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)10.5.248.0/21

network10.5.248.0/21

broadcast10.5.255.255

first host10.5.248.1

last host10.5.255.254

subnet mask255.255.248.0

wildcard0.0.7.255

addresses2,048

usable hosts2,046

classA

ipcalc 10.5.248.0/21

address00001010.00000101.11111000.00000000

subnet mask11111111.11111111.11111000.00000000

network00001010.00000101.11111000.00000000

broadcast00001010.00000101.11111111.11111111

green = network part, grey = host part

hex0x0a05f800

decimal168163328

reverse dns0.248.5.10.in-addr.arpa

ipv4-mapped::ffff:a05:f800

/21 split into /29 · 256 subnets

close ×

#	network	host range	broadcast
1	10.5.248.0/29	10.5.248.1 – 10.5.248.6	10.5.248.7
2	10.5.248.8/29	10.5.248.9 – 10.5.248.14	10.5.248.15
3	10.5.248.16/29	10.5.248.17 – 10.5.248.22	10.5.248.23
4	10.5.248.24/29	10.5.248.25 – 10.5.248.30	10.5.248.31
5	10.5.248.32/29	10.5.248.33 – 10.5.248.38	10.5.248.39
6	10.5.248.40/29	10.5.248.41 – 10.5.248.46	10.5.248.47
7	10.5.248.48/29	10.5.248.49 – 10.5.248.54	10.5.248.55
8	10.5.248.56/29	10.5.248.57 – 10.5.248.62	10.5.248.63
9	10.5.248.64/29	10.5.248.65 – 10.5.248.70	10.5.248.71
10	10.5.248.72/29	10.5.248.73 – 10.5.248.78	10.5.248.79
11	10.5.248.80/29	10.5.248.81 – 10.5.248.86	10.5.248.87
12	10.5.248.88/29	10.5.248.89 – 10.5.248.94	10.5.248.95
13	10.5.248.96/29	10.5.248.97 – 10.5.248.102	10.5.248.103
14	10.5.248.104/29	10.5.248.105 – 10.5.248.110	10.5.248.111
15	10.5.248.112/29	10.5.248.113 – 10.5.248.118	10.5.248.119
16	10.5.248.120/29	10.5.248.121 – 10.5.248.126	10.5.248.127
17	10.5.248.128/29	10.5.248.129 – 10.5.248.134	10.5.248.135
18	10.5.248.136/29	10.5.248.137 – 10.5.248.142	10.5.248.143
19	10.5.248.144/29	10.5.248.145 – 10.5.248.150	10.5.248.151
20	10.5.248.152/29	10.5.248.153 – 10.5.248.158	10.5.248.159
21	10.5.248.160/29	10.5.248.161 – 10.5.248.166	10.5.248.167
22	10.5.248.168/29	10.5.248.169 – 10.5.248.174	10.5.248.175
23	10.5.248.176/29	10.5.248.177 – 10.5.248.182	10.5.248.183
24	10.5.248.184/29	10.5.248.185 – 10.5.248.190	10.5.248.191
25	10.5.248.192/29	10.5.248.193 – 10.5.248.198	10.5.248.199
26	10.5.248.200/29	10.5.248.201 – 10.5.248.206	10.5.248.207
27	10.5.248.208/29	10.5.248.209 – 10.5.248.214	10.5.248.215
28	10.5.248.216/29	10.5.248.217 – 10.5.248.222	10.5.248.223
29	10.5.248.224/29	10.5.248.225 – 10.5.248.230	10.5.248.231
30	10.5.248.232/29	10.5.248.233 – 10.5.248.238	10.5.248.239
31	10.5.248.240/29	10.5.248.241 – 10.5.248.246	10.5.248.247
32	10.5.248.248/29	10.5.248.249 – 10.5.248.254	10.5.248.255
33	10.5.249.0/29	10.5.249.1 – 10.5.249.6	10.5.249.7
34	10.5.249.8/29	10.5.249.9 – 10.5.249.14	10.5.249.15
