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)10.5.16.0/21

network10.5.16.0/21

broadcast10.5.23.255

first host10.5.16.1

last host10.5.23.254

subnet mask255.255.248.0

wildcard0.0.7.255

addresses2,048

usable hosts2,046

classA

ipcalc 10.5.16.0/21

address00001010.00000101.00010000.00000000

subnet mask11111111.11111111.11111000.00000000

network00001010.00000101.00010000.00000000

broadcast00001010.00000101.00010111.11111111

green = network part, grey = host part

hex0x0a051000

decimal168103936

reverse dns0.16.5.10.in-addr.arpa

ipv4-mapped::ffff:a05:1000

/21 split into /29 · 256 subnets

close ×

#	network	host range	broadcast
1	10.5.16.0/29	10.5.16.1 – 10.5.16.6	10.5.16.7
2	10.5.16.8/29	10.5.16.9 – 10.5.16.14	10.5.16.15
3	10.5.16.16/29	10.5.16.17 – 10.5.16.22	10.5.16.23
4	10.5.16.24/29	10.5.16.25 – 10.5.16.30	10.5.16.31
5	10.5.16.32/29	10.5.16.33 – 10.5.16.38	10.5.16.39
6	10.5.16.40/29	10.5.16.41 – 10.5.16.46	10.5.16.47
7	10.5.16.48/29	10.5.16.49 – 10.5.16.54	10.5.16.55
8	10.5.16.56/29	10.5.16.57 – 10.5.16.62	10.5.16.63
9	10.5.16.64/29	10.5.16.65 – 10.5.16.70	10.5.16.71
10	10.5.16.72/29	10.5.16.73 – 10.5.16.78	10.5.16.79
11	10.5.16.80/29	10.5.16.81 – 10.5.16.86	10.5.16.87
12	10.5.16.88/29	10.5.16.89 – 10.5.16.94	10.5.16.95
13	10.5.16.96/29	10.5.16.97 – 10.5.16.102	10.5.16.103
14	10.5.16.104/29	10.5.16.105 – 10.5.16.110	10.5.16.111
15	10.5.16.112/29	10.5.16.113 – 10.5.16.118	10.5.16.119
16	10.5.16.120/29	10.5.16.121 – 10.5.16.126	10.5.16.127
17	10.5.16.128/29	10.5.16.129 – 10.5.16.134	10.5.16.135
18	10.5.16.136/29	10.5.16.137 – 10.5.16.142	10.5.16.143
19	10.5.16.144/29	10.5.16.145 – 10.5.16.150	10.5.16.151
20	10.5.16.152/29	10.5.16.153 – 10.5.16.158	10.5.16.159
21	10.5.16.160/29	10.5.16.161 – 10.5.16.166	10.5.16.167
22	10.5.16.168/29	10.5.16.169 – 10.5.16.174	10.5.16.175
23	10.5.16.176/29	10.5.16.177 – 10.5.16.182	10.5.16.183
24	10.5.16.184/29	10.5.16.185 – 10.5.16.190	10.5.16.191
25	10.5.16.192/29	10.5.16.193 – 10.5.16.198	10.5.16.199
26	10.5.16.200/29	10.5.16.201 – 10.5.16.206	10.5.16.207
27	10.5.16.208/29	10.5.16.209 – 10.5.16.214	10.5.16.215
28	10.5.16.216/29	10.5.16.217 – 10.5.16.222	10.5.16.223
29	10.5.16.224/29	10.5.16.225 – 10.5.16.230	10.5.16.231
30	10.5.16.232/29	10.5.16.233 – 10.5.16.238	10.5.16.239
31	10.5.16.240/29	10.5.16.241 – 10.5.16.246	10.5.16.247
32	10.5.16.248/29	10.5.16.249 – 10.5.16.254	10.5.16.255
33	10.5.17.0/29	10.5.17.1 – 10.5.17.6	10.5.17.7
34	10.5.17.8/29	10.5.17.9 – 10.5.17.14	10.5.17.15
