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)172.16.8.0/21

network172.16.8.0/21

broadcast172.16.15.255

first host172.16.8.1

last host172.16.15.254

subnet mask255.255.248.0

wildcard0.0.7.255

addresses2,048

usable hosts2,046

classB

ipcalc 172.16.8.0/21

address10101100.00010000.00001000.00000000

subnet mask11111111.11111111.11111000.00000000

network10101100.00010000.00001000.00000000

broadcast10101100.00010000.00001111.11111111

green = network part, grey = host part

hex0xac100800

decimal2886731776

reverse dns0.8.16.172.in-addr.arpa

ipv4-mapped::ffff:ac10:800

/21 split into /29 · 256 subnets

close ×

#	network	host range	broadcast
1	172.16.8.0/29	172.16.8.1 – 172.16.8.6	172.16.8.7
2	172.16.8.8/29	172.16.8.9 – 172.16.8.14	172.16.8.15
3	172.16.8.16/29	172.16.8.17 – 172.16.8.22	172.16.8.23
4	172.16.8.24/29	172.16.8.25 – 172.16.8.30	172.16.8.31
5	172.16.8.32/29	172.16.8.33 – 172.16.8.38	172.16.8.39
6	172.16.8.40/29	172.16.8.41 – 172.16.8.46	172.16.8.47
7	172.16.8.48/29	172.16.8.49 – 172.16.8.54	172.16.8.55
8	172.16.8.56/29	172.16.8.57 – 172.16.8.62	172.16.8.63
9	172.16.8.64/29	172.16.8.65 – 172.16.8.70	172.16.8.71
10	172.16.8.72/29	172.16.8.73 – 172.16.8.78	172.16.8.79
11	172.16.8.80/29	172.16.8.81 – 172.16.8.86	172.16.8.87
12	172.16.8.88/29	172.16.8.89 – 172.16.8.94	172.16.8.95
13	172.16.8.96/29	172.16.8.97 – 172.16.8.102	172.16.8.103
14	172.16.8.104/29	172.16.8.105 – 172.16.8.110	172.16.8.111
15	172.16.8.112/29	172.16.8.113 – 172.16.8.118	172.16.8.119
16	172.16.8.120/29	172.16.8.121 – 172.16.8.126	172.16.8.127
17	172.16.8.128/29	172.16.8.129 – 172.16.8.134	172.16.8.135
18	172.16.8.136/29	172.16.8.137 – 172.16.8.142	172.16.8.143
19	172.16.8.144/29	172.16.8.145 – 172.16.8.150	172.16.8.151
20	172.16.8.152/29	172.16.8.153 – 172.16.8.158	172.16.8.159
21	172.16.8.160/29	172.16.8.161 – 172.16.8.166	172.16.8.167
22	172.16.8.168/29	172.16.8.169 – 172.16.8.174	172.16.8.175
23	172.16.8.176/29	172.16.8.177 – 172.16.8.182	172.16.8.183
24	172.16.8.184/29	172.16.8.185 – 172.16.8.190	172.16.8.191
25	172.16.8.192/29	172.16.8.193 – 172.16.8.198	172.16.8.199
26	172.16.8.200/29	172.16.8.201 – 172.16.8.206	172.16.8.207
27	172.16.8.208/29	172.16.8.209 – 172.16.8.214	172.16.8.215
28	172.16.8.216/29	172.16.8.217 – 172.16.8.222	172.16.8.223
29	172.16.8.224/29	172.16.8.225 – 172.16.8.230	172.16.8.231
30	172.16.8.232/29	172.16.8.233 – 172.16.8.238	172.16.8.239
31	172.16.8.240/29	172.16.8.241 – 172.16.8.246	172.16.8.247
32	172.16.8.248/29	172.16.8.249 – 172.16.8.254	172.16.8.255
33	172.16.9.0/29	172.16.9.1 – 172.16.9.6	172.16.9.7
34	172.16.9.8/29	172.16.9.9 – 172.16.9.14	172.16.9.15
35	172.16.9.16/29	172.16.9.17 – 172.16.9.22	172.16.9.23
36	172.16.9.24/29	172.16.9.25 – 172.16.9.30	172.16.9.31
