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)10.5.16.0/21

network10.5.16.0/21

broadcast10.5.23.255

first host10.5.16.1

last host10.5.23.254

subnet mask255.255.248.0

wildcard0.0.7.255

addresses2,048

usable hosts2,046

classA

ipcalc 10.5.16.0/21

address00001010.00000101.00010000.00000000

subnet mask11111111.11111111.11111000.00000000

network00001010.00000101.00010000.00000000

broadcast00001010.00000101.00010111.11111111

green = network part, grey = host part

hex0x0a051000

decimal168103936

reverse dns0.16.5.10.in-addr.arpa

ipv4-mapped::ffff:a05:1000

/21 split into /31 · 1,024 subnets

close ×

#	network	host range	broadcast
1	10.5.16.0/31	10.5.16.0 – 10.5.16.1	10.5.16.1
2	10.5.16.2/31	10.5.16.2 – 10.5.16.3	10.5.16.3
3	10.5.16.4/31	10.5.16.4 – 10.5.16.5	10.5.16.5
4	10.5.16.6/31	10.5.16.6 – 10.5.16.7	10.5.16.7
5	10.5.16.8/31	10.5.16.8 – 10.5.16.9	10.5.16.9
6	10.5.16.10/31	10.5.16.10 – 10.5.16.11	10.5.16.11
7	10.5.16.12/31	10.5.16.12 – 10.5.16.13	10.5.16.13
8	10.5.16.14/31	10.5.16.14 – 10.5.16.15	10.5.16.15
9	10.5.16.16/31	10.5.16.16 – 10.5.16.17	10.5.16.17
10	10.5.16.18/31	10.5.16.18 – 10.5.16.19	10.5.16.19
11	10.5.16.20/31	10.5.16.20 – 10.5.16.21	10.5.16.21
12	10.5.16.22/31	10.5.16.22 – 10.5.16.23	10.5.16.23
13	10.5.16.24/31	10.5.16.24 – 10.5.16.25	10.5.16.25
14	10.5.16.26/31	10.5.16.26 – 10.5.16.27	10.5.16.27
15	10.5.16.28/31	10.5.16.28 – 10.5.16.29	10.5.16.29
16	10.5.16.30/31	10.5.16.30 – 10.5.16.31	10.5.16.31
17	10.5.16.32/31	10.5.16.32 – 10.5.16.33	10.5.16.33
18	10.5.16.34/31	10.5.16.34 – 10.5.16.35	10.5.16.35
19	10.5.16.36/31	10.5.16.36 – 10.5.16.37	10.5.16.37
20	10.5.16.38/31	10.5.16.38 – 10.5.16.39	10.5.16.39
21	10.5.16.40/31	10.5.16.40 – 10.5.16.41	10.5.16.41
22	10.5.16.42/31	10.5.16.42 – 10.5.16.43	10.5.16.43
23	10.5.16.44/31	10.5.16.44 – 10.5.16.45	10.5.16.45
24	10.5.16.46/31	10.5.16.46 – 10.5.16.47	10.5.16.47
25	10.5.16.48/31	10.5.16.48 – 10.5.16.49	10.5.16.49
26	10.5.16.50/31	10.5.16.50 – 10.5.16.51	10.5.16.51
27	10.5.16.52/31	10.5.16.52 – 10.5.16.53	10.5.16.53
28	10.5.16.54/31	10.5.16.54 – 10.5.16.55	10.5.16.55
29	10.5.16.56/31	10.5.16.56 – 10.5.16.57	10.5.16.57
30	10.5.16.58/31	10.5.16.58 – 10.5.16.59	10.5.16.59
31	10.5.16.60/31	10.5.16.60 – 10.5.16.61	10.5.16.61
32	10.5.16.62/31	10.5.16.62 – 10.5.16.63	10.5.16.63
33	10.5.16.64/31	10.5.16.64 – 10.5.16.65	10.5.16.65
34	10.5.16.66/31	10.5.16.66 – 10.5.16.67	10.5.16.67
35	10.5.16.68/31	10.5.16.68 – 10.5.16.69	10.5.16.69