35	10.5.17.16/29	10.5.17.17 – 10.5.17.22	10.5.17.23
36	10.5.17.24/29	10.5.17.25 – 10.5.17.30	10.5.17.31
37	10.5.17.32/29	10.5.17.33 – 10.5.17.38	10.5.17.39
38	10.5.17.40/29	10.5.17.41 – 10.5.17.46	10.5.17.47
39	10.5.17.48/29	10.5.17.49 – 10.5.17.54	10.5.17.55
40	10.5.17.56/29	10.5.17.57 – 10.5.17.62	10.5.17.63
41	10.5.17.64/29	10.5.17.65 – 10.5.17.70	10.5.17.71
42	10.5.17.72/29	10.5.17.73 – 10.5.17.78	10.5.17.79
43	10.5.17.80/29	10.5.17.81 – 10.5.17.86	10.5.17.87
44	10.5.17.88/29	10.5.17.89 – 10.5.17.94	10.5.17.95
45	10.5.17.96/29	10.5.17.97 – 10.5.17.102	10.5.17.103
46	10.5.17.104/29	10.5.17.105 – 10.5.17.110	10.5.17.111
47	10.5.17.112/29	10.5.17.113 – 10.5.17.118	10.5.17.119
48	10.5.17.120/29	10.5.17.121 – 10.5.17.126	10.5.17.127
49	10.5.17.128/29	10.5.17.129 – 10.5.17.134	10.5.17.135
50	10.5.17.136/29	10.5.17.137 – 10.5.17.142	10.5.17.143
51	10.5.17.144/29	10.5.17.145 – 10.5.17.150	10.5.17.151
52	10.5.17.152/29	10.5.17.153 – 10.5.17.158	10.5.17.159
53	10.5.17.160/29	10.5.17.161 – 10.5.17.166	10.5.17.167
54	10.5.17.168/29	10.5.17.169 – 10.5.17.174	10.5.17.175
55	10.5.17.176/29	10.5.17.177 – 10.5.17.182	10.5.17.183
56	10.5.17.184/29	10.5.17.185 – 10.5.17.190	10.5.17.191
57	10.5.17.192/29	10.5.17.193 – 10.5.17.198	10.5.17.199
58	10.5.17.200/29	10.5.17.201 – 10.5.17.206	10.5.17.207
59	10.5.17.208/29	10.5.17.209 – 10.5.17.214	10.5.17.215
60	10.5.17.216/29	10.5.17.217 – 10.5.17.222	10.5.17.223
61	10.5.17.224/29	10.5.17.225 – 10.5.17.230	10.5.17.231
62	10.5.17.232/29	10.5.17.233 – 10.5.17.238	10.5.17.239
63	10.5.17.240/29	10.5.17.241 – 10.5.17.246	10.5.17.247
64	10.5.17.248/29	10.5.17.249 – 10.5.17.254	10.5.17.255
65	10.5.18.0/29	10.5.18.1 – 10.5.18.6	10.5.18.7
66	10.5.18.8/29	10.5.18.9 – 10.5.18.14	10.5.18.15
67	10.5.18.16/29	10.5.18.17 – 10.5.18.22	10.5.18.23
68	10.5.18.24/29	10.5.18.25 – 10.5.18.30	10.5.18.31
69	10.5.18.32/29	10.5.18.33 – 10.5.18.38	10.5.18.39
70	10.5.18.40/29	10.5.18.41 – 10.5.18.46	10.5.18.47
71	10.5.18.48/29	10.5.18.49 – 10.5.18.54	10.5.18.55
72	10.5.18.56/29	10.5.18.57 – 10.5.18.62	10.5.18.63
73	10.5.18.64/29	10.5.18.65 – 10.5.18.70	10.5.18.71
74	10.5.18.72/29	10.5.18.73 – 10.5.18.78	10.5.18.79
75	10.5.18.80/29	10.5.18.81 – 10.5.18.86	10.5.18.87
76	10.5.18.88/29	10.5.18.89 – 10.5.18.94	10.5.18.95
77	10.5.18.96/29	10.5.18.97 – 10.5.18.102	10.5.18.103
78	10.5.18.104/29	10.5.18.105 – 10.5.18.110	10.5.18.111
79	10.5.18.112/29	10.5.18.113 – 10.5.18.118	10.5.18.119
