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)10.3.120.0/21

network10.3.120.0/21

broadcast10.3.127.255

first host10.3.120.1

last host10.3.127.254

subnet mask255.255.248.0

wildcard0.0.7.255

addresses2,048

usable hosts2,046

classA

ipcalc 10.3.120.0/21

address00001010.00000011.01111000.00000000

subnet mask11111111.11111111.11111000.00000000

network00001010.00000011.01111000.00000000

broadcast00001010.00000011.01111111.11111111

green = network part, grey = host part

hex0x0a037800

decimal167999488

reverse dns0.120.3.10.in-addr.arpa

ipv4-mapped::ffff:a03:7800

/21 split into /29 · 256 subnets

close ×

#	network	host range	broadcast
1	10.3.120.0/29	10.3.120.1 – 10.3.120.6	10.3.120.7
2	10.3.120.8/29	10.3.120.9 – 10.3.120.14	10.3.120.15
3	10.3.120.16/29	10.3.120.17 – 10.3.120.22	10.3.120.23
4	10.3.120.24/29	10.3.120.25 – 10.3.120.30	10.3.120.31
5	10.3.120.32/29	10.3.120.33 – 10.3.120.38	10.3.120.39
6	10.3.120.40/29	10.3.120.41 – 10.3.120.46	10.3.120.47
7	10.3.120.48/29	10.3.120.49 – 10.3.120.54	10.3.120.55
8	10.3.120.56/29	10.3.120.57 – 10.3.120.62	10.3.120.63
9	10.3.120.64/29	10.3.120.65 – 10.3.120.70	10.3.120.71
10	10.3.120.72/29	10.3.120.73 – 10.3.120.78	10.3.120.79
11	10.3.120.80/29	10.3.120.81 – 10.3.120.86	10.3.120.87
12	10.3.120.88/29	10.3.120.89 – 10.3.120.94	10.3.120.95
13	10.3.120.96/29	10.3.120.97 – 10.3.120.102	10.3.120.103
14	10.3.120.104/29	10.3.120.105 – 10.3.120.110	10.3.120.111
15	10.3.120.112/29	10.3.120.113 – 10.3.120.118	10.3.120.119
16	10.3.120.120/29	10.3.120.121 – 10.3.120.126	10.3.120.127
17	10.3.120.128/29	10.3.120.129 – 10.3.120.134	10.3.120.135
18	10.3.120.136/29	10.3.120.137 – 10.3.120.142	10.3.120.143
19	10.3.120.144/29	10.3.120.145 – 10.3.120.150	10.3.120.151
20	10.3.120.152/29	10.3.120.153 – 10.3.120.158	10.3.120.159
21	10.3.120.160/29	10.3.120.161 – 10.3.120.166	10.3.120.167
22	10.3.120.168/29	10.3.120.169 – 10.3.120.174	10.3.120.175
23	10.3.120.176/29	10.3.120.177 – 10.3.120.182	10.3.120.183
24	10.3.120.184/29	10.3.120.185 – 10.3.120.190	10.3.120.191
25	10.3.120.192/29	10.3.120.193 – 10.3.120.198	10.3.120.199
26	10.3.120.200/29	10.3.120.201 – 10.3.120.206	10.3.120.207
27	10.3.120.208/29	10.3.120.209 – 10.3.120.214	10.3.120.215
28	10.3.120.216/29	10.3.120.217 – 10.3.120.222	10.3.120.223
29	10.3.120.224/29	10.3.120.225 – 10.3.120.230	10.3.120.231
30	10.3.120.232/29	10.3.120.233 – 10.3.120.238	10.3.120.239
31	10.3.120.240/29	10.3.120.241 – 10.3.120.246	10.3.120.247
32	10.3.120.248/29	10.3.120.249 – 10.3.120.254	10.3.120.255
33	10.3.121.0/29	10.3.121.1 – 10.3.121.6	10.3.121.7
34	10.3.121.8/29	10.3.121.9 – 10.3.121.14	10.3.121.15