35	10.5.249.16/29	10.5.249.17 – 10.5.249.22	10.5.249.23
36	10.5.249.24/29	10.5.249.25 – 10.5.249.30	10.5.249.31
37	10.5.249.32/29	10.5.249.33 – 10.5.249.38	10.5.249.39
38	10.5.249.40/29	10.5.249.41 – 10.5.249.46	10.5.249.47
39	10.5.249.48/29	10.5.249.49 – 10.5.249.54	10.5.249.55
40	10.5.249.56/29	10.5.249.57 – 10.5.249.62	10.5.249.63
41	10.5.249.64/29	10.5.249.65 – 10.5.249.70	10.5.249.71
42	10.5.249.72/29	10.5.249.73 – 10.5.249.78	10.5.249.79
43	10.5.249.80/29	10.5.249.81 – 10.5.249.86	10.5.249.87
44	10.5.249.88/29	10.5.249.89 – 10.5.249.94	10.5.249.95
45	10.5.249.96/29	10.5.249.97 – 10.5.249.102	10.5.249.103
46	10.5.249.104/29	10.5.249.105 – 10.5.249.110	10.5.249.111
47	10.5.249.112/29	10.5.249.113 – 10.5.249.118	10.5.249.119
48	10.5.249.120/29	10.5.249.121 – 10.5.249.126	10.5.249.127
49	10.5.249.128/29	10.5.249.129 – 10.5.249.134	10.5.249.135
50	10.5.249.136/29	10.5.249.137 – 10.5.249.142	10.5.249.143
51	10.5.249.144/29	10.5.249.145 – 10.5.249.150	10.5.249.151
52	10.5.249.152/29	10.5.249.153 – 10.5.249.158	10.5.249.159
53	10.5.249.160/29	10.5.249.161 – 10.5.249.166	10.5.249.167
54	10.5.249.168/29	10.5.249.169 – 10.5.249.174	10.5.249.175
55	10.5.249.176/29	10.5.249.177 – 10.5.249.182	10.5.249.183
56	10.5.249.184/29	10.5.249.185 – 10.5.249.190	10.5.249.191
57	10.5.249.192/29	10.5.249.193 – 10.5.249.198	10.5.249.199
58	10.5.249.200/29	10.5.249.201 – 10.5.249.206	10.5.249.207
59	10.5.249.208/29	10.5.249.209 – 10.5.249.214	10.5.249.215
60	10.5.249.216/29	10.5.249.217 – 10.5.249.222	10.5.249.223
61	10.5.249.224/29	10.5.249.225 – 10.5.249.230	10.5.249.231
62	10.5.249.232/29	10.5.249.233 – 10.5.249.238	10.5.249.239
63	10.5.249.240/29	10.5.249.241 – 10.5.249.246	10.5.249.247
64	10.5.249.248/29	10.5.249.249 – 10.5.249.254	10.5.249.255
65	10.5.250.0/29	10.5.250.1 – 10.5.250.6	10.5.250.7
66	10.5.250.8/29	10.5.250.9 – 10.5.250.14	10.5.250.15
67	10.5.250.16/29	10.5.250.17 – 10.5.250.22	10.5.250.23
68	10.5.250.24/29	10.5.250.25 – 10.5.250.30	10.5.250.31
69	10.5.250.32/29	10.5.250.33 – 10.5.250.38	10.5.250.39
70	10.5.250.40/29	10.5.250.41 – 10.5.250.46	10.5.250.47
71	10.5.250.48/29	10.5.250.49 – 10.5.250.54	10.5.250.55
72	10.5.250.56/29	10.5.250.57 – 10.5.250.62	10.5.250.63
73	10.5.250.64/29	10.5.250.65 – 10.5.250.70	10.5.250.71
74	10.5.250.72/29	10.5.250.73 – 10.5.250.78	10.5.250.79
75	10.5.250.80/29	10.5.250.81 – 10.5.250.86	10.5.250.87
76	10.5.250.88/29	10.5.250.89 – 10.5.250.94	10.5.250.95
77	10.5.250.96/29	10.5.250.97 – 10.5.250.102	10.5.250.103
78	10.5.250.104/29	10.5.250.105 – 10.5.250.110	10.5.250.111
79	10.5.250.112/29	10.5.250.113 – 10.5.250.118	10.5.250.119
80	10.5.250.120/29	10.5.250.121 – 10.5.250.126	10.5.250.127
