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)10.6.72.0/21

network10.6.72.0/21

broadcast10.6.79.255

first host10.6.72.1

last host10.6.79.254

subnet mask255.255.248.0

wildcard0.0.7.255

addresses2,048

usable hosts2,046

classA

ipcalc 10.6.72.0/21

address00001010.00000110.01001000.00000000

subnet mask11111111.11111111.11111000.00000000

network00001010.00000110.01001000.00000000

broadcast00001010.00000110.01001111.11111111

green = network part, grey = host part

hex0x0a064800

decimal168183808

reverse dns0.72.6.10.in-addr.arpa

ipv4-mapped::ffff:a06:4800

/21 split into /29 · 256 subnets

close ×

#	network	host range	broadcast
1	10.6.72.0/29	10.6.72.1 – 10.6.72.6	10.6.72.7
2	10.6.72.8/29	10.6.72.9 – 10.6.72.14	10.6.72.15
3	10.6.72.16/29	10.6.72.17 – 10.6.72.22	10.6.72.23
4	10.6.72.24/29	10.6.72.25 – 10.6.72.30	10.6.72.31
5	10.6.72.32/29	10.6.72.33 – 10.6.72.38	10.6.72.39
6	10.6.72.40/29	10.6.72.41 – 10.6.72.46	10.6.72.47
7	10.6.72.48/29	10.6.72.49 – 10.6.72.54	10.6.72.55
8	10.6.72.56/29	10.6.72.57 – 10.6.72.62	10.6.72.63
9	10.6.72.64/29	10.6.72.65 – 10.6.72.70	10.6.72.71
10	10.6.72.72/29	10.6.72.73 – 10.6.72.78	10.6.72.79
11	10.6.72.80/29	10.6.72.81 – 10.6.72.86	10.6.72.87
12	10.6.72.88/29	10.6.72.89 – 10.6.72.94	10.6.72.95
13	10.6.72.96/29	10.6.72.97 – 10.6.72.102	10.6.72.103
14	10.6.72.104/29	10.6.72.105 – 10.6.72.110	10.6.72.111
15	10.6.72.112/29	10.6.72.113 – 10.6.72.118	10.6.72.119
16	10.6.72.120/29	10.6.72.121 – 10.6.72.126	10.6.72.127
17	10.6.72.128/29	10.6.72.129 – 10.6.72.134	10.6.72.135
18	10.6.72.136/29	10.6.72.137 – 10.6.72.142	10.6.72.143
19	10.6.72.144/29	10.6.72.145 – 10.6.72.150	10.6.72.151
20	10.6.72.152/29	10.6.72.153 – 10.6.72.158	10.6.72.159
21	10.6.72.160/29	10.6.72.161 – 10.6.72.166	10.6.72.167
22	10.6.72.168/29	10.6.72.169 – 10.6.72.174	10.6.72.175
23	10.6.72.176/29	10.6.72.177 – 10.6.72.182	10.6.72.183
24	10.6.72.184/29	10.6.72.185 – 10.6.72.190	10.6.72.191
25	10.6.72.192/29	10.6.72.193 – 10.6.72.198	10.6.72.199
26	10.6.72.200/29	10.6.72.201 – 10.6.72.206	10.6.72.207
27	10.6.72.208/29	10.6.72.209 – 10.6.72.214	10.6.72.215
28	10.6.72.216/29	10.6.72.217 – 10.6.72.222	10.6.72.223
29	10.6.72.224/29	10.6.72.225 – 10.6.72.230	10.6.72.231
30	10.6.72.232/29	10.6.72.233 – 10.6.72.238	10.6.72.239
31	10.6.72.240/29	10.6.72.241 – 10.6.72.246	10.6.72.247
32	10.6.72.248/29	10.6.72.249 – 10.6.72.254	10.6.72.255
33	10.6.73.0/29	10.6.73.1 – 10.6.73.6	10.6.73.7
34	10.6.73.8/29	10.6.73.9 – 10.6.73.14	10.6.73.15