36	10.5.16.70/31	10.5.16.70 – 10.5.16.71	10.5.16.71
37	10.5.16.72/31	10.5.16.72 – 10.5.16.73	10.5.16.73
38	10.5.16.74/31	10.5.16.74 – 10.5.16.75	10.5.16.75
39	10.5.16.76/31	10.5.16.76 – 10.5.16.77	10.5.16.77
40	10.5.16.78/31	10.5.16.78 – 10.5.16.79	10.5.16.79
41	10.5.16.80/31	10.5.16.80 – 10.5.16.81	10.5.16.81
42	10.5.16.82/31	10.5.16.82 – 10.5.16.83	10.5.16.83
43	10.5.16.84/31	10.5.16.84 – 10.5.16.85	10.5.16.85
44	10.5.16.86/31	10.5.16.86 – 10.5.16.87	10.5.16.87
45	10.5.16.88/31	10.5.16.88 – 10.5.16.89	10.5.16.89
46	10.5.16.90/31	10.5.16.90 – 10.5.16.91	10.5.16.91
47	10.5.16.92/31	10.5.16.92 – 10.5.16.93	10.5.16.93
48	10.5.16.94/31	10.5.16.94 – 10.5.16.95	10.5.16.95
49	10.5.16.96/31	10.5.16.96 – 10.5.16.97	10.5.16.97
50	10.5.16.98/31	10.5.16.98 – 10.5.16.99	10.5.16.99
51	10.5.16.100/31	10.5.16.100 – 10.5.16.101	10.5.16.101
52	10.5.16.102/31	10.5.16.102 – 10.5.16.103	10.5.16.103
53	10.5.16.104/31	10.5.16.104 – 10.5.16.105	10.5.16.105
54	10.5.16.106/31	10.5.16.106 – 10.5.16.107	10.5.16.107
55	10.5.16.108/31	10.5.16.108 – 10.5.16.109	10.5.16.109
56	10.5.16.110/31	10.5.16.110 – 10.5.16.111	10.5.16.111
57	10.5.16.112/31	10.5.16.112 – 10.5.16.113	10.5.16.113
58	10.5.16.114/31	10.5.16.114 – 10.5.16.115	10.5.16.115
59	10.5.16.116/31	10.5.16.116 – 10.5.16.117	10.5.16.117
60	10.5.16.118/31	10.5.16.118 – 10.5.16.119	10.5.16.119
61	10.5.16.120/31	10.5.16.120 – 10.5.16.121	10.5.16.121
62	10.5.16.122/31	10.5.16.122 – 10.5.16.123	10.5.16.123
63	10.5.16.124/31	10.5.16.124 – 10.5.16.125	10.5.16.125
64	10.5.16.126/31	10.5.16.126 – 10.5.16.127	10.5.16.127
65	10.5.16.128/31	10.5.16.128 – 10.5.16.129	10.5.16.129
66	10.5.16.130/31	10.5.16.130 – 10.5.16.131	10.5.16.131
67	10.5.16.132/31	10.5.16.132 – 10.5.16.133	10.5.16.133
68	10.5.16.134/31	10.5.16.134 – 10.5.16.135	10.5.16.135
69	10.5.16.136/31	10.5.16.136 – 10.5.16.137	10.5.16.137
70	10.5.16.138/31	10.5.16.138 – 10.5.16.139	10.5.16.139
71	10.5.16.140/31	10.5.16.140 – 10.5.16.141	10.5.16.141
72	10.5.16.142/31	10.5.16.142 – 10.5.16.143	10.5.16.143
73	10.5.16.144/31	10.5.16.144 – 10.5.16.145	10.5.16.145
74	10.5.16.146/31	10.5.16.146 – 10.5.16.147	10.5.16.147
75	10.5.16.148/31	10.5.16.148 – 10.5.16.149	10.5.16.149
76	10.5.16.150/31	10.5.16.150 – 10.5.16.151	10.5.16.151
77	10.5.16.152/31	10.5.16.152 – 10.5.16.153	10.5.16.153
78	10.5.16.154/31	10.5.16.154 – 10.5.16.155	10.5.16.155
79	10.5.16.156/31	10.5.16.156 – 10.5.16.157	10.5.16.157
80	10.5.16.158/31	10.5.16.158 – 10.5.16.159	10.5.16.159