35	10.3.121.16/29	10.3.121.17 – 10.3.121.22	10.3.121.23
36	10.3.121.24/29	10.3.121.25 – 10.3.121.30	10.3.121.31
37	10.3.121.32/29	10.3.121.33 – 10.3.121.38	10.3.121.39
38	10.3.121.40/29	10.3.121.41 – 10.3.121.46	10.3.121.47
39	10.3.121.48/29	10.3.121.49 – 10.3.121.54	10.3.121.55
40	10.3.121.56/29	10.3.121.57 – 10.3.121.62	10.3.121.63
41	10.3.121.64/29	10.3.121.65 – 10.3.121.70	10.3.121.71
42	10.3.121.72/29	10.3.121.73 – 10.3.121.78	10.3.121.79
43	10.3.121.80/29	10.3.121.81 – 10.3.121.86	10.3.121.87
44	10.3.121.88/29	10.3.121.89 – 10.3.121.94	10.3.121.95
45	10.3.121.96/29	10.3.121.97 – 10.3.121.102	10.3.121.103
46	10.3.121.104/29	10.3.121.105 – 10.3.121.110	10.3.121.111
47	10.3.121.112/29	10.3.121.113 – 10.3.121.118	10.3.121.119
48	10.3.121.120/29	10.3.121.121 – 10.3.121.126	10.3.121.127
49	10.3.121.128/29	10.3.121.129 – 10.3.121.134	10.3.121.135
50	10.3.121.136/29	10.3.121.137 – 10.3.121.142	10.3.121.143
51	10.3.121.144/29	10.3.121.145 – 10.3.121.150	10.3.121.151
52	10.3.121.152/29	10.3.121.153 – 10.3.121.158	10.3.121.159
53	10.3.121.160/29	10.3.121.161 – 10.3.121.166	10.3.121.167
54	10.3.121.168/29	10.3.121.169 – 10.3.121.174	10.3.121.175
55	10.3.121.176/29	10.3.121.177 – 10.3.121.182	10.3.121.183
56	10.3.121.184/29	10.3.121.185 – 10.3.121.190	10.3.121.191
57	10.3.121.192/29	10.3.121.193 – 10.3.121.198	10.3.121.199
58	10.3.121.200/29	10.3.121.201 – 10.3.121.206	10.3.121.207
59	10.3.121.208/29	10.3.121.209 – 10.3.121.214	10.3.121.215
60	10.3.121.216/29	10.3.121.217 – 10.3.121.222	10.3.121.223
61	10.3.121.224/29	10.3.121.225 – 10.3.121.230	10.3.121.231
62	10.3.121.232/29	10.3.121.233 – 10.3.121.238	10.3.121.239
63	10.3.121.240/29	10.3.121.241 – 10.3.121.246	10.3.121.247
64	10.3.121.248/29	10.3.121.249 – 10.3.121.254	10.3.121.255
65	10.3.122.0/29	10.3.122.1 – 10.3.122.6	10.3.122.7
66	10.3.122.8/29	10.3.122.9 – 10.3.122.14	10.3.122.15
67	10.3.122.16/29	10.3.122.17 – 10.3.122.22	10.3.122.23
68	10.3.122.24/29	10.3.122.25 – 10.3.122.30	10.3.122.31
69	10.3.122.32/29	10.3.122.33 – 10.3.122.38	10.3.122.39
70	10.3.122.40/29	10.3.122.41 – 10.3.122.46	10.3.122.47
71	10.3.122.48/29	10.3.122.49 – 10.3.122.54	10.3.122.55
72	10.3.122.56/29	10.3.122.57 – 10.3.122.62	10.3.122.63
73	10.3.122.64/29	10.3.122.65 – 10.3.122.70	10.3.122.71
74	10.3.122.72/29	10.3.122.73 – 10.3.122.78	10.3.122.79
75	10.3.122.80/29	10.3.122.81 – 10.3.122.86	10.3.122.87
76	10.3.122.88/29	10.3.122.89 – 10.3.122.94	10.3.122.95
77	10.3.122.96/29	10.3.122.97 – 10.3.122.102	10.3.122.103
78	10.3.122.104/29	10.3.122.105 – 10.3.122.110	10.3.122.111
79	10.3.122.112/29	10.3.122.113 – 10.3.122.118	10.3.122.119
80	10.3.122.120/29	10.3.122.121 – 10.3.122.126	10.3.122.127