35	10.6.73.16/29	10.6.73.17 – 10.6.73.22	10.6.73.23
36	10.6.73.24/29	10.6.73.25 – 10.6.73.30	10.6.73.31
37	10.6.73.32/29	10.6.73.33 – 10.6.73.38	10.6.73.39
38	10.6.73.40/29	10.6.73.41 – 10.6.73.46	10.6.73.47
39	10.6.73.48/29	10.6.73.49 – 10.6.73.54	10.6.73.55
40	10.6.73.56/29	10.6.73.57 – 10.6.73.62	10.6.73.63
41	10.6.73.64/29	10.6.73.65 – 10.6.73.70	10.6.73.71
42	10.6.73.72/29	10.6.73.73 – 10.6.73.78	10.6.73.79
43	10.6.73.80/29	10.6.73.81 – 10.6.73.86	10.6.73.87
44	10.6.73.88/29	10.6.73.89 – 10.6.73.94	10.6.73.95
45	10.6.73.96/29	10.6.73.97 – 10.6.73.102	10.6.73.103
46	10.6.73.104/29	10.6.73.105 – 10.6.73.110	10.6.73.111
47	10.6.73.112/29	10.6.73.113 – 10.6.73.118	10.6.73.119
48	10.6.73.120/29	10.6.73.121 – 10.6.73.126	10.6.73.127
49	10.6.73.128/29	10.6.73.129 – 10.6.73.134	10.6.73.135
50	10.6.73.136/29	10.6.73.137 – 10.6.73.142	10.6.73.143
51	10.6.73.144/29	10.6.73.145 – 10.6.73.150	10.6.73.151
52	10.6.73.152/29	10.6.73.153 – 10.6.73.158	10.6.73.159
53	10.6.73.160/29	10.6.73.161 – 10.6.73.166	10.6.73.167
54	10.6.73.168/29	10.6.73.169 – 10.6.73.174	10.6.73.175
55	10.6.73.176/29	10.6.73.177 – 10.6.73.182	10.6.73.183
56	10.6.73.184/29	10.6.73.185 – 10.6.73.190	10.6.73.191
57	10.6.73.192/29	10.6.73.193 – 10.6.73.198	10.6.73.199
58	10.6.73.200/29	10.6.73.201 – 10.6.73.206	10.6.73.207
59	10.6.73.208/29	10.6.73.209 – 10.6.73.214	10.6.73.215
60	10.6.73.216/29	10.6.73.217 – 10.6.73.222	10.6.73.223
61	10.6.73.224/29	10.6.73.225 – 10.6.73.230	10.6.73.231
62	10.6.73.232/29	10.6.73.233 – 10.6.73.238	10.6.73.239
63	10.6.73.240/29	10.6.73.241 – 10.6.73.246	10.6.73.247
64	10.6.73.248/29	10.6.73.249 – 10.6.73.254	10.6.73.255
65	10.6.74.0/29	10.6.74.1 – 10.6.74.6	10.6.74.7
66	10.6.74.8/29	10.6.74.9 – 10.6.74.14	10.6.74.15
67	10.6.74.16/29	10.6.74.17 – 10.6.74.22	10.6.74.23
68	10.6.74.24/29	10.6.74.25 – 10.6.74.30	10.6.74.31
69	10.6.74.32/29	10.6.74.33 – 10.6.74.38	10.6.74.39
70	10.6.74.40/29	10.6.74.41 – 10.6.74.46	10.6.74.47
71	10.6.74.48/29	10.6.74.49 – 10.6.74.54	10.6.74.55
72	10.6.74.56/29	10.6.74.57 – 10.6.74.62	10.6.74.63
73	10.6.74.64/29	10.6.74.65 – 10.6.74.70	10.6.74.71
74	10.6.74.72/29	10.6.74.73 – 10.6.74.78	10.6.74.79
75	10.6.74.80/29	10.6.74.81 – 10.6.74.86	10.6.74.87
76	10.6.74.88/29	10.6.74.89 – 10.6.74.94	10.6.74.95
77	10.6.74.96/29	10.6.74.97 – 10.6.74.102	10.6.74.103
78	10.6.74.104/29	10.6.74.105 – 10.6.74.110	10.6.74.111
79	10.6.74.112/29	10.6.74.113 – 10.6.74.118	10.6.74.119
