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)10.2.40.0/21

network10.2.40.0/21

broadcast10.2.47.255

first host10.2.40.1

last host10.2.47.254

subnet mask255.255.248.0

wildcard0.0.7.255

addresses2,048

usable hosts2,046

classA

ipcalc 10.2.40.0/21

address00001010.00000010.00101000.00000000

subnet mask11111111.11111111.11111000.00000000

network00001010.00000010.00101000.00000000

broadcast00001010.00000010.00101111.11111111

green = network part, grey = host part

hex0x0a022800

decimal167913472

reverse dns0.40.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:2800

/21 split into /31 · 1,024 subnets

close ×

#	network	host range	broadcast
1	10.2.40.0/31	10.2.40.0 – 10.2.40.1	10.2.40.1
2	10.2.40.2/31	10.2.40.2 – 10.2.40.3	10.2.40.3
3	10.2.40.4/31	10.2.40.4 – 10.2.40.5	10.2.40.5
4	10.2.40.6/31	10.2.40.6 – 10.2.40.7	10.2.40.7
5	10.2.40.8/31	10.2.40.8 – 10.2.40.9	10.2.40.9
6	10.2.40.10/31	10.2.40.10 – 10.2.40.11	10.2.40.11
7	10.2.40.12/31	10.2.40.12 – 10.2.40.13	10.2.40.13
8	10.2.40.14/31	10.2.40.14 – 10.2.40.15	10.2.40.15
9	10.2.40.16/31	10.2.40.16 – 10.2.40.17	10.2.40.17
10	10.2.40.18/31	10.2.40.18 – 10.2.40.19	10.2.40.19
11	10.2.40.20/31	10.2.40.20 – 10.2.40.21	10.2.40.21
12	10.2.40.22/31	10.2.40.22 – 10.2.40.23	10.2.40.23
13	10.2.40.24/31	10.2.40.24 – 10.2.40.25	10.2.40.25
14	10.2.40.26/31	10.2.40.26 – 10.2.40.27	10.2.40.27
15	10.2.40.28/31	10.2.40.28 – 10.2.40.29	10.2.40.29
16	10.2.40.30/31	10.2.40.30 – 10.2.40.31	10.2.40.31
17	10.2.40.32/31	10.2.40.32 – 10.2.40.33	10.2.40.33
18	10.2.40.34/31	10.2.40.34 – 10.2.40.35	10.2.40.35
19	10.2.40.36/31	10.2.40.36 – 10.2.40.37	10.2.40.37
20	10.2.40.38/31	10.2.40.38 – 10.2.40.39	10.2.40.39
21	10.2.40.40/31	10.2.40.40 – 10.2.40.41	10.2.40.41
22	10.2.40.42/31	10.2.40.42 – 10.2.40.43	10.2.40.43
23	10.2.40.44/31	10.2.40.44 – 10.2.40.45	10.2.40.45
24	10.2.40.46/31	10.2.40.46 – 10.2.40.47	10.2.40.47
25	10.2.40.48/31	10.2.40.48 – 10.2.40.49	10.2.40.49
26	10.2.40.50/31	10.2.40.50 – 10.2.40.51	10.2.40.51
27	10.2.40.52/31	10.2.40.52 – 10.2.40.53	10.2.40.53
28	10.2.40.54/31	10.2.40.54 – 10.2.40.55	10.2.40.55
29	10.2.40.56/31	10.2.40.56 – 10.2.40.57	10.2.40.57
30	10.2.40.58/31	10.2.40.58 – 10.2.40.59	10.2.40.59
31	10.2.40.60/31	10.2.40.60 – 10.2.40.61	10.2.40.61
32	10.2.40.62/31	10.2.40.62 – 10.2.40.63	10.2.40.63
33	10.2.40.64/31	10.2.40.64 – 10.2.40.65	10.2.40.65
34	10.2.40.66/31	10.2.40.66 – 10.2.40.67	10.2.40.67
35	10.2.40.68/31	10.2.40.68 – 10.2.40.69	10.2.40.69
