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)10.4.40.0/21

network10.4.40.0/21

broadcast10.4.47.255

first host10.4.40.1

last host10.4.47.254

subnet mask255.255.248.0

wildcard0.0.7.255

addresses2,048

usable hosts2,046

classA

ipcalc 10.4.40.0/21

address00001010.00000100.00101000.00000000

subnet mask11111111.11111111.11111000.00000000

network00001010.00000100.00101000.00000000

broadcast00001010.00000100.00101111.11111111

green = network part, grey = host part

hex0x0a042800

decimal168044544

reverse dns0.40.4.10.in-addr.arpa

ipv4-mapped::ffff:a04:2800

/21 split into /29 · 256 subnets

close ×

#	network	host range	broadcast
1	10.4.40.0/29	10.4.40.1 – 10.4.40.6	10.4.40.7
2	10.4.40.8/29	10.4.40.9 – 10.4.40.14	10.4.40.15
3	10.4.40.16/29	10.4.40.17 – 10.4.40.22	10.4.40.23
4	10.4.40.24/29	10.4.40.25 – 10.4.40.30	10.4.40.31
5	10.4.40.32/29	10.4.40.33 – 10.4.40.38	10.4.40.39
6	10.4.40.40/29	10.4.40.41 – 10.4.40.46	10.4.40.47
7	10.4.40.48/29	10.4.40.49 – 10.4.40.54	10.4.40.55
8	10.4.40.56/29	10.4.40.57 – 10.4.40.62	10.4.40.63
9	10.4.40.64/29	10.4.40.65 – 10.4.40.70	10.4.40.71
10	10.4.40.72/29	10.4.40.73 – 10.4.40.78	10.4.40.79
11	10.4.40.80/29	10.4.40.81 – 10.4.40.86	10.4.40.87
12	10.4.40.88/29	10.4.40.89 – 10.4.40.94	10.4.40.95
13	10.4.40.96/29	10.4.40.97 – 10.4.40.102	10.4.40.103
14	10.4.40.104/29	10.4.40.105 – 10.4.40.110	10.4.40.111
15	10.4.40.112/29	10.4.40.113 – 10.4.40.118	10.4.40.119
16	10.4.40.120/29	10.4.40.121 – 10.4.40.126	10.4.40.127
17	10.4.40.128/29	10.4.40.129 – 10.4.40.134	10.4.40.135
18	10.4.40.136/29	10.4.40.137 – 10.4.40.142	10.4.40.143
19	10.4.40.144/29	10.4.40.145 – 10.4.40.150	10.4.40.151
20	10.4.40.152/29	10.4.40.153 – 10.4.40.158	10.4.40.159
21	10.4.40.160/29	10.4.40.161 – 10.4.40.166	10.4.40.167
22	10.4.40.168/29	10.4.40.169 – 10.4.40.174	10.4.40.175
23	10.4.40.176/29	10.4.40.177 – 10.4.40.182	10.4.40.183
24	10.4.40.184/29	10.4.40.185 – 10.4.40.190	10.4.40.191
25	10.4.40.192/29	10.4.40.193 – 10.4.40.198	10.4.40.199
26	10.4.40.200/29	10.4.40.201 – 10.4.40.206	10.4.40.207
27	10.4.40.208/29	10.4.40.209 – 10.4.40.214	10.4.40.215
28	10.4.40.216/29	10.4.40.217 – 10.4.40.222	10.4.40.223
29	10.4.40.224/29	10.4.40.225 – 10.4.40.230	10.4.40.231
30	10.4.40.232/29	10.4.40.233 – 10.4.40.238	10.4.40.239
31	10.4.40.240/29	10.4.40.241 – 10.4.40.246	10.4.40.247
32	10.4.40.248/29	10.4.40.249 – 10.4.40.254	10.4.40.255
33	10.4.41.0/29	10.4.41.1 – 10.4.41.6	10.4.41.7
34	10.4.41.8/29	10.4.41.9 – 10.4.41.14	10.4.41.15