80	10.5.18.120/29	10.5.18.121 – 10.5.18.126	10.5.18.127
81	10.5.18.128/29	10.5.18.129 – 10.5.18.134	10.5.18.135
82	10.5.18.136/29	10.5.18.137 – 10.5.18.142	10.5.18.143
83	10.5.18.144/29	10.5.18.145 – 10.5.18.150	10.5.18.151
84	10.5.18.152/29	10.5.18.153 – 10.5.18.158	10.5.18.159
85	10.5.18.160/29	10.5.18.161 – 10.5.18.166	10.5.18.167
86	10.5.18.168/29	10.5.18.169 – 10.5.18.174	10.5.18.175
87	10.5.18.176/29	10.5.18.177 – 10.5.18.182	10.5.18.183
88	10.5.18.184/29	10.5.18.185 – 10.5.18.190	10.5.18.191
89	10.5.18.192/29	10.5.18.193 – 10.5.18.198	10.5.18.199
90	10.5.18.200/29	10.5.18.201 – 10.5.18.206	10.5.18.207
91	10.5.18.208/29	10.5.18.209 – 10.5.18.214	10.5.18.215
92	10.5.18.216/29	10.5.18.217 – 10.5.18.222	10.5.18.223
93	10.5.18.224/29	10.5.18.225 – 10.5.18.230	10.5.18.231
94	10.5.18.232/29	10.5.18.233 – 10.5.18.238	10.5.18.239
95	10.5.18.240/29	10.5.18.241 – 10.5.18.246	10.5.18.247
96	10.5.18.248/29	10.5.18.249 – 10.5.18.254	10.5.18.255
97	10.5.19.0/29	10.5.19.1 – 10.5.19.6	10.5.19.7
98	10.5.19.8/29	10.5.19.9 – 10.5.19.14	10.5.19.15
99	10.5.19.16/29	10.5.19.17 – 10.5.19.22	10.5.19.23
100	10.5.19.24/29	10.5.19.25 – 10.5.19.30	10.5.19.31
101	10.5.19.32/29	10.5.19.33 – 10.5.19.38	10.5.19.39
102	10.5.19.40/29	10.5.19.41 – 10.5.19.46	10.5.19.47
103	10.5.19.48/29	10.5.19.49 – 10.5.19.54	10.5.19.55
104	10.5.19.56/29	10.5.19.57 – 10.5.19.62	10.5.19.63
105	10.5.19.64/29	10.5.19.65 – 10.5.19.70	10.5.19.71
106	10.5.19.72/29	10.5.19.73 – 10.5.19.78	10.5.19.79
107	10.5.19.80/29	10.5.19.81 – 10.5.19.86	10.5.19.87
108	10.5.19.88/29	10.5.19.89 – 10.5.19.94	10.5.19.95
109	10.5.19.96/29	10.5.19.97 – 10.5.19.102	10.5.19.103
110	10.5.19.104/29	10.5.19.105 – 10.5.19.110	10.5.19.111
111	10.5.19.112/29	10.5.19.113 – 10.5.19.118	10.5.19.119
112	10.5.19.120/29	10.5.19.121 – 10.5.19.126	10.5.19.127
113	10.5.19.128/29	10.5.19.129 – 10.5.19.134	10.5.19.135
114	10.5.19.136/29	10.5.19.137 – 10.5.19.142	10.5.19.143
115	10.5.19.144/29	10.5.19.145 – 10.5.19.150	10.5.19.151
116	10.5.19.152/29	10.5.19.153 – 10.5.19.158	10.5.19.159
117	10.5.19.160/29	10.5.19.161 – 10.5.19.166	10.5.19.167
118	10.5.19.168/29	10.5.19.169 – 10.5.19.174	10.5.19.175
119	10.5.19.176/29	10.5.19.177 – 10.5.19.182	10.5.19.183
120	10.5.19.184/29	10.5.19.185 – 10.5.19.190	10.5.19.191
121	10.5.19.192/29	10.5.19.193 – 10.5.19.198	10.5.19.199
122	10.5.19.200/29	10.5.19.201 – 10.5.19.206	10.5.19.207
123	10.5.19.208/29	10.5.19.209 – 10.5.19.214	10.5.19.215
124	10.5.19.216/29	10.5.19.217 – 10.5.19.222	10.5.19.223
