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)10.2.80.0/21

network10.2.80.0/21

broadcast10.2.87.255

first host10.2.80.1

last host10.2.87.254

subnet mask255.255.248.0

wildcard0.0.7.255

addresses2,048

usable hosts2,046

classA

ipcalc 10.2.80.0/21

address00001010.00000010.01010000.00000000

subnet mask11111111.11111111.11111000.00000000

network00001010.00000010.01010000.00000000

broadcast00001010.00000010.01010111.11111111

green = network part, grey = host part

hex0x0a025000

decimal167923712

reverse dns0.80.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:5000

/21 split into /29 · 256 subnets

close ×

#	network	host range	broadcast
1	10.2.80.0/29	10.2.80.1 – 10.2.80.6	10.2.80.7
2	10.2.80.8/29	10.2.80.9 – 10.2.80.14	10.2.80.15
3	10.2.80.16/29	10.2.80.17 – 10.2.80.22	10.2.80.23
4	10.2.80.24/29	10.2.80.25 – 10.2.80.30	10.2.80.31
5	10.2.80.32/29	10.2.80.33 – 10.2.80.38	10.2.80.39
6	10.2.80.40/29	10.2.80.41 – 10.2.80.46	10.2.80.47
7	10.2.80.48/29	10.2.80.49 – 10.2.80.54	10.2.80.55
8	10.2.80.56/29	10.2.80.57 – 10.2.80.62	10.2.80.63
9	10.2.80.64/29	10.2.80.65 – 10.2.80.70	10.2.80.71
10	10.2.80.72/29	10.2.80.73 – 10.2.80.78	10.2.80.79
11	10.2.80.80/29	10.2.80.81 – 10.2.80.86	10.2.80.87
12	10.2.80.88/29	10.2.80.89 – 10.2.80.94	10.2.80.95
13	10.2.80.96/29	10.2.80.97 – 10.2.80.102	10.2.80.103
14	10.2.80.104/29	10.2.80.105 – 10.2.80.110	10.2.80.111
15	10.2.80.112/29	10.2.80.113 – 10.2.80.118	10.2.80.119
16	10.2.80.120/29	10.2.80.121 – 10.2.80.126	10.2.80.127
17	10.2.80.128/29	10.2.80.129 – 10.2.80.134	10.2.80.135
18	10.2.80.136/29	10.2.80.137 – 10.2.80.142	10.2.80.143
19	10.2.80.144/29	10.2.80.145 – 10.2.80.150	10.2.80.151
20	10.2.80.152/29	10.2.80.153 – 10.2.80.158	10.2.80.159
21	10.2.80.160/29	10.2.80.161 – 10.2.80.166	10.2.80.167
22	10.2.80.168/29	10.2.80.169 – 10.2.80.174	10.2.80.175
23	10.2.80.176/29	10.2.80.177 – 10.2.80.182	10.2.80.183
24	10.2.80.184/29	10.2.80.185 – 10.2.80.190	10.2.80.191
25	10.2.80.192/29	10.2.80.193 – 10.2.80.198	10.2.80.199
26	10.2.80.200/29	10.2.80.201 – 10.2.80.206	10.2.80.207
27	10.2.80.208/29	10.2.80.209 – 10.2.80.214	10.2.80.215
28	10.2.80.216/29	10.2.80.217 – 10.2.80.222	10.2.80.223
29	10.2.80.224/29	10.2.80.225 – 10.2.80.230	10.2.80.231
30	10.2.80.232/29	10.2.80.233 – 10.2.80.238	10.2.80.239
31	10.2.80.240/29	10.2.80.241 – 10.2.80.246	10.2.80.247
32	10.2.80.248/29	10.2.80.249 – 10.2.80.254	10.2.80.255
33	10.2.81.0/29	10.2.81.1 – 10.2.81.6	10.2.81.7
