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)10.2.56.0/21

network10.2.56.0/21

broadcast10.2.63.255

first host10.2.56.1

last host10.2.63.254

subnet mask255.255.248.0

wildcard0.0.7.255

addresses2,048

usable hosts2,046

classA

ipcalc 10.2.56.0/21

address00001010.00000010.00111000.00000000

subnet mask11111111.11111111.11111000.00000000

network00001010.00000010.00111000.00000000

broadcast00001010.00000010.00111111.11111111

green = network part, grey = host part

hex0x0a023800

decimal167917568

reverse dns0.56.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:3800

/21 split into /29 · 256 subnets

close ×

#	network	host range	broadcast
1	10.2.56.0/29	10.2.56.1 – 10.2.56.6	10.2.56.7
2	10.2.56.8/29	10.2.56.9 – 10.2.56.14	10.2.56.15
3	10.2.56.16/29	10.2.56.17 – 10.2.56.22	10.2.56.23
4	10.2.56.24/29	10.2.56.25 – 10.2.56.30	10.2.56.31
5	10.2.56.32/29	10.2.56.33 – 10.2.56.38	10.2.56.39
6	10.2.56.40/29	10.2.56.41 – 10.2.56.46	10.2.56.47
7	10.2.56.48/29	10.2.56.49 – 10.2.56.54	10.2.56.55
8	10.2.56.56/29	10.2.56.57 – 10.2.56.62	10.2.56.63
9	10.2.56.64/29	10.2.56.65 – 10.2.56.70	10.2.56.71
10	10.2.56.72/29	10.2.56.73 – 10.2.56.78	10.2.56.79
11	10.2.56.80/29	10.2.56.81 – 10.2.56.86	10.2.56.87
12	10.2.56.88/29	10.2.56.89 – 10.2.56.94	10.2.56.95
13	10.2.56.96/29	10.2.56.97 – 10.2.56.102	10.2.56.103
14	10.2.56.104/29	10.2.56.105 – 10.2.56.110	10.2.56.111
15	10.2.56.112/29	10.2.56.113 – 10.2.56.118	10.2.56.119
16	10.2.56.120/29	10.2.56.121 – 10.2.56.126	10.2.56.127
17	10.2.56.128/29	10.2.56.129 – 10.2.56.134	10.2.56.135
18	10.2.56.136/29	10.2.56.137 – 10.2.56.142	10.2.56.143
19	10.2.56.144/29	10.2.56.145 – 10.2.56.150	10.2.56.151
20	10.2.56.152/29	10.2.56.153 – 10.2.56.158	10.2.56.159
21	10.2.56.160/29	10.2.56.161 – 10.2.56.166	10.2.56.167
22	10.2.56.168/29	10.2.56.169 – 10.2.56.174	10.2.56.175
23	10.2.56.176/29	10.2.56.177 – 10.2.56.182	10.2.56.183
24	10.2.56.184/29	10.2.56.185 – 10.2.56.190	10.2.56.191
25	10.2.56.192/29	10.2.56.193 – 10.2.56.198	10.2.56.199
26	10.2.56.200/29	10.2.56.201 – 10.2.56.206	10.2.56.207
27	10.2.56.208/29	10.2.56.209 – 10.2.56.214	10.2.56.215
28	10.2.56.216/29	10.2.56.217 – 10.2.56.222	10.2.56.223
29	10.2.56.224/29	10.2.56.225 – 10.2.56.230	10.2.56.231
30	10.2.56.232/29	10.2.56.233 – 10.2.56.238	10.2.56.239
31	10.2.56.240/29	10.2.56.241 – 10.2.56.246	10.2.56.247
32	10.2.56.248/29	10.2.56.249 – 10.2.56.254	10.2.56.255
33	10.2.57.0/29	10.2.57.1 – 10.2.57.6	10.2.57.7
34	10.2.57.8/29	10.2.57.9 – 10.2.57.14	10.2.57.15
