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)10.3.40.0/21

network10.3.40.0/21

broadcast10.3.47.255

first host10.3.40.1

last host10.3.47.254

subnet mask255.255.248.0

wildcard0.0.7.255

addresses2,048

usable hosts2,046

classA

ipcalc 10.3.40.0/21

address00001010.00000011.00101000.00000000

subnet mask11111111.11111111.11111000.00000000

network00001010.00000011.00101000.00000000

broadcast00001010.00000011.00101111.11111111

green = network part, grey = host part

hex0x0a032800

decimal167979008

reverse dns0.40.3.10.in-addr.arpa

ipv4-mapped::ffff:a03:2800

/21 split into /30 · 512 subnets

close ×

#	network	host range	broadcast
1	10.3.40.0/30	10.3.40.1 – 10.3.40.2	10.3.40.3
2	10.3.40.4/30	10.3.40.5 – 10.3.40.6	10.3.40.7
3	10.3.40.8/30	10.3.40.9 – 10.3.40.10	10.3.40.11
4	10.3.40.12/30	10.3.40.13 – 10.3.40.14	10.3.40.15
5	10.3.40.16/30	10.3.40.17 – 10.3.40.18	10.3.40.19
6	10.3.40.20/30	10.3.40.21 – 10.3.40.22	10.3.40.23
7	10.3.40.24/30	10.3.40.25 – 10.3.40.26	10.3.40.27
8	10.3.40.28/30	10.3.40.29 – 10.3.40.30	10.3.40.31
9	10.3.40.32/30	10.3.40.33 – 10.3.40.34	10.3.40.35
10	10.3.40.36/30	10.3.40.37 – 10.3.40.38	10.3.40.39
11	10.3.40.40/30	10.3.40.41 – 10.3.40.42	10.3.40.43
12	10.3.40.44/30	10.3.40.45 – 10.3.40.46	10.3.40.47
13	10.3.40.48/30	10.3.40.49 – 10.3.40.50	10.3.40.51
14	10.3.40.52/30	10.3.40.53 – 10.3.40.54	10.3.40.55
15	10.3.40.56/30	10.3.40.57 – 10.3.40.58	10.3.40.59
16	10.3.40.60/30	10.3.40.61 – 10.3.40.62	10.3.40.63
17	10.3.40.64/30	10.3.40.65 – 10.3.40.66	10.3.40.67
18	10.3.40.68/30	10.3.40.69 – 10.3.40.70	10.3.40.71
19	10.3.40.72/30	10.3.40.73 – 10.3.40.74	10.3.40.75
20	10.3.40.76/30	10.3.40.77 – 10.3.40.78	10.3.40.79
21	10.3.40.80/30	10.3.40.81 – 10.3.40.82	10.3.40.83
22	10.3.40.84/30	10.3.40.85 – 10.3.40.86	10.3.40.87
23	10.3.40.88/30	10.3.40.89 – 10.3.40.90	10.3.40.91
24	10.3.40.92/30	10.3.40.93 – 10.3.40.94	10.3.40.95
25	10.3.40.96/30	10.3.40.97 – 10.3.40.98	10.3.40.99
26	10.3.40.100/30	10.3.40.101 – 10.3.40.102	10.3.40.103
27	10.3.40.104/30	10.3.40.105 – 10.3.40.106	10.3.40.107
28	10.3.40.108/30	10.3.40.109 – 10.3.40.110	10.3.40.111
29	10.3.40.112/30	10.3.40.113 – 10.3.40.114	10.3.40.115
30	10.3.40.116/30	10.3.40.117 – 10.3.40.118	10.3.40.119
31	10.3.40.120/30	10.3.40.121 – 10.3.40.122	10.3.40.123
32	10.3.40.124/30	10.3.40.125 – 10.3.40.126	10.3.40.127
33	10.3.40.128/30	10.3.40.129 – 10.3.40.130	10.3.40.131
34	10.3.40.132/30	10.3.40.133 – 10.3.40.134	10.3.40.135
