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)10.21.0.0/19

network10.21.0.0/19

broadcast10.21.31.255

first host10.21.0.1

last host10.21.31.254

subnet mask255.255.224.0

wildcard0.0.31.255

addresses8,192

usable hosts8,190

classA

ipcalc 10.21.0.0/19

address00001010.00010101.00000000.00000000

subnet mask11111111.11111111.11100000.00000000

network00001010.00010101.00000000.00000000

broadcast00001010.00010101.00011111.11111111

green = network part, grey = host part

hex0x0a150000

decimal169148416

reverse dns0.0.21.10.in-addr.arpa

ipv4-mapped::ffff:a15:0

/19 split into /30 · 2,048 subnets

close ×

#	network	host range	broadcast
1	10.21.0.0/30	10.21.0.1 – 10.21.0.2	10.21.0.3
2	10.21.0.4/30	10.21.0.5 – 10.21.0.6	10.21.0.7
3	10.21.0.8/30	10.21.0.9 – 10.21.0.10	10.21.0.11
4	10.21.0.12/30	10.21.0.13 – 10.21.0.14	10.21.0.15
5	10.21.0.16/30	10.21.0.17 – 10.21.0.18	10.21.0.19
6	10.21.0.20/30	10.21.0.21 – 10.21.0.22	10.21.0.23
7	10.21.0.24/30	10.21.0.25 – 10.21.0.26	10.21.0.27
8	10.21.0.28/30	10.21.0.29 – 10.21.0.30	10.21.0.31
9	10.21.0.32/30	10.21.0.33 – 10.21.0.34	10.21.0.35
10	10.21.0.36/30	10.21.0.37 – 10.21.0.38	10.21.0.39
11	10.21.0.40/30	10.21.0.41 – 10.21.0.42	10.21.0.43
12	10.21.0.44/30	10.21.0.45 – 10.21.0.46	10.21.0.47
13	10.21.0.48/30	10.21.0.49 – 10.21.0.50	10.21.0.51
14	10.21.0.52/30	10.21.0.53 – 10.21.0.54	10.21.0.55
15	10.21.0.56/30	10.21.0.57 – 10.21.0.58	10.21.0.59
16	10.21.0.60/30	10.21.0.61 – 10.21.0.62	10.21.0.63
17	10.21.0.64/30	10.21.0.65 – 10.21.0.66	10.21.0.67
18	10.21.0.68/30	10.21.0.69 – 10.21.0.70	10.21.0.71
19	10.21.0.72/30	10.21.0.73 – 10.21.0.74	10.21.0.75
20	10.21.0.76/30	10.21.0.77 – 10.21.0.78	10.21.0.79
21	10.21.0.80/30	10.21.0.81 – 10.21.0.82	10.21.0.83
22	10.21.0.84/30	10.21.0.85 – 10.21.0.86	10.21.0.87
23	10.21.0.88/30	10.21.0.89 – 10.21.0.90	10.21.0.91
24	10.21.0.92/30	10.21.0.93 – 10.21.0.94	10.21.0.95
25	10.21.0.96/30	10.21.0.97 – 10.21.0.98	10.21.0.99
26	10.21.0.100/30	10.21.0.101 – 10.21.0.102	10.21.0.103
27	10.21.0.104/30	10.21.0.105 – 10.21.0.106	10.21.0.107
28	10.21.0.108/30	10.21.0.109 – 10.21.0.110	10.21.0.111
29	10.21.0.112/30	10.21.0.113 – 10.21.0.114	10.21.0.115
30	10.21.0.116/30	10.21.0.117 – 10.21.0.118	10.21.0.119
31	10.21.0.120/30	10.21.0.121 – 10.21.0.122	10.21.0.123
32	10.21.0.124/30	10.21.0.125 – 10.21.0.126	10.21.0.127
33	10.21.0.128/30	10.21.0.129 – 10.21.0.130	10.21.0.131
34	10.21.0.132/30	10.21.0.133 – 10.21.0.134	10.21.0.135
35	10.21.0.136/30	10.21.0.137 – 10.21.0.138	10.21.0.139
36	10.21.0.140/30	10.21.0.141 – 10.21.0.142	10.21.0.143