35	10.2.57.16/29	10.2.57.17 – 10.2.57.22	10.2.57.23
36	10.2.57.24/29	10.2.57.25 – 10.2.57.30	10.2.57.31
37	10.2.57.32/29	10.2.57.33 – 10.2.57.38	10.2.57.39
38	10.2.57.40/29	10.2.57.41 – 10.2.57.46	10.2.57.47
39	10.2.57.48/29	10.2.57.49 – 10.2.57.54	10.2.57.55
40	10.2.57.56/29	10.2.57.57 – 10.2.57.62	10.2.57.63
41	10.2.57.64/29	10.2.57.65 – 10.2.57.70	10.2.57.71
42	10.2.57.72/29	10.2.57.73 – 10.2.57.78	10.2.57.79
43	10.2.57.80/29	10.2.57.81 – 10.2.57.86	10.2.57.87
44	10.2.57.88/29	10.2.57.89 – 10.2.57.94	10.2.57.95
45	10.2.57.96/29	10.2.57.97 – 10.2.57.102	10.2.57.103
46	10.2.57.104/29	10.2.57.105 – 10.2.57.110	10.2.57.111
47	10.2.57.112/29	10.2.57.113 – 10.2.57.118	10.2.57.119
48	10.2.57.120/29	10.2.57.121 – 10.2.57.126	10.2.57.127
49	10.2.57.128/29	10.2.57.129 – 10.2.57.134	10.2.57.135
50	10.2.57.136/29	10.2.57.137 – 10.2.57.142	10.2.57.143
51	10.2.57.144/29	10.2.57.145 – 10.2.57.150	10.2.57.151
52	10.2.57.152/29	10.2.57.153 – 10.2.57.158	10.2.57.159
53	10.2.57.160/29	10.2.57.161 – 10.2.57.166	10.2.57.167
54	10.2.57.168/29	10.2.57.169 – 10.2.57.174	10.2.57.175
55	10.2.57.176/29	10.2.57.177 – 10.2.57.182	10.2.57.183
56	10.2.57.184/29	10.2.57.185 – 10.2.57.190	10.2.57.191
57	10.2.57.192/29	10.2.57.193 – 10.2.57.198	10.2.57.199
58	10.2.57.200/29	10.2.57.201 – 10.2.57.206	10.2.57.207
59	10.2.57.208/29	10.2.57.209 – 10.2.57.214	10.2.57.215
60	10.2.57.216/29	10.2.57.217 – 10.2.57.222	10.2.57.223
61	10.2.57.224/29	10.2.57.225 – 10.2.57.230	10.2.57.231
62	10.2.57.232/29	10.2.57.233 – 10.2.57.238	10.2.57.239
63	10.2.57.240/29	10.2.57.241 – 10.2.57.246	10.2.57.247
64	10.2.57.248/29	10.2.57.249 – 10.2.57.254	10.2.57.255
65	10.2.58.0/29	10.2.58.1 – 10.2.58.6	10.2.58.7
66	10.2.58.8/29	10.2.58.9 – 10.2.58.14	10.2.58.15
67	10.2.58.16/29	10.2.58.17 – 10.2.58.22	10.2.58.23
68	10.2.58.24/29	10.2.58.25 – 10.2.58.30	10.2.58.31
69	10.2.58.32/29	10.2.58.33 – 10.2.58.38	10.2.58.39
70	10.2.58.40/29	10.2.58.41 – 10.2.58.46	10.2.58.47
71	10.2.58.48/29	10.2.58.49 – 10.2.58.54	10.2.58.55
72	10.2.58.56/29	10.2.58.57 – 10.2.58.62	10.2.58.63
73	10.2.58.64/29	10.2.58.65 – 10.2.58.70	10.2.58.71
74	10.2.58.72/29	10.2.58.73 – 10.2.58.78	10.2.58.79
75	10.2.58.80/29	10.2.58.81 – 10.2.58.86	10.2.58.87
76	10.2.58.88/29	10.2.58.89 – 10.2.58.94	10.2.58.95
77	10.2.58.96/29	10.2.58.97 – 10.2.58.102	10.2.58.103
78	10.2.58.104/29	10.2.58.105 – 10.2.58.110	10.2.58.111
79	10.2.58.112/29	10.2.58.113 – 10.2.58.118	10.2.58.119
80	10.2.58.120/29	10.2.58.121 – 10.2.58.126	10.2.58.127
81	10.2.58.128/29	10.2.58.129 – 10.2.58.134	10.2.58.135
