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)10.21.0.0/17

network10.21.0.0/17

broadcast10.21.127.255

first host10.21.0.1

last host10.21.127.254

subnet mask255.255.128.0

wildcard0.0.127.255

addresses32,768

usable hosts32,766

classA

ipcalc 10.21.0.0/17

address00001010.00010101.00000000.00000000

subnet mask11111111.11111111.10000000.00000000

network00001010.00010101.00000000.00000000

broadcast00001010.00010101.01111111.11111111

green = network part, grey = host part

hex0x0a150000

decimal169148416

reverse dns0.0.21.10.in-addr.arpa

ipv4-mapped::ffff:a15:0

/17 split into /29 · 4,096 subnets

close ×

#	network	host range	broadcast
1	10.21.0.0/29	10.21.0.1 – 10.21.0.6	10.21.0.7
2	10.21.0.8/29	10.21.0.9 – 10.21.0.14	10.21.0.15
3	10.21.0.16/29	10.21.0.17 – 10.21.0.22	10.21.0.23
4	10.21.0.24/29	10.21.0.25 – 10.21.0.30	10.21.0.31
5	10.21.0.32/29	10.21.0.33 – 10.21.0.38	10.21.0.39
6	10.21.0.40/29	10.21.0.41 – 10.21.0.46	10.21.0.47
7	10.21.0.48/29	10.21.0.49 – 10.21.0.54	10.21.0.55
8	10.21.0.56/29	10.21.0.57 – 10.21.0.62	10.21.0.63
9	10.21.0.64/29	10.21.0.65 – 10.21.0.70	10.21.0.71
10	10.21.0.72/29	10.21.0.73 – 10.21.0.78	10.21.0.79
11	10.21.0.80/29	10.21.0.81 – 10.21.0.86	10.21.0.87
12	10.21.0.88/29	10.21.0.89 – 10.21.0.94	10.21.0.95
13	10.21.0.96/29	10.21.0.97 – 10.21.0.102	10.21.0.103
14	10.21.0.104/29	10.21.0.105 – 10.21.0.110	10.21.0.111
15	10.21.0.112/29	10.21.0.113 – 10.21.0.118	10.21.0.119
16	10.21.0.120/29	10.21.0.121 – 10.21.0.126	10.21.0.127
17	10.21.0.128/29	10.21.0.129 – 10.21.0.134	10.21.0.135
18	10.21.0.136/29	10.21.0.137 – 10.21.0.142	10.21.0.143
19	10.21.0.144/29	10.21.0.145 – 10.21.0.150	10.21.0.151
20	10.21.0.152/29	10.21.0.153 – 10.21.0.158	10.21.0.159
21	10.21.0.160/29	10.21.0.161 – 10.21.0.166	10.21.0.167
22	10.21.0.168/29	10.21.0.169 – 10.21.0.174	10.21.0.175
23	10.21.0.176/29	10.21.0.177 – 10.21.0.182	10.21.0.183
24	10.21.0.184/29	10.21.0.185 – 10.21.0.190	10.21.0.191
25	10.21.0.192/29	10.21.0.193 – 10.21.0.198	10.21.0.199
26	10.21.0.200/29	10.21.0.201 – 10.21.0.206	10.21.0.207
27	10.21.0.208/29	10.21.0.209 – 10.21.0.214	10.21.0.215
28	10.21.0.216/29	10.21.0.217 – 10.21.0.222	10.21.0.223
29	10.21.0.224/29	10.21.0.225 – 10.21.0.230	10.21.0.231
30	10.21.0.232/29	10.21.0.233 – 10.21.0.238	10.21.0.239
31	10.21.0.240/29	10.21.0.241 – 10.21.0.246	10.21.0.247
32	10.21.0.248/29	10.21.0.249 – 10.21.0.254	10.21.0.255
33	10.21.1.0/29	10.21.1.1 – 10.21.1.6	10.21.1.7
34	10.21.1.8/29	10.21.1.9 – 10.21.1.14	10.21.1.15
35	10.21.1.16/29	10.21.1.17 – 10.21.1.22	10.21.1.23
36	10.21.1.24/29	10.21.1.25 – 10.21.1.30	10.21.1.31