35	10.3.40.136/30	10.3.40.137 – 10.3.40.138	10.3.40.139
36	10.3.40.140/30	10.3.40.141 – 10.3.40.142	10.3.40.143
37	10.3.40.144/30	10.3.40.145 – 10.3.40.146	10.3.40.147
38	10.3.40.148/30	10.3.40.149 – 10.3.40.150	10.3.40.151
39	10.3.40.152/30	10.3.40.153 – 10.3.40.154	10.3.40.155
40	10.3.40.156/30	10.3.40.157 – 10.3.40.158	10.3.40.159
41	10.3.40.160/30	10.3.40.161 – 10.3.40.162	10.3.40.163
42	10.3.40.164/30	10.3.40.165 – 10.3.40.166	10.3.40.167
43	10.3.40.168/30	10.3.40.169 – 10.3.40.170	10.3.40.171
44	10.3.40.172/30	10.3.40.173 – 10.3.40.174	10.3.40.175
45	10.3.40.176/30	10.3.40.177 – 10.3.40.178	10.3.40.179
46	10.3.40.180/30	10.3.40.181 – 10.3.40.182	10.3.40.183
47	10.3.40.184/30	10.3.40.185 – 10.3.40.186	10.3.40.187
48	10.3.40.188/30	10.3.40.189 – 10.3.40.190	10.3.40.191
49	10.3.40.192/30	10.3.40.193 – 10.3.40.194	10.3.40.195
50	10.3.40.196/30	10.3.40.197 – 10.3.40.198	10.3.40.199
51	10.3.40.200/30	10.3.40.201 – 10.3.40.202	10.3.40.203
52	10.3.40.204/30	10.3.40.205 – 10.3.40.206	10.3.40.207
53	10.3.40.208/30	10.3.40.209 – 10.3.40.210	10.3.40.211
54	10.3.40.212/30	10.3.40.213 – 10.3.40.214	10.3.40.215
55	10.3.40.216/30	10.3.40.217 – 10.3.40.218	10.3.40.219
56	10.3.40.220/30	10.3.40.221 – 10.3.40.222	10.3.40.223
57	10.3.40.224/30	10.3.40.225 – 10.3.40.226	10.3.40.227
58	10.3.40.228/30	10.3.40.229 – 10.3.40.230	10.3.40.231
59	10.3.40.232/30	10.3.40.233 – 10.3.40.234	10.3.40.235
60	10.3.40.236/30	10.3.40.237 – 10.3.40.238	10.3.40.239
61	10.3.40.240/30	10.3.40.241 – 10.3.40.242	10.3.40.243
62	10.3.40.244/30	10.3.40.245 – 10.3.40.246	10.3.40.247
63	10.3.40.248/30	10.3.40.249 – 10.3.40.250	10.3.40.251
64	10.3.40.252/30	10.3.40.253 – 10.3.40.254	10.3.40.255
65	10.3.41.0/30	10.3.41.1 – 10.3.41.2	10.3.41.3
66	10.3.41.4/30	10.3.41.5 – 10.3.41.6	10.3.41.7
67	10.3.41.8/30	10.3.41.9 – 10.3.41.10	10.3.41.11
68	10.3.41.12/30	10.3.41.13 – 10.3.41.14	10.3.41.15
69	10.3.41.16/30	10.3.41.17 – 10.3.41.18	10.3.41.19
70	10.3.41.20/30	10.3.41.21 – 10.3.41.22	10.3.41.23
71	10.3.41.24/30	10.3.41.25 – 10.3.41.26	10.3.41.27
72	10.3.41.28/30	10.3.41.29 – 10.3.41.30	10.3.41.31
73	10.3.41.32/30	10.3.41.33 – 10.3.41.34	10.3.41.35
74	10.3.41.36/30	10.3.41.37 – 10.3.41.38	10.3.41.39
75	10.3.41.40/30	10.3.41.41 – 10.3.41.42	10.3.41.43
76	10.3.41.44/30	10.3.41.45 – 10.3.41.46	10.3.41.47
77	10.3.41.48/30	10.3.41.49 – 10.3.41.50	10.3.41.51
78	10.3.41.52/30	10.3.41.53 – 10.3.41.54	10.3.41.55
79	10.3.41.56/30	10.3.41.57 – 10.3.41.58	10.3.41.59
80	10.3.41.60/30	10.3.41.61 – 10.3.41.62	10.3.41.63