37	10.21.0.144/30	10.21.0.145 – 10.21.0.146	10.21.0.147
38	10.21.0.148/30	10.21.0.149 – 10.21.0.150	10.21.0.151
39	10.21.0.152/30	10.21.0.153 – 10.21.0.154	10.21.0.155
40	10.21.0.156/30	10.21.0.157 – 10.21.0.158	10.21.0.159
41	10.21.0.160/30	10.21.0.161 – 10.21.0.162	10.21.0.163
42	10.21.0.164/30	10.21.0.165 – 10.21.0.166	10.21.0.167
43	10.21.0.168/30	10.21.0.169 – 10.21.0.170	10.21.0.171
44	10.21.0.172/30	10.21.0.173 – 10.21.0.174	10.21.0.175
45	10.21.0.176/30	10.21.0.177 – 10.21.0.178	10.21.0.179
46	10.21.0.180/30	10.21.0.181 – 10.21.0.182	10.21.0.183
47	10.21.0.184/30	10.21.0.185 – 10.21.0.186	10.21.0.187
48	10.21.0.188/30	10.21.0.189 – 10.21.0.190	10.21.0.191
49	10.21.0.192/30	10.21.0.193 – 10.21.0.194	10.21.0.195
50	10.21.0.196/30	10.21.0.197 – 10.21.0.198	10.21.0.199
51	10.21.0.200/30	10.21.0.201 – 10.21.0.202	10.21.0.203
52	10.21.0.204/30	10.21.0.205 – 10.21.0.206	10.21.0.207
53	10.21.0.208/30	10.21.0.209 – 10.21.0.210	10.21.0.211
54	10.21.0.212/30	10.21.0.213 – 10.21.0.214	10.21.0.215
55	10.21.0.216/30	10.21.0.217 – 10.21.0.218	10.21.0.219
56	10.21.0.220/30	10.21.0.221 – 10.21.0.222	10.21.0.223
57	10.21.0.224/30	10.21.0.225 – 10.21.0.226	10.21.0.227
58	10.21.0.228/30	10.21.0.229 – 10.21.0.230	10.21.0.231
59	10.21.0.232/30	10.21.0.233 – 10.21.0.234	10.21.0.235
60	10.21.0.236/30	10.21.0.237 – 10.21.0.238	10.21.0.239
61	10.21.0.240/30	10.21.0.241 – 10.21.0.242	10.21.0.243
62	10.21.0.244/30	10.21.0.245 – 10.21.0.246	10.21.0.247
63	10.21.0.248/30	10.21.0.249 – 10.21.0.250	10.21.0.251
64	10.21.0.252/30	10.21.0.253 – 10.21.0.254	10.21.0.255
65	10.21.1.0/30	10.21.1.1 – 10.21.1.2	10.21.1.3
66	10.21.1.4/30	10.21.1.5 – 10.21.1.6	10.21.1.7
67	10.21.1.8/30	10.21.1.9 – 10.21.1.10	10.21.1.11
68	10.21.1.12/30	10.21.1.13 – 10.21.1.14	10.21.1.15
69	10.21.1.16/30	10.21.1.17 – 10.21.1.18	10.21.1.19
70	10.21.1.20/30	10.21.1.21 – 10.21.1.22	10.21.1.23
71	10.21.1.24/30	10.21.1.25 – 10.21.1.26	10.21.1.27
72	10.21.1.28/30	10.21.1.29 – 10.21.1.30	10.21.1.31
73	10.21.1.32/30	10.21.1.33 – 10.21.1.34	10.21.1.35
74	10.21.1.36/30	10.21.1.37 – 10.21.1.38	10.21.1.39
75	10.21.1.40/30	10.21.1.41 – 10.21.1.42	10.21.1.43
76	10.21.1.44/30	10.21.1.45 – 10.21.1.46	10.21.1.47
77	10.21.1.48/30	10.21.1.49 – 10.21.1.50	10.21.1.51
78	10.21.1.52/30	10.21.1.53 – 10.21.1.54	10.21.1.55
79	10.21.1.56/30	10.21.1.57 – 10.21.1.58	10.21.1.59
80	10.21.1.60/30	10.21.1.61 – 10.21.1.62	10.21.1.63
81	10.21.1.64/30	10.21.1.65 – 10.21.1.66	10.21.1.67
82	10.21.1.68/30	10.21.1.69 – 10.21.1.70	10.21.1.71
83	10.21.1.72/30	10.21.1.73 – 10.21.1.74	10.21.1.75
84	10.21.1.76/30	10.21.1.77 – 10.21.1.78	10.21.1.79