37	172.16.9.32/29	172.16.9.33 – 172.16.9.38	172.16.9.39
38	172.16.9.40/29	172.16.9.41 – 172.16.9.46	172.16.9.47
39	172.16.9.48/29	172.16.9.49 – 172.16.9.54	172.16.9.55
40	172.16.9.56/29	172.16.9.57 – 172.16.9.62	172.16.9.63
41	172.16.9.64/29	172.16.9.65 – 172.16.9.70	172.16.9.71
42	172.16.9.72/29	172.16.9.73 – 172.16.9.78	172.16.9.79
43	172.16.9.80/29	172.16.9.81 – 172.16.9.86	172.16.9.87
44	172.16.9.88/29	172.16.9.89 – 172.16.9.94	172.16.9.95
45	172.16.9.96/29	172.16.9.97 – 172.16.9.102	172.16.9.103
46	172.16.9.104/29	172.16.9.105 – 172.16.9.110	172.16.9.111
47	172.16.9.112/29	172.16.9.113 – 172.16.9.118	172.16.9.119
48	172.16.9.120/29	172.16.9.121 – 172.16.9.126	172.16.9.127
49	172.16.9.128/29	172.16.9.129 – 172.16.9.134	172.16.9.135
50	172.16.9.136/29	172.16.9.137 – 172.16.9.142	172.16.9.143
51	172.16.9.144/29	172.16.9.145 – 172.16.9.150	172.16.9.151
52	172.16.9.152/29	172.16.9.153 – 172.16.9.158	172.16.9.159
53	172.16.9.160/29	172.16.9.161 – 172.16.9.166	172.16.9.167
54	172.16.9.168/29	172.16.9.169 – 172.16.9.174	172.16.9.175
55	172.16.9.176/29	172.16.9.177 – 172.16.9.182	172.16.9.183
56	172.16.9.184/29	172.16.9.185 – 172.16.9.190	172.16.9.191
57	172.16.9.192/29	172.16.9.193 – 172.16.9.198	172.16.9.199
58	172.16.9.200/29	172.16.9.201 – 172.16.9.206	172.16.9.207
59	172.16.9.208/29	172.16.9.209 – 172.16.9.214	172.16.9.215
60	172.16.9.216/29	172.16.9.217 – 172.16.9.222	172.16.9.223
61	172.16.9.224/29	172.16.9.225 – 172.16.9.230	172.16.9.231
62	172.16.9.232/29	172.16.9.233 – 172.16.9.238	172.16.9.239
63	172.16.9.240/29	172.16.9.241 – 172.16.9.246	172.16.9.247
64	172.16.9.248/29	172.16.9.249 – 172.16.9.254	172.16.9.255
65	172.16.10.0/29	172.16.10.1 – 172.16.10.6	172.16.10.7
66	172.16.10.8/29	172.16.10.9 – 172.16.10.14	172.16.10.15
67	172.16.10.16/29	172.16.10.17 – 172.16.10.22	172.16.10.23
68	172.16.10.24/29	172.16.10.25 – 172.16.10.30	172.16.10.31
69	172.16.10.32/29	172.16.10.33 – 172.16.10.38	172.16.10.39
70	172.16.10.40/29	172.16.10.41 – 172.16.10.46	172.16.10.47
71	172.16.10.48/29	172.16.10.49 – 172.16.10.54	172.16.10.55
72	172.16.10.56/29	172.16.10.57 – 172.16.10.62	172.16.10.63
73	172.16.10.64/29	172.16.10.65 – 172.16.10.70	172.16.10.71
74	172.16.10.72/29	172.16.10.73 – 172.16.10.78	172.16.10.79
75	172.16.10.80/29	172.16.10.81 – 172.16.10.86	172.16.10.87
76	172.16.10.88/29	172.16.10.89 – 172.16.10.94	172.16.10.95
77	172.16.10.96/29	172.16.10.97 – 172.16.10.102	172.16.10.103
78	172.16.10.104/29	172.16.10.105 – 172.16.10.110	172.16.10.111
79	172.16.10.112/29	172.16.10.113 – 172.16.10.118	172.16.10.119
80	172.16.10.120/29	172.16.10.121 – 172.16.10.126	172.16.10.127
81	172.16.10.128/29	172.16.10.129 – 172.16.10.134	172.16.10.135
82	172.16.10.136/29	172.16.10.137 – 172.16.10.142	172.16.10.143
83	172.16.10.144/29	172.16.10.145 – 172.16.10.150	172.16.10.151