81	10.5.250.128/29	10.5.250.129 – 10.5.250.134	10.5.250.135
82	10.5.250.136/29	10.5.250.137 – 10.5.250.142	10.5.250.143
83	10.5.250.144/29	10.5.250.145 – 10.5.250.150	10.5.250.151
84	10.5.250.152/29	10.5.250.153 – 10.5.250.158	10.5.250.159
85	10.5.250.160/29	10.5.250.161 – 10.5.250.166	10.5.250.167
86	10.5.250.168/29	10.5.250.169 – 10.5.250.174	10.5.250.175
87	10.5.250.176/29	10.5.250.177 – 10.5.250.182	10.5.250.183
88	10.5.250.184/29	10.5.250.185 – 10.5.250.190	10.5.250.191
89	10.5.250.192/29	10.5.250.193 – 10.5.250.198	10.5.250.199
90	10.5.250.200/29	10.5.250.201 – 10.5.250.206	10.5.250.207
91	10.5.250.208/29	10.5.250.209 – 10.5.250.214	10.5.250.215
92	10.5.250.216/29	10.5.250.217 – 10.5.250.222	10.5.250.223
93	10.5.250.224/29	10.5.250.225 – 10.5.250.230	10.5.250.231
94	10.5.250.232/29	10.5.250.233 – 10.5.250.238	10.5.250.239
95	10.5.250.240/29	10.5.250.241 – 10.5.250.246	10.5.250.247
96	10.5.250.248/29	10.5.250.249 – 10.5.250.254	10.5.250.255
97	10.5.251.0/29	10.5.251.1 – 10.5.251.6	10.5.251.7
98	10.5.251.8/29	10.5.251.9 – 10.5.251.14	10.5.251.15
99	10.5.251.16/29	10.5.251.17 – 10.5.251.22	10.5.251.23
100	10.5.251.24/29	10.5.251.25 – 10.5.251.30	10.5.251.31
101	10.5.251.32/29	10.5.251.33 – 10.5.251.38	10.5.251.39
102	10.5.251.40/29	10.5.251.41 – 10.5.251.46	10.5.251.47
103	10.5.251.48/29	10.5.251.49 – 10.5.251.54	10.5.251.55
104	10.5.251.56/29	10.5.251.57 – 10.5.251.62	10.5.251.63
105	10.5.251.64/29	10.5.251.65 – 10.5.251.70	10.5.251.71
106	10.5.251.72/29	10.5.251.73 – 10.5.251.78	10.5.251.79
107	10.5.251.80/29	10.5.251.81 – 10.5.251.86	10.5.251.87
108	10.5.251.88/29	10.5.251.89 – 10.5.251.94	10.5.251.95
109	10.5.251.96/29	10.5.251.97 – 10.5.251.102	10.5.251.103
110	10.5.251.104/29	10.5.251.105 – 10.5.251.110	10.5.251.111
111	10.5.251.112/29	10.5.251.113 – 10.5.251.118	10.5.251.119
112	10.5.251.120/29	10.5.251.121 – 10.5.251.126	10.5.251.127
113	10.5.251.128/29	10.5.251.129 – 10.5.251.134	10.5.251.135
114	10.5.251.136/29	10.5.251.137 – 10.5.251.142	10.5.251.143
115	10.5.251.144/29	10.5.251.145 – 10.5.251.150	10.5.251.151
116	10.5.251.152/29	10.5.251.153 – 10.5.251.158	10.5.251.159
117	10.5.251.160/29	10.5.251.161 – 10.5.251.166	10.5.251.167
118	10.5.251.168/29	10.5.251.169 – 10.5.251.174	10.5.251.175
119	10.5.251.176/29	10.5.251.177 – 10.5.251.182	10.5.251.183
120	10.5.251.184/29	10.5.251.185 – 10.5.251.190	10.5.251.191
121	10.5.251.192/29	10.5.251.193 – 10.5.251.198	10.5.251.199
122	10.5.251.200/29	10.5.251.201 – 10.5.251.206	10.5.251.207
123	10.5.251.208/29	10.5.251.209 – 10.5.251.214	10.5.251.215
124	10.5.251.216/29	10.5.251.217 – 10.5.251.222	10.5.251.223