35	10.4.41.16/29	10.4.41.17 – 10.4.41.22	10.4.41.23
36	10.4.41.24/29	10.4.41.25 – 10.4.41.30	10.4.41.31
37	10.4.41.32/29	10.4.41.33 – 10.4.41.38	10.4.41.39
38	10.4.41.40/29	10.4.41.41 – 10.4.41.46	10.4.41.47
39	10.4.41.48/29	10.4.41.49 – 10.4.41.54	10.4.41.55
40	10.4.41.56/29	10.4.41.57 – 10.4.41.62	10.4.41.63
41	10.4.41.64/29	10.4.41.65 – 10.4.41.70	10.4.41.71
42	10.4.41.72/29	10.4.41.73 – 10.4.41.78	10.4.41.79
43	10.4.41.80/29	10.4.41.81 – 10.4.41.86	10.4.41.87
44	10.4.41.88/29	10.4.41.89 – 10.4.41.94	10.4.41.95
45	10.4.41.96/29	10.4.41.97 – 10.4.41.102	10.4.41.103
46	10.4.41.104/29	10.4.41.105 – 10.4.41.110	10.4.41.111
47	10.4.41.112/29	10.4.41.113 – 10.4.41.118	10.4.41.119
48	10.4.41.120/29	10.4.41.121 – 10.4.41.126	10.4.41.127
49	10.4.41.128/29	10.4.41.129 – 10.4.41.134	10.4.41.135
50	10.4.41.136/29	10.4.41.137 – 10.4.41.142	10.4.41.143
51	10.4.41.144/29	10.4.41.145 – 10.4.41.150	10.4.41.151
52	10.4.41.152/29	10.4.41.153 – 10.4.41.158	10.4.41.159
53	10.4.41.160/29	10.4.41.161 – 10.4.41.166	10.4.41.167
54	10.4.41.168/29	10.4.41.169 – 10.4.41.174	10.4.41.175
55	10.4.41.176/29	10.4.41.177 – 10.4.41.182	10.4.41.183
56	10.4.41.184/29	10.4.41.185 – 10.4.41.190	10.4.41.191
57	10.4.41.192/29	10.4.41.193 – 10.4.41.198	10.4.41.199
58	10.4.41.200/29	10.4.41.201 – 10.4.41.206	10.4.41.207
59	10.4.41.208/29	10.4.41.209 – 10.4.41.214	10.4.41.215
60	10.4.41.216/29	10.4.41.217 – 10.4.41.222	10.4.41.223
61	10.4.41.224/29	10.4.41.225 – 10.4.41.230	10.4.41.231
62	10.4.41.232/29	10.4.41.233 – 10.4.41.238	10.4.41.239
63	10.4.41.240/29	10.4.41.241 – 10.4.41.246	10.4.41.247
64	10.4.41.248/29	10.4.41.249 – 10.4.41.254	10.4.41.255
65	10.4.42.0/29	10.4.42.1 – 10.4.42.6	10.4.42.7
66	10.4.42.8/29	10.4.42.9 – 10.4.42.14	10.4.42.15
67	10.4.42.16/29	10.4.42.17 – 10.4.42.22	10.4.42.23
68	10.4.42.24/29	10.4.42.25 – 10.4.42.30	10.4.42.31
69	10.4.42.32/29	10.4.42.33 – 10.4.42.38	10.4.42.39
70	10.4.42.40/29	10.4.42.41 – 10.4.42.46	10.4.42.47
71	10.4.42.48/29	10.4.42.49 – 10.4.42.54	10.4.42.55
72	10.4.42.56/29	10.4.42.57 – 10.4.42.62	10.4.42.63
73	10.4.42.64/29	10.4.42.65 – 10.4.42.70	10.4.42.71
74	10.4.42.72/29	10.4.42.73 – 10.4.42.78	10.4.42.79
75	10.4.42.80/29	10.4.42.81 – 10.4.42.86	10.4.42.87
76	10.4.42.88/29	10.4.42.89 – 10.4.42.94	10.4.42.95
77	10.4.42.96/29	10.4.42.97 – 10.4.42.102	10.4.42.103
78	10.4.42.104/29	10.4.42.105 – 10.4.42.110	10.4.42.111
79	10.4.42.112/29	10.4.42.113 – 10.4.42.118	10.4.42.119