125	10.5.19.224/29	10.5.19.225 – 10.5.19.230	10.5.19.231
126	10.5.19.232/29	10.5.19.233 – 10.5.19.238	10.5.19.239
127	10.5.19.240/29	10.5.19.241 – 10.5.19.246	10.5.19.247
128	10.5.19.248/29	10.5.19.249 – 10.5.19.254	10.5.19.255
129	10.5.20.0/29	10.5.20.1 – 10.5.20.6	10.5.20.7
130	10.5.20.8/29	10.5.20.9 – 10.5.20.14	10.5.20.15
131	10.5.20.16/29	10.5.20.17 – 10.5.20.22	10.5.20.23
132	10.5.20.24/29	10.5.20.25 – 10.5.20.30	10.5.20.31
133	10.5.20.32/29	10.5.20.33 – 10.5.20.38	10.5.20.39
134	10.5.20.40/29	10.5.20.41 – 10.5.20.46	10.5.20.47
135	10.5.20.48/29	10.5.20.49 – 10.5.20.54	10.5.20.55
136	10.5.20.56/29	10.5.20.57 – 10.5.20.62	10.5.20.63
137	10.5.20.64/29	10.5.20.65 – 10.5.20.70	10.5.20.71
138	10.5.20.72/29	10.5.20.73 – 10.5.20.78	10.5.20.79
139	10.5.20.80/29	10.5.20.81 – 10.5.20.86	10.5.20.87
140	10.5.20.88/29	10.5.20.89 – 10.5.20.94	10.5.20.95
141	10.5.20.96/29	10.5.20.97 – 10.5.20.102	10.5.20.103
142	10.5.20.104/29	10.5.20.105 – 10.5.20.110	10.5.20.111
143	10.5.20.112/29	10.5.20.113 – 10.5.20.118	10.5.20.119
144	10.5.20.120/29	10.5.20.121 – 10.5.20.126	10.5.20.127
145	10.5.20.128/29	10.5.20.129 – 10.5.20.134	10.5.20.135
146	10.5.20.136/29	10.5.20.137 – 10.5.20.142	10.5.20.143
147	10.5.20.144/29	10.5.20.145 – 10.5.20.150	10.5.20.151
148	10.5.20.152/29	10.5.20.153 – 10.5.20.158	10.5.20.159
149	10.5.20.160/29	10.5.20.161 – 10.5.20.166	10.5.20.167
150	10.5.20.168/29	10.5.20.169 – 10.5.20.174	10.5.20.175
151	10.5.20.176/29	10.5.20.177 – 10.5.20.182	10.5.20.183
152	10.5.20.184/29	10.5.20.185 – 10.5.20.190	10.5.20.191
153	10.5.20.192/29	10.5.20.193 – 10.5.20.198	10.5.20.199
154	10.5.20.200/29	10.5.20.201 – 10.5.20.206	10.5.20.207
155	10.5.20.208/29	10.5.20.209 – 10.5.20.214	10.5.20.215
156	10.5.20.216/29	10.5.20.217 – 10.5.20.222	10.5.20.223
157	10.5.20.224/29	10.5.20.225 – 10.5.20.230	10.5.20.231
158	10.5.20.232/29	10.5.20.233 – 10.5.20.238	10.5.20.239
159	10.5.20.240/29	10.5.20.241 – 10.5.20.246	10.5.20.247
160	10.5.20.248/29	10.5.20.249 – 10.5.20.254	10.5.20.255
161	10.5.21.0/29	10.5.21.1 – 10.5.21.6	10.5.21.7
162	10.5.21.8/29	10.5.21.9 – 10.5.21.14	10.5.21.15
163	10.5.21.16/29	10.5.21.17 – 10.5.21.22	10.5.21.23
164	10.5.21.24/29	10.5.21.25 – 10.5.21.30	10.5.21.31
165	10.5.21.32/29	10.5.21.33 – 10.5.21.38	10.5.21.39
166	10.5.21.40/29	10.5.21.41 – 10.5.21.46	10.5.21.47
167	10.5.21.48/29	10.5.21.49 – 10.5.21.54	10.5.21.55
168	10.5.21.56/29	10.5.21.57 – 10.5.21.62	10.5.21.63