85	10.21.1.80/30	10.21.1.81 – 10.21.1.82	10.21.1.83
86	10.21.1.84/30	10.21.1.85 – 10.21.1.86	10.21.1.87
87	10.21.1.88/30	10.21.1.89 – 10.21.1.90	10.21.1.91
88	10.21.1.92/30	10.21.1.93 – 10.21.1.94	10.21.1.95
89	10.21.1.96/30	10.21.1.97 – 10.21.1.98	10.21.1.99
90	10.21.1.100/30	10.21.1.101 – 10.21.1.102	10.21.1.103
91	10.21.1.104/30	10.21.1.105 – 10.21.1.106	10.21.1.107
92	10.21.1.108/30	10.21.1.109 – 10.21.1.110	10.21.1.111
93	10.21.1.112/30	10.21.1.113 – 10.21.1.114	10.21.1.115
94	10.21.1.116/30	10.21.1.117 – 10.21.1.118	10.21.1.119
95	10.21.1.120/30	10.21.1.121 – 10.21.1.122	10.21.1.123
96	10.21.1.124/30	10.21.1.125 – 10.21.1.126	10.21.1.127
97	10.21.1.128/30	10.21.1.129 – 10.21.1.130	10.21.1.131
98	10.21.1.132/30	10.21.1.133 – 10.21.1.134	10.21.1.135
99	10.21.1.136/30	10.21.1.137 – 10.21.1.138	10.21.1.139
100	10.21.1.140/30	10.21.1.141 – 10.21.1.142	10.21.1.143
101	10.21.1.144/30	10.21.1.145 – 10.21.1.146	10.21.1.147
102	10.21.1.148/30	10.21.1.149 – 10.21.1.150	10.21.1.151
103	10.21.1.152/30	10.21.1.153 – 10.21.1.154	10.21.1.155
104	10.21.1.156/30	10.21.1.157 – 10.21.1.158	10.21.1.159
105	10.21.1.160/30	10.21.1.161 – 10.21.1.162	10.21.1.163
106	10.21.1.164/30	10.21.1.165 – 10.21.1.166	10.21.1.167
107	10.21.1.168/30	10.21.1.169 – 10.21.1.170	10.21.1.171
108	10.21.1.172/30	10.21.1.173 – 10.21.1.174	10.21.1.175
109	10.21.1.176/30	10.21.1.177 – 10.21.1.178	10.21.1.179
110	10.21.1.180/30	10.21.1.181 – 10.21.1.182	10.21.1.183
111	10.21.1.184/30	10.21.1.185 – 10.21.1.186	10.21.1.187
112	10.21.1.188/30	10.21.1.189 – 10.21.1.190	10.21.1.191
113	10.21.1.192/30	10.21.1.193 – 10.21.1.194	10.21.1.195
114	10.21.1.196/30	10.21.1.197 – 10.21.1.198	10.21.1.199
115	10.21.1.200/30	10.21.1.201 – 10.21.1.202	10.21.1.203
116	10.21.1.204/30	10.21.1.205 – 10.21.1.206	10.21.1.207
117	10.21.1.208/30	10.21.1.209 – 10.21.1.210	10.21.1.211
118	10.21.1.212/30	10.21.1.213 – 10.21.1.214	10.21.1.215
119	10.21.1.216/30	10.21.1.217 – 10.21.1.218	10.21.1.219
120	10.21.1.220/30	10.21.1.221 – 10.21.1.222	10.21.1.223
121	10.21.1.224/30	10.21.1.225 – 10.21.1.226	10.21.1.227
122	10.21.1.228/30	10.21.1.229 – 10.21.1.230	10.21.1.231
123	10.21.1.232/30	10.21.1.233 – 10.21.1.234	10.21.1.235
124	10.21.1.236/30	10.21.1.237 – 10.21.1.238	10.21.1.239
125	10.21.1.240/30	10.21.1.241 – 10.21.1.242	10.21.1.243
126	10.21.1.244/30	10.21.1.245 – 10.21.1.246	10.21.1.247
127	10.21.1.248/30	10.21.1.249 – 10.21.1.250	10.21.1.251
128	10.21.1.252/30	10.21.1.253 – 10.21.1.254	10.21.1.255
129	10.21.2.0/30	10.21.2.1 – 10.21.2.2	10.21.2.3