37	10.21.1.32/29	10.21.1.33 – 10.21.1.38	10.21.1.39
38	10.21.1.40/29	10.21.1.41 – 10.21.1.46	10.21.1.47
39	10.21.1.48/29	10.21.1.49 – 10.21.1.54	10.21.1.55
40	10.21.1.56/29	10.21.1.57 – 10.21.1.62	10.21.1.63
41	10.21.1.64/29	10.21.1.65 – 10.21.1.70	10.21.1.71
42	10.21.1.72/29	10.21.1.73 – 10.21.1.78	10.21.1.79
43	10.21.1.80/29	10.21.1.81 – 10.21.1.86	10.21.1.87
44	10.21.1.88/29	10.21.1.89 – 10.21.1.94	10.21.1.95
45	10.21.1.96/29	10.21.1.97 – 10.21.1.102	10.21.1.103
46	10.21.1.104/29	10.21.1.105 – 10.21.1.110	10.21.1.111
47	10.21.1.112/29	10.21.1.113 – 10.21.1.118	10.21.1.119
48	10.21.1.120/29	10.21.1.121 – 10.21.1.126	10.21.1.127
49	10.21.1.128/29	10.21.1.129 – 10.21.1.134	10.21.1.135
50	10.21.1.136/29	10.21.1.137 – 10.21.1.142	10.21.1.143
51	10.21.1.144/29	10.21.1.145 – 10.21.1.150	10.21.1.151
52	10.21.1.152/29	10.21.1.153 – 10.21.1.158	10.21.1.159
53	10.21.1.160/29	10.21.1.161 – 10.21.1.166	10.21.1.167
54	10.21.1.168/29	10.21.1.169 – 10.21.1.174	10.21.1.175
55	10.21.1.176/29	10.21.1.177 – 10.21.1.182	10.21.1.183
56	10.21.1.184/29	10.21.1.185 – 10.21.1.190	10.21.1.191
57	10.21.1.192/29	10.21.1.193 – 10.21.1.198	10.21.1.199
58	10.21.1.200/29	10.21.1.201 – 10.21.1.206	10.21.1.207
59	10.21.1.208/29	10.21.1.209 – 10.21.1.214	10.21.1.215
60	10.21.1.216/29	10.21.1.217 – 10.21.1.222	10.21.1.223
61	10.21.1.224/29	10.21.1.225 – 10.21.1.230	10.21.1.231
62	10.21.1.232/29	10.21.1.233 – 10.21.1.238	10.21.1.239
63	10.21.1.240/29	10.21.1.241 – 10.21.1.246	10.21.1.247
64	10.21.1.248/29	10.21.1.249 – 10.21.1.254	10.21.1.255
65	10.21.2.0/29	10.21.2.1 – 10.21.2.6	10.21.2.7
66	10.21.2.8/29	10.21.2.9 – 10.21.2.14	10.21.2.15
67	10.21.2.16/29	10.21.2.17 – 10.21.2.22	10.21.2.23
68	10.21.2.24/29	10.21.2.25 – 10.21.2.30	10.21.2.31
69	10.21.2.32/29	10.21.2.33 – 10.21.2.38	10.21.2.39
70	10.21.2.40/29	10.21.2.41 – 10.21.2.46	10.21.2.47
71	10.21.2.48/29	10.21.2.49 – 10.21.2.54	10.21.2.55
72	10.21.2.56/29	10.21.2.57 – 10.21.2.62	10.21.2.63
73	10.21.2.64/29	10.21.2.65 – 10.21.2.70	10.21.2.71
74	10.21.2.72/29	10.21.2.73 – 10.21.2.78	10.21.2.79
75	10.21.2.80/29	10.21.2.81 – 10.21.2.86	10.21.2.87
76	10.21.2.88/29	10.21.2.89 – 10.21.2.94	10.21.2.95
77	10.21.2.96/29	10.21.2.97 – 10.21.2.102	10.21.2.103
78	10.21.2.104/29	10.21.2.105 – 10.21.2.110	10.21.2.111
79	10.21.2.112/29	10.21.2.113 – 10.21.2.118	10.21.2.119
80	10.21.2.120/29	10.21.2.121 – 10.21.2.126	10.21.2.127
81	10.21.2.128/29	10.21.2.129 – 10.21.2.134	10.21.2.135
82	10.21.2.136/29	10.21.2.137 – 10.21.2.142	10.21.2.143
83	10.21.2.144/29	10.21.2.145 – 10.21.2.150	10.21.2.151