81	10.3.41.64/30	10.3.41.65 – 10.3.41.66	10.3.41.67
82	10.3.41.68/30	10.3.41.69 – 10.3.41.70	10.3.41.71
83	10.3.41.72/30	10.3.41.73 – 10.3.41.74	10.3.41.75
84	10.3.41.76/30	10.3.41.77 – 10.3.41.78	10.3.41.79
85	10.3.41.80/30	10.3.41.81 – 10.3.41.82	10.3.41.83
86	10.3.41.84/30	10.3.41.85 – 10.3.41.86	10.3.41.87
87	10.3.41.88/30	10.3.41.89 – 10.3.41.90	10.3.41.91
88	10.3.41.92/30	10.3.41.93 – 10.3.41.94	10.3.41.95
89	10.3.41.96/30	10.3.41.97 – 10.3.41.98	10.3.41.99
90	10.3.41.100/30	10.3.41.101 – 10.3.41.102	10.3.41.103
91	10.3.41.104/30	10.3.41.105 – 10.3.41.106	10.3.41.107
92	10.3.41.108/30	10.3.41.109 – 10.3.41.110	10.3.41.111
93	10.3.41.112/30	10.3.41.113 – 10.3.41.114	10.3.41.115
94	10.3.41.116/30	10.3.41.117 – 10.3.41.118	10.3.41.119
95	10.3.41.120/30	10.3.41.121 – 10.3.41.122	10.3.41.123
96	10.3.41.124/30	10.3.41.125 – 10.3.41.126	10.3.41.127
97	10.3.41.128/30	10.3.41.129 – 10.3.41.130	10.3.41.131
98	10.3.41.132/30	10.3.41.133 – 10.3.41.134	10.3.41.135
99	10.3.41.136/30	10.3.41.137 – 10.3.41.138	10.3.41.139
100	10.3.41.140/30	10.3.41.141 – 10.3.41.142	10.3.41.143
101	10.3.41.144/30	10.3.41.145 – 10.3.41.146	10.3.41.147
102	10.3.41.148/30	10.3.41.149 – 10.3.41.150	10.3.41.151
103	10.3.41.152/30	10.3.41.153 – 10.3.41.154	10.3.41.155
104	10.3.41.156/30	10.3.41.157 – 10.3.41.158	10.3.41.159
105	10.3.41.160/30	10.3.41.161 – 10.3.41.162	10.3.41.163
106	10.3.41.164/30	10.3.41.165 – 10.3.41.166	10.3.41.167
107	10.3.41.168/30	10.3.41.169 – 10.3.41.170	10.3.41.171
108	10.3.41.172/30	10.3.41.173 – 10.3.41.174	10.3.41.175
109	10.3.41.176/30	10.3.41.177 – 10.3.41.178	10.3.41.179
110	10.3.41.180/30	10.3.41.181 – 10.3.41.182	10.3.41.183
111	10.3.41.184/30	10.3.41.185 – 10.3.41.186	10.3.41.187
112	10.3.41.188/30	10.3.41.189 – 10.3.41.190	10.3.41.191
113	10.3.41.192/30	10.3.41.193 – 10.3.41.194	10.3.41.195
114	10.3.41.196/30	10.3.41.197 – 10.3.41.198	10.3.41.199
115	10.3.41.200/30	10.3.41.201 – 10.3.41.202	10.3.41.203
116	10.3.41.204/30	10.3.41.205 – 10.3.41.206	10.3.41.207
117	10.3.41.208/30	10.3.41.209 – 10.3.41.210	10.3.41.211
118	10.3.41.212/30	10.3.41.213 – 10.3.41.214	10.3.41.215
119	10.3.41.216/30	10.3.41.217 – 10.3.41.218	10.3.41.219
120	10.3.41.220/30	10.3.41.221 – 10.3.41.222	10.3.41.223
121	10.3.41.224/30	10.3.41.225 – 10.3.41.226	10.3.41.227
122	10.3.41.228/30	10.3.41.229 – 10.3.41.230	10.3.41.231
123	10.3.41.232/30	10.3.41.233 – 10.3.41.234	10.3.41.235
124	10.3.41.236/30	10.3.41.237 – 10.3.41.238	10.3.41.239