80	10.4.42.120/29	10.4.42.121 – 10.4.42.126	10.4.42.127
81	10.4.42.128/29	10.4.42.129 – 10.4.42.134	10.4.42.135
82	10.4.42.136/29	10.4.42.137 – 10.4.42.142	10.4.42.143
83	10.4.42.144/29	10.4.42.145 – 10.4.42.150	10.4.42.151
84	10.4.42.152/29	10.4.42.153 – 10.4.42.158	10.4.42.159
85	10.4.42.160/29	10.4.42.161 – 10.4.42.166	10.4.42.167
86	10.4.42.168/29	10.4.42.169 – 10.4.42.174	10.4.42.175
87	10.4.42.176/29	10.4.42.177 – 10.4.42.182	10.4.42.183
88	10.4.42.184/29	10.4.42.185 – 10.4.42.190	10.4.42.191
89	10.4.42.192/29	10.4.42.193 – 10.4.42.198	10.4.42.199
90	10.4.42.200/29	10.4.42.201 – 10.4.42.206	10.4.42.207
91	10.4.42.208/29	10.4.42.209 – 10.4.42.214	10.4.42.215
92	10.4.42.216/29	10.4.42.217 – 10.4.42.222	10.4.42.223
93	10.4.42.224/29	10.4.42.225 – 10.4.42.230	10.4.42.231
94	10.4.42.232/29	10.4.42.233 – 10.4.42.238	10.4.42.239
95	10.4.42.240/29	10.4.42.241 – 10.4.42.246	10.4.42.247
96	10.4.42.248/29	10.4.42.249 – 10.4.42.254	10.4.42.255
97	10.4.43.0/29	10.4.43.1 – 10.4.43.6	10.4.43.7
98	10.4.43.8/29	10.4.43.9 – 10.4.43.14	10.4.43.15
99	10.4.43.16/29	10.4.43.17 – 10.4.43.22	10.4.43.23
100	10.4.43.24/29	10.4.43.25 – 10.4.43.30	10.4.43.31
101	10.4.43.32/29	10.4.43.33 – 10.4.43.38	10.4.43.39
102	10.4.43.40/29	10.4.43.41 – 10.4.43.46	10.4.43.47
103	10.4.43.48/29	10.4.43.49 – 10.4.43.54	10.4.43.55
104	10.4.43.56/29	10.4.43.57 – 10.4.43.62	10.4.43.63
105	10.4.43.64/29	10.4.43.65 – 10.4.43.70	10.4.43.71
106	10.4.43.72/29	10.4.43.73 – 10.4.43.78	10.4.43.79
107	10.4.43.80/29	10.4.43.81 – 10.4.43.86	10.4.43.87
108	10.4.43.88/29	10.4.43.89 – 10.4.43.94	10.4.43.95
109	10.4.43.96/29	10.4.43.97 – 10.4.43.102	10.4.43.103
110	10.4.43.104/29	10.4.43.105 – 10.4.43.110	10.4.43.111
111	10.4.43.112/29	10.4.43.113 – 10.4.43.118	10.4.43.119
112	10.4.43.120/29	10.4.43.121 – 10.4.43.126	10.4.43.127
113	10.4.43.128/29	10.4.43.129 – 10.4.43.134	10.4.43.135
114	10.4.43.136/29	10.4.43.137 – 10.4.43.142	10.4.43.143
115	10.4.43.144/29	10.4.43.145 – 10.4.43.150	10.4.43.151
116	10.4.43.152/29	10.4.43.153 – 10.4.43.158	10.4.43.159
117	10.4.43.160/29	10.4.43.161 – 10.4.43.166	10.4.43.167
118	10.4.43.168/29	10.4.43.169 – 10.4.43.174	10.4.43.175
119	10.4.43.176/29	10.4.43.177 – 10.4.43.182	10.4.43.183
120	10.4.43.184/29	10.4.43.185 – 10.4.43.190	10.4.43.191
121	10.4.43.192/29	10.4.43.193 – 10.4.43.198	10.4.43.199
122	10.4.43.200/29	10.4.43.201 – 10.4.43.206	10.4.43.207
123	10.4.43.208/29	10.4.43.209 – 10.4.43.214	10.4.43.215
124	10.4.43.216/29	10.4.43.217 – 10.4.43.222	10.4.43.223