81	10.5.16.160/31	10.5.16.160 – 10.5.16.161	10.5.16.161
82	10.5.16.162/31	10.5.16.162 – 10.5.16.163	10.5.16.163
83	10.5.16.164/31	10.5.16.164 – 10.5.16.165	10.5.16.165
84	10.5.16.166/31	10.5.16.166 – 10.5.16.167	10.5.16.167
85	10.5.16.168/31	10.5.16.168 – 10.5.16.169	10.5.16.169
86	10.5.16.170/31	10.5.16.170 – 10.5.16.171	10.5.16.171
87	10.5.16.172/31	10.5.16.172 – 10.5.16.173	10.5.16.173
88	10.5.16.174/31	10.5.16.174 – 10.5.16.175	10.5.16.175
89	10.5.16.176/31	10.5.16.176 – 10.5.16.177	10.5.16.177
90	10.5.16.178/31	10.5.16.178 – 10.5.16.179	10.5.16.179
91	10.5.16.180/31	10.5.16.180 – 10.5.16.181	10.5.16.181
92	10.5.16.182/31	10.5.16.182 – 10.5.16.183	10.5.16.183
93	10.5.16.184/31	10.5.16.184 – 10.5.16.185	10.5.16.185
94	10.5.16.186/31	10.5.16.186 – 10.5.16.187	10.5.16.187
95	10.5.16.188/31	10.5.16.188 – 10.5.16.189	10.5.16.189
96	10.5.16.190/31	10.5.16.190 – 10.5.16.191	10.5.16.191
97	10.5.16.192/31	10.5.16.192 – 10.5.16.193	10.5.16.193
98	10.5.16.194/31	10.5.16.194 – 10.5.16.195	10.5.16.195
99	10.5.16.196/31	10.5.16.196 – 10.5.16.197	10.5.16.197
100	10.5.16.198/31	10.5.16.198 – 10.5.16.199	10.5.16.199
101	10.5.16.200/31	10.5.16.200 – 10.5.16.201	10.5.16.201
102	10.5.16.202/31	10.5.16.202 – 10.5.16.203	10.5.16.203
103	10.5.16.204/31	10.5.16.204 – 10.5.16.205	10.5.16.205
104	10.5.16.206/31	10.5.16.206 – 10.5.16.207	10.5.16.207
105	10.5.16.208/31	10.5.16.208 – 10.5.16.209	10.5.16.209
106	10.5.16.210/31	10.5.16.210 – 10.5.16.211	10.5.16.211
107	10.5.16.212/31	10.5.16.212 – 10.5.16.213	10.5.16.213
108	10.5.16.214/31	10.5.16.214 – 10.5.16.215	10.5.16.215
109	10.5.16.216/31	10.5.16.216 – 10.5.16.217	10.5.16.217
110	10.5.16.218/31	10.5.16.218 – 10.5.16.219	10.5.16.219
111	10.5.16.220/31	10.5.16.220 – 10.5.16.221	10.5.16.221
112	10.5.16.222/31	10.5.16.222 – 10.5.16.223	10.5.16.223
113	10.5.16.224/31	10.5.16.224 – 10.5.16.225	10.5.16.225
114	10.5.16.226/31	10.5.16.226 – 10.5.16.227	10.5.16.227
115	10.5.16.228/31	10.5.16.228 – 10.5.16.229	10.5.16.229
116	10.5.16.230/31	10.5.16.230 – 10.5.16.231	10.5.16.231
117	10.5.16.232/31	10.5.16.232 – 10.5.16.233	10.5.16.233
118	10.5.16.234/31	10.5.16.234 – 10.5.16.235	10.5.16.235
119	10.5.16.236/31	10.5.16.236 – 10.5.16.237	10.5.16.237
120	10.5.16.238/31	10.5.16.238 – 10.5.16.239	10.5.16.239
121	10.5.16.240/31	10.5.16.240 – 10.5.16.241	10.5.16.241
122	10.5.16.242/31	10.5.16.242 – 10.5.16.243	10.5.16.243
123	10.5.16.244/31	10.5.16.244 – 10.5.16.245	10.5.16.245
124	10.5.16.246/31	10.5.16.246 – 10.5.16.247	10.5.16.247