80	10.6.74.120/29	10.6.74.121 – 10.6.74.126	10.6.74.127
81	10.6.74.128/29	10.6.74.129 – 10.6.74.134	10.6.74.135
82	10.6.74.136/29	10.6.74.137 – 10.6.74.142	10.6.74.143
83	10.6.74.144/29	10.6.74.145 – 10.6.74.150	10.6.74.151
84	10.6.74.152/29	10.6.74.153 – 10.6.74.158	10.6.74.159
85	10.6.74.160/29	10.6.74.161 – 10.6.74.166	10.6.74.167
86	10.6.74.168/29	10.6.74.169 – 10.6.74.174	10.6.74.175
87	10.6.74.176/29	10.6.74.177 – 10.6.74.182	10.6.74.183
88	10.6.74.184/29	10.6.74.185 – 10.6.74.190	10.6.74.191
89	10.6.74.192/29	10.6.74.193 – 10.6.74.198	10.6.74.199
90	10.6.74.200/29	10.6.74.201 – 10.6.74.206	10.6.74.207
91	10.6.74.208/29	10.6.74.209 – 10.6.74.214	10.6.74.215
92	10.6.74.216/29	10.6.74.217 – 10.6.74.222	10.6.74.223
93	10.6.74.224/29	10.6.74.225 – 10.6.74.230	10.6.74.231
94	10.6.74.232/29	10.6.74.233 – 10.6.74.238	10.6.74.239
95	10.6.74.240/29	10.6.74.241 – 10.6.74.246	10.6.74.247
96	10.6.74.248/29	10.6.74.249 – 10.6.74.254	10.6.74.255
97	10.6.75.0/29	10.6.75.1 – 10.6.75.6	10.6.75.7
98	10.6.75.8/29	10.6.75.9 – 10.6.75.14	10.6.75.15
99	10.6.75.16/29	10.6.75.17 – 10.6.75.22	10.6.75.23
100	10.6.75.24/29	10.6.75.25 – 10.6.75.30	10.6.75.31
101	10.6.75.32/29	10.6.75.33 – 10.6.75.38	10.6.75.39
102	10.6.75.40/29	10.6.75.41 – 10.6.75.46	10.6.75.47
103	10.6.75.48/29	10.6.75.49 – 10.6.75.54	10.6.75.55
104	10.6.75.56/29	10.6.75.57 – 10.6.75.62	10.6.75.63
105	10.6.75.64/29	10.6.75.65 – 10.6.75.70	10.6.75.71
106	10.6.75.72/29	10.6.75.73 – 10.6.75.78	10.6.75.79
107	10.6.75.80/29	10.6.75.81 – 10.6.75.86	10.6.75.87
108	10.6.75.88/29	10.6.75.89 – 10.6.75.94	10.6.75.95
109	10.6.75.96/29	10.6.75.97 – 10.6.75.102	10.6.75.103
110	10.6.75.104/29	10.6.75.105 – 10.6.75.110	10.6.75.111
111	10.6.75.112/29	10.6.75.113 – 10.6.75.118	10.6.75.119
112	10.6.75.120/29	10.6.75.121 – 10.6.75.126	10.6.75.127
113	10.6.75.128/29	10.6.75.129 – 10.6.75.134	10.6.75.135
114	10.6.75.136/29	10.6.75.137 – 10.6.75.142	10.6.75.143
115	10.6.75.144/29	10.6.75.145 – 10.6.75.150	10.6.75.151
116	10.6.75.152/29	10.6.75.153 – 10.6.75.158	10.6.75.159
117	10.6.75.160/29	10.6.75.161 – 10.6.75.166	10.6.75.167
118	10.6.75.168/29	10.6.75.169 – 10.6.75.174	10.6.75.175
119	10.6.75.176/29	10.6.75.177 – 10.6.75.182	10.6.75.183
120	10.6.75.184/29	10.6.75.185 – 10.6.75.190	10.6.75.191
121	10.6.75.192/29	10.6.75.193 – 10.6.75.198	10.6.75.199
122	10.6.75.200/29	10.6.75.201 – 10.6.75.206	10.6.75.207
123	10.6.75.208/29	10.6.75.209 – 10.6.75.214	10.6.75.215
124	10.6.75.216/29	10.6.75.217 – 10.6.75.222	10.6.75.223