84	10.21.2.152/29	10.21.2.153 – 10.21.2.158	10.21.2.159
85	10.21.2.160/29	10.21.2.161 – 10.21.2.166	10.21.2.167
86	10.21.2.168/29	10.21.2.169 – 10.21.2.174	10.21.2.175
87	10.21.2.176/29	10.21.2.177 – 10.21.2.182	10.21.2.183
88	10.21.2.184/29	10.21.2.185 – 10.21.2.190	10.21.2.191
89	10.21.2.192/29	10.21.2.193 – 10.21.2.198	10.21.2.199
90	10.21.2.200/29	10.21.2.201 – 10.21.2.206	10.21.2.207
91	10.21.2.208/29	10.21.2.209 – 10.21.2.214	10.21.2.215
92	10.21.2.216/29	10.21.2.217 – 10.21.2.222	10.21.2.223
93	10.21.2.224/29	10.21.2.225 – 10.21.2.230	10.21.2.231
94	10.21.2.232/29	10.21.2.233 – 10.21.2.238	10.21.2.239
95	10.21.2.240/29	10.21.2.241 – 10.21.2.246	10.21.2.247
96	10.21.2.248/29	10.21.2.249 – 10.21.2.254	10.21.2.255
97	10.21.3.0/29	10.21.3.1 – 10.21.3.6	10.21.3.7
98	10.21.3.8/29	10.21.3.9 – 10.21.3.14	10.21.3.15
99	10.21.3.16/29	10.21.3.17 – 10.21.3.22	10.21.3.23
100	10.21.3.24/29	10.21.3.25 – 10.21.3.30	10.21.3.31
101	10.21.3.32/29	10.21.3.33 – 10.21.3.38	10.21.3.39
102	10.21.3.40/29	10.21.3.41 – 10.21.3.46	10.21.3.47
103	10.21.3.48/29	10.21.3.49 – 10.21.3.54	10.21.3.55
104	10.21.3.56/29	10.21.3.57 – 10.21.3.62	10.21.3.63
105	10.21.3.64/29	10.21.3.65 – 10.21.3.70	10.21.3.71
106	10.21.3.72/29	10.21.3.73 – 10.21.3.78	10.21.3.79
107	10.21.3.80/29	10.21.3.81 – 10.21.3.86	10.21.3.87
108	10.21.3.88/29	10.21.3.89 – 10.21.3.94	10.21.3.95
109	10.21.3.96/29	10.21.3.97 – 10.21.3.102	10.21.3.103
110	10.21.3.104/29	10.21.3.105 – 10.21.3.110	10.21.3.111
111	10.21.3.112/29	10.21.3.113 – 10.21.3.118	10.21.3.119
112	10.21.3.120/29	10.21.3.121 – 10.21.3.126	10.21.3.127
113	10.21.3.128/29	10.21.3.129 – 10.21.3.134	10.21.3.135
114	10.21.3.136/29	10.21.3.137 – 10.21.3.142	10.21.3.143
115	10.21.3.144/29	10.21.3.145 – 10.21.3.150	10.21.3.151
116	10.21.3.152/29	10.21.3.153 – 10.21.3.158	10.21.3.159
117	10.21.3.160/29	10.21.3.161 – 10.21.3.166	10.21.3.167
118	10.21.3.168/29	10.21.3.169 – 10.21.3.174	10.21.3.175
119	10.21.3.176/29	10.21.3.177 – 10.21.3.182	10.21.3.183
120	10.21.3.184/29	10.21.3.185 – 10.21.3.190	10.21.3.191
121	10.21.3.192/29	10.21.3.193 – 10.21.3.198	10.21.3.199
122	10.21.3.200/29	10.21.3.201 – 10.21.3.206	10.21.3.207
123	10.21.3.208/29	10.21.3.209 – 10.21.3.214	10.21.3.215
124	10.21.3.216/29	10.21.3.217 – 10.21.3.222	10.21.3.223
125	10.21.3.224/29	10.21.3.225 – 10.21.3.230	10.21.3.231
126	10.21.3.232/29	10.21.3.233 – 10.21.3.238	10.21.3.239
127	10.21.3.240/29	10.21.3.241 – 10.21.3.246	10.21.3.247
128	10.21.3.248/29	10.21.3.249 – 10.21.3.254	10.21.3.255
129	10.21.4.0/29	10.21.4.1 – 10.21.4.6	10.21.4.7
130	10.21.4.8/29	10.21.4.9 – 10.21.4.14	10.21.4.15