169	10.5.21.64/29	10.5.21.65 – 10.5.21.70	10.5.21.71
170	10.5.21.72/29	10.5.21.73 – 10.5.21.78	10.5.21.79
171	10.5.21.80/29	10.5.21.81 – 10.5.21.86	10.5.21.87
172	10.5.21.88/29	10.5.21.89 – 10.5.21.94	10.5.21.95
173	10.5.21.96/29	10.5.21.97 – 10.5.21.102	10.5.21.103
174	10.5.21.104/29	10.5.21.105 – 10.5.21.110	10.5.21.111
175	10.5.21.112/29	10.5.21.113 – 10.5.21.118	10.5.21.119
176	10.5.21.120/29	10.5.21.121 – 10.5.21.126	10.5.21.127
177	10.5.21.128/29	10.5.21.129 – 10.5.21.134	10.5.21.135
178	10.5.21.136/29	10.5.21.137 – 10.5.21.142	10.5.21.143
179	10.5.21.144/29	10.5.21.145 – 10.5.21.150	10.5.21.151
180	10.5.21.152/29	10.5.21.153 – 10.5.21.158	10.5.21.159
181	10.5.21.160/29	10.5.21.161 – 10.5.21.166	10.5.21.167
182	10.5.21.168/29	10.5.21.169 – 10.5.21.174	10.5.21.175
183	10.5.21.176/29	10.5.21.177 – 10.5.21.182	10.5.21.183
184	10.5.21.184/29	10.5.21.185 – 10.5.21.190	10.5.21.191
185	10.5.21.192/29	10.5.21.193 – 10.5.21.198	10.5.21.199
186	10.5.21.200/29	10.5.21.201 – 10.5.21.206	10.5.21.207
187	10.5.21.208/29	10.5.21.209 – 10.5.21.214	10.5.21.215
188	10.5.21.216/29	10.5.21.217 – 10.5.21.222	10.5.21.223
189	10.5.21.224/29	10.5.21.225 – 10.5.21.230	10.5.21.231
190	10.5.21.232/29	10.5.21.233 – 10.5.21.238	10.5.21.239
191	10.5.21.240/29	10.5.21.241 – 10.5.21.246	10.5.21.247
192	10.5.21.248/29	10.5.21.249 – 10.5.21.254	10.5.21.255
193	10.5.22.0/29	10.5.22.1 – 10.5.22.6	10.5.22.7
194	10.5.22.8/29	10.5.22.9 – 10.5.22.14	10.5.22.15
195	10.5.22.16/29	10.5.22.17 – 10.5.22.22	10.5.22.23
196	10.5.22.24/29	10.5.22.25 – 10.5.22.30	10.5.22.31
197	10.5.22.32/29	10.5.22.33 – 10.5.22.38	10.5.22.39
198	10.5.22.40/29	10.5.22.41 – 10.5.22.46	10.5.22.47
199	10.5.22.48/29	10.5.22.49 – 10.5.22.54	10.5.22.55
200	10.5.22.56/29	10.5.22.57 – 10.5.22.62	10.5.22.63
201	10.5.22.64/29	10.5.22.65 – 10.5.22.70	10.5.22.71
202	10.5.22.72/29	10.5.22.73 – 10.5.22.78	10.5.22.79
203	10.5.22.80/29	10.5.22.81 – 10.5.22.86	10.5.22.87
204	10.5.22.88/29	10.5.22.89 – 10.5.22.94	10.5.22.95
205	10.5.22.96/29	10.5.22.97 – 10.5.22.102	10.5.22.103
206	10.5.22.104/29	10.5.22.105 – 10.5.22.110	10.5.22.111
207	10.5.22.112/29	10.5.22.113 – 10.5.22.118	10.5.22.119
208	10.5.22.120/29	10.5.22.121 – 10.5.22.126	10.5.22.127
209	10.5.22.128/29	10.5.22.129 – 10.5.22.134	10.5.22.135
210	10.5.22.136/29	10.5.22.137 – 10.5.22.142	10.5.22.143
211	10.5.22.144/29	10.5.22.145 – 10.5.22.150	10.5.22.151
212	10.5.22.152/29	10.5.22.153 – 10.5.22.158	10.5.22.159
213	10.5.22.160/29	10.5.22.161 – 10.5.22.166	10.5.22.167