125	10.5.251.224/29	10.5.251.225 – 10.5.251.230	10.5.251.231
126	10.5.251.232/29	10.5.251.233 – 10.5.251.238	10.5.251.239
127	10.5.251.240/29	10.5.251.241 – 10.5.251.246	10.5.251.247
128	10.5.251.248/29	10.5.251.249 – 10.5.251.254	10.5.251.255
129	10.5.252.0/29	10.5.252.1 – 10.5.252.6	10.5.252.7
130	10.5.252.8/29	10.5.252.9 – 10.5.252.14	10.5.252.15
131	10.5.252.16/29	10.5.252.17 – 10.5.252.22	10.5.252.23
132	10.5.252.24/29	10.5.252.25 – 10.5.252.30	10.5.252.31
133	10.5.252.32/29	10.5.252.33 – 10.5.252.38	10.5.252.39
134	10.5.252.40/29	10.5.252.41 – 10.5.252.46	10.5.252.47
135	10.5.252.48/29	10.5.252.49 – 10.5.252.54	10.5.252.55
136	10.5.252.56/29	10.5.252.57 – 10.5.252.62	10.5.252.63
137	10.5.252.64/29	10.5.252.65 – 10.5.252.70	10.5.252.71
138	10.5.252.72/29	10.5.252.73 – 10.5.252.78	10.5.252.79
139	10.5.252.80/29	10.5.252.81 – 10.5.252.86	10.5.252.87
140	10.5.252.88/29	10.5.252.89 – 10.5.252.94	10.5.252.95
141	10.5.252.96/29	10.5.252.97 – 10.5.252.102	10.5.252.103
142	10.5.252.104/29	10.5.252.105 – 10.5.252.110	10.5.252.111
143	10.5.252.112/29	10.5.252.113 – 10.5.252.118	10.5.252.119
144	10.5.252.120/29	10.5.252.121 – 10.5.252.126	10.5.252.127
145	10.5.252.128/29	10.5.252.129 – 10.5.252.134	10.5.252.135
146	10.5.252.136/29	10.5.252.137 – 10.5.252.142	10.5.252.143
147	10.5.252.144/29	10.5.252.145 – 10.5.252.150	10.5.252.151
148	10.5.252.152/29	10.5.252.153 – 10.5.252.158	10.5.252.159
149	10.5.252.160/29	10.5.252.161 – 10.5.252.166	10.5.252.167
150	10.5.252.168/29	10.5.252.169 – 10.5.252.174	10.5.252.175
151	10.5.252.176/29	10.5.252.177 – 10.5.252.182	10.5.252.183
152	10.5.252.184/29	10.5.252.185 – 10.5.252.190	10.5.252.191
153	10.5.252.192/29	10.5.252.193 – 10.5.252.198	10.5.252.199
154	10.5.252.200/29	10.5.252.201 – 10.5.252.206	10.5.252.207
155	10.5.252.208/29	10.5.252.209 – 10.5.252.214	10.5.252.215
156	10.5.252.216/29	10.5.252.217 – 10.5.252.222	10.5.252.223
157	10.5.252.224/29	10.5.252.225 – 10.5.252.230	10.5.252.231
158	10.5.252.232/29	10.5.252.233 – 10.5.252.238	10.5.252.239
159	10.5.252.240/29	10.5.252.241 – 10.5.252.246	10.5.252.247
160	10.5.252.248/29	10.5.252.249 – 10.5.252.254	10.5.252.255
161	10.5.253.0/29	10.5.253.1 – 10.5.253.6	10.5.253.7
162	10.5.253.8/29	10.5.253.9 – 10.5.253.14	10.5.253.15
163	10.5.253.16/29	10.5.253.17 – 10.5.253.22	10.5.253.23
164	10.5.253.24/29	10.5.253.25 – 10.5.253.30	10.5.253.31
165	10.5.253.32/29	10.5.253.33 – 10.5.253.38	10.5.253.39
166	10.5.253.40/29	10.5.253.41 – 10.5.253.46	10.5.253.47
167	10.5.253.48/29	10.5.253.49 – 10.5.253.54	10.5.253.55
168	10.5.253.56/29	10.5.253.57 – 10.5.253.62	10.5.253.63
169	10.5.253.64/29	10.5.253.65 – 10.5.253.70	10.5.253.71