84	172.16.10.152/29	172.16.10.153 – 172.16.10.158	172.16.10.159
85	172.16.10.160/29	172.16.10.161 – 172.16.10.166	172.16.10.167
86	172.16.10.168/29	172.16.10.169 – 172.16.10.174	172.16.10.175
87	172.16.10.176/29	172.16.10.177 – 172.16.10.182	172.16.10.183
88	172.16.10.184/29	172.16.10.185 – 172.16.10.190	172.16.10.191
89	172.16.10.192/29	172.16.10.193 – 172.16.10.198	172.16.10.199
90	172.16.10.200/29	172.16.10.201 – 172.16.10.206	172.16.10.207
91	172.16.10.208/29	172.16.10.209 – 172.16.10.214	172.16.10.215
92	172.16.10.216/29	172.16.10.217 – 172.16.10.222	172.16.10.223
93	172.16.10.224/29	172.16.10.225 – 172.16.10.230	172.16.10.231
94	172.16.10.232/29	172.16.10.233 – 172.16.10.238	172.16.10.239
95	172.16.10.240/29	172.16.10.241 – 172.16.10.246	172.16.10.247
96	172.16.10.248/29	172.16.10.249 – 172.16.10.254	172.16.10.255
97	172.16.11.0/29	172.16.11.1 – 172.16.11.6	172.16.11.7
98	172.16.11.8/29	172.16.11.9 – 172.16.11.14	172.16.11.15
99	172.16.11.16/29	172.16.11.17 – 172.16.11.22	172.16.11.23
100	172.16.11.24/29	172.16.11.25 – 172.16.11.30	172.16.11.31
101	172.16.11.32/29	172.16.11.33 – 172.16.11.38	172.16.11.39
102	172.16.11.40/29	172.16.11.41 – 172.16.11.46	172.16.11.47
103	172.16.11.48/29	172.16.11.49 – 172.16.11.54	172.16.11.55
104	172.16.11.56/29	172.16.11.57 – 172.16.11.62	172.16.11.63
105	172.16.11.64/29	172.16.11.65 – 172.16.11.70	172.16.11.71
106	172.16.11.72/29	172.16.11.73 – 172.16.11.78	172.16.11.79
107	172.16.11.80/29	172.16.11.81 – 172.16.11.86	172.16.11.87
108	172.16.11.88/29	172.16.11.89 – 172.16.11.94	172.16.11.95
109	172.16.11.96/29	172.16.11.97 – 172.16.11.102	172.16.11.103
110	172.16.11.104/29	172.16.11.105 – 172.16.11.110	172.16.11.111
111	172.16.11.112/29	172.16.11.113 – 172.16.11.118	172.16.11.119
112	172.16.11.120/29	172.16.11.121 – 172.16.11.126	172.16.11.127
113	172.16.11.128/29	172.16.11.129 – 172.16.11.134	172.16.11.135
114	172.16.11.136/29	172.16.11.137 – 172.16.11.142	172.16.11.143
115	172.16.11.144/29	172.16.11.145 – 172.16.11.150	172.16.11.151
116	172.16.11.152/29	172.16.11.153 – 172.16.11.158	172.16.11.159
117	172.16.11.160/29	172.16.11.161 – 172.16.11.166	172.16.11.167
118	172.16.11.168/29	172.16.11.169 – 172.16.11.174	172.16.11.175
119	172.16.11.176/29	172.16.11.177 – 172.16.11.182	172.16.11.183
120	172.16.11.184/29	172.16.11.185 – 172.16.11.190	172.16.11.191
121	172.16.11.192/29	172.16.11.193 – 172.16.11.198	172.16.11.199
122	172.16.11.200/29	172.16.11.201 – 172.16.11.206	172.16.11.207
123	172.16.11.208/29	172.16.11.209 – 172.16.11.214	172.16.11.215
124	172.16.11.216/29	172.16.11.217 – 172.16.11.222	172.16.11.223
125	172.16.11.224/29	172.16.11.225 – 172.16.11.230	172.16.11.231
126	172.16.11.232/29	172.16.11.233 – 172.16.11.238	172.16.11.239