36	10.2.40.70/31	10.2.40.70 – 10.2.40.71	10.2.40.71
37	10.2.40.72/31	10.2.40.72 – 10.2.40.73	10.2.40.73
38	10.2.40.74/31	10.2.40.74 – 10.2.40.75	10.2.40.75
39	10.2.40.76/31	10.2.40.76 – 10.2.40.77	10.2.40.77
40	10.2.40.78/31	10.2.40.78 – 10.2.40.79	10.2.40.79
41	10.2.40.80/31	10.2.40.80 – 10.2.40.81	10.2.40.81
42	10.2.40.82/31	10.2.40.82 – 10.2.40.83	10.2.40.83
43	10.2.40.84/31	10.2.40.84 – 10.2.40.85	10.2.40.85
44	10.2.40.86/31	10.2.40.86 – 10.2.40.87	10.2.40.87
45	10.2.40.88/31	10.2.40.88 – 10.2.40.89	10.2.40.89
46	10.2.40.90/31	10.2.40.90 – 10.2.40.91	10.2.40.91
47	10.2.40.92/31	10.2.40.92 – 10.2.40.93	10.2.40.93
48	10.2.40.94/31	10.2.40.94 – 10.2.40.95	10.2.40.95
49	10.2.40.96/31	10.2.40.96 – 10.2.40.97	10.2.40.97
50	10.2.40.98/31	10.2.40.98 – 10.2.40.99	10.2.40.99
51	10.2.40.100/31	10.2.40.100 – 10.2.40.101	10.2.40.101
52	10.2.40.102/31	10.2.40.102 – 10.2.40.103	10.2.40.103
53	10.2.40.104/31	10.2.40.104 – 10.2.40.105	10.2.40.105
54	10.2.40.106/31	10.2.40.106 – 10.2.40.107	10.2.40.107
55	10.2.40.108/31	10.2.40.108 – 10.2.40.109	10.2.40.109
56	10.2.40.110/31	10.2.40.110 – 10.2.40.111	10.2.40.111
57	10.2.40.112/31	10.2.40.112 – 10.2.40.113	10.2.40.113
58	10.2.40.114/31	10.2.40.114 – 10.2.40.115	10.2.40.115
59	10.2.40.116/31	10.2.40.116 – 10.2.40.117	10.2.40.117
60	10.2.40.118/31	10.2.40.118 – 10.2.40.119	10.2.40.119
61	10.2.40.120/31	10.2.40.120 – 10.2.40.121	10.2.40.121
62	10.2.40.122/31	10.2.40.122 – 10.2.40.123	10.2.40.123
63	10.2.40.124/31	10.2.40.124 – 10.2.40.125	10.2.40.125
64	10.2.40.126/31	10.2.40.126 – 10.2.40.127	10.2.40.127
65	10.2.40.128/31	10.2.40.128 – 10.2.40.129	10.2.40.129
66	10.2.40.130/31	10.2.40.130 – 10.2.40.131	10.2.40.131
67	10.2.40.132/31	10.2.40.132 – 10.2.40.133	10.2.40.133
68	10.2.40.134/31	10.2.40.134 – 10.2.40.135	10.2.40.135
69	10.2.40.136/31	10.2.40.136 – 10.2.40.137	10.2.40.137
70	10.2.40.138/31	10.2.40.138 – 10.2.40.139	10.2.40.139
71	10.2.40.140/31	10.2.40.140 – 10.2.40.141	10.2.40.141
72	10.2.40.142/31	10.2.40.142 – 10.2.40.143	10.2.40.143
73	10.2.40.144/31	10.2.40.144 – 10.2.40.145	10.2.40.145
74	10.2.40.146/31	10.2.40.146 – 10.2.40.147	10.2.40.147
75	10.2.40.148/31	10.2.40.148 – 10.2.40.149	10.2.40.149
76	10.2.40.150/31	10.2.40.150 – 10.2.40.151	10.2.40.151
77	10.2.40.152/31	10.2.40.152 – 10.2.40.153	10.2.40.153
78	10.2.40.154/31	10.2.40.154 – 10.2.40.155	10.2.40.155
79	10.2.40.156/31	10.2.40.156 – 10.2.40.157	10.2.40.157
80	10.2.40.158/31	10.2.40.158 – 10.2.40.159	10.2.40.159