82	10.2.58.136/29	10.2.58.137 – 10.2.58.142	10.2.58.143
83	10.2.58.144/29	10.2.58.145 – 10.2.58.150	10.2.58.151
84	10.2.58.152/29	10.2.58.153 – 10.2.58.158	10.2.58.159
85	10.2.58.160/29	10.2.58.161 – 10.2.58.166	10.2.58.167
86	10.2.58.168/29	10.2.58.169 – 10.2.58.174	10.2.58.175
87	10.2.58.176/29	10.2.58.177 – 10.2.58.182	10.2.58.183
88	10.2.58.184/29	10.2.58.185 – 10.2.58.190	10.2.58.191
89	10.2.58.192/29	10.2.58.193 – 10.2.58.198	10.2.58.199
90	10.2.58.200/29	10.2.58.201 – 10.2.58.206	10.2.58.207
91	10.2.58.208/29	10.2.58.209 – 10.2.58.214	10.2.58.215
92	10.2.58.216/29	10.2.58.217 – 10.2.58.222	10.2.58.223
93	10.2.58.224/29	10.2.58.225 – 10.2.58.230	10.2.58.231
94	10.2.58.232/29	10.2.58.233 – 10.2.58.238	10.2.58.239
95	10.2.58.240/29	10.2.58.241 – 10.2.58.246	10.2.58.247
96	10.2.58.248/29	10.2.58.249 – 10.2.58.254	10.2.58.255
97	10.2.59.0/29	10.2.59.1 – 10.2.59.6	10.2.59.7
98	10.2.59.8/29	10.2.59.9 – 10.2.59.14	10.2.59.15
99	10.2.59.16/29	10.2.59.17 – 10.2.59.22	10.2.59.23
100	10.2.59.24/29	10.2.59.25 – 10.2.59.30	10.2.59.31
101	10.2.59.32/29	10.2.59.33 – 10.2.59.38	10.2.59.39
102	10.2.59.40/29	10.2.59.41 – 10.2.59.46	10.2.59.47
103	10.2.59.48/29	10.2.59.49 – 10.2.59.54	10.2.59.55
104	10.2.59.56/29	10.2.59.57 – 10.2.59.62	10.2.59.63
105	10.2.59.64/29	10.2.59.65 – 10.2.59.70	10.2.59.71
106	10.2.59.72/29	10.2.59.73 – 10.2.59.78	10.2.59.79
107	10.2.59.80/29	10.2.59.81 – 10.2.59.86	10.2.59.87
108	10.2.59.88/29	10.2.59.89 – 10.2.59.94	10.2.59.95
109	10.2.59.96/29	10.2.59.97 – 10.2.59.102	10.2.59.103
110	10.2.59.104/29	10.2.59.105 – 10.2.59.110	10.2.59.111
111	10.2.59.112/29	10.2.59.113 – 10.2.59.118	10.2.59.119
112	10.2.59.120/29	10.2.59.121 – 10.2.59.126	10.2.59.127
113	10.2.59.128/29	10.2.59.129 – 10.2.59.134	10.2.59.135
114	10.2.59.136/29	10.2.59.137 – 10.2.59.142	10.2.59.143
115	10.2.59.144/29	10.2.59.145 – 10.2.59.150	10.2.59.151
116	10.2.59.152/29	10.2.59.153 – 10.2.59.158	10.2.59.159
117	10.2.59.160/29	10.2.59.161 – 10.2.59.166	10.2.59.167
118	10.2.59.168/29	10.2.59.169 – 10.2.59.174	10.2.59.175
119	10.2.59.176/29	10.2.59.177 – 10.2.59.182	10.2.59.183
120	10.2.59.184/29	10.2.59.185 – 10.2.59.190	10.2.59.191
121	10.2.59.192/29	10.2.59.193 – 10.2.59.198	10.2.59.199
122	10.2.59.200/29	10.2.59.201 – 10.2.59.206	10.2.59.207
123	10.2.59.208/29	10.2.59.209 – 10.2.59.214	10.2.59.215
124	10.2.59.216/29	10.2.59.217 – 10.2.59.222	10.2.59.223
125	10.2.59.224/29	10.2.59.225 – 10.2.59.230	10.2.59.231
126	10.2.59.232/29	10.2.59.233 – 10.2.59.238	10.2.59.239
127	10.2.59.240/29	10.2.59.241 – 10.2.59.246	10.2.59.247