125	10.6.75.224/29	10.6.75.225 – 10.6.75.230	10.6.75.231
126	10.6.75.232/29	10.6.75.233 – 10.6.75.238	10.6.75.239
127	10.6.75.240/29	10.6.75.241 – 10.6.75.246	10.6.75.247
128	10.6.75.248/29	10.6.75.249 – 10.6.75.254	10.6.75.255
129	10.6.76.0/29	10.6.76.1 – 10.6.76.6	10.6.76.7
130	10.6.76.8/29	10.6.76.9 – 10.6.76.14	10.6.76.15
131	10.6.76.16/29	10.6.76.17 – 10.6.76.22	10.6.76.23
132	10.6.76.24/29	10.6.76.25 – 10.6.76.30	10.6.76.31
133	10.6.76.32/29	10.6.76.33 – 10.6.76.38	10.6.76.39
134	10.6.76.40/29	10.6.76.41 – 10.6.76.46	10.6.76.47
135	10.6.76.48/29	10.6.76.49 – 10.6.76.54	10.6.76.55
136	10.6.76.56/29	10.6.76.57 – 10.6.76.62	10.6.76.63
137	10.6.76.64/29	10.6.76.65 – 10.6.76.70	10.6.76.71
138	10.6.76.72/29	10.6.76.73 – 10.6.76.78	10.6.76.79
139	10.6.76.80/29	10.6.76.81 – 10.6.76.86	10.6.76.87
140	10.6.76.88/29	10.6.76.89 – 10.6.76.94	10.6.76.95
141	10.6.76.96/29	10.6.76.97 – 10.6.76.102	10.6.76.103
142	10.6.76.104/29	10.6.76.105 – 10.6.76.110	10.6.76.111
143	10.6.76.112/29	10.6.76.113 – 10.6.76.118	10.6.76.119
144	10.6.76.120/29	10.6.76.121 – 10.6.76.126	10.6.76.127
145	10.6.76.128/29	10.6.76.129 – 10.6.76.134	10.6.76.135
146	10.6.76.136/29	10.6.76.137 – 10.6.76.142	10.6.76.143
147	10.6.76.144/29	10.6.76.145 – 10.6.76.150	10.6.76.151
148	10.6.76.152/29	10.6.76.153 – 10.6.76.158	10.6.76.159
149	10.6.76.160/29	10.6.76.161 – 10.6.76.166	10.6.76.167
150	10.6.76.168/29	10.6.76.169 – 10.6.76.174	10.6.76.175
151	10.6.76.176/29	10.6.76.177 – 10.6.76.182	10.6.76.183
152	10.6.76.184/29	10.6.76.185 – 10.6.76.190	10.6.76.191
153	10.6.76.192/29	10.6.76.193 – 10.6.76.198	10.6.76.199
154	10.6.76.200/29	10.6.76.201 – 10.6.76.206	10.6.76.207
155	10.6.76.208/29	10.6.76.209 – 10.6.76.214	10.6.76.215
156	10.6.76.216/29	10.6.76.217 – 10.6.76.222	10.6.76.223
157	10.6.76.224/29	10.6.76.225 – 10.6.76.230	10.6.76.231
158	10.6.76.232/29	10.6.76.233 – 10.6.76.238	10.6.76.239
159	10.6.76.240/29	10.6.76.241 – 10.6.76.246	10.6.76.247
160	10.6.76.248/29	10.6.76.249 – 10.6.76.254	10.6.76.255
161	10.6.77.0/29	10.6.77.1 – 10.6.77.6	10.6.77.7
162	10.6.77.8/29	10.6.77.9 – 10.6.77.14	10.6.77.15
163	10.6.77.16/29	10.6.77.17 – 10.6.77.22	10.6.77.23
164	10.6.77.24/29	10.6.77.25 – 10.6.77.30	10.6.77.31
165	10.6.77.32/29	10.6.77.33 – 10.6.77.38	10.6.77.39
166	10.6.77.40/29	10.6.77.41 – 10.6.77.46	10.6.77.47
167	10.6.77.48/29	10.6.77.49 – 10.6.77.54	10.6.77.55
168	10.6.77.56/29	10.6.77.57 – 10.6.77.62	10.6.77.63