170	10.5.253.72/29	10.5.253.73 – 10.5.253.78	10.5.253.79
171	10.5.253.80/29	10.5.253.81 – 10.5.253.86	10.5.253.87
172	10.5.253.88/29	10.5.253.89 – 10.5.253.94	10.5.253.95
173	10.5.253.96/29	10.5.253.97 – 10.5.253.102	10.5.253.103
174	10.5.253.104/29	10.5.253.105 – 10.5.253.110	10.5.253.111
175	10.5.253.112/29	10.5.253.113 – 10.5.253.118	10.5.253.119
176	10.5.253.120/29	10.5.253.121 – 10.5.253.126	10.5.253.127
177	10.5.253.128/29	10.5.253.129 – 10.5.253.134	10.5.253.135
178	10.5.253.136/29	10.5.253.137 – 10.5.253.142	10.5.253.143
179	10.5.253.144/29	10.5.253.145 – 10.5.253.150	10.5.253.151
180	10.5.253.152/29	10.5.253.153 – 10.5.253.158	10.5.253.159
181	10.5.253.160/29	10.5.253.161 – 10.5.253.166	10.5.253.167
182	10.5.253.168/29	10.5.253.169 – 10.5.253.174	10.5.253.175
183	10.5.253.176/29	10.5.253.177 – 10.5.253.182	10.5.253.183
184	10.5.253.184/29	10.5.253.185 – 10.5.253.190	10.5.253.191
185	10.5.253.192/29	10.5.253.193 – 10.5.253.198	10.5.253.199
186	10.5.253.200/29	10.5.253.201 – 10.5.253.206	10.5.253.207
187	10.5.253.208/29	10.5.253.209 – 10.5.253.214	10.5.253.215
188	10.5.253.216/29	10.5.253.217 – 10.5.253.222	10.5.253.223
189	10.5.253.224/29	10.5.253.225 – 10.5.253.230	10.5.253.231
190	10.5.253.232/29	10.5.253.233 – 10.5.253.238	10.5.253.239
191	10.5.253.240/29	10.5.253.241 – 10.5.253.246	10.5.253.247
192	10.5.253.248/29	10.5.253.249 – 10.5.253.254	10.5.253.255
193	10.5.254.0/29	10.5.254.1 – 10.5.254.6	10.5.254.7
194	10.5.254.8/29	10.5.254.9 – 10.5.254.14	10.5.254.15
195	10.5.254.16/29	10.5.254.17 – 10.5.254.22	10.5.254.23
196	10.5.254.24/29	10.5.254.25 – 10.5.254.30	10.5.254.31
197	10.5.254.32/29	10.5.254.33 – 10.5.254.38	10.5.254.39
198	10.5.254.40/29	10.5.254.41 – 10.5.254.46	10.5.254.47
199	10.5.254.48/29	10.5.254.49 – 10.5.254.54	10.5.254.55
200	10.5.254.56/29	10.5.254.57 – 10.5.254.62	10.5.254.63
201	10.5.254.64/29	10.5.254.65 – 10.5.254.70	10.5.254.71
202	10.5.254.72/29	10.5.254.73 – 10.5.254.78	10.5.254.79
203	10.5.254.80/29	10.5.254.81 – 10.5.254.86	10.5.254.87
204	10.5.254.88/29	10.5.254.89 – 10.5.254.94	10.5.254.95
205	10.5.254.96/29	10.5.254.97 – 10.5.254.102	10.5.254.103
206	10.5.254.104/29	10.5.254.105 – 10.5.254.110	10.5.254.111
207	10.5.254.112/29	10.5.254.113 – 10.5.254.118	10.5.254.119
208	10.5.254.120/29	10.5.254.121 – 10.5.254.126	10.5.254.127
209	10.5.254.128/29	10.5.254.129 – 10.5.254.134	10.5.254.135
210	10.5.254.136/29	10.5.254.137 – 10.5.254.142	10.5.254.143
211	10.5.254.144/29	10.5.254.145 – 10.5.254.150	10.5.254.151
212	10.5.254.152/29	10.5.254.153 – 10.5.254.158	10.5.254.159
213	10.5.254.160/29	10.5.254.161 – 10.5.254.166	10.5.254.167