81	10.2.40.160/31	10.2.40.160 – 10.2.40.161	10.2.40.161
82	10.2.40.162/31	10.2.40.162 – 10.2.40.163	10.2.40.163
83	10.2.40.164/31	10.2.40.164 – 10.2.40.165	10.2.40.165
84	10.2.40.166/31	10.2.40.166 – 10.2.40.167	10.2.40.167
85	10.2.40.168/31	10.2.40.168 – 10.2.40.169	10.2.40.169
86	10.2.40.170/31	10.2.40.170 – 10.2.40.171	10.2.40.171
87	10.2.40.172/31	10.2.40.172 – 10.2.40.173	10.2.40.173
88	10.2.40.174/31	10.2.40.174 – 10.2.40.175	10.2.40.175
89	10.2.40.176/31	10.2.40.176 – 10.2.40.177	10.2.40.177
90	10.2.40.178/31	10.2.40.178 – 10.2.40.179	10.2.40.179
91	10.2.40.180/31	10.2.40.180 – 10.2.40.181	10.2.40.181
92	10.2.40.182/31	10.2.40.182 – 10.2.40.183	10.2.40.183
93	10.2.40.184/31	10.2.40.184 – 10.2.40.185	10.2.40.185
94	10.2.40.186/31	10.2.40.186 – 10.2.40.187	10.2.40.187
95	10.2.40.188/31	10.2.40.188 – 10.2.40.189	10.2.40.189
96	10.2.40.190/31	10.2.40.190 – 10.2.40.191	10.2.40.191
97	10.2.40.192/31	10.2.40.192 – 10.2.40.193	10.2.40.193
98	10.2.40.194/31	10.2.40.194 – 10.2.40.195	10.2.40.195
99	10.2.40.196/31	10.2.40.196 – 10.2.40.197	10.2.40.197
100	10.2.40.198/31	10.2.40.198 – 10.2.40.199	10.2.40.199
101	10.2.40.200/31	10.2.40.200 – 10.2.40.201	10.2.40.201
102	10.2.40.202/31	10.2.40.202 – 10.2.40.203	10.2.40.203
103	10.2.40.204/31	10.2.40.204 – 10.2.40.205	10.2.40.205
104	10.2.40.206/31	10.2.40.206 – 10.2.40.207	10.2.40.207
105	10.2.40.208/31	10.2.40.208 – 10.2.40.209	10.2.40.209
106	10.2.40.210/31	10.2.40.210 – 10.2.40.211	10.2.40.211
107	10.2.40.212/31	10.2.40.212 – 10.2.40.213	10.2.40.213
108	10.2.40.214/31	10.2.40.214 – 10.2.40.215	10.2.40.215
109	10.2.40.216/31	10.2.40.216 – 10.2.40.217	10.2.40.217
110	10.2.40.218/31	10.2.40.218 – 10.2.40.219	10.2.40.219
111	10.2.40.220/31	10.2.40.220 – 10.2.40.221	10.2.40.221
112	10.2.40.222/31	10.2.40.222 – 10.2.40.223	10.2.40.223
113	10.2.40.224/31	10.2.40.224 – 10.2.40.225	10.2.40.225
114	10.2.40.226/31	10.2.40.226 – 10.2.40.227	10.2.40.227
115	10.2.40.228/31	10.2.40.228 – 10.2.40.229	10.2.40.229
116	10.2.40.230/31	10.2.40.230 – 10.2.40.231	10.2.40.231
117	10.2.40.232/31	10.2.40.232 – 10.2.40.233	10.2.40.233
118	10.2.40.234/31	10.2.40.234 – 10.2.40.235	10.2.40.235
119	10.2.40.236/31	10.2.40.236 – 10.2.40.237	10.2.40.237
120	10.2.40.238/31	10.2.40.238 – 10.2.40.239	10.2.40.239
121	10.2.40.240/31	10.2.40.240 – 10.2.40.241	10.2.40.241
122	10.2.40.242/31	10.2.40.242 – 10.2.40.243	10.2.40.243
123	10.2.40.244/31	10.2.40.244 – 10.2.40.245	10.2.40.245