130	10.21.2.4/30	10.21.2.5 – 10.21.2.6	10.21.2.7
131	10.21.2.8/30	10.21.2.9 – 10.21.2.10	10.21.2.11
132	10.21.2.12/30	10.21.2.13 – 10.21.2.14	10.21.2.15
133	10.21.2.16/30	10.21.2.17 – 10.21.2.18	10.21.2.19
134	10.21.2.20/30	10.21.2.21 – 10.21.2.22	10.21.2.23
135	10.21.2.24/30	10.21.2.25 – 10.21.2.26	10.21.2.27
136	10.21.2.28/30	10.21.2.29 – 10.21.2.30	10.21.2.31
137	10.21.2.32/30	10.21.2.33 – 10.21.2.34	10.21.2.35
138	10.21.2.36/30	10.21.2.37 – 10.21.2.38	10.21.2.39
139	10.21.2.40/30	10.21.2.41 – 10.21.2.42	10.21.2.43
140	10.21.2.44/30	10.21.2.45 – 10.21.2.46	10.21.2.47
141	10.21.2.48/30	10.21.2.49 – 10.21.2.50	10.21.2.51
142	10.21.2.52/30	10.21.2.53 – 10.21.2.54	10.21.2.55
143	10.21.2.56/30	10.21.2.57 – 10.21.2.58	10.21.2.59
144	10.21.2.60/30	10.21.2.61 – 10.21.2.62	10.21.2.63
145	10.21.2.64/30	10.21.2.65 – 10.21.2.66	10.21.2.67
146	10.21.2.68/30	10.21.2.69 – 10.21.2.70	10.21.2.71
147	10.21.2.72/30	10.21.2.73 – 10.21.2.74	10.21.2.75
148	10.21.2.76/30	10.21.2.77 – 10.21.2.78	10.21.2.79
149	10.21.2.80/30	10.21.2.81 – 10.21.2.82	10.21.2.83
150	10.21.2.84/30	10.21.2.85 – 10.21.2.86	10.21.2.87
151	10.21.2.88/30	10.21.2.89 – 10.21.2.90	10.21.2.91
152	10.21.2.92/30	10.21.2.93 – 10.21.2.94	10.21.2.95
153	10.21.2.96/30	10.21.2.97 – 10.21.2.98	10.21.2.99
154	10.21.2.100/30	10.21.2.101 – 10.21.2.102	10.21.2.103
155	10.21.2.104/30	10.21.2.105 – 10.21.2.106	10.21.2.107
156	10.21.2.108/30	10.21.2.109 – 10.21.2.110	10.21.2.111
157	10.21.2.112/30	10.21.2.113 – 10.21.2.114	10.21.2.115
158	10.21.2.116/30	10.21.2.117 – 10.21.2.118	10.21.2.119
159	10.21.2.120/30	10.21.2.121 – 10.21.2.122	10.21.2.123
160	10.21.2.124/30	10.21.2.125 – 10.21.2.126	10.21.2.127
161	10.21.2.128/30	10.21.2.129 – 10.21.2.130	10.21.2.131
162	10.21.2.132/30	10.21.2.133 – 10.21.2.134	10.21.2.135
163	10.21.2.136/30	10.21.2.137 – 10.21.2.138	10.21.2.139
164	10.21.2.140/30	10.21.2.141 – 10.21.2.142	10.21.2.143
165	10.21.2.144/30	10.21.2.145 – 10.21.2.146	10.21.2.147
166	10.21.2.148/30	10.21.2.149 – 10.21.2.150	10.21.2.151
167	10.21.2.152/30	10.21.2.153 – 10.21.2.154	10.21.2.155
168	10.21.2.156/30	10.21.2.157 – 10.21.2.158	10.21.2.159
169	10.21.2.160/30	10.21.2.161 – 10.21.2.162	10.21.2.163
170	10.21.2.164/30	10.21.2.165 – 10.21.2.166	10.21.2.167
171	10.21.2.168/30	10.21.2.169 – 10.21.2.170	10.21.2.171
172	10.21.2.172/30	10.21.2.173 – 10.21.2.174	10.21.2.175
173	10.21.2.176/30	10.21.2.177 – 10.21.2.178	10.21.2.179
174	10.21.2.180/30	10.21.2.181 – 10.21.2.182	10.21.2.183
175	10.21.2.184/30	10.21.2.185 – 10.21.2.186	10.21.2.187
176	10.21.2.188/30	10.21.2.189 – 10.21.2.190	10.21.2.191