125	10.3.41.240/30	10.3.41.241 – 10.3.41.242	10.3.41.243
126	10.3.41.244/30	10.3.41.245 – 10.3.41.246	10.3.41.247
127	10.3.41.248/30	10.3.41.249 – 10.3.41.250	10.3.41.251
128	10.3.41.252/30	10.3.41.253 – 10.3.41.254	10.3.41.255
129	10.3.42.0/30	10.3.42.1 – 10.3.42.2	10.3.42.3
130	10.3.42.4/30	10.3.42.5 – 10.3.42.6	10.3.42.7
131	10.3.42.8/30	10.3.42.9 – 10.3.42.10	10.3.42.11
132	10.3.42.12/30	10.3.42.13 – 10.3.42.14	10.3.42.15
133	10.3.42.16/30	10.3.42.17 – 10.3.42.18	10.3.42.19
134	10.3.42.20/30	10.3.42.21 – 10.3.42.22	10.3.42.23
135	10.3.42.24/30	10.3.42.25 – 10.3.42.26	10.3.42.27
136	10.3.42.28/30	10.3.42.29 – 10.3.42.30	10.3.42.31
137	10.3.42.32/30	10.3.42.33 – 10.3.42.34	10.3.42.35
138	10.3.42.36/30	10.3.42.37 – 10.3.42.38	10.3.42.39
139	10.3.42.40/30	10.3.42.41 – 10.3.42.42	10.3.42.43
140	10.3.42.44/30	10.3.42.45 – 10.3.42.46	10.3.42.47
141	10.3.42.48/30	10.3.42.49 – 10.3.42.50	10.3.42.51
142	10.3.42.52/30	10.3.42.53 – 10.3.42.54	10.3.42.55
143	10.3.42.56/30	10.3.42.57 – 10.3.42.58	10.3.42.59
144	10.3.42.60/30	10.3.42.61 – 10.3.42.62	10.3.42.63
145	10.3.42.64/30	10.3.42.65 – 10.3.42.66	10.3.42.67
146	10.3.42.68/30	10.3.42.69 – 10.3.42.70	10.3.42.71
147	10.3.42.72/30	10.3.42.73 – 10.3.42.74	10.3.42.75
148	10.3.42.76/30	10.3.42.77 – 10.3.42.78	10.3.42.79
149	10.3.42.80/30	10.3.42.81 – 10.3.42.82	10.3.42.83
150	10.3.42.84/30	10.3.42.85 – 10.3.42.86	10.3.42.87
151	10.3.42.88/30	10.3.42.89 – 10.3.42.90	10.3.42.91
152	10.3.42.92/30	10.3.42.93 – 10.3.42.94	10.3.42.95
153	10.3.42.96/30	10.3.42.97 – 10.3.42.98	10.3.42.99
154	10.3.42.100/30	10.3.42.101 – 10.3.42.102	10.3.42.103
155	10.3.42.104/30	10.3.42.105 – 10.3.42.106	10.3.42.107
156	10.3.42.108/30	10.3.42.109 – 10.3.42.110	10.3.42.111
157	10.3.42.112/30	10.3.42.113 – 10.3.42.114	10.3.42.115
158	10.3.42.116/30	10.3.42.117 – 10.3.42.118	10.3.42.119
159	10.3.42.120/30	10.3.42.121 – 10.3.42.122	10.3.42.123
160	10.3.42.124/30	10.3.42.125 – 10.3.42.126	10.3.42.127
161	10.3.42.128/30	10.3.42.129 – 10.3.42.130	10.3.42.131
162	10.3.42.132/30	10.3.42.133 – 10.3.42.134	10.3.42.135
163	10.3.42.136/30	10.3.42.137 – 10.3.42.138	10.3.42.139
164	10.3.42.140/30	10.3.42.141 – 10.3.42.142	10.3.42.143
165	10.3.42.144/30	10.3.42.145 – 10.3.42.146	10.3.42.147
166	10.3.42.148/30	10.3.42.149 – 10.3.42.150	10.3.42.151
167	10.3.42.152/30	10.3.42.153 – 10.3.42.154	10.3.42.155
168	10.3.42.156/30	10.3.42.157 – 10.3.42.158	10.3.42.159
169	10.3.42.160/30	10.3.42.161 – 10.3.42.162	10.3.42.163