127	172.16.11.240/29	172.16.11.241 – 172.16.11.246	172.16.11.247
128	172.16.11.248/29	172.16.11.249 – 172.16.11.254	172.16.11.255
129	172.16.12.0/29	172.16.12.1 – 172.16.12.6	172.16.12.7
130	172.16.12.8/29	172.16.12.9 – 172.16.12.14	172.16.12.15
131	172.16.12.16/29	172.16.12.17 – 172.16.12.22	172.16.12.23
132	172.16.12.24/29	172.16.12.25 – 172.16.12.30	172.16.12.31
133	172.16.12.32/29	172.16.12.33 – 172.16.12.38	172.16.12.39
134	172.16.12.40/29	172.16.12.41 – 172.16.12.46	172.16.12.47
135	172.16.12.48/29	172.16.12.49 – 172.16.12.54	172.16.12.55
136	172.16.12.56/29	172.16.12.57 – 172.16.12.62	172.16.12.63
137	172.16.12.64/29	172.16.12.65 – 172.16.12.70	172.16.12.71
138	172.16.12.72/29	172.16.12.73 – 172.16.12.78	172.16.12.79
139	172.16.12.80/29	172.16.12.81 – 172.16.12.86	172.16.12.87
140	172.16.12.88/29	172.16.12.89 – 172.16.12.94	172.16.12.95
141	172.16.12.96/29	172.16.12.97 – 172.16.12.102	172.16.12.103
142	172.16.12.104/29	172.16.12.105 – 172.16.12.110	172.16.12.111
143	172.16.12.112/29	172.16.12.113 – 172.16.12.118	172.16.12.119
144	172.16.12.120/29	172.16.12.121 – 172.16.12.126	172.16.12.127
145	172.16.12.128/29	172.16.12.129 – 172.16.12.134	172.16.12.135
146	172.16.12.136/29	172.16.12.137 – 172.16.12.142	172.16.12.143
147	172.16.12.144/29	172.16.12.145 – 172.16.12.150	172.16.12.151
148	172.16.12.152/29	172.16.12.153 – 172.16.12.158	172.16.12.159
149	172.16.12.160/29	172.16.12.161 – 172.16.12.166	172.16.12.167
150	172.16.12.168/29	172.16.12.169 – 172.16.12.174	172.16.12.175
151	172.16.12.176/29	172.16.12.177 – 172.16.12.182	172.16.12.183
152	172.16.12.184/29	172.16.12.185 – 172.16.12.190	172.16.12.191
153	172.16.12.192/29	172.16.12.193 – 172.16.12.198	172.16.12.199
154	172.16.12.200/29	172.16.12.201 – 172.16.12.206	172.16.12.207
155	172.16.12.208/29	172.16.12.209 – 172.16.12.214	172.16.12.215
156	172.16.12.216/29	172.16.12.217 – 172.16.12.222	172.16.12.223
157	172.16.12.224/29	172.16.12.225 – 172.16.12.230	172.16.12.231
158	172.16.12.232/29	172.16.12.233 – 172.16.12.238	172.16.12.239
159	172.16.12.240/29	172.16.12.241 – 172.16.12.246	172.16.12.247
160	172.16.12.248/29	172.16.12.249 – 172.16.12.254	172.16.12.255
161	172.16.13.0/29	172.16.13.1 – 172.16.13.6	172.16.13.7
162	172.16.13.8/29	172.16.13.9 – 172.16.13.14	172.16.13.15
163	172.16.13.16/29	172.16.13.17 – 172.16.13.22	172.16.13.23
164	172.16.13.24/29	172.16.13.25 – 172.16.13.30	172.16.13.31
165	172.16.13.32/29	172.16.13.33 – 172.16.13.38	172.16.13.39
166	172.16.13.40/29	172.16.13.41 – 172.16.13.46	172.16.13.47
167	172.16.13.48/29	172.16.13.49 – 172.16.13.54	172.16.13.55
168	172.16.13.56/29	172.16.13.57 – 172.16.13.62	172.16.13.63
169	172.16.13.64/29	172.16.13.65 – 172.16.13.70	172.16.13.71
170	172.16.13.72/29	172.16.13.73 – 172.16.13.78	172.16.13.79