34	10.2.81.8/29	10.2.81.9 – 10.2.81.14	10.2.81.15
35	10.2.81.16/29	10.2.81.17 – 10.2.81.22	10.2.81.23
36	10.2.81.24/29	10.2.81.25 – 10.2.81.30	10.2.81.31
37	10.2.81.32/29	10.2.81.33 – 10.2.81.38	10.2.81.39
38	10.2.81.40/29	10.2.81.41 – 10.2.81.46	10.2.81.47
39	10.2.81.48/29	10.2.81.49 – 10.2.81.54	10.2.81.55
40	10.2.81.56/29	10.2.81.57 – 10.2.81.62	10.2.81.63
41	10.2.81.64/29	10.2.81.65 – 10.2.81.70	10.2.81.71
42	10.2.81.72/29	10.2.81.73 – 10.2.81.78	10.2.81.79
43	10.2.81.80/29	10.2.81.81 – 10.2.81.86	10.2.81.87
44	10.2.81.88/29	10.2.81.89 – 10.2.81.94	10.2.81.95
45	10.2.81.96/29	10.2.81.97 – 10.2.81.102	10.2.81.103
46	10.2.81.104/29	10.2.81.105 – 10.2.81.110	10.2.81.111
47	10.2.81.112/29	10.2.81.113 – 10.2.81.118	10.2.81.119
48	10.2.81.120/29	10.2.81.121 – 10.2.81.126	10.2.81.127
49	10.2.81.128/29	10.2.81.129 – 10.2.81.134	10.2.81.135
50	10.2.81.136/29	10.2.81.137 – 10.2.81.142	10.2.81.143
51	10.2.81.144/29	10.2.81.145 – 10.2.81.150	10.2.81.151
52	10.2.81.152/29	10.2.81.153 – 10.2.81.158	10.2.81.159
53	10.2.81.160/29	10.2.81.161 – 10.2.81.166	10.2.81.167
54	10.2.81.168/29	10.2.81.169 – 10.2.81.174	10.2.81.175
55	10.2.81.176/29	10.2.81.177 – 10.2.81.182	10.2.81.183
56	10.2.81.184/29	10.2.81.185 – 10.2.81.190	10.2.81.191
57	10.2.81.192/29	10.2.81.193 – 10.2.81.198	10.2.81.199
58	10.2.81.200/29	10.2.81.201 – 10.2.81.206	10.2.81.207
59	10.2.81.208/29	10.2.81.209 – 10.2.81.214	10.2.81.215
60	10.2.81.216/29	10.2.81.217 – 10.2.81.222	10.2.81.223
61	10.2.81.224/29	10.2.81.225 – 10.2.81.230	10.2.81.231
62	10.2.81.232/29	10.2.81.233 – 10.2.81.238	10.2.81.239
63	10.2.81.240/29	10.2.81.241 – 10.2.81.246	10.2.81.247
64	10.2.81.248/29	10.2.81.249 – 10.2.81.254	10.2.81.255
65	10.2.82.0/29	10.2.82.1 – 10.2.82.6	10.2.82.7
66	10.2.82.8/29	10.2.82.9 – 10.2.82.14	10.2.82.15
67	10.2.82.16/29	10.2.82.17 – 10.2.82.22	10.2.82.23
68	10.2.82.24/29	10.2.82.25 – 10.2.82.30	10.2.82.31
69	10.2.82.32/29	10.2.82.33 – 10.2.82.38	10.2.82.39
70	10.2.82.40/29	10.2.82.41 – 10.2.82.46	10.2.82.47
71	10.2.82.48/29	10.2.82.49 – 10.2.82.54	10.2.82.55
72	10.2.82.56/29	10.2.82.57 – 10.2.82.62	10.2.82.63
73	10.2.82.64/29	10.2.82.65 – 10.2.82.70	10.2.82.71
74	10.2.82.72/29	10.2.82.73 – 10.2.82.78	10.2.82.79
75	10.2.82.80/29	10.2.82.81 – 10.2.82.86	10.2.82.87
76	10.2.82.88/29	10.2.82.89 – 10.2.82.94	10.2.82.95
77	10.2.82.96/29	10.2.82.97 – 10.2.82.102	10.2.82.103
78	10.2.82.104/29	10.2.82.105 – 10.2.82.110	10.2.82.111
79	10.2.82.112/29	10.2.82.113 – 10.2.82.118	10.2.82.119