170	10.3.42.164/30	10.3.42.165 – 10.3.42.166	10.3.42.167
171	10.3.42.168/30	10.3.42.169 – 10.3.42.170	10.3.42.171
172	10.3.42.172/30	10.3.42.173 – 10.3.42.174	10.3.42.175
173	10.3.42.176/30	10.3.42.177 – 10.3.42.178	10.3.42.179
174	10.3.42.180/30	10.3.42.181 – 10.3.42.182	10.3.42.183
175	10.3.42.184/30	10.3.42.185 – 10.3.42.186	10.3.42.187
176	10.3.42.188/30	10.3.42.189 – 10.3.42.190	10.3.42.191
177	10.3.42.192/30	10.3.42.193 – 10.3.42.194	10.3.42.195
178	10.3.42.196/30	10.3.42.197 – 10.3.42.198	10.3.42.199
179	10.3.42.200/30	10.3.42.201 – 10.3.42.202	10.3.42.203
180	10.3.42.204/30	10.3.42.205 – 10.3.42.206	10.3.42.207
181	10.3.42.208/30	10.3.42.209 – 10.3.42.210	10.3.42.211
182	10.3.42.212/30	10.3.42.213 – 10.3.42.214	10.3.42.215
183	10.3.42.216/30	10.3.42.217 – 10.3.42.218	10.3.42.219
184	10.3.42.220/30	10.3.42.221 – 10.3.42.222	10.3.42.223
185	10.3.42.224/30	10.3.42.225 – 10.3.42.226	10.3.42.227
186	10.3.42.228/30	10.3.42.229 – 10.3.42.230	10.3.42.231
187	10.3.42.232/30	10.3.42.233 – 10.3.42.234	10.3.42.235
188	10.3.42.236/30	10.3.42.237 – 10.3.42.238	10.3.42.239
189	10.3.42.240/30	10.3.42.241 – 10.3.42.242	10.3.42.243
190	10.3.42.244/30	10.3.42.245 – 10.3.42.246	10.3.42.247
191	10.3.42.248/30	10.3.42.249 – 10.3.42.250	10.3.42.251
192	10.3.42.252/30	10.3.42.253 – 10.3.42.254	10.3.42.255
193	10.3.43.0/30	10.3.43.1 – 10.3.43.2	10.3.43.3
194	10.3.43.4/30	10.3.43.5 – 10.3.43.6	10.3.43.7
195	10.3.43.8/30	10.3.43.9 – 10.3.43.10	10.3.43.11
196	10.3.43.12/30	10.3.43.13 – 10.3.43.14	10.3.43.15
197	10.3.43.16/30	10.3.43.17 – 10.3.43.18	10.3.43.19
198	10.3.43.20/30	10.3.43.21 – 10.3.43.22	10.3.43.23
199	10.3.43.24/30	10.3.43.25 – 10.3.43.26	10.3.43.27
200	10.3.43.28/30	10.3.43.29 – 10.3.43.30	10.3.43.31
201	10.3.43.32/30	10.3.43.33 – 10.3.43.34	10.3.43.35
202	10.3.43.36/30	10.3.43.37 – 10.3.43.38	10.3.43.39
203	10.3.43.40/30	10.3.43.41 – 10.3.43.42	10.3.43.43
204	10.3.43.44/30	10.3.43.45 – 10.3.43.46	10.3.43.47
205	10.3.43.48/30	10.3.43.49 – 10.3.43.50	10.3.43.51
206	10.3.43.52/30	10.3.43.53 – 10.3.43.54	10.3.43.55
207	10.3.43.56/30	10.3.43.57 – 10.3.43.58	10.3.43.59
208	10.3.43.60/30	10.3.43.61 – 10.3.43.62	10.3.43.63
209	10.3.43.64/30	10.3.43.65 – 10.3.43.66	10.3.43.67
210	10.3.43.68/30	10.3.43.69 – 10.3.43.70	10.3.43.71
211	10.3.43.72/30	10.3.43.73 – 10.3.43.74	10.3.43.75
212	10.3.43.76/30	10.3.43.77 – 10.3.43.78	10.3.43.79
213	10.3.43.80/30	10.3.43.81 – 10.3.43.82	10.3.43.83
214	10.3.43.84/30	10.3.43.85 – 10.3.43.86	10.3.43.87