125	10.5.16.248/31	10.5.16.248 – 10.5.16.249	10.5.16.249
126	10.5.16.250/31	10.5.16.250 – 10.5.16.251	10.5.16.251
127	10.5.16.252/31	10.5.16.252 – 10.5.16.253	10.5.16.253
128	10.5.16.254/31	10.5.16.254 – 10.5.16.255	10.5.16.255
129	10.5.17.0/31	10.5.17.0 – 10.5.17.1	10.5.17.1
130	10.5.17.2/31	10.5.17.2 – 10.5.17.3	10.5.17.3
131	10.5.17.4/31	10.5.17.4 – 10.5.17.5	10.5.17.5
132	10.5.17.6/31	10.5.17.6 – 10.5.17.7	10.5.17.7
133	10.5.17.8/31	10.5.17.8 – 10.5.17.9	10.5.17.9
134	10.5.17.10/31	10.5.17.10 – 10.5.17.11	10.5.17.11
135	10.5.17.12/31	10.5.17.12 – 10.5.17.13	10.5.17.13
136	10.5.17.14/31	10.5.17.14 – 10.5.17.15	10.5.17.15
137	10.5.17.16/31	10.5.17.16 – 10.5.17.17	10.5.17.17
138	10.5.17.18/31	10.5.17.18 – 10.5.17.19	10.5.17.19
139	10.5.17.20/31	10.5.17.20 – 10.5.17.21	10.5.17.21
140	10.5.17.22/31	10.5.17.22 – 10.5.17.23	10.5.17.23
141	10.5.17.24/31	10.5.17.24 – 10.5.17.25	10.5.17.25
142	10.5.17.26/31	10.5.17.26 – 10.5.17.27	10.5.17.27
143	10.5.17.28/31	10.5.17.28 – 10.5.17.29	10.5.17.29
144	10.5.17.30/31	10.5.17.30 – 10.5.17.31	10.5.17.31
145	10.5.17.32/31	10.5.17.32 – 10.5.17.33	10.5.17.33
146	10.5.17.34/31	10.5.17.34 – 10.5.17.35	10.5.17.35
147	10.5.17.36/31	10.5.17.36 – 10.5.17.37	10.5.17.37
148	10.5.17.38/31	10.5.17.38 – 10.5.17.39	10.5.17.39
149	10.5.17.40/31	10.5.17.40 – 10.5.17.41	10.5.17.41
150	10.5.17.42/31	10.5.17.42 – 10.5.17.43	10.5.17.43
151	10.5.17.44/31	10.5.17.44 – 10.5.17.45	10.5.17.45
152	10.5.17.46/31	10.5.17.46 – 10.5.17.47	10.5.17.47
153	10.5.17.48/31	10.5.17.48 – 10.5.17.49	10.5.17.49
154	10.5.17.50/31	10.5.17.50 – 10.5.17.51	10.5.17.51
155	10.5.17.52/31	10.5.17.52 – 10.5.17.53	10.5.17.53
156	10.5.17.54/31	10.5.17.54 – 10.5.17.55	10.5.17.55
157	10.5.17.56/31	10.5.17.56 – 10.5.17.57	10.5.17.57
158	10.5.17.58/31	10.5.17.58 – 10.5.17.59	10.5.17.59
159	10.5.17.60/31	10.5.17.60 – 10.5.17.61	10.5.17.61
160	10.5.17.62/31	10.5.17.62 – 10.5.17.63	10.5.17.63
161	10.5.17.64/31	10.5.17.64 – 10.5.17.65	10.5.17.65
162	10.5.17.66/31	10.5.17.66 – 10.5.17.67	10.5.17.67
163	10.5.17.68/31	10.5.17.68 – 10.5.17.69	10.5.17.69
164	10.5.17.70/31	10.5.17.70 – 10.5.17.71	10.5.17.71
165	10.5.17.72/31	10.5.17.72 – 10.5.17.73	10.5.17.73
166	10.5.17.74/31	10.5.17.74 – 10.5.17.75	10.5.17.75
167	10.5.17.76/31	10.5.17.76 – 10.5.17.77	10.5.17.77
168	10.5.17.78/31	10.5.17.78 – 10.5.17.79	10.5.17.79
169	10.5.17.80/31	10.5.17.80 – 10.5.17.81	10.5.17.81
170	10.5.17.82/31	10.5.17.82 – 10.5.17.83	10.5.17.83