80	10.2.82.120/29	10.2.82.121 – 10.2.82.126	10.2.82.127
81	10.2.82.128/29	10.2.82.129 – 10.2.82.134	10.2.82.135
82	10.2.82.136/29	10.2.82.137 – 10.2.82.142	10.2.82.143
83	10.2.82.144/29	10.2.82.145 – 10.2.82.150	10.2.82.151
84	10.2.82.152/29	10.2.82.153 – 10.2.82.158	10.2.82.159
85	10.2.82.160/29	10.2.82.161 – 10.2.82.166	10.2.82.167
86	10.2.82.168/29	10.2.82.169 – 10.2.82.174	10.2.82.175
87	10.2.82.176/29	10.2.82.177 – 10.2.82.182	10.2.82.183
88	10.2.82.184/29	10.2.82.185 – 10.2.82.190	10.2.82.191
89	10.2.82.192/29	10.2.82.193 – 10.2.82.198	10.2.82.199
90	10.2.82.200/29	10.2.82.201 – 10.2.82.206	10.2.82.207
91	10.2.82.208/29	10.2.82.209 – 10.2.82.214	10.2.82.215
92	10.2.82.216/29	10.2.82.217 – 10.2.82.222	10.2.82.223
93	10.2.82.224/29	10.2.82.225 – 10.2.82.230	10.2.82.231
94	10.2.82.232/29	10.2.82.233 – 10.2.82.238	10.2.82.239
95	10.2.82.240/29	10.2.82.241 – 10.2.82.246	10.2.82.247
96	10.2.82.248/29	10.2.82.249 – 10.2.82.254	10.2.82.255
97	10.2.83.0/29	10.2.83.1 – 10.2.83.6	10.2.83.7
98	10.2.83.8/29	10.2.83.9 – 10.2.83.14	10.2.83.15
99	10.2.83.16/29	10.2.83.17 – 10.2.83.22	10.2.83.23
100	10.2.83.24/29	10.2.83.25 – 10.2.83.30	10.2.83.31
101	10.2.83.32/29	10.2.83.33 – 10.2.83.38	10.2.83.39
102	10.2.83.40/29	10.2.83.41 – 10.2.83.46	10.2.83.47
103	10.2.83.48/29	10.2.83.49 – 10.2.83.54	10.2.83.55
104	10.2.83.56/29	10.2.83.57 – 10.2.83.62	10.2.83.63
105	10.2.83.64/29	10.2.83.65 – 10.2.83.70	10.2.83.71
106	10.2.83.72/29	10.2.83.73 – 10.2.83.78	10.2.83.79
107	10.2.83.80/29	10.2.83.81 – 10.2.83.86	10.2.83.87
108	10.2.83.88/29	10.2.83.89 – 10.2.83.94	10.2.83.95
109	10.2.83.96/29	10.2.83.97 – 10.2.83.102	10.2.83.103
110	10.2.83.104/29	10.2.83.105 – 10.2.83.110	10.2.83.111
111	10.2.83.112/29	10.2.83.113 – 10.2.83.118	10.2.83.119
112	10.2.83.120/29	10.2.83.121 – 10.2.83.126	10.2.83.127
113	10.2.83.128/29	10.2.83.129 – 10.2.83.134	10.2.83.135
114	10.2.83.136/29	10.2.83.137 – 10.2.83.142	10.2.83.143
115	10.2.83.144/29	10.2.83.145 – 10.2.83.150	10.2.83.151
116	10.2.83.152/29	10.2.83.153 – 10.2.83.158	10.2.83.159
117	10.2.83.160/29	10.2.83.161 – 10.2.83.166	10.2.83.167
118	10.2.83.168/29	10.2.83.169 – 10.2.83.174	10.2.83.175
119	10.2.83.176/29	10.2.83.177 – 10.2.83.182	10.2.83.183
120	10.2.83.184/29	10.2.83.185 – 10.2.83.190	10.2.83.191
121	10.2.83.192/29	10.2.83.193 – 10.2.83.198	10.2.83.199
122	10.2.83.200/29	10.2.83.201 – 10.2.83.206	10.2.83.207
123	10.2.83.208/29	10.2.83.209 – 10.2.83.214	10.2.83.215
124	10.2.83.216/29	10.2.83.217 – 10.2.83.222	10.2.83.223