128	10.2.59.248/29	10.2.59.249 – 10.2.59.254	10.2.59.255
129	10.2.60.0/29	10.2.60.1 – 10.2.60.6	10.2.60.7
130	10.2.60.8/29	10.2.60.9 – 10.2.60.14	10.2.60.15
131	10.2.60.16/29	10.2.60.17 – 10.2.60.22	10.2.60.23
132	10.2.60.24/29	10.2.60.25 – 10.2.60.30	10.2.60.31
133	10.2.60.32/29	10.2.60.33 – 10.2.60.38	10.2.60.39
134	10.2.60.40/29	10.2.60.41 – 10.2.60.46	10.2.60.47
135	10.2.60.48/29	10.2.60.49 – 10.2.60.54	10.2.60.55
136	10.2.60.56/29	10.2.60.57 – 10.2.60.62	10.2.60.63
137	10.2.60.64/29	10.2.60.65 – 10.2.60.70	10.2.60.71
138	10.2.60.72/29	10.2.60.73 – 10.2.60.78	10.2.60.79
139	10.2.60.80/29	10.2.60.81 – 10.2.60.86	10.2.60.87
140	10.2.60.88/29	10.2.60.89 – 10.2.60.94	10.2.60.95
141	10.2.60.96/29	10.2.60.97 – 10.2.60.102	10.2.60.103
142	10.2.60.104/29	10.2.60.105 – 10.2.60.110	10.2.60.111
143	10.2.60.112/29	10.2.60.113 – 10.2.60.118	10.2.60.119
144	10.2.60.120/29	10.2.60.121 – 10.2.60.126	10.2.60.127
145	10.2.60.128/29	10.2.60.129 – 10.2.60.134	10.2.60.135
146	10.2.60.136/29	10.2.60.137 – 10.2.60.142	10.2.60.143
147	10.2.60.144/29	10.2.60.145 – 10.2.60.150	10.2.60.151
148	10.2.60.152/29	10.2.60.153 – 10.2.60.158	10.2.60.159
149	10.2.60.160/29	10.2.60.161 – 10.2.60.166	10.2.60.167
150	10.2.60.168/29	10.2.60.169 – 10.2.60.174	10.2.60.175
151	10.2.60.176/29	10.2.60.177 – 10.2.60.182	10.2.60.183
152	10.2.60.184/29	10.2.60.185 – 10.2.60.190	10.2.60.191
153	10.2.60.192/29	10.2.60.193 – 10.2.60.198	10.2.60.199
154	10.2.60.200/29	10.2.60.201 – 10.2.60.206	10.2.60.207
155	10.2.60.208/29	10.2.60.209 – 10.2.60.214	10.2.60.215
156	10.2.60.216/29	10.2.60.217 – 10.2.60.222	10.2.60.223
157	10.2.60.224/29	10.2.60.225 – 10.2.60.230	10.2.60.231
158	10.2.60.232/29	10.2.60.233 – 10.2.60.238	10.2.60.239
159	10.2.60.240/29	10.2.60.241 – 10.2.60.246	10.2.60.247
160	10.2.60.248/29	10.2.60.249 – 10.2.60.254	10.2.60.255
161	10.2.61.0/29	10.2.61.1 – 10.2.61.6	10.2.61.7
162	10.2.61.8/29	10.2.61.9 – 10.2.61.14	10.2.61.15
163	10.2.61.16/29	10.2.61.17 – 10.2.61.22	10.2.61.23
164	10.2.61.24/29	10.2.61.25 – 10.2.61.30	10.2.61.31
165	10.2.61.32/29	10.2.61.33 – 10.2.61.38	10.2.61.39
166	10.2.61.40/29	10.2.61.41 – 10.2.61.46	10.2.61.47
167	10.2.61.48/29	10.2.61.49 – 10.2.61.54	10.2.61.55
168	10.2.61.56/29	10.2.61.57 – 10.2.61.62	10.2.61.63
169	10.2.61.64/29	10.2.61.65 – 10.2.61.70	10.2.61.71
170	10.2.61.72/29	10.2.61.73 – 10.2.61.78	10.2.61.79
171	10.2.61.80/29	10.2.61.81 – 10.2.61.86	10.2.61.87
172	10.2.61.88/29	10.2.61.89 – 10.2.61.94	10.2.61.95
173	10.2.61.96/29	10.2.61.97 – 10.2.61.102	10.2.61.103