171	172.16.13.80/29	172.16.13.81 – 172.16.13.86	172.16.13.87
172	172.16.13.88/29	172.16.13.89 – 172.16.13.94	172.16.13.95
173	172.16.13.96/29	172.16.13.97 – 172.16.13.102	172.16.13.103
174	172.16.13.104/29	172.16.13.105 – 172.16.13.110	172.16.13.111
175	172.16.13.112/29	172.16.13.113 – 172.16.13.118	172.16.13.119
176	172.16.13.120/29	172.16.13.121 – 172.16.13.126	172.16.13.127
177	172.16.13.128/29	172.16.13.129 – 172.16.13.134	172.16.13.135
178	172.16.13.136/29	172.16.13.137 – 172.16.13.142	172.16.13.143
179	172.16.13.144/29	172.16.13.145 – 172.16.13.150	172.16.13.151
180	172.16.13.152/29	172.16.13.153 – 172.16.13.158	172.16.13.159
181	172.16.13.160/29	172.16.13.161 – 172.16.13.166	172.16.13.167
182	172.16.13.168/29	172.16.13.169 – 172.16.13.174	172.16.13.175
183	172.16.13.176/29	172.16.13.177 – 172.16.13.182	172.16.13.183
184	172.16.13.184/29	172.16.13.185 – 172.16.13.190	172.16.13.191
185	172.16.13.192/29	172.16.13.193 – 172.16.13.198	172.16.13.199
186	172.16.13.200/29	172.16.13.201 – 172.16.13.206	172.16.13.207
187	172.16.13.208/29	172.16.13.209 – 172.16.13.214	172.16.13.215
188	172.16.13.216/29	172.16.13.217 – 172.16.13.222	172.16.13.223
189	172.16.13.224/29	172.16.13.225 – 172.16.13.230	172.16.13.231
190	172.16.13.232/29	172.16.13.233 – 172.16.13.238	172.16.13.239
191	172.16.13.240/29	172.16.13.241 – 172.16.13.246	172.16.13.247
192	172.16.13.248/29	172.16.13.249 – 172.16.13.254	172.16.13.255
193	172.16.14.0/29	172.16.14.1 – 172.16.14.6	172.16.14.7
194	172.16.14.8/29	172.16.14.9 – 172.16.14.14	172.16.14.15
195	172.16.14.16/29	172.16.14.17 – 172.16.14.22	172.16.14.23
196	172.16.14.24/29	172.16.14.25 – 172.16.14.30	172.16.14.31
197	172.16.14.32/29	172.16.14.33 – 172.16.14.38	172.16.14.39
198	172.16.14.40/29	172.16.14.41 – 172.16.14.46	172.16.14.47
199	172.16.14.48/29	172.16.14.49 – 172.16.14.54	172.16.14.55
200	172.16.14.56/29	172.16.14.57 – 172.16.14.62	172.16.14.63
201	172.16.14.64/29	172.16.14.65 – 172.16.14.70	172.16.14.71
202	172.16.14.72/29	172.16.14.73 – 172.16.14.78	172.16.14.79
203	172.16.14.80/29	172.16.14.81 – 172.16.14.86	172.16.14.87
204	172.16.14.88/29	172.16.14.89 – 172.16.14.94	172.16.14.95
205	172.16.14.96/29	172.16.14.97 – 172.16.14.102	172.16.14.103
206	172.16.14.104/29	172.16.14.105 – 172.16.14.110	172.16.14.111
207	172.16.14.112/29	172.16.14.113 – 172.16.14.118	172.16.14.119
208	172.16.14.120/29	172.16.14.121 – 172.16.14.126	172.16.14.127
209	172.16.14.128/29	172.16.14.129 – 172.16.14.134	172.16.14.135
210	172.16.14.136/29	172.16.14.137 – 172.16.14.142	172.16.14.143
211	172.16.14.144/29	172.16.14.145 – 172.16.14.150	172.16.14.151
212	172.16.14.152/29	172.16.14.153 – 172.16.14.158	172.16.14.159
213	172.16.14.160/29	172.16.14.161 – 172.16.14.166	172.16.14.167
214	172.16.14.168/29	172.16.14.169 – 172.16.14.174	172.16.14.175