177	10.21.2.192/30	10.21.2.193 – 10.21.2.194	10.21.2.195
178	10.21.2.196/30	10.21.2.197 – 10.21.2.198	10.21.2.199
179	10.21.2.200/30	10.21.2.201 – 10.21.2.202	10.21.2.203
180	10.21.2.204/30	10.21.2.205 – 10.21.2.206	10.21.2.207
181	10.21.2.208/30	10.21.2.209 – 10.21.2.210	10.21.2.211
182	10.21.2.212/30	10.21.2.213 – 10.21.2.214	10.21.2.215
183	10.21.2.216/30	10.21.2.217 – 10.21.2.218	10.21.2.219
184	10.21.2.220/30	10.21.2.221 – 10.21.2.222	10.21.2.223
185	10.21.2.224/30	10.21.2.225 – 10.21.2.226	10.21.2.227
186	10.21.2.228/30	10.21.2.229 – 10.21.2.230	10.21.2.231
187	10.21.2.232/30	10.21.2.233 – 10.21.2.234	10.21.2.235
188	10.21.2.236/30	10.21.2.237 – 10.21.2.238	10.21.2.239
189	10.21.2.240/30	10.21.2.241 – 10.21.2.242	10.21.2.243
190	10.21.2.244/30	10.21.2.245 – 10.21.2.246	10.21.2.247
191	10.21.2.248/30	10.21.2.249 – 10.21.2.250	10.21.2.251
192	10.21.2.252/30	10.21.2.253 – 10.21.2.254	10.21.2.255
193	10.21.3.0/30	10.21.3.1 – 10.21.3.2	10.21.3.3
194	10.21.3.4/30	10.21.3.5 – 10.21.3.6	10.21.3.7
195	10.21.3.8/30	10.21.3.9 – 10.21.3.10	10.21.3.11
196	10.21.3.12/30	10.21.3.13 – 10.21.3.14	10.21.3.15
197	10.21.3.16/30	10.21.3.17 – 10.21.3.18	10.21.3.19
198	10.21.3.20/30	10.21.3.21 – 10.21.3.22	10.21.3.23
199	10.21.3.24/30	10.21.3.25 – 10.21.3.26	10.21.3.27
200	10.21.3.28/30	10.21.3.29 – 10.21.3.30	10.21.3.31
201	10.21.3.32/30	10.21.3.33 – 10.21.3.34	10.21.3.35
202	10.21.3.36/30	10.21.3.37 – 10.21.3.38	10.21.3.39
203	10.21.3.40/30	10.21.3.41 – 10.21.3.42	10.21.3.43
204	10.21.3.44/30	10.21.3.45 – 10.21.3.46	10.21.3.47
205	10.21.3.48/30	10.21.3.49 – 10.21.3.50	10.21.3.51
206	10.21.3.52/30	10.21.3.53 – 10.21.3.54	10.21.3.55
207	10.21.3.56/30	10.21.3.57 – 10.21.3.58	10.21.3.59
208	10.21.3.60/30	10.21.3.61 – 10.21.3.62	10.21.3.63
209	10.21.3.64/30	10.21.3.65 – 10.21.3.66	10.21.3.67
210	10.21.3.68/30	10.21.3.69 – 10.21.3.70	10.21.3.71
211	10.21.3.72/30	10.21.3.73 – 10.21.3.74	10.21.3.75
212	10.21.3.76/30	10.21.3.77 – 10.21.3.78	10.21.3.79
213	10.21.3.80/30	10.21.3.81 – 10.21.3.82	10.21.3.83
214	10.21.3.84/30	10.21.3.85 – 10.21.3.86	10.21.3.87
215	10.21.3.88/30	10.21.3.89 – 10.21.3.90	10.21.3.91
216	10.21.3.92/30	10.21.3.93 – 10.21.3.94	10.21.3.95
217	10.21.3.96/30	10.21.3.97 – 10.21.3.98	10.21.3.99
218	10.21.3.100/30	10.21.3.101 – 10.21.3.102	10.21.3.103
219	10.21.3.104/30	10.21.3.105 – 10.21.3.106	10.21.3.107
220	10.21.3.108/30	10.21.3.109 – 10.21.3.110	10.21.3.111
221	10.21.3.112/30	10.21.3.113 – 10.21.3.114	10.21.3.115
222	10.21.3.116/30	10.21.3.117 – 10.21.3.118	10.21.3.119
223	10.21.3.120/30	10.21.3.121 – 10.21.3.122	10.21.3.123