81	10.3.122.128/29	10.3.122.129 – 10.3.122.134	10.3.122.135
82	10.3.122.136/29	10.3.122.137 – 10.3.122.142	10.3.122.143
83	10.3.122.144/29	10.3.122.145 – 10.3.122.150	10.3.122.151
84	10.3.122.152/29	10.3.122.153 – 10.3.122.158	10.3.122.159
85	10.3.122.160/29	10.3.122.161 – 10.3.122.166	10.3.122.167
86	10.3.122.168/29	10.3.122.169 – 10.3.122.174	10.3.122.175
87	10.3.122.176/29	10.3.122.177 – 10.3.122.182	10.3.122.183
88	10.3.122.184/29	10.3.122.185 – 10.3.122.190	10.3.122.191
89	10.3.122.192/29	10.3.122.193 – 10.3.122.198	10.3.122.199
90	10.3.122.200/29	10.3.122.201 – 10.3.122.206	10.3.122.207
91	10.3.122.208/29	10.3.122.209 – 10.3.122.214	10.3.122.215
92	10.3.122.216/29	10.3.122.217 – 10.3.122.222	10.3.122.223
93	10.3.122.224/29	10.3.122.225 – 10.3.122.230	10.3.122.231
94	10.3.122.232/29	10.3.122.233 – 10.3.122.238	10.3.122.239
95	10.3.122.240/29	10.3.122.241 – 10.3.122.246	10.3.122.247
96	10.3.122.248/29	10.3.122.249 – 10.3.122.254	10.3.122.255
97	10.3.123.0/29	10.3.123.1 – 10.3.123.6	10.3.123.7
98	10.3.123.8/29	10.3.123.9 – 10.3.123.14	10.3.123.15
99	10.3.123.16/29	10.3.123.17 – 10.3.123.22	10.3.123.23
100	10.3.123.24/29	10.3.123.25 – 10.3.123.30	10.3.123.31
101	10.3.123.32/29	10.3.123.33 – 10.3.123.38	10.3.123.39
102	10.3.123.40/29	10.3.123.41 – 10.3.123.46	10.3.123.47
103	10.3.123.48/29	10.3.123.49 – 10.3.123.54	10.3.123.55
104	10.3.123.56/29	10.3.123.57 – 10.3.123.62	10.3.123.63
105	10.3.123.64/29	10.3.123.65 – 10.3.123.70	10.3.123.71
106	10.3.123.72/29	10.3.123.73 – 10.3.123.78	10.3.123.79
107	10.3.123.80/29	10.3.123.81 – 10.3.123.86	10.3.123.87
108	10.3.123.88/29	10.3.123.89 – 10.3.123.94	10.3.123.95
109	10.3.123.96/29	10.3.123.97 – 10.3.123.102	10.3.123.103
110	10.3.123.104/29	10.3.123.105 – 10.3.123.110	10.3.123.111
111	10.3.123.112/29	10.3.123.113 – 10.3.123.118	10.3.123.119
112	10.3.123.120/29	10.3.123.121 – 10.3.123.126	10.3.123.127
113	10.3.123.128/29	10.3.123.129 – 10.3.123.134	10.3.123.135
114	10.3.123.136/29	10.3.123.137 – 10.3.123.142	10.3.123.143
115	10.3.123.144/29	10.3.123.145 – 10.3.123.150	10.3.123.151
116	10.3.123.152/29	10.3.123.153 – 10.3.123.158	10.3.123.159
117	10.3.123.160/29	10.3.123.161 – 10.3.123.166	10.3.123.167
118	10.3.123.168/29	10.3.123.169 – 10.3.123.174	10.3.123.175
119	10.3.123.176/29	10.3.123.177 – 10.3.123.182	10.3.123.183
120	10.3.123.184/29	10.3.123.185 – 10.3.123.190	10.3.123.191
121	10.3.123.192/29	10.3.123.193 – 10.3.123.198	10.3.123.199
122	10.3.123.200/29	10.3.123.201 – 10.3.123.206	10.3.123.207
123	10.3.123.208/29	10.3.123.209 – 10.3.123.214	10.3.123.215
124	10.3.123.216/29	10.3.123.217 – 10.3.123.222	10.3.123.223