214	10.5.254.168/29	10.5.254.169 – 10.5.254.174	10.5.254.175
215	10.5.254.176/29	10.5.254.177 – 10.5.254.182	10.5.254.183
216	10.5.254.184/29	10.5.254.185 – 10.5.254.190	10.5.254.191
217	10.5.254.192/29	10.5.254.193 – 10.5.254.198	10.5.254.199
218	10.5.254.200/29	10.5.254.201 – 10.5.254.206	10.5.254.207
219	10.5.254.208/29	10.5.254.209 – 10.5.254.214	10.5.254.215
220	10.5.254.216/29	10.5.254.217 – 10.5.254.222	10.5.254.223
221	10.5.254.224/29	10.5.254.225 – 10.5.254.230	10.5.254.231
222	10.5.254.232/29	10.5.254.233 – 10.5.254.238	10.5.254.239
223	10.5.254.240/29	10.5.254.241 – 10.5.254.246	10.5.254.247
224	10.5.254.248/29	10.5.254.249 – 10.5.254.254	10.5.254.255
225	10.5.255.0/29	10.5.255.1 – 10.5.255.6	10.5.255.7
226	10.5.255.8/29	10.5.255.9 – 10.5.255.14	10.5.255.15
227	10.5.255.16/29	10.5.255.17 – 10.5.255.22	10.5.255.23
228	10.5.255.24/29	10.5.255.25 – 10.5.255.30	10.5.255.31
229	10.5.255.32/29	10.5.255.33 – 10.5.255.38	10.5.255.39
230	10.5.255.40/29	10.5.255.41 – 10.5.255.46	10.5.255.47
231	10.5.255.48/29	10.5.255.49 – 10.5.255.54	10.5.255.55
232	10.5.255.56/29	10.5.255.57 – 10.5.255.62	10.5.255.63
233	10.5.255.64/29	10.5.255.65 – 10.5.255.70	10.5.255.71
234	10.5.255.72/29	10.5.255.73 – 10.5.255.78	10.5.255.79
235	10.5.255.80/29	10.5.255.81 – 10.5.255.86	10.5.255.87
236	10.5.255.88/29	10.5.255.89 – 10.5.255.94	10.5.255.95
237	10.5.255.96/29	10.5.255.97 – 10.5.255.102	10.5.255.103
238	10.5.255.104/29	10.5.255.105 – 10.5.255.110	10.5.255.111
239	10.5.255.112/29	10.5.255.113 – 10.5.255.118	10.5.255.119
240	10.5.255.120/29	10.5.255.121 – 10.5.255.126	10.5.255.127
241	10.5.255.128/29	10.5.255.129 – 10.5.255.134	10.5.255.135
242	10.5.255.136/29	10.5.255.137 – 10.5.255.142	10.5.255.143
243	10.5.255.144/29	10.5.255.145 – 10.5.255.150	10.5.255.151
244	10.5.255.152/29	10.5.255.153 – 10.5.255.158	10.5.255.159
245	10.5.255.160/29	10.5.255.161 – 10.5.255.166	10.5.255.167
246	10.5.255.168/29	10.5.255.169 – 10.5.255.174	10.5.255.175
247	10.5.255.176/29	10.5.255.177 – 10.5.255.182	10.5.255.183
248	10.5.255.184/29	10.5.255.185 – 10.5.255.190	10.5.255.191
249	10.5.255.192/29	10.5.255.193 – 10.5.255.198	10.5.255.199
250	10.5.255.200/29	10.5.255.201 – 10.5.255.206	10.5.255.207
251	10.5.255.208/29	10.5.255.209 – 10.5.255.214	10.5.255.215
252	10.5.255.216/29	10.5.255.217 – 10.5.255.222	10.5.255.223
253	10.5.255.224/29	10.5.255.225 – 10.5.255.230	10.5.255.231
254	10.5.255.232/29	10.5.255.233 – 10.5.255.238	10.5.255.239
255	10.5.255.240/29	10.5.255.241 – 10.5.255.246	10.5.255.247
256	10.5.255.248/29	10.5.255.249 – 10.5.255.254	10.5.255.255

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 →