125	10.2.83.224/29	10.2.83.225 – 10.2.83.230	10.2.83.231
126	10.2.83.232/29	10.2.83.233 – 10.2.83.238	10.2.83.239
127	10.2.83.240/29	10.2.83.241 – 10.2.83.246	10.2.83.247
128	10.2.83.248/29	10.2.83.249 – 10.2.83.254	10.2.83.255
129	10.2.84.0/29	10.2.84.1 – 10.2.84.6	10.2.84.7
130	10.2.84.8/29	10.2.84.9 – 10.2.84.14	10.2.84.15
131	10.2.84.16/29	10.2.84.17 – 10.2.84.22	10.2.84.23
132	10.2.84.24/29	10.2.84.25 – 10.2.84.30	10.2.84.31
133	10.2.84.32/29	10.2.84.33 – 10.2.84.38	10.2.84.39
134	10.2.84.40/29	10.2.84.41 – 10.2.84.46	10.2.84.47
135	10.2.84.48/29	10.2.84.49 – 10.2.84.54	10.2.84.55
136	10.2.84.56/29	10.2.84.57 – 10.2.84.62	10.2.84.63
137	10.2.84.64/29	10.2.84.65 – 10.2.84.70	10.2.84.71
138	10.2.84.72/29	10.2.84.73 – 10.2.84.78	10.2.84.79
139	10.2.84.80/29	10.2.84.81 – 10.2.84.86	10.2.84.87
140	10.2.84.88/29	10.2.84.89 – 10.2.84.94	10.2.84.95
141	10.2.84.96/29	10.2.84.97 – 10.2.84.102	10.2.84.103
142	10.2.84.104/29	10.2.84.105 – 10.2.84.110	10.2.84.111
143	10.2.84.112/29	10.2.84.113 – 10.2.84.118	10.2.84.119
144	10.2.84.120/29	10.2.84.121 – 10.2.84.126	10.2.84.127
145	10.2.84.128/29	10.2.84.129 – 10.2.84.134	10.2.84.135
146	10.2.84.136/29	10.2.84.137 – 10.2.84.142	10.2.84.143
147	10.2.84.144/29	10.2.84.145 – 10.2.84.150	10.2.84.151
148	10.2.84.152/29	10.2.84.153 – 10.2.84.158	10.2.84.159
149	10.2.84.160/29	10.2.84.161 – 10.2.84.166	10.2.84.167
150	10.2.84.168/29	10.2.84.169 – 10.2.84.174	10.2.84.175
151	10.2.84.176/29	10.2.84.177 – 10.2.84.182	10.2.84.183
152	10.2.84.184/29	10.2.84.185 – 10.2.84.190	10.2.84.191
153	10.2.84.192/29	10.2.84.193 – 10.2.84.198	10.2.84.199
154	10.2.84.200/29	10.2.84.201 – 10.2.84.206	10.2.84.207
155	10.2.84.208/29	10.2.84.209 – 10.2.84.214	10.2.84.215
156	10.2.84.216/29	10.2.84.217 – 10.2.84.222	10.2.84.223
157	10.2.84.224/29	10.2.84.225 – 10.2.84.230	10.2.84.231
158	10.2.84.232/29	10.2.84.233 – 10.2.84.238	10.2.84.239
159	10.2.84.240/29	10.2.84.241 – 10.2.84.246	10.2.84.247
160	10.2.84.248/29	10.2.84.249 – 10.2.84.254	10.2.84.255
161	10.2.85.0/29	10.2.85.1 – 10.2.85.6	10.2.85.7
162	10.2.85.8/29	10.2.85.9 – 10.2.85.14	10.2.85.15
163	10.2.85.16/29	10.2.85.17 – 10.2.85.22	10.2.85.23
164	10.2.85.24/29	10.2.85.25 – 10.2.85.30	10.2.85.31
165	10.2.85.32/29	10.2.85.33 – 10.2.85.38	10.2.85.39
166	10.2.85.40/29	10.2.85.41 – 10.2.85.46	10.2.85.47
167	10.2.85.48/29	10.2.85.49 – 10.2.85.54	10.2.85.55
168	10.2.85.56/29	10.2.85.57 – 10.2.85.62	10.2.85.63