125	10.3.123.224/29	10.3.123.225 – 10.3.123.230	10.3.123.231
126	10.3.123.232/29	10.3.123.233 – 10.3.123.238	10.3.123.239
127	10.3.123.240/29	10.3.123.241 – 10.3.123.246	10.3.123.247
128	10.3.123.248/29	10.3.123.249 – 10.3.123.254	10.3.123.255
129	10.3.124.0/29	10.3.124.1 – 10.3.124.6	10.3.124.7
130	10.3.124.8/29	10.3.124.9 – 10.3.124.14	10.3.124.15
131	10.3.124.16/29	10.3.124.17 – 10.3.124.22	10.3.124.23
132	10.3.124.24/29	10.3.124.25 – 10.3.124.30	10.3.124.31
133	10.3.124.32/29	10.3.124.33 – 10.3.124.38	10.3.124.39
134	10.3.124.40/29	10.3.124.41 – 10.3.124.46	10.3.124.47
135	10.3.124.48/29	10.3.124.49 – 10.3.124.54	10.3.124.55
136	10.3.124.56/29	10.3.124.57 – 10.3.124.62	10.3.124.63
137	10.3.124.64/29	10.3.124.65 – 10.3.124.70	10.3.124.71
138	10.3.124.72/29	10.3.124.73 – 10.3.124.78	10.3.124.79
139	10.3.124.80/29	10.3.124.81 – 10.3.124.86	10.3.124.87
140	10.3.124.88/29	10.3.124.89 – 10.3.124.94	10.3.124.95
141	10.3.124.96/29	10.3.124.97 – 10.3.124.102	10.3.124.103
142	10.3.124.104/29	10.3.124.105 – 10.3.124.110	10.3.124.111
143	10.3.124.112/29	10.3.124.113 – 10.3.124.118	10.3.124.119
144	10.3.124.120/29	10.3.124.121 – 10.3.124.126	10.3.124.127
145	10.3.124.128/29	10.3.124.129 – 10.3.124.134	10.3.124.135
146	10.3.124.136/29	10.3.124.137 – 10.3.124.142	10.3.124.143
147	10.3.124.144/29	10.3.124.145 – 10.3.124.150	10.3.124.151
148	10.3.124.152/29	10.3.124.153 – 10.3.124.158	10.3.124.159
149	10.3.124.160/29	10.3.124.161 – 10.3.124.166	10.3.124.167
150	10.3.124.168/29	10.3.124.169 – 10.3.124.174	10.3.124.175
151	10.3.124.176/29	10.3.124.177 – 10.3.124.182	10.3.124.183
152	10.3.124.184/29	10.3.124.185 – 10.3.124.190	10.3.124.191
153	10.3.124.192/29	10.3.124.193 – 10.3.124.198	10.3.124.199
154	10.3.124.200/29	10.3.124.201 – 10.3.124.206	10.3.124.207
155	10.3.124.208/29	10.3.124.209 – 10.3.124.214	10.3.124.215
156	10.3.124.216/29	10.3.124.217 – 10.3.124.222	10.3.124.223
157	10.3.124.224/29	10.3.124.225 – 10.3.124.230	10.3.124.231
158	10.3.124.232/29	10.3.124.233 – 10.3.124.238	10.3.124.239
159	10.3.124.240/29	10.3.124.241 – 10.3.124.246	10.3.124.247
160	10.3.124.248/29	10.3.124.249 – 10.3.124.254	10.3.124.255
161	10.3.125.0/29	10.3.125.1 – 10.3.125.6	10.3.125.7
162	10.3.125.8/29	10.3.125.9 – 10.3.125.14	10.3.125.15
163	10.3.125.16/29	10.3.125.17 – 10.3.125.22	10.3.125.23
164	10.3.125.24/29	10.3.125.25 – 10.3.125.30	10.3.125.31
165	10.3.125.32/29	10.3.125.33 – 10.3.125.38	10.3.125.39
166	10.3.125.40/29	10.3.125.41 – 10.3.125.46	10.3.125.47
167	10.3.125.48/29	10.3.125.49 – 10.3.125.54	10.3.125.55
168	10.3.125.56/29	10.3.125.57 – 10.3.125.62	10.3.125.63
169	10.3.125.64/29	10.3.125.65 – 10.3.125.70	10.3.125.71