169	10.6.77.64/29	10.6.77.65 – 10.6.77.70	10.6.77.71
170	10.6.77.72/29	10.6.77.73 – 10.6.77.78	10.6.77.79
171	10.6.77.80/29	10.6.77.81 – 10.6.77.86	10.6.77.87
172	10.6.77.88/29	10.6.77.89 – 10.6.77.94	10.6.77.95
173	10.6.77.96/29	10.6.77.97 – 10.6.77.102	10.6.77.103
174	10.6.77.104/29	10.6.77.105 – 10.6.77.110	10.6.77.111
175	10.6.77.112/29	10.6.77.113 – 10.6.77.118	10.6.77.119
176	10.6.77.120/29	10.6.77.121 – 10.6.77.126	10.6.77.127
177	10.6.77.128/29	10.6.77.129 – 10.6.77.134	10.6.77.135
178	10.6.77.136/29	10.6.77.137 – 10.6.77.142	10.6.77.143
179	10.6.77.144/29	10.6.77.145 – 10.6.77.150	10.6.77.151
180	10.6.77.152/29	10.6.77.153 – 10.6.77.158	10.6.77.159
181	10.6.77.160/29	10.6.77.161 – 10.6.77.166	10.6.77.167
182	10.6.77.168/29	10.6.77.169 – 10.6.77.174	10.6.77.175
183	10.6.77.176/29	10.6.77.177 – 10.6.77.182	10.6.77.183
184	10.6.77.184/29	10.6.77.185 – 10.6.77.190	10.6.77.191
185	10.6.77.192/29	10.6.77.193 – 10.6.77.198	10.6.77.199
186	10.6.77.200/29	10.6.77.201 – 10.6.77.206	10.6.77.207
187	10.6.77.208/29	10.6.77.209 – 10.6.77.214	10.6.77.215
188	10.6.77.216/29	10.6.77.217 – 10.6.77.222	10.6.77.223
189	10.6.77.224/29	10.6.77.225 – 10.6.77.230	10.6.77.231
190	10.6.77.232/29	10.6.77.233 – 10.6.77.238	10.6.77.239
191	10.6.77.240/29	10.6.77.241 – 10.6.77.246	10.6.77.247
192	10.6.77.248/29	10.6.77.249 – 10.6.77.254	10.6.77.255
193	10.6.78.0/29	10.6.78.1 – 10.6.78.6	10.6.78.7
194	10.6.78.8/29	10.6.78.9 – 10.6.78.14	10.6.78.15
195	10.6.78.16/29	10.6.78.17 – 10.6.78.22	10.6.78.23
196	10.6.78.24/29	10.6.78.25 – 10.6.78.30	10.6.78.31
197	10.6.78.32/29	10.6.78.33 – 10.6.78.38	10.6.78.39
198	10.6.78.40/29	10.6.78.41 – 10.6.78.46	10.6.78.47
199	10.6.78.48/29	10.6.78.49 – 10.6.78.54	10.6.78.55
200	10.6.78.56/29	10.6.78.57 – 10.6.78.62	10.6.78.63
201	10.6.78.64/29	10.6.78.65 – 10.6.78.70	10.6.78.71
202	10.6.78.72/29	10.6.78.73 – 10.6.78.78	10.6.78.79
203	10.6.78.80/29	10.6.78.81 – 10.6.78.86	10.6.78.87
204	10.6.78.88/29	10.6.78.89 – 10.6.78.94	10.6.78.95
205	10.6.78.96/29	10.6.78.97 – 10.6.78.102	10.6.78.103
206	10.6.78.104/29	10.6.78.105 – 10.6.78.110	10.6.78.111
207	10.6.78.112/29	10.6.78.113 – 10.6.78.118	10.6.78.119
208	10.6.78.120/29	10.6.78.121 – 10.6.78.126	10.6.78.127
209	10.6.78.128/29	10.6.78.129 – 10.6.78.134	10.6.78.135
210	10.6.78.136/29	10.6.78.137 – 10.6.78.142	10.6.78.143
211	10.6.78.144/29	10.6.78.145 – 10.6.78.150	10.6.78.151
212	10.6.78.152/29	10.6.78.153 – 10.6.78.158	10.6.78.159
213	10.6.78.160/29	10.6.78.161 – 10.6.78.166	10.6.78.167