124	10.2.40.246/31	10.2.40.246 – 10.2.40.247	10.2.40.247
125	10.2.40.248/31	10.2.40.248 – 10.2.40.249	10.2.40.249
126	10.2.40.250/31	10.2.40.250 – 10.2.40.251	10.2.40.251
127	10.2.40.252/31	10.2.40.252 – 10.2.40.253	10.2.40.253
128	10.2.40.254/31	10.2.40.254 – 10.2.40.255	10.2.40.255
129	10.2.41.0/31	10.2.41.0 – 10.2.41.1	10.2.41.1
130	10.2.41.2/31	10.2.41.2 – 10.2.41.3	10.2.41.3
131	10.2.41.4/31	10.2.41.4 – 10.2.41.5	10.2.41.5
132	10.2.41.6/31	10.2.41.6 – 10.2.41.7	10.2.41.7
133	10.2.41.8/31	10.2.41.8 – 10.2.41.9	10.2.41.9
134	10.2.41.10/31	10.2.41.10 – 10.2.41.11	10.2.41.11
135	10.2.41.12/31	10.2.41.12 – 10.2.41.13	10.2.41.13
136	10.2.41.14/31	10.2.41.14 – 10.2.41.15	10.2.41.15
137	10.2.41.16/31	10.2.41.16 – 10.2.41.17	10.2.41.17
138	10.2.41.18/31	10.2.41.18 – 10.2.41.19	10.2.41.19
139	10.2.41.20/31	10.2.41.20 – 10.2.41.21	10.2.41.21
140	10.2.41.22/31	10.2.41.22 – 10.2.41.23	10.2.41.23
141	10.2.41.24/31	10.2.41.24 – 10.2.41.25	10.2.41.25
142	10.2.41.26/31	10.2.41.26 – 10.2.41.27	10.2.41.27
143	10.2.41.28/31	10.2.41.28 – 10.2.41.29	10.2.41.29
144	10.2.41.30/31	10.2.41.30 – 10.2.41.31	10.2.41.31
145	10.2.41.32/31	10.2.41.32 – 10.2.41.33	10.2.41.33
146	10.2.41.34/31	10.2.41.34 – 10.2.41.35	10.2.41.35
147	10.2.41.36/31	10.2.41.36 – 10.2.41.37	10.2.41.37
148	10.2.41.38/31	10.2.41.38 – 10.2.41.39	10.2.41.39
149	10.2.41.40/31	10.2.41.40 – 10.2.41.41	10.2.41.41
150	10.2.41.42/31	10.2.41.42 – 10.2.41.43	10.2.41.43
151	10.2.41.44/31	10.2.41.44 – 10.2.41.45	10.2.41.45
152	10.2.41.46/31	10.2.41.46 – 10.2.41.47	10.2.41.47
153	10.2.41.48/31	10.2.41.48 – 10.2.41.49	10.2.41.49
154	10.2.41.50/31	10.2.41.50 – 10.2.41.51	10.2.41.51
155	10.2.41.52/31	10.2.41.52 – 10.2.41.53	10.2.41.53
156	10.2.41.54/31	10.2.41.54 – 10.2.41.55	10.2.41.55
157	10.2.41.56/31	10.2.41.56 – 10.2.41.57	10.2.41.57
158	10.2.41.58/31	10.2.41.58 – 10.2.41.59	10.2.41.59
159	10.2.41.60/31	10.2.41.60 – 10.2.41.61	10.2.41.61
160	10.2.41.62/31	10.2.41.62 – 10.2.41.63	10.2.41.63
161	10.2.41.64/31	10.2.41.64 – 10.2.41.65	10.2.41.65
162	10.2.41.66/31	10.2.41.66 – 10.2.41.67	10.2.41.67
163	10.2.41.68/31	10.2.41.68 – 10.2.41.69	10.2.41.69
164	10.2.41.70/31	10.2.41.70 – 10.2.41.71	10.2.41.71
165	10.2.41.72/31	10.2.41.72 – 10.2.41.73	10.2.41.73
166	10.2.41.74/31	10.2.41.74 – 10.2.41.75	10.2.41.75
167	10.2.41.76/31	10.2.41.76 – 10.2.41.77	10.2.41.77
168	10.2.41.78/31	10.2.41.78 – 10.2.41.79	10.2.41.79
169	10.2.41.80/31	10.2.41.80 – 10.2.41.81	10.2.41.81