170	10.3.125.72/29	10.3.125.73 – 10.3.125.78	10.3.125.79
171	10.3.125.80/29	10.3.125.81 – 10.3.125.86	10.3.125.87
172	10.3.125.88/29	10.3.125.89 – 10.3.125.94	10.3.125.95
173	10.3.125.96/29	10.3.125.97 – 10.3.125.102	10.3.125.103
174	10.3.125.104/29	10.3.125.105 – 10.3.125.110	10.3.125.111
175	10.3.125.112/29	10.3.125.113 – 10.3.125.118	10.3.125.119
176	10.3.125.120/29	10.3.125.121 – 10.3.125.126	10.3.125.127
177	10.3.125.128/29	10.3.125.129 – 10.3.125.134	10.3.125.135
178	10.3.125.136/29	10.3.125.137 – 10.3.125.142	10.3.125.143
179	10.3.125.144/29	10.3.125.145 – 10.3.125.150	10.3.125.151
180	10.3.125.152/29	10.3.125.153 – 10.3.125.158	10.3.125.159
181	10.3.125.160/29	10.3.125.161 – 10.3.125.166	10.3.125.167
182	10.3.125.168/29	10.3.125.169 – 10.3.125.174	10.3.125.175
183	10.3.125.176/29	10.3.125.177 – 10.3.125.182	10.3.125.183
184	10.3.125.184/29	10.3.125.185 – 10.3.125.190	10.3.125.191
185	10.3.125.192/29	10.3.125.193 – 10.3.125.198	10.3.125.199
186	10.3.125.200/29	10.3.125.201 – 10.3.125.206	10.3.125.207
187	10.3.125.208/29	10.3.125.209 – 10.3.125.214	10.3.125.215
188	10.3.125.216/29	10.3.125.217 – 10.3.125.222	10.3.125.223
189	10.3.125.224/29	10.3.125.225 – 10.3.125.230	10.3.125.231
190	10.3.125.232/29	10.3.125.233 – 10.3.125.238	10.3.125.239
191	10.3.125.240/29	10.3.125.241 – 10.3.125.246	10.3.125.247
192	10.3.125.248/29	10.3.125.249 – 10.3.125.254	10.3.125.255
193	10.3.126.0/29	10.3.126.1 – 10.3.126.6	10.3.126.7
194	10.3.126.8/29	10.3.126.9 – 10.3.126.14	10.3.126.15
195	10.3.126.16/29	10.3.126.17 – 10.3.126.22	10.3.126.23
196	10.3.126.24/29	10.3.126.25 – 10.3.126.30	10.3.126.31
197	10.3.126.32/29	10.3.126.33 – 10.3.126.38	10.3.126.39
198	10.3.126.40/29	10.3.126.41 – 10.3.126.46	10.3.126.47
199	10.3.126.48/29	10.3.126.49 – 10.3.126.54	10.3.126.55
200	10.3.126.56/29	10.3.126.57 – 10.3.126.62	10.3.126.63
201	10.3.126.64/29	10.3.126.65 – 10.3.126.70	10.3.126.71
202	10.3.126.72/29	10.3.126.73 – 10.3.126.78	10.3.126.79
203	10.3.126.80/29	10.3.126.81 – 10.3.126.86	10.3.126.87
204	10.3.126.88/29	10.3.126.89 – 10.3.126.94	10.3.126.95
205	10.3.126.96/29	10.3.126.97 – 10.3.126.102	10.3.126.103
206	10.3.126.104/29	10.3.126.105 – 10.3.126.110	10.3.126.111
207	10.3.126.112/29	10.3.126.113 – 10.3.126.118	10.3.126.119
208	10.3.126.120/29	10.3.126.121 – 10.3.126.126	10.3.126.127
209	10.3.126.128/29	10.3.126.129 – 10.3.126.134	10.3.126.135
210	10.3.126.136/29	10.3.126.137 – 10.3.126.142	10.3.126.143
211	10.3.126.144/29	10.3.126.145 – 10.3.126.150	10.3.126.151
212	10.3.126.152/29	10.3.126.153 – 10.3.126.158	10.3.126.159
213	10.3.126.160/29	10.3.126.161 – 10.3.126.166	10.3.126.167