224	10.21.3.124/30	10.21.3.125 – 10.21.3.126	10.21.3.127
225	10.21.3.128/30	10.21.3.129 – 10.21.3.130	10.21.3.131
226	10.21.3.132/30	10.21.3.133 – 10.21.3.134	10.21.3.135
227	10.21.3.136/30	10.21.3.137 – 10.21.3.138	10.21.3.139
228	10.21.3.140/30	10.21.3.141 – 10.21.3.142	10.21.3.143
229	10.21.3.144/30	10.21.3.145 – 10.21.3.146	10.21.3.147
230	10.21.3.148/30	10.21.3.149 – 10.21.3.150	10.21.3.151
231	10.21.3.152/30	10.21.3.153 – 10.21.3.154	10.21.3.155
232	10.21.3.156/30	10.21.3.157 – 10.21.3.158	10.21.3.159
233	10.21.3.160/30	10.21.3.161 – 10.21.3.162	10.21.3.163
234	10.21.3.164/30	10.21.3.165 – 10.21.3.166	10.21.3.167
235	10.21.3.168/30	10.21.3.169 – 10.21.3.170	10.21.3.171
236	10.21.3.172/30	10.21.3.173 – 10.21.3.174	10.21.3.175
237	10.21.3.176/30	10.21.3.177 – 10.21.3.178	10.21.3.179
238	10.21.3.180/30	10.21.3.181 – 10.21.3.182	10.21.3.183
239	10.21.3.184/30	10.21.3.185 – 10.21.3.186	10.21.3.187
240	10.21.3.188/30	10.21.3.189 – 10.21.3.190	10.21.3.191
241	10.21.3.192/30	10.21.3.193 – 10.21.3.194	10.21.3.195
242	10.21.3.196/30	10.21.3.197 – 10.21.3.198	10.21.3.199
243	10.21.3.200/30	10.21.3.201 – 10.21.3.202	10.21.3.203
244	10.21.3.204/30	10.21.3.205 – 10.21.3.206	10.21.3.207
245	10.21.3.208/30	10.21.3.209 – 10.21.3.210	10.21.3.211
246	10.21.3.212/30	10.21.3.213 – 10.21.3.214	10.21.3.215
247	10.21.3.216/30	10.21.3.217 – 10.21.3.218	10.21.3.219
248	10.21.3.220/30	10.21.3.221 – 10.21.3.222	10.21.3.223
249	10.21.3.224/30	10.21.3.225 – 10.21.3.226	10.21.3.227
250	10.21.3.228/30	10.21.3.229 – 10.21.3.230	10.21.3.231
251	10.21.3.232/30	10.21.3.233 – 10.21.3.234	10.21.3.235
252	10.21.3.236/30	10.21.3.237 – 10.21.3.238	10.21.3.239
253	10.21.3.240/30	10.21.3.241 – 10.21.3.242	10.21.3.243
254	10.21.3.244/30	10.21.3.245 – 10.21.3.246	10.21.3.247
255	10.21.3.248/30	10.21.3.249 – 10.21.3.250	10.21.3.251
256	10.21.3.252/30	10.21.3.253 – 10.21.3.254	10.21.3.255

showing 256 of 2,048

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 /19
/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	1
/20	255.255.240.0	4,096	4,094	2 split →
/21	255.255.248.0	2,048	2,046	4 split →
/22	255.255.252.0	1,024	1,022	8 split →
/23	255.255.254.0	512	510	16 split →
/24	255.255.255.0	256	254	32 split →
/25	255.255.255.128	128	126	64 split →
/26	255.255.255.192	64	62	128 split →
/27	255.255.255.224	32	30	256 split →
/28	255.255.255.240	16	14	512 split →
/29	255.255.255.248	8	6	1,024 split →
/30	255.255.255.252	4	2	2,048 split →
/31	255.255.255.254	2	2	4,096 split →
/32	255.255.255.255	1	1	8,192 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 →