170	10.2.41.82/31	10.2.41.82 – 10.2.41.83	10.2.41.83
171	10.2.41.84/31	10.2.41.84 – 10.2.41.85	10.2.41.85
172	10.2.41.86/31	10.2.41.86 – 10.2.41.87	10.2.41.87
173	10.2.41.88/31	10.2.41.88 – 10.2.41.89	10.2.41.89
174	10.2.41.90/31	10.2.41.90 – 10.2.41.91	10.2.41.91
175	10.2.41.92/31	10.2.41.92 – 10.2.41.93	10.2.41.93
176	10.2.41.94/31	10.2.41.94 – 10.2.41.95	10.2.41.95
177	10.2.41.96/31	10.2.41.96 – 10.2.41.97	10.2.41.97
178	10.2.41.98/31	10.2.41.98 – 10.2.41.99	10.2.41.99
179	10.2.41.100/31	10.2.41.100 – 10.2.41.101	10.2.41.101
180	10.2.41.102/31	10.2.41.102 – 10.2.41.103	10.2.41.103
181	10.2.41.104/31	10.2.41.104 – 10.2.41.105	10.2.41.105
182	10.2.41.106/31	10.2.41.106 – 10.2.41.107	10.2.41.107
183	10.2.41.108/31	10.2.41.108 – 10.2.41.109	10.2.41.109
184	10.2.41.110/31	10.2.41.110 – 10.2.41.111	10.2.41.111
185	10.2.41.112/31	10.2.41.112 – 10.2.41.113	10.2.41.113
186	10.2.41.114/31	10.2.41.114 – 10.2.41.115	10.2.41.115
187	10.2.41.116/31	10.2.41.116 – 10.2.41.117	10.2.41.117
188	10.2.41.118/31	10.2.41.118 – 10.2.41.119	10.2.41.119
189	10.2.41.120/31	10.2.41.120 – 10.2.41.121	10.2.41.121
190	10.2.41.122/31	10.2.41.122 – 10.2.41.123	10.2.41.123
191	10.2.41.124/31	10.2.41.124 – 10.2.41.125	10.2.41.125
192	10.2.41.126/31	10.2.41.126 – 10.2.41.127	10.2.41.127
193	10.2.41.128/31	10.2.41.128 – 10.2.41.129	10.2.41.129
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196	10.2.41.134/31	10.2.41.134 – 10.2.41.135	10.2.41.135
197	10.2.41.136/31	10.2.41.136 – 10.2.41.137	10.2.41.137
198	10.2.41.138/31	10.2.41.138 – 10.2.41.139	10.2.41.139
199	10.2.41.140/31	10.2.41.140 – 10.2.41.141	10.2.41.141
200	10.2.41.142/31	10.2.41.142 – 10.2.41.143	10.2.41.143
201	10.2.41.144/31	10.2.41.144 – 10.2.41.145	10.2.41.145
202	10.2.41.146/31	10.2.41.146 – 10.2.41.147	10.2.41.147
203	10.2.41.148/31	10.2.41.148 – 10.2.41.149	10.2.41.149
204	10.2.41.150/31	10.2.41.150 – 10.2.41.151	10.2.41.151
205	10.2.41.152/31	10.2.41.152 – 10.2.41.153	10.2.41.153
206	10.2.41.154/31	10.2.41.154 – 10.2.41.155	10.2.41.155
207	10.2.41.156/31	10.2.41.156 – 10.2.41.157	10.2.41.157
208	10.2.41.158/31	10.2.41.158 – 10.2.41.159	10.2.41.159
209	10.2.41.160/31	10.2.41.160 – 10.2.41.161	10.2.41.161
210	10.2.41.162/31	10.2.41.162 – 10.2.41.163	10.2.41.163
211	10.2.41.164/31	10.2.41.164 – 10.2.41.165	10.2.41.165
212	10.2.41.166/31	10.2.41.166 – 10.2.41.167	10.2.41.167
213	10.2.41.168/31	10.2.41.168 – 10.2.41.169	10.2.41.169
214	10.2.41.170/31	10.2.41.170 – 10.2.41.171	10.2.41.171