214	10.3.126.168/29	10.3.126.169 – 10.3.126.174	10.3.126.175
215	10.3.126.176/29	10.3.126.177 – 10.3.126.182	10.3.126.183
216	10.3.126.184/29	10.3.126.185 – 10.3.126.190	10.3.126.191
217	10.3.126.192/29	10.3.126.193 – 10.3.126.198	10.3.126.199
218	10.3.126.200/29	10.3.126.201 – 10.3.126.206	10.3.126.207
219	10.3.126.208/29	10.3.126.209 – 10.3.126.214	10.3.126.215
220	10.3.126.216/29	10.3.126.217 – 10.3.126.222	10.3.126.223
221	10.3.126.224/29	10.3.126.225 – 10.3.126.230	10.3.126.231
222	10.3.126.232/29	10.3.126.233 – 10.3.126.238	10.3.126.239
223	10.3.126.240/29	10.3.126.241 – 10.3.126.246	10.3.126.247
224	10.3.126.248/29	10.3.126.249 – 10.3.126.254	10.3.126.255
225	10.3.127.0/29	10.3.127.1 – 10.3.127.6	10.3.127.7
226	10.3.127.8/29	10.3.127.9 – 10.3.127.14	10.3.127.15
227	10.3.127.16/29	10.3.127.17 – 10.3.127.22	10.3.127.23
228	10.3.127.24/29	10.3.127.25 – 10.3.127.30	10.3.127.31
229	10.3.127.32/29	10.3.127.33 – 10.3.127.38	10.3.127.39
230	10.3.127.40/29	10.3.127.41 – 10.3.127.46	10.3.127.47
231	10.3.127.48/29	10.3.127.49 – 10.3.127.54	10.3.127.55
232	10.3.127.56/29	10.3.127.57 – 10.3.127.62	10.3.127.63
233	10.3.127.64/29	10.3.127.65 – 10.3.127.70	10.3.127.71
234	10.3.127.72/29	10.3.127.73 – 10.3.127.78	10.3.127.79
235	10.3.127.80/29	10.3.127.81 – 10.3.127.86	10.3.127.87
236	10.3.127.88/29	10.3.127.89 – 10.3.127.94	10.3.127.95
237	10.3.127.96/29	10.3.127.97 – 10.3.127.102	10.3.127.103
238	10.3.127.104/29	10.3.127.105 – 10.3.127.110	10.3.127.111
239	10.3.127.112/29	10.3.127.113 – 10.3.127.118	10.3.127.119
240	10.3.127.120/29	10.3.127.121 – 10.3.127.126	10.3.127.127
241	10.3.127.128/29	10.3.127.129 – 10.3.127.134	10.3.127.135
242	10.3.127.136/29	10.3.127.137 – 10.3.127.142	10.3.127.143
243	10.3.127.144/29	10.3.127.145 – 10.3.127.150	10.3.127.151
244	10.3.127.152/29	10.3.127.153 – 10.3.127.158	10.3.127.159
245	10.3.127.160/29	10.3.127.161 – 10.3.127.166	10.3.127.167
246	10.3.127.168/29	10.3.127.169 – 10.3.127.174	10.3.127.175
247	10.3.127.176/29	10.3.127.177 – 10.3.127.182	10.3.127.183
248	10.3.127.184/29	10.3.127.185 – 10.3.127.190	10.3.127.191
249	10.3.127.192/29	10.3.127.193 – 10.3.127.198	10.3.127.199
250	10.3.127.200/29	10.3.127.201 – 10.3.127.206	10.3.127.207
251	10.3.127.208/29	10.3.127.209 – 10.3.127.214	10.3.127.215
252	10.3.127.216/29	10.3.127.217 – 10.3.127.222	10.3.127.223
253	10.3.127.224/29	10.3.127.225 – 10.3.127.230	10.3.127.231
254	10.3.127.232/29	10.3.127.233 – 10.3.127.238	10.3.127.239
255	10.3.127.240/29	10.3.127.241 – 10.3.127.246	10.3.127.247
256	10.3.127.248/29	10.3.127.249 – 10.3.127.254	10.3.127.255

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 →