171	10.5.17.84/31	10.5.17.84 – 10.5.17.85	10.5.17.85
172	10.5.17.86/31	10.5.17.86 – 10.5.17.87	10.5.17.87
173	10.5.17.88/31	10.5.17.88 – 10.5.17.89	10.5.17.89
174	10.5.17.90/31	10.5.17.90 – 10.5.17.91	10.5.17.91
175	10.5.17.92/31	10.5.17.92 – 10.5.17.93	10.5.17.93
176	10.5.17.94/31	10.5.17.94 – 10.5.17.95	10.5.17.95
177	10.5.17.96/31	10.5.17.96 – 10.5.17.97	10.5.17.97
178	10.5.17.98/31	10.5.17.98 – 10.5.17.99	10.5.17.99
179	10.5.17.100/31	10.5.17.100 – 10.5.17.101	10.5.17.101
180	10.5.17.102/31	10.5.17.102 – 10.5.17.103	10.5.17.103
181	10.5.17.104/31	10.5.17.104 – 10.5.17.105	10.5.17.105
182	10.5.17.106/31	10.5.17.106 – 10.5.17.107	10.5.17.107
183	10.5.17.108/31	10.5.17.108 – 10.5.17.109	10.5.17.109
184	10.5.17.110/31	10.5.17.110 – 10.5.17.111	10.5.17.111
185	10.5.17.112/31	10.5.17.112 – 10.5.17.113	10.5.17.113
186	10.5.17.114/31	10.5.17.114 – 10.5.17.115	10.5.17.115
187	10.5.17.116/31	10.5.17.116 – 10.5.17.117	10.5.17.117
188	10.5.17.118/31	10.5.17.118 – 10.5.17.119	10.5.17.119
189	10.5.17.120/31	10.5.17.120 – 10.5.17.121	10.5.17.121
190	10.5.17.122/31	10.5.17.122 – 10.5.17.123	10.5.17.123
191	10.5.17.124/31	10.5.17.124 – 10.5.17.125	10.5.17.125
192	10.5.17.126/31	10.5.17.126 – 10.5.17.127	10.5.17.127
193	10.5.17.128/31	10.5.17.128 – 10.5.17.129	10.5.17.129
194	10.5.17.130/31	10.5.17.130 – 10.5.17.131	10.5.17.131
195	10.5.17.132/31	10.5.17.132 – 10.5.17.133	10.5.17.133
196	10.5.17.134/31	10.5.17.134 – 10.5.17.135	10.5.17.135
197	10.5.17.136/31	10.5.17.136 – 10.5.17.137	10.5.17.137
198	10.5.17.138/31	10.5.17.138 – 10.5.17.139	10.5.17.139
199	10.5.17.140/31	10.5.17.140 – 10.5.17.141	10.5.17.141
200	10.5.17.142/31	10.5.17.142 – 10.5.17.143	10.5.17.143
201	10.5.17.144/31	10.5.17.144 – 10.5.17.145	10.5.17.145
202	10.5.17.146/31	10.5.17.146 – 10.5.17.147	10.5.17.147
203	10.5.17.148/31	10.5.17.148 – 10.5.17.149	10.5.17.149
204	10.5.17.150/31	10.5.17.150 – 10.5.17.151	10.5.17.151
205	10.5.17.152/31	10.5.17.152 – 10.5.17.153	10.5.17.153
206	10.5.17.154/31	10.5.17.154 – 10.5.17.155	10.5.17.155
207	10.5.17.156/31	10.5.17.156 – 10.5.17.157	10.5.17.157
208	10.5.17.158/31	10.5.17.158 – 10.5.17.159	10.5.17.159
209	10.5.17.160/31	10.5.17.160 – 10.5.17.161	10.5.17.161
210	10.5.17.162/31	10.5.17.162 – 10.5.17.163	10.5.17.163
211	10.5.17.164/31	10.5.17.164 – 10.5.17.165	10.5.17.165
212	10.5.17.166/31	10.5.17.166 – 10.5.17.167	10.5.17.167
213	10.5.17.168/31	10.5.17.168 – 10.5.17.169	10.5.17.169
214	10.5.17.170/31	10.5.17.170 – 10.5.17.171	10.5.17.171