215	10.3.43.88/30	10.3.43.89 – 10.3.43.90	10.3.43.91
216	10.3.43.92/30	10.3.43.93 – 10.3.43.94	10.3.43.95
217	10.3.43.96/30	10.3.43.97 – 10.3.43.98	10.3.43.99
218	10.3.43.100/30	10.3.43.101 – 10.3.43.102	10.3.43.103
219	10.3.43.104/30	10.3.43.105 – 10.3.43.106	10.3.43.107
220	10.3.43.108/30	10.3.43.109 – 10.3.43.110	10.3.43.111
221	10.3.43.112/30	10.3.43.113 – 10.3.43.114	10.3.43.115
222	10.3.43.116/30	10.3.43.117 – 10.3.43.118	10.3.43.119
223	10.3.43.120/30	10.3.43.121 – 10.3.43.122	10.3.43.123
224	10.3.43.124/30	10.3.43.125 – 10.3.43.126	10.3.43.127
225	10.3.43.128/30	10.3.43.129 – 10.3.43.130	10.3.43.131
226	10.3.43.132/30	10.3.43.133 – 10.3.43.134	10.3.43.135
227	10.3.43.136/30	10.3.43.137 – 10.3.43.138	10.3.43.139
228	10.3.43.140/30	10.3.43.141 – 10.3.43.142	10.3.43.143
229	10.3.43.144/30	10.3.43.145 – 10.3.43.146	10.3.43.147
230	10.3.43.148/30	10.3.43.149 – 10.3.43.150	10.3.43.151
231	10.3.43.152/30	10.3.43.153 – 10.3.43.154	10.3.43.155
232	10.3.43.156/30	10.3.43.157 – 10.3.43.158	10.3.43.159
233	10.3.43.160/30	10.3.43.161 – 10.3.43.162	10.3.43.163
234	10.3.43.164/30	10.3.43.165 – 10.3.43.166	10.3.43.167
235	10.3.43.168/30	10.3.43.169 – 10.3.43.170	10.3.43.171
236	10.3.43.172/30	10.3.43.173 – 10.3.43.174	10.3.43.175
237	10.3.43.176/30	10.3.43.177 – 10.3.43.178	10.3.43.179
238	10.3.43.180/30	10.3.43.181 – 10.3.43.182	10.3.43.183
239	10.3.43.184/30	10.3.43.185 – 10.3.43.186	10.3.43.187
240	10.3.43.188/30	10.3.43.189 – 10.3.43.190	10.3.43.191
241	10.3.43.192/30	10.3.43.193 – 10.3.43.194	10.3.43.195
242	10.3.43.196/30	10.3.43.197 – 10.3.43.198	10.3.43.199
243	10.3.43.200/30	10.3.43.201 – 10.3.43.202	10.3.43.203
244	10.3.43.204/30	10.3.43.205 – 10.3.43.206	10.3.43.207
245	10.3.43.208/30	10.3.43.209 – 10.3.43.210	10.3.43.211
246	10.3.43.212/30	10.3.43.213 – 10.3.43.214	10.3.43.215
247	10.3.43.216/30	10.3.43.217 – 10.3.43.218	10.3.43.219
248	10.3.43.220/30	10.3.43.221 – 10.3.43.222	10.3.43.223
249	10.3.43.224/30	10.3.43.225 – 10.3.43.226	10.3.43.227
250	10.3.43.228/30	10.3.43.229 – 10.3.43.230	10.3.43.231
251	10.3.43.232/30	10.3.43.233 – 10.3.43.234	10.3.43.235
252	10.3.43.236/30	10.3.43.237 – 10.3.43.238	10.3.43.239
253	10.3.43.240/30	10.3.43.241 – 10.3.43.242	10.3.43.243
254	10.3.43.244/30	10.3.43.245 – 10.3.43.246	10.3.43.247
255	10.3.43.248/30	10.3.43.249 – 10.3.43.250	10.3.43.251
256	10.3.43.252/30	10.3.43.253 – 10.3.43.254	10.3.43.255

showing 256 of 512

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 →