125	10.4.43.224/29	10.4.43.225 – 10.4.43.230	10.4.43.231
126	10.4.43.232/29	10.4.43.233 – 10.4.43.238	10.4.43.239
127	10.4.43.240/29	10.4.43.241 – 10.4.43.246	10.4.43.247
128	10.4.43.248/29	10.4.43.249 – 10.4.43.254	10.4.43.255
129	10.4.44.0/29	10.4.44.1 – 10.4.44.6	10.4.44.7
130	10.4.44.8/29	10.4.44.9 – 10.4.44.14	10.4.44.15
131	10.4.44.16/29	10.4.44.17 – 10.4.44.22	10.4.44.23
132	10.4.44.24/29	10.4.44.25 – 10.4.44.30	10.4.44.31
133	10.4.44.32/29	10.4.44.33 – 10.4.44.38	10.4.44.39
134	10.4.44.40/29	10.4.44.41 – 10.4.44.46	10.4.44.47
135	10.4.44.48/29	10.4.44.49 – 10.4.44.54	10.4.44.55
136	10.4.44.56/29	10.4.44.57 – 10.4.44.62	10.4.44.63
137	10.4.44.64/29	10.4.44.65 – 10.4.44.70	10.4.44.71
138	10.4.44.72/29	10.4.44.73 – 10.4.44.78	10.4.44.79
139	10.4.44.80/29	10.4.44.81 – 10.4.44.86	10.4.44.87
140	10.4.44.88/29	10.4.44.89 – 10.4.44.94	10.4.44.95
141	10.4.44.96/29	10.4.44.97 – 10.4.44.102	10.4.44.103
142	10.4.44.104/29	10.4.44.105 – 10.4.44.110	10.4.44.111
143	10.4.44.112/29	10.4.44.113 – 10.4.44.118	10.4.44.119
144	10.4.44.120/29	10.4.44.121 – 10.4.44.126	10.4.44.127
145	10.4.44.128/29	10.4.44.129 – 10.4.44.134	10.4.44.135
146	10.4.44.136/29	10.4.44.137 – 10.4.44.142	10.4.44.143
147	10.4.44.144/29	10.4.44.145 – 10.4.44.150	10.4.44.151
148	10.4.44.152/29	10.4.44.153 – 10.4.44.158	10.4.44.159
149	10.4.44.160/29	10.4.44.161 – 10.4.44.166	10.4.44.167
150	10.4.44.168/29	10.4.44.169 – 10.4.44.174	10.4.44.175
151	10.4.44.176/29	10.4.44.177 – 10.4.44.182	10.4.44.183
152	10.4.44.184/29	10.4.44.185 – 10.4.44.190	10.4.44.191
153	10.4.44.192/29	10.4.44.193 – 10.4.44.198	10.4.44.199
154	10.4.44.200/29	10.4.44.201 – 10.4.44.206	10.4.44.207
155	10.4.44.208/29	10.4.44.209 – 10.4.44.214	10.4.44.215
156	10.4.44.216/29	10.4.44.217 – 10.4.44.222	10.4.44.223
157	10.4.44.224/29	10.4.44.225 – 10.4.44.230	10.4.44.231
158	10.4.44.232/29	10.4.44.233 – 10.4.44.238	10.4.44.239
159	10.4.44.240/29	10.4.44.241 – 10.4.44.246	10.4.44.247
160	10.4.44.248/29	10.4.44.249 – 10.4.44.254	10.4.44.255
161	10.4.45.0/29	10.4.45.1 – 10.4.45.6	10.4.45.7
162	10.4.45.8/29	10.4.45.9 – 10.4.45.14	10.4.45.15
163	10.4.45.16/29	10.4.45.17 – 10.4.45.22	10.4.45.23
164	10.4.45.24/29	10.4.45.25 – 10.4.45.30	10.4.45.31
165	10.4.45.32/29	10.4.45.33 – 10.4.45.38	10.4.45.39
166	10.4.45.40/29	10.4.45.41 – 10.4.45.46	10.4.45.47
167	10.4.45.48/29	10.4.45.49 – 10.4.45.54	10.4.45.55
168	10.4.45.56/29	10.4.45.57 – 10.4.45.62	10.4.45.63