131	10.21.4.16/29	10.21.4.17 – 10.21.4.22	10.21.4.23
132	10.21.4.24/29	10.21.4.25 – 10.21.4.30	10.21.4.31
133	10.21.4.32/29	10.21.4.33 – 10.21.4.38	10.21.4.39
134	10.21.4.40/29	10.21.4.41 – 10.21.4.46	10.21.4.47
135	10.21.4.48/29	10.21.4.49 – 10.21.4.54	10.21.4.55
136	10.21.4.56/29	10.21.4.57 – 10.21.4.62	10.21.4.63
137	10.21.4.64/29	10.21.4.65 – 10.21.4.70	10.21.4.71
138	10.21.4.72/29	10.21.4.73 – 10.21.4.78	10.21.4.79
139	10.21.4.80/29	10.21.4.81 – 10.21.4.86	10.21.4.87
140	10.21.4.88/29	10.21.4.89 – 10.21.4.94	10.21.4.95
141	10.21.4.96/29	10.21.4.97 – 10.21.4.102	10.21.4.103
142	10.21.4.104/29	10.21.4.105 – 10.21.4.110	10.21.4.111
143	10.21.4.112/29	10.21.4.113 – 10.21.4.118	10.21.4.119
144	10.21.4.120/29	10.21.4.121 – 10.21.4.126	10.21.4.127
145	10.21.4.128/29	10.21.4.129 – 10.21.4.134	10.21.4.135
146	10.21.4.136/29	10.21.4.137 – 10.21.4.142	10.21.4.143
147	10.21.4.144/29	10.21.4.145 – 10.21.4.150	10.21.4.151
148	10.21.4.152/29	10.21.4.153 – 10.21.4.158	10.21.4.159
149	10.21.4.160/29	10.21.4.161 – 10.21.4.166	10.21.4.167
150	10.21.4.168/29	10.21.4.169 – 10.21.4.174	10.21.4.175
151	10.21.4.176/29	10.21.4.177 – 10.21.4.182	10.21.4.183
152	10.21.4.184/29	10.21.4.185 – 10.21.4.190	10.21.4.191
153	10.21.4.192/29	10.21.4.193 – 10.21.4.198	10.21.4.199
154	10.21.4.200/29	10.21.4.201 – 10.21.4.206	10.21.4.207
155	10.21.4.208/29	10.21.4.209 – 10.21.4.214	10.21.4.215
156	10.21.4.216/29	10.21.4.217 – 10.21.4.222	10.21.4.223
157	10.21.4.224/29	10.21.4.225 – 10.21.4.230	10.21.4.231
158	10.21.4.232/29	10.21.4.233 – 10.21.4.238	10.21.4.239
159	10.21.4.240/29	10.21.4.241 – 10.21.4.246	10.21.4.247
160	10.21.4.248/29	10.21.4.249 – 10.21.4.254	10.21.4.255
161	10.21.5.0/29	10.21.5.1 – 10.21.5.6	10.21.5.7
162	10.21.5.8/29	10.21.5.9 – 10.21.5.14	10.21.5.15
163	10.21.5.16/29	10.21.5.17 – 10.21.5.22	10.21.5.23
164	10.21.5.24/29	10.21.5.25 – 10.21.5.30	10.21.5.31
165	10.21.5.32/29	10.21.5.33 – 10.21.5.38	10.21.5.39
166	10.21.5.40/29	10.21.5.41 – 10.21.5.46	10.21.5.47
167	10.21.5.48/29	10.21.5.49 – 10.21.5.54	10.21.5.55
168	10.21.5.56/29	10.21.5.57 – 10.21.5.62	10.21.5.63
169	10.21.5.64/29	10.21.5.65 – 10.21.5.70	10.21.5.71
170	10.21.5.72/29	10.21.5.73 – 10.21.5.78	10.21.5.79
171	10.21.5.80/29	10.21.5.81 – 10.21.5.86	10.21.5.87
172	10.21.5.88/29	10.21.5.89 – 10.21.5.94	10.21.5.95
173	10.21.5.96/29	10.21.5.97 – 10.21.5.102	10.21.5.103
174	10.21.5.104/29	10.21.5.105 – 10.21.5.110	10.21.5.111
175	10.21.5.112/29	10.21.5.113 – 10.21.5.118	10.21.5.119
176	10.21.5.120/29	10.21.5.121 – 10.21.5.126	10.21.5.127
177	10.21.5.128/29	10.21.5.129 – 10.21.5.134	10.21.5.135