214	10.5.22.168/29	10.5.22.169 – 10.5.22.174	10.5.22.175
215	10.5.22.176/29	10.5.22.177 – 10.5.22.182	10.5.22.183
216	10.5.22.184/29	10.5.22.185 – 10.5.22.190	10.5.22.191
217	10.5.22.192/29	10.5.22.193 – 10.5.22.198	10.5.22.199
218	10.5.22.200/29	10.5.22.201 – 10.5.22.206	10.5.22.207
219	10.5.22.208/29	10.5.22.209 – 10.5.22.214	10.5.22.215
220	10.5.22.216/29	10.5.22.217 – 10.5.22.222	10.5.22.223
221	10.5.22.224/29	10.5.22.225 – 10.5.22.230	10.5.22.231
222	10.5.22.232/29	10.5.22.233 – 10.5.22.238	10.5.22.239
223	10.5.22.240/29	10.5.22.241 – 10.5.22.246	10.5.22.247
224	10.5.22.248/29	10.5.22.249 – 10.5.22.254	10.5.22.255
225	10.5.23.0/29	10.5.23.1 – 10.5.23.6	10.5.23.7
226	10.5.23.8/29	10.5.23.9 – 10.5.23.14	10.5.23.15
227	10.5.23.16/29	10.5.23.17 – 10.5.23.22	10.5.23.23
228	10.5.23.24/29	10.5.23.25 – 10.5.23.30	10.5.23.31
229	10.5.23.32/29	10.5.23.33 – 10.5.23.38	10.5.23.39
230	10.5.23.40/29	10.5.23.41 – 10.5.23.46	10.5.23.47
231	10.5.23.48/29	10.5.23.49 – 10.5.23.54	10.5.23.55
232	10.5.23.56/29	10.5.23.57 – 10.5.23.62	10.5.23.63
233	10.5.23.64/29	10.5.23.65 – 10.5.23.70	10.5.23.71
234	10.5.23.72/29	10.5.23.73 – 10.5.23.78	10.5.23.79
235	10.5.23.80/29	10.5.23.81 – 10.5.23.86	10.5.23.87
236	10.5.23.88/29	10.5.23.89 – 10.5.23.94	10.5.23.95
237	10.5.23.96/29	10.5.23.97 – 10.5.23.102	10.5.23.103
238	10.5.23.104/29	10.5.23.105 – 10.5.23.110	10.5.23.111
239	10.5.23.112/29	10.5.23.113 – 10.5.23.118	10.5.23.119
240	10.5.23.120/29	10.5.23.121 – 10.5.23.126	10.5.23.127
241	10.5.23.128/29	10.5.23.129 – 10.5.23.134	10.5.23.135
242	10.5.23.136/29	10.5.23.137 – 10.5.23.142	10.5.23.143
243	10.5.23.144/29	10.5.23.145 – 10.5.23.150	10.5.23.151
244	10.5.23.152/29	10.5.23.153 – 10.5.23.158	10.5.23.159
245	10.5.23.160/29	10.5.23.161 – 10.5.23.166	10.5.23.167
246	10.5.23.168/29	10.5.23.169 – 10.5.23.174	10.5.23.175
247	10.5.23.176/29	10.5.23.177 – 10.5.23.182	10.5.23.183
248	10.5.23.184/29	10.5.23.185 – 10.5.23.190	10.5.23.191
249	10.5.23.192/29	10.5.23.193 – 10.5.23.198	10.5.23.199
250	10.5.23.200/29	10.5.23.201 – 10.5.23.206	10.5.23.207
251	10.5.23.208/29	10.5.23.209 – 10.5.23.214	10.5.23.215
252	10.5.23.216/29	10.5.23.217 – 10.5.23.222	10.5.23.223
253	10.5.23.224/29	10.5.23.225 – 10.5.23.230	10.5.23.231
254	10.5.23.232/29	10.5.23.233 – 10.5.23.238	10.5.23.239
255	10.5.23.240/29	10.5.23.241 – 10.5.23.246	10.5.23.247
256	10.5.23.248/29	10.5.23.249 – 10.5.23.254	10.5.23.255

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 →