215	172.16.14.176/29	172.16.14.177 – 172.16.14.182	172.16.14.183
216	172.16.14.184/29	172.16.14.185 – 172.16.14.190	172.16.14.191
217	172.16.14.192/29	172.16.14.193 – 172.16.14.198	172.16.14.199
218	172.16.14.200/29	172.16.14.201 – 172.16.14.206	172.16.14.207
219	172.16.14.208/29	172.16.14.209 – 172.16.14.214	172.16.14.215
220	172.16.14.216/29	172.16.14.217 – 172.16.14.222	172.16.14.223
221	172.16.14.224/29	172.16.14.225 – 172.16.14.230	172.16.14.231
222	172.16.14.232/29	172.16.14.233 – 172.16.14.238	172.16.14.239
223	172.16.14.240/29	172.16.14.241 – 172.16.14.246	172.16.14.247
224	172.16.14.248/29	172.16.14.249 – 172.16.14.254	172.16.14.255
225	172.16.15.0/29	172.16.15.1 – 172.16.15.6	172.16.15.7
226	172.16.15.8/29	172.16.15.9 – 172.16.15.14	172.16.15.15
227	172.16.15.16/29	172.16.15.17 – 172.16.15.22	172.16.15.23
228	172.16.15.24/29	172.16.15.25 – 172.16.15.30	172.16.15.31
229	172.16.15.32/29	172.16.15.33 – 172.16.15.38	172.16.15.39
230	172.16.15.40/29	172.16.15.41 – 172.16.15.46	172.16.15.47
231	172.16.15.48/29	172.16.15.49 – 172.16.15.54	172.16.15.55
232	172.16.15.56/29	172.16.15.57 – 172.16.15.62	172.16.15.63
233	172.16.15.64/29	172.16.15.65 – 172.16.15.70	172.16.15.71
234	172.16.15.72/29	172.16.15.73 – 172.16.15.78	172.16.15.79
235	172.16.15.80/29	172.16.15.81 – 172.16.15.86	172.16.15.87
236	172.16.15.88/29	172.16.15.89 – 172.16.15.94	172.16.15.95
237	172.16.15.96/29	172.16.15.97 – 172.16.15.102	172.16.15.103
238	172.16.15.104/29	172.16.15.105 – 172.16.15.110	172.16.15.111
239	172.16.15.112/29	172.16.15.113 – 172.16.15.118	172.16.15.119
240	172.16.15.120/29	172.16.15.121 – 172.16.15.126	172.16.15.127
241	172.16.15.128/29	172.16.15.129 – 172.16.15.134	172.16.15.135
242	172.16.15.136/29	172.16.15.137 – 172.16.15.142	172.16.15.143
243	172.16.15.144/29	172.16.15.145 – 172.16.15.150	172.16.15.151
244	172.16.15.152/29	172.16.15.153 – 172.16.15.158	172.16.15.159
245	172.16.15.160/29	172.16.15.161 – 172.16.15.166	172.16.15.167
246	172.16.15.168/29	172.16.15.169 – 172.16.15.174	172.16.15.175
247	172.16.15.176/29	172.16.15.177 – 172.16.15.182	172.16.15.183
248	172.16.15.184/29	172.16.15.185 – 172.16.15.190	172.16.15.191
249	172.16.15.192/29	172.16.15.193 – 172.16.15.198	172.16.15.199
250	172.16.15.200/29	172.16.15.201 – 172.16.15.206	172.16.15.207
251	172.16.15.208/29	172.16.15.209 – 172.16.15.214	172.16.15.215
252	172.16.15.216/29	172.16.15.217 – 172.16.15.222	172.16.15.223
253	172.16.15.224/29	172.16.15.225 – 172.16.15.230	172.16.15.231
254	172.16.15.232/29	172.16.15.233 – 172.16.15.238	172.16.15.239
255	172.16.15.240/29	172.16.15.241 – 172.16.15.246	172.16.15.247
256	172.16.15.248/29	172.16.15.249 – 172.16.15.254	172.16.15.255

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 →