215	10.5.17.172/31	10.5.17.172 – 10.5.17.173	10.5.17.173
216	10.5.17.174/31	10.5.17.174 – 10.5.17.175	10.5.17.175
217	10.5.17.176/31	10.5.17.176 – 10.5.17.177	10.5.17.177
218	10.5.17.178/31	10.5.17.178 – 10.5.17.179	10.5.17.179
219	10.5.17.180/31	10.5.17.180 – 10.5.17.181	10.5.17.181
220	10.5.17.182/31	10.5.17.182 – 10.5.17.183	10.5.17.183
221	10.5.17.184/31	10.5.17.184 – 10.5.17.185	10.5.17.185
222	10.5.17.186/31	10.5.17.186 – 10.5.17.187	10.5.17.187
223	10.5.17.188/31	10.5.17.188 – 10.5.17.189	10.5.17.189
224	10.5.17.190/31	10.5.17.190 – 10.5.17.191	10.5.17.191
225	10.5.17.192/31	10.5.17.192 – 10.5.17.193	10.5.17.193
226	10.5.17.194/31	10.5.17.194 – 10.5.17.195	10.5.17.195
227	10.5.17.196/31	10.5.17.196 – 10.5.17.197	10.5.17.197
228	10.5.17.198/31	10.5.17.198 – 10.5.17.199	10.5.17.199
229	10.5.17.200/31	10.5.17.200 – 10.5.17.201	10.5.17.201
230	10.5.17.202/31	10.5.17.202 – 10.5.17.203	10.5.17.203
231	10.5.17.204/31	10.5.17.204 – 10.5.17.205	10.5.17.205
232	10.5.17.206/31	10.5.17.206 – 10.5.17.207	10.5.17.207
233	10.5.17.208/31	10.5.17.208 – 10.5.17.209	10.5.17.209
234	10.5.17.210/31	10.5.17.210 – 10.5.17.211	10.5.17.211
235	10.5.17.212/31	10.5.17.212 – 10.5.17.213	10.5.17.213
236	10.5.17.214/31	10.5.17.214 – 10.5.17.215	10.5.17.215
237	10.5.17.216/31	10.5.17.216 – 10.5.17.217	10.5.17.217
238	10.5.17.218/31	10.5.17.218 – 10.5.17.219	10.5.17.219
239	10.5.17.220/31	10.5.17.220 – 10.5.17.221	10.5.17.221
240	10.5.17.222/31	10.5.17.222 – 10.5.17.223	10.5.17.223
241	10.5.17.224/31	10.5.17.224 – 10.5.17.225	10.5.17.225
242	10.5.17.226/31	10.5.17.226 – 10.5.17.227	10.5.17.227
243	10.5.17.228/31	10.5.17.228 – 10.5.17.229	10.5.17.229
244	10.5.17.230/31	10.5.17.230 – 10.5.17.231	10.5.17.231
245	10.5.17.232/31	10.5.17.232 – 10.5.17.233	10.5.17.233
246	10.5.17.234/31	10.5.17.234 – 10.5.17.235	10.5.17.235
247	10.5.17.236/31	10.5.17.236 – 10.5.17.237	10.5.17.237
248	10.5.17.238/31	10.5.17.238 – 10.5.17.239	10.5.17.239
249	10.5.17.240/31	10.5.17.240 – 10.5.17.241	10.5.17.241
250	10.5.17.242/31	10.5.17.242 – 10.5.17.243	10.5.17.243
251	10.5.17.244/31	10.5.17.244 – 10.5.17.245	10.5.17.245
252	10.5.17.246/31	10.5.17.246 – 10.5.17.247	10.5.17.247
253	10.5.17.248/31	10.5.17.248 – 10.5.17.249	10.5.17.249
254	10.5.17.250/31	10.5.17.250 – 10.5.17.251	10.5.17.251
255	10.5.17.252/31	10.5.17.252 – 10.5.17.253	10.5.17.253
256	10.5.17.254/31	10.5.17.254 – 10.5.17.255	10.5.17.255

showing 256 of 1,024

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 →