215	10.2.41.172/31	10.2.41.172 – 10.2.41.173	10.2.41.173
216	10.2.41.174/31	10.2.41.174 – 10.2.41.175	10.2.41.175
217	10.2.41.176/31	10.2.41.176 – 10.2.41.177	10.2.41.177
218	10.2.41.178/31	10.2.41.178 – 10.2.41.179	10.2.41.179
219	10.2.41.180/31	10.2.41.180 – 10.2.41.181	10.2.41.181
220	10.2.41.182/31	10.2.41.182 – 10.2.41.183	10.2.41.183
221	10.2.41.184/31	10.2.41.184 – 10.2.41.185	10.2.41.185
222	10.2.41.186/31	10.2.41.186 – 10.2.41.187	10.2.41.187
223	10.2.41.188/31	10.2.41.188 – 10.2.41.189	10.2.41.189
224	10.2.41.190/31	10.2.41.190 – 10.2.41.191	10.2.41.191
225	10.2.41.192/31	10.2.41.192 – 10.2.41.193	10.2.41.193
226	10.2.41.194/31	10.2.41.194 – 10.2.41.195	10.2.41.195
227	10.2.41.196/31	10.2.41.196 – 10.2.41.197	10.2.41.197
228	10.2.41.198/31	10.2.41.198 – 10.2.41.199	10.2.41.199
229	10.2.41.200/31	10.2.41.200 – 10.2.41.201	10.2.41.201
230	10.2.41.202/31	10.2.41.202 – 10.2.41.203	10.2.41.203
231	10.2.41.204/31	10.2.41.204 – 10.2.41.205	10.2.41.205
232	10.2.41.206/31	10.2.41.206 – 10.2.41.207	10.2.41.207
233	10.2.41.208/31	10.2.41.208 – 10.2.41.209	10.2.41.209
234	10.2.41.210/31	10.2.41.210 – 10.2.41.211	10.2.41.211
235	10.2.41.212/31	10.2.41.212 – 10.2.41.213	10.2.41.213
236	10.2.41.214/31	10.2.41.214 – 10.2.41.215	10.2.41.215
237	10.2.41.216/31	10.2.41.216 – 10.2.41.217	10.2.41.217
238	10.2.41.218/31	10.2.41.218 – 10.2.41.219	10.2.41.219
239	10.2.41.220/31	10.2.41.220 – 10.2.41.221	10.2.41.221
240	10.2.41.222/31	10.2.41.222 – 10.2.41.223	10.2.41.223
241	10.2.41.224/31	10.2.41.224 – 10.2.41.225	10.2.41.225
242	10.2.41.226/31	10.2.41.226 – 10.2.41.227	10.2.41.227
243	10.2.41.228/31	10.2.41.228 – 10.2.41.229	10.2.41.229
244	10.2.41.230/31	10.2.41.230 – 10.2.41.231	10.2.41.231
245	10.2.41.232/31	10.2.41.232 – 10.2.41.233	10.2.41.233
246	10.2.41.234/31	10.2.41.234 – 10.2.41.235	10.2.41.235
247	10.2.41.236/31	10.2.41.236 – 10.2.41.237	10.2.41.237
248	10.2.41.238/31	10.2.41.238 – 10.2.41.239	10.2.41.239
249	10.2.41.240/31	10.2.41.240 – 10.2.41.241	10.2.41.241
250	10.2.41.242/31	10.2.41.242 – 10.2.41.243	10.2.41.243
251	10.2.41.244/31	10.2.41.244 – 10.2.41.245	10.2.41.245
252	10.2.41.246/31	10.2.41.246 – 10.2.41.247	10.2.41.247
253	10.2.41.248/31	10.2.41.248 – 10.2.41.249	10.2.41.249
254	10.2.41.250/31	10.2.41.250 – 10.2.41.251	10.2.41.251
255	10.2.41.252/31	10.2.41.252 – 10.2.41.253	10.2.41.253
256	10.2.41.254/31	10.2.41.254 – 10.2.41.255	10.2.41.255

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 →