169	10.2.85.64/29	10.2.85.65 – 10.2.85.70	10.2.85.71
170	10.2.85.72/29	10.2.85.73 – 10.2.85.78	10.2.85.79
171	10.2.85.80/29	10.2.85.81 – 10.2.85.86	10.2.85.87
172	10.2.85.88/29	10.2.85.89 – 10.2.85.94	10.2.85.95
173	10.2.85.96/29	10.2.85.97 – 10.2.85.102	10.2.85.103
174	10.2.85.104/29	10.2.85.105 – 10.2.85.110	10.2.85.111
175	10.2.85.112/29	10.2.85.113 – 10.2.85.118	10.2.85.119
176	10.2.85.120/29	10.2.85.121 – 10.2.85.126	10.2.85.127
177	10.2.85.128/29	10.2.85.129 – 10.2.85.134	10.2.85.135
178	10.2.85.136/29	10.2.85.137 – 10.2.85.142	10.2.85.143
179	10.2.85.144/29	10.2.85.145 – 10.2.85.150	10.2.85.151
180	10.2.85.152/29	10.2.85.153 – 10.2.85.158	10.2.85.159
181	10.2.85.160/29	10.2.85.161 – 10.2.85.166	10.2.85.167
182	10.2.85.168/29	10.2.85.169 – 10.2.85.174	10.2.85.175
183	10.2.85.176/29	10.2.85.177 – 10.2.85.182	10.2.85.183
184	10.2.85.184/29	10.2.85.185 – 10.2.85.190	10.2.85.191
185	10.2.85.192/29	10.2.85.193 – 10.2.85.198	10.2.85.199
186	10.2.85.200/29	10.2.85.201 – 10.2.85.206	10.2.85.207
187	10.2.85.208/29	10.2.85.209 – 10.2.85.214	10.2.85.215
188	10.2.85.216/29	10.2.85.217 – 10.2.85.222	10.2.85.223
189	10.2.85.224/29	10.2.85.225 – 10.2.85.230	10.2.85.231
190	10.2.85.232/29	10.2.85.233 – 10.2.85.238	10.2.85.239
191	10.2.85.240/29	10.2.85.241 – 10.2.85.246	10.2.85.247
192	10.2.85.248/29	10.2.85.249 – 10.2.85.254	10.2.85.255
193	10.2.86.0/29	10.2.86.1 – 10.2.86.6	10.2.86.7
194	10.2.86.8/29	10.2.86.9 – 10.2.86.14	10.2.86.15
195	10.2.86.16/29	10.2.86.17 – 10.2.86.22	10.2.86.23
196	10.2.86.24/29	10.2.86.25 – 10.2.86.30	10.2.86.31
197	10.2.86.32/29	10.2.86.33 – 10.2.86.38	10.2.86.39
198	10.2.86.40/29	10.2.86.41 – 10.2.86.46	10.2.86.47
199	10.2.86.48/29	10.2.86.49 – 10.2.86.54	10.2.86.55
200	10.2.86.56/29	10.2.86.57 – 10.2.86.62	10.2.86.63
201	10.2.86.64/29	10.2.86.65 – 10.2.86.70	10.2.86.71
202	10.2.86.72/29	10.2.86.73 – 10.2.86.78	10.2.86.79
203	10.2.86.80/29	10.2.86.81 – 10.2.86.86	10.2.86.87
204	10.2.86.88/29	10.2.86.89 – 10.2.86.94	10.2.86.95
205	10.2.86.96/29	10.2.86.97 – 10.2.86.102	10.2.86.103
206	10.2.86.104/29	10.2.86.105 – 10.2.86.110	10.2.86.111
207	10.2.86.112/29	10.2.86.113 – 10.2.86.118	10.2.86.119
208	10.2.86.120/29	10.2.86.121 – 10.2.86.126	10.2.86.127
209	10.2.86.128/29	10.2.86.129 – 10.2.86.134	10.2.86.135
210	10.2.86.136/29	10.2.86.137 – 10.2.86.142	10.2.86.143
211	10.2.86.144/29	10.2.86.145 – 10.2.86.150	10.2.86.151
212	10.2.86.152/29	10.2.86.153 – 10.2.86.158	10.2.86.159
213	10.2.86.160/29	10.2.86.161 – 10.2.86.166	10.2.86.167
