
212	10.4.142.152/29	10.4.142.153 – 10.4.142.158	10.4.142.159
213	10.4.142.160/29	10.4.142.161 – 10.4.142.166	10.4.142.167
214	10.4.142.168/29	10.4.142.169 – 10.4.142.174	10.4.142.175
215	10.4.142.176/29	10.4.142.177 – 10.4.142.182	10.4.142.183
216	10.4.142.184/29	10.4.142.185 – 10.4.142.190	10.4.142.191
217	10.4.142.192/29	10.4.142.193 – 10.4.142.198	10.4.142.199
218	10.4.142.200/29	10.4.142.201 – 10.4.142.206	10.4.142.207
219	10.4.142.208/29	10.4.142.209 – 10.4.142.214	10.4.142.215
220	10.4.142.216/29	10.4.142.217 – 10.4.142.222	10.4.142.223
221	10.4.142.224/29	10.4.142.225 – 10.4.142.230	10.4.142.231
222	10.4.142.232/29	10.4.142.233 – 10.4.142.238	10.4.142.239
223	10.4.142.240/29	10.4.142.241 – 10.4.142.246	10.4.142.247
224	10.4.142.248/29	10.4.142.249 – 10.4.142.254	10.4.142.255
225	10.4.143.0/29	10.4.143.1 – 10.4.143.6	10.4.143.7
226	10.4.143.8/29	10.4.143.9 – 10.4.143.14	10.4.143.15
227	10.4.143.16/29	10.4.143.17 – 10.4.143.22	10.4.143.23
228	10.4.143.24/29	10.4.143.25 – 10.4.143.30	10.4.143.31
229	10.4.143.32/29	10.4.143.33 – 10.4.143.38	10.4.143.39
230	10.4.143.40/29	10.4.143.41 – 10.4.143.46	10.4.143.47
231	10.4.143.48/29	10.4.143.49 – 10.4.143.54	10.4.143.55
232	10.4.143.56/29	10.4.143.57 – 10.4.143.62	10.4.143.63
233	10.4.143.64/29	10.4.143.65 – 10.4.143.70	10.4.143.71
234	10.4.143.72/29	10.4.143.73 – 10.4.143.78	10.4.143.79
235	10.4.143.80/29	10.4.143.81 – 10.4.143.86	10.4.143.87
236	10.4.143.88/29	10.4.143.89 – 10.4.143.94	10.4.143.95
237	10.4.143.96/29	10.4.143.97 – 10.4.143.102	10.4.143.103
238	10.4.143.104/29	10.4.143.105 – 10.4.143.110	10.4.143.111
239	10.4.143.112/29	10.4.143.113 – 10.4.143.118	10.4.143.119
240	10.4.143.120/29	10.4.143.121 – 10.4.143.126	10.4.143.127
241	10.4.143.128/29	10.4.143.129 – 10.4.143.134	10.4.143.135
242	10.4.143.136/29	10.4.143.137 – 10.4.143.142	10.4.143.143
243	10.4.143.144/29	10.4.143.145 – 10.4.143.150	10.4.143.151
244	10.4.143.152/29	10.4.143.153 – 10.4.143.158	10.4.143.159
245	10.4.143.160/29	10.4.143.161 – 10.4.143.166	10.4.143.167
246	10.4.143.168/29	10.4.143.169 – 10.4.143.174	10.4.143.175
247	10.4.143.176/29	10.4.143.177 – 10.4.143.182	10.4.143.183
248	10.4.143.184/29	10.4.143.185 – 10.4.143.190	10.4.143.191
249	10.4.143.192/29	10.4.143.193 – 10.4.143.198	10.4.143.199
250	10.4.143.200/29	10.4.143.201 – 10.4.143.206	10.4.143.207
251	10.4.143.208/29	10.4.143.209 – 10.4.143.214	10.4.143.215
252	10.4.143.216/29	10.4.143.217 – 10.4.143.222	10.4.143.223
253	10.4.143.224/29	10.4.143.225 – 10.4.143.230	10.4.143.231
254	10.4.143.232/29	10.4.143.233 – 10.4.143.238	10.4.143.239
255	10.4.143.240/29	10.4.143.241 – 10.4.143.246	10.4.143.247
256	10.4.143.248/29	10.4.143.249 – 10.4.143.254	10.4.143.255

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 →