214	10.6.78.168/29	10.6.78.169 – 10.6.78.174	10.6.78.175
215	10.6.78.176/29	10.6.78.177 – 10.6.78.182	10.6.78.183
216	10.6.78.184/29	10.6.78.185 – 10.6.78.190	10.6.78.191
217	10.6.78.192/29	10.6.78.193 – 10.6.78.198	10.6.78.199
218	10.6.78.200/29	10.6.78.201 – 10.6.78.206	10.6.78.207
219	10.6.78.208/29	10.6.78.209 – 10.6.78.214	10.6.78.215
220	10.6.78.216/29	10.6.78.217 – 10.6.78.222	10.6.78.223
221	10.6.78.224/29	10.6.78.225 – 10.6.78.230	10.6.78.231
222	10.6.78.232/29	10.6.78.233 – 10.6.78.238	10.6.78.239
223	10.6.78.240/29	10.6.78.241 – 10.6.78.246	10.6.78.247
224	10.6.78.248/29	10.6.78.249 – 10.6.78.254	10.6.78.255
225	10.6.79.0/29	10.6.79.1 – 10.6.79.6	10.6.79.7
226	10.6.79.8/29	10.6.79.9 – 10.6.79.14	10.6.79.15
227	10.6.79.16/29	10.6.79.17 – 10.6.79.22	10.6.79.23
228	10.6.79.24/29	10.6.79.25 – 10.6.79.30	10.6.79.31
229	10.6.79.32/29	10.6.79.33 – 10.6.79.38	10.6.79.39
230	10.6.79.40/29	10.6.79.41 – 10.6.79.46	10.6.79.47
231	10.6.79.48/29	10.6.79.49 – 10.6.79.54	10.6.79.55
232	10.6.79.56/29	10.6.79.57 – 10.6.79.62	10.6.79.63
233	10.6.79.64/29	10.6.79.65 – 10.6.79.70	10.6.79.71
234	10.6.79.72/29	10.6.79.73 – 10.6.79.78	10.6.79.79
235	10.6.79.80/29	10.6.79.81 – 10.6.79.86	10.6.79.87
236	10.6.79.88/29	10.6.79.89 – 10.6.79.94	10.6.79.95
237	10.6.79.96/29	10.6.79.97 – 10.6.79.102	10.6.79.103
238	10.6.79.104/29	10.6.79.105 – 10.6.79.110	10.6.79.111
239	10.6.79.112/29	10.6.79.113 – 10.6.79.118	10.6.79.119
240	10.6.79.120/29	10.6.79.121 – 10.6.79.126	10.6.79.127
241	10.6.79.128/29	10.6.79.129 – 10.6.79.134	10.6.79.135
242	10.6.79.136/29	10.6.79.137 – 10.6.79.142	10.6.79.143
243	10.6.79.144/29	10.6.79.145 – 10.6.79.150	10.6.79.151
244	10.6.79.152/29	10.6.79.153 – 10.6.79.158	10.6.79.159
245	10.6.79.160/29	10.6.79.161 – 10.6.79.166	10.6.79.167
246	10.6.79.168/29	10.6.79.169 – 10.6.79.174	10.6.79.175
247	10.6.79.176/29	10.6.79.177 – 10.6.79.182	10.6.79.183
248	10.6.79.184/29	10.6.79.185 – 10.6.79.190	10.6.79.191
249	10.6.79.192/29	10.6.79.193 – 10.6.79.198	10.6.79.199
250	10.6.79.200/29	10.6.79.201 – 10.6.79.206	10.6.79.207
251	10.6.79.208/29	10.6.79.209 – 10.6.79.214	10.6.79.215
252	10.6.79.216/29	10.6.79.217 – 10.6.79.222	10.6.79.223
253	10.6.79.224/29	10.6.79.225 – 10.6.79.230	10.6.79.231
254	10.6.79.232/29	10.6.79.233 – 10.6.79.238	10.6.79.239
255	10.6.79.240/29	10.6.79.241 – 10.6.79.246	10.6.79.247
256	10.6.79.248/29	10.6.79.249 – 10.6.79.254	10.6.79.255

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 →