214	10.2.86.168/29	10.2.86.169 – 10.2.86.174	10.2.86.175
215	10.2.86.176/29	10.2.86.177 – 10.2.86.182	10.2.86.183
216	10.2.86.184/29	10.2.86.185 – 10.2.86.190	10.2.86.191
217	10.2.86.192/29	10.2.86.193 – 10.2.86.198	10.2.86.199
218	10.2.86.200/29	10.2.86.201 – 10.2.86.206	10.2.86.207
219	10.2.86.208/29	10.2.86.209 – 10.2.86.214	10.2.86.215
220	10.2.86.216/29	10.2.86.217 – 10.2.86.222	10.2.86.223
221	10.2.86.224/29	10.2.86.225 – 10.2.86.230	10.2.86.231
222	10.2.86.232/29	10.2.86.233 – 10.2.86.238	10.2.86.239
223	10.2.86.240/29	10.2.86.241 – 10.2.86.246	10.2.86.247
224	10.2.86.248/29	10.2.86.249 – 10.2.86.254	10.2.86.255
225	10.2.87.0/29	10.2.87.1 – 10.2.87.6	10.2.87.7
226	10.2.87.8/29	10.2.87.9 – 10.2.87.14	10.2.87.15
227	10.2.87.16/29	10.2.87.17 – 10.2.87.22	10.2.87.23
228	10.2.87.24/29	10.2.87.25 – 10.2.87.30	10.2.87.31
229	10.2.87.32/29	10.2.87.33 – 10.2.87.38	10.2.87.39
230	10.2.87.40/29	10.2.87.41 – 10.2.87.46	10.2.87.47
231	10.2.87.48/29	10.2.87.49 – 10.2.87.54	10.2.87.55
232	10.2.87.56/29	10.2.87.57 – 10.2.87.62	10.2.87.63
233	10.2.87.64/29	10.2.87.65 – 10.2.87.70	10.2.87.71
234	10.2.87.72/29	10.2.87.73 – 10.2.87.78	10.2.87.79
235	10.2.87.80/29	10.2.87.81 – 10.2.87.86	10.2.87.87
236	10.2.87.88/29	10.2.87.89 – 10.2.87.94	10.2.87.95
237	10.2.87.96/29	10.2.87.97 – 10.2.87.102	10.2.87.103
238	10.2.87.104/29	10.2.87.105 – 10.2.87.110	10.2.87.111
239	10.2.87.112/29	10.2.87.113 – 10.2.87.118	10.2.87.119
240	10.2.87.120/29	10.2.87.121 – 10.2.87.126	10.2.87.127
241	10.2.87.128/29	10.2.87.129 – 10.2.87.134	10.2.87.135
242	10.2.87.136/29	10.2.87.137 – 10.2.87.142	10.2.87.143
243	10.2.87.144/29	10.2.87.145 – 10.2.87.150	10.2.87.151
244	10.2.87.152/29	10.2.87.153 – 10.2.87.158	10.2.87.159
245	10.2.87.160/29	10.2.87.161 – 10.2.87.166	10.2.87.167
246	10.2.87.168/29	10.2.87.169 – 10.2.87.174	10.2.87.175
247	10.2.87.176/29	10.2.87.177 – 10.2.87.182	10.2.87.183
248	10.2.87.184/29	10.2.87.185 – 10.2.87.190	10.2.87.191
249	10.2.87.192/29	10.2.87.193 – 10.2.87.198	10.2.87.199
250	10.2.87.200/29	10.2.87.201 – 10.2.87.206	10.2.87.207
251	10.2.87.208/29	10.2.87.209 – 10.2.87.214	10.2.87.215
252	10.2.87.216/29	10.2.87.217 – 10.2.87.222	10.2.87.223
253	10.2.87.224/29	10.2.87.225 – 10.2.87.230	10.2.87.231
254	10.2.87.232/29	10.2.87.233 – 10.2.87.238	10.2.87.239
255	10.2.87.240/29	10.2.87.241 – 10.2.87.246	10.2.87.247
256	10.2.87.248/29	10.2.87.249 – 10.2.87.254	10.2.87.255

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 →