169	10.4.45.64/29	10.4.45.65 – 10.4.45.70	10.4.45.71
170	10.4.45.72/29	10.4.45.73 – 10.4.45.78	10.4.45.79
171	10.4.45.80/29	10.4.45.81 – 10.4.45.86	10.4.45.87
172	10.4.45.88/29	10.4.45.89 – 10.4.45.94	10.4.45.95
173	10.4.45.96/29	10.4.45.97 – 10.4.45.102	10.4.45.103
174	10.4.45.104/29	10.4.45.105 – 10.4.45.110	10.4.45.111
175	10.4.45.112/29	10.4.45.113 – 10.4.45.118	10.4.45.119
176	10.4.45.120/29	10.4.45.121 – 10.4.45.126	10.4.45.127
177	10.4.45.128/29	10.4.45.129 – 10.4.45.134	10.4.45.135
178	10.4.45.136/29	10.4.45.137 – 10.4.45.142	10.4.45.143
179	10.4.45.144/29	10.4.45.145 – 10.4.45.150	10.4.45.151
180	10.4.45.152/29	10.4.45.153 – 10.4.45.158	10.4.45.159
181	10.4.45.160/29	10.4.45.161 – 10.4.45.166	10.4.45.167
182	10.4.45.168/29	10.4.45.169 – 10.4.45.174	10.4.45.175
183	10.4.45.176/29	10.4.45.177 – 10.4.45.182	10.4.45.183
184	10.4.45.184/29	10.4.45.185 – 10.4.45.190	10.4.45.191
185	10.4.45.192/29	10.4.45.193 – 10.4.45.198	10.4.45.199
186	10.4.45.200/29	10.4.45.201 – 10.4.45.206	10.4.45.207
187	10.4.45.208/29	10.4.45.209 – 10.4.45.214	10.4.45.215
188	10.4.45.216/29	10.4.45.217 – 10.4.45.222	10.4.45.223
189	10.4.45.224/29	10.4.45.225 – 10.4.45.230	10.4.45.231
190	10.4.45.232/29	10.4.45.233 – 10.4.45.238	10.4.45.239
191	10.4.45.240/29	10.4.45.241 – 10.4.45.246	10.4.45.247
192	10.4.45.248/29	10.4.45.249 – 10.4.45.254	10.4.45.255
193	10.4.46.0/29	10.4.46.1 – 10.4.46.6	10.4.46.7
194	10.4.46.8/29	10.4.46.9 – 10.4.46.14	10.4.46.15
195	10.4.46.16/29	10.4.46.17 – 10.4.46.22	10.4.46.23
196	10.4.46.24/29	10.4.46.25 – 10.4.46.30	10.4.46.31
197	10.4.46.32/29	10.4.46.33 – 10.4.46.38	10.4.46.39
198	10.4.46.40/29	10.4.46.41 – 10.4.46.46	10.4.46.47
199	10.4.46.48/29	10.4.46.49 – 10.4.46.54	10.4.46.55
200	10.4.46.56/29	10.4.46.57 – 10.4.46.62	10.4.46.63
201	10.4.46.64/29	10.4.46.65 – 10.4.46.70	10.4.46.71
202	10.4.46.72/29	10.4.46.73 – 10.4.46.78	10.4.46.79
203	10.4.46.80/29	10.4.46.81 – 10.4.46.86	10.4.46.87
204	10.4.46.88/29	10.4.46.89 – 10.4.46.94	10.4.46.95
205	10.4.46.96/29	10.4.46.97 – 10.4.46.102	10.4.46.103
206	10.4.46.104/29	10.4.46.105 – 10.4.46.110	10.4.46.111
207	10.4.46.112/29	10.4.46.113 – 10.4.46.118	10.4.46.119
208	10.4.46.120/29	10.4.46.121 – 10.4.46.126	10.4.46.127
209	10.4.46.128/29	10.4.46.129 – 10.4.46.134	10.4.46.135
210	10.4.46.136/29	10.4.46.137 – 10.4.46.142	10.4.46.143
211	10.4.46.144/29	10.4.46.145 – 10.4.46.150	10.4.46.151
212	10.4.46.152/29	10.4.46.153 – 10.4.46.158	10.4.46.159
213	10.4.46.160/29	10.4.46.161 – 10.4.46.166	10.4.46.167