178	10.21.5.136/29	10.21.5.137 – 10.21.5.142	10.21.5.143
179	10.21.5.144/29	10.21.5.145 – 10.21.5.150	10.21.5.151
180	10.21.5.152/29	10.21.5.153 – 10.21.5.158	10.21.5.159
181	10.21.5.160/29	10.21.5.161 – 10.21.5.166	10.21.5.167
182	10.21.5.168/29	10.21.5.169 – 10.21.5.174	10.21.5.175
183	10.21.5.176/29	10.21.5.177 – 10.21.5.182	10.21.5.183
184	10.21.5.184/29	10.21.5.185 – 10.21.5.190	10.21.5.191
185	10.21.5.192/29	10.21.5.193 – 10.21.5.198	10.21.5.199
186	10.21.5.200/29	10.21.5.201 – 10.21.5.206	10.21.5.207
187	10.21.5.208/29	10.21.5.209 – 10.21.5.214	10.21.5.215
188	10.21.5.216/29	10.21.5.217 – 10.21.5.222	10.21.5.223
189	10.21.5.224/29	10.21.5.225 – 10.21.5.230	10.21.5.231
190	10.21.5.232/29	10.21.5.233 – 10.21.5.238	10.21.5.239
191	10.21.5.240/29	10.21.5.241 – 10.21.5.246	10.21.5.247
192	10.21.5.248/29	10.21.5.249 – 10.21.5.254	10.21.5.255
193	10.21.6.0/29	10.21.6.1 – 10.21.6.6	10.21.6.7
194	10.21.6.8/29	10.21.6.9 – 10.21.6.14	10.21.6.15
195	10.21.6.16/29	10.21.6.17 – 10.21.6.22	10.21.6.23
196	10.21.6.24/29	10.21.6.25 – 10.21.6.30	10.21.6.31
197	10.21.6.32/29	10.21.6.33 – 10.21.6.38	10.21.6.39
198	10.21.6.40/29	10.21.6.41 – 10.21.6.46	10.21.6.47
199	10.21.6.48/29	10.21.6.49 – 10.21.6.54	10.21.6.55
200	10.21.6.56/29	10.21.6.57 – 10.21.6.62	10.21.6.63
201	10.21.6.64/29	10.21.6.65 – 10.21.6.70	10.21.6.71
202	10.21.6.72/29	10.21.6.73 – 10.21.6.78	10.21.6.79
203	10.21.6.80/29	10.21.6.81 – 10.21.6.86	10.21.6.87
204	10.21.6.88/29	10.21.6.89 – 10.21.6.94	10.21.6.95
205	10.21.6.96/29	10.21.6.97 – 10.21.6.102	10.21.6.103
206	10.21.6.104/29	10.21.6.105 – 10.21.6.110	10.21.6.111
207	10.21.6.112/29	10.21.6.113 – 10.21.6.118	10.21.6.119
208	10.21.6.120/29	10.21.6.121 – 10.21.6.126	10.21.6.127
209	10.21.6.128/29	10.21.6.129 – 10.21.6.134	10.21.6.135
210	10.21.6.136/29	10.21.6.137 – 10.21.6.142	10.21.6.143
211	10.21.6.144/29	10.21.6.145 – 10.21.6.150	10.21.6.151
212	10.21.6.152/29	10.21.6.153 – 10.21.6.158	10.21.6.159
213	10.21.6.160/29	10.21.6.161 – 10.21.6.166	10.21.6.167
214	10.21.6.168/29	10.21.6.169 – 10.21.6.174	10.21.6.175
215	10.21.6.176/29	10.21.6.177 – 10.21.6.182	10.21.6.183
216	10.21.6.184/29	10.21.6.185 – 10.21.6.190	10.21.6.191
217	10.21.6.192/29	10.21.6.193 – 10.21.6.198	10.21.6.199
218	10.21.6.200/29	10.21.6.201 – 10.21.6.206	10.21.6.207
219	10.21.6.208/29	10.21.6.209 – 10.21.6.214	10.21.6.215
220	10.21.6.216/29	10.21.6.217 – 10.21.6.222	10.21.6.223
221	10.21.6.224/29	10.21.6.225 – 10.21.6.230	10.21.6.231
222	10.21.6.232/29	10.21.6.233 – 10.21.6.238	10.21.6.239
223	10.21.6.240/29	10.21.6.241 – 10.21.6.246	10.21.6.247