214	10.4.46.168/29	10.4.46.169 – 10.4.46.174	10.4.46.175
215	10.4.46.176/29	10.4.46.177 – 10.4.46.182	10.4.46.183
216	10.4.46.184/29	10.4.46.185 – 10.4.46.190	10.4.46.191
217	10.4.46.192/29	10.4.46.193 – 10.4.46.198	10.4.46.199
218	10.4.46.200/29	10.4.46.201 – 10.4.46.206	10.4.46.207
219	10.4.46.208/29	10.4.46.209 – 10.4.46.214	10.4.46.215
220	10.4.46.216/29	10.4.46.217 – 10.4.46.222	10.4.46.223
221	10.4.46.224/29	10.4.46.225 – 10.4.46.230	10.4.46.231
222	10.4.46.232/29	10.4.46.233 – 10.4.46.238	10.4.46.239
223	10.4.46.240/29	10.4.46.241 – 10.4.46.246	10.4.46.247
224	10.4.46.248/29	10.4.46.249 – 10.4.46.254	10.4.46.255
225	10.4.47.0/29	10.4.47.1 – 10.4.47.6	10.4.47.7
226	10.4.47.8/29	10.4.47.9 – 10.4.47.14	10.4.47.15
227	10.4.47.16/29	10.4.47.17 – 10.4.47.22	10.4.47.23
228	10.4.47.24/29	10.4.47.25 – 10.4.47.30	10.4.47.31
229	10.4.47.32/29	10.4.47.33 – 10.4.47.38	10.4.47.39
230	10.4.47.40/29	10.4.47.41 – 10.4.47.46	10.4.47.47
231	10.4.47.48/29	10.4.47.49 – 10.4.47.54	10.4.47.55
232	10.4.47.56/29	10.4.47.57 – 10.4.47.62	10.4.47.63
233	10.4.47.64/29	10.4.47.65 – 10.4.47.70	10.4.47.71
234	10.4.47.72/29	10.4.47.73 – 10.4.47.78	10.4.47.79
235	10.4.47.80/29	10.4.47.81 – 10.4.47.86	10.4.47.87
236	10.4.47.88/29	10.4.47.89 – 10.4.47.94	10.4.47.95
237	10.4.47.96/29	10.4.47.97 – 10.4.47.102	10.4.47.103
238	10.4.47.104/29	10.4.47.105 – 10.4.47.110	10.4.47.111
239	10.4.47.112/29	10.4.47.113 – 10.4.47.118	10.4.47.119
240	10.4.47.120/29	10.4.47.121 – 10.4.47.126	10.4.47.127
241	10.4.47.128/29	10.4.47.129 – 10.4.47.134	10.4.47.135
242	10.4.47.136/29	10.4.47.137 – 10.4.47.142	10.4.47.143
243	10.4.47.144/29	10.4.47.145 – 10.4.47.150	10.4.47.151
244	10.4.47.152/29	10.4.47.153 – 10.4.47.158	10.4.47.159
245	10.4.47.160/29	10.4.47.161 – 10.4.47.166	10.4.47.167
246	10.4.47.168/29	10.4.47.169 – 10.4.47.174	10.4.47.175
247	10.4.47.176/29	10.4.47.177 – 10.4.47.182	10.4.47.183
248	10.4.47.184/29	10.4.47.185 – 10.4.47.190	10.4.47.191
249	10.4.47.192/29	10.4.47.193 – 10.4.47.198	10.4.47.199
250	10.4.47.200/29	10.4.47.201 – 10.4.47.206	10.4.47.207
251	10.4.47.208/29	10.4.47.209 – 10.4.47.214	10.4.47.215
252	10.4.47.216/29	10.4.47.217 – 10.4.47.222	10.4.47.223
253	10.4.47.224/29	10.4.47.225 – 10.4.47.230	10.4.47.231
254	10.4.47.232/29	10.4.47.233 – 10.4.47.238	10.4.47.239
255	10.4.47.240/29	10.4.47.241 – 10.4.47.246	10.4.47.247
256	10.4.47.248/29	10.4.47.249 – 10.4.47.254	10.4.47.255

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 →