224	10.21.6.248/29	10.21.6.249 – 10.21.6.254	10.21.6.255
225	10.21.7.0/29	10.21.7.1 – 10.21.7.6	10.21.7.7
226	10.21.7.8/29	10.21.7.9 – 10.21.7.14	10.21.7.15
227	10.21.7.16/29	10.21.7.17 – 10.21.7.22	10.21.7.23
228	10.21.7.24/29	10.21.7.25 – 10.21.7.30	10.21.7.31
229	10.21.7.32/29	10.21.7.33 – 10.21.7.38	10.21.7.39
230	10.21.7.40/29	10.21.7.41 – 10.21.7.46	10.21.7.47
231	10.21.7.48/29	10.21.7.49 – 10.21.7.54	10.21.7.55
232	10.21.7.56/29	10.21.7.57 – 10.21.7.62	10.21.7.63
233	10.21.7.64/29	10.21.7.65 – 10.21.7.70	10.21.7.71
234	10.21.7.72/29	10.21.7.73 – 10.21.7.78	10.21.7.79
235	10.21.7.80/29	10.21.7.81 – 10.21.7.86	10.21.7.87
236	10.21.7.88/29	10.21.7.89 – 10.21.7.94	10.21.7.95
237	10.21.7.96/29	10.21.7.97 – 10.21.7.102	10.21.7.103
238	10.21.7.104/29	10.21.7.105 – 10.21.7.110	10.21.7.111
239	10.21.7.112/29	10.21.7.113 – 10.21.7.118	10.21.7.119
240	10.21.7.120/29	10.21.7.121 – 10.21.7.126	10.21.7.127
241	10.21.7.128/29	10.21.7.129 – 10.21.7.134	10.21.7.135
242	10.21.7.136/29	10.21.7.137 – 10.21.7.142	10.21.7.143
243	10.21.7.144/29	10.21.7.145 – 10.21.7.150	10.21.7.151
244	10.21.7.152/29	10.21.7.153 – 10.21.7.158	10.21.7.159
245	10.21.7.160/29	10.21.7.161 – 10.21.7.166	10.21.7.167
246	10.21.7.168/29	10.21.7.169 – 10.21.7.174	10.21.7.175
247	10.21.7.176/29	10.21.7.177 – 10.21.7.182	10.21.7.183
248	10.21.7.184/29	10.21.7.185 – 10.21.7.190	10.21.7.191
249	10.21.7.192/29	10.21.7.193 – 10.21.7.198	10.21.7.199
250	10.21.7.200/29	10.21.7.201 – 10.21.7.206	10.21.7.207
251	10.21.7.208/29	10.21.7.209 – 10.21.7.214	10.21.7.215
252	10.21.7.216/29	10.21.7.217 – 10.21.7.222	10.21.7.223
253	10.21.7.224/29	10.21.7.225 – 10.21.7.230	10.21.7.231
254	10.21.7.232/29	10.21.7.233 – 10.21.7.238	10.21.7.239
255	10.21.7.240/29	10.21.7.241 – 10.21.7.246	10.21.7.247
256	10.21.7.248/29	10.21.7.249 – 10.21.7.254	10.21.7.255

showing 256 of 4,096

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 /17
/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	1
/18	255.255.192.0	16,384	16,382	2 split →
/19	255.255.224.0	8,192	8,190	4 split →
/20	255.255.240.0	4,096	4,094	8 split →
/21	255.255.248.0	2,048	2,046	16 split →
/22	255.255.252.0	1,024	1,022	32 split →
/23	255.255.254.0	512	510	64 split →
/24	255.255.255.0	256	254	128 split →
/25	255.255.255.128	128	126	256 split →
/26	255.255.255.192	64	62	512 split →
/27	255.255.255.224	32	30	1,024 split →
/28	255.255.255.240	16	14	2,048 split →
/29	255.255.255.248	8	6	4,096 split →
/30	255.255.255.252	4	2	8,192 split →
/31	255.255.255.254	2	2	16,384 split →
/32	255.255.255.255	1	1	32,768 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 →