174	10.2.61.104/29	10.2.61.105 – 10.2.61.110	10.2.61.111
175	10.2.61.112/29	10.2.61.113 – 10.2.61.118	10.2.61.119
176	10.2.61.120/29	10.2.61.121 – 10.2.61.126	10.2.61.127
177	10.2.61.128/29	10.2.61.129 – 10.2.61.134	10.2.61.135
178	10.2.61.136/29	10.2.61.137 – 10.2.61.142	10.2.61.143
179	10.2.61.144/29	10.2.61.145 – 10.2.61.150	10.2.61.151
180	10.2.61.152/29	10.2.61.153 – 10.2.61.158	10.2.61.159
181	10.2.61.160/29	10.2.61.161 – 10.2.61.166	10.2.61.167
182	10.2.61.168/29	10.2.61.169 – 10.2.61.174	10.2.61.175
183	10.2.61.176/29	10.2.61.177 – 10.2.61.182	10.2.61.183
184	10.2.61.184/29	10.2.61.185 – 10.2.61.190	10.2.61.191
185	10.2.61.192/29	10.2.61.193 – 10.2.61.198	10.2.61.199
186	10.2.61.200/29	10.2.61.201 – 10.2.61.206	10.2.61.207
187	10.2.61.208/29	10.2.61.209 – 10.2.61.214	10.2.61.215
188	10.2.61.216/29	10.2.61.217 – 10.2.61.222	10.2.61.223
189	10.2.61.224/29	10.2.61.225 – 10.2.61.230	10.2.61.231
190	10.2.61.232/29	10.2.61.233 – 10.2.61.238	10.2.61.239
191	10.2.61.240/29	10.2.61.241 – 10.2.61.246	10.2.61.247
192	10.2.61.248/29	10.2.61.249 – 10.2.61.254	10.2.61.255
193	10.2.62.0/29	10.2.62.1 – 10.2.62.6	10.2.62.7
194	10.2.62.8/29	10.2.62.9 – 10.2.62.14	10.2.62.15
195	10.2.62.16/29	10.2.62.17 – 10.2.62.22	10.2.62.23
196	10.2.62.24/29	10.2.62.25 – 10.2.62.30	10.2.62.31
197	10.2.62.32/29	10.2.62.33 – 10.2.62.38	10.2.62.39
198	10.2.62.40/29	10.2.62.41 – 10.2.62.46	10.2.62.47
199	10.2.62.48/29	10.2.62.49 – 10.2.62.54	10.2.62.55
200	10.2.62.56/29	10.2.62.57 – 10.2.62.62	10.2.62.63
201	10.2.62.64/29	10.2.62.65 – 10.2.62.70	10.2.62.71
202	10.2.62.72/29	10.2.62.73 – 10.2.62.78	10.2.62.79
203	10.2.62.80/29	10.2.62.81 – 10.2.62.86	10.2.62.87
204	10.2.62.88/29	10.2.62.89 – 10.2.62.94	10.2.62.95
205	10.2.62.96/29	10.2.62.97 – 10.2.62.102	10.2.62.103
206	10.2.62.104/29	10.2.62.105 – 10.2.62.110	10.2.62.111
207	10.2.62.112/29	10.2.62.113 – 10.2.62.118	10.2.62.119
208	10.2.62.120/29	10.2.62.121 – 10.2.62.126	10.2.62.127
209	10.2.62.128/29	10.2.62.129 – 10.2.62.134	10.2.62.135
210	10.2.62.136/29	10.2.62.137 – 10.2.62.142	10.2.62.143
211	10.2.62.144/29	10.2.62.145 – 10.2.62.150	10.2.62.151
212	10.2.62.152/29	10.2.62.153 – 10.2.62.158	10.2.62.159
213	10.2.62.160/29	10.2.62.161 – 10.2.62.166	10.2.62.167
214	10.2.62.168/29	10.2.62.169 – 10.2.62.174	10.2.62.175
215	10.2.62.176/29	10.2.62.177 – 10.2.62.182	10.2.62.183
216	10.2.62.184/29	10.2.62.185 – 10.2.62.190	10.2.62.191
217	10.2.62.192/29	10.2.62.193 – 10.2.62.198	10.2.62.199
218	10.2.62.200/29	10.2.62.201 – 10.2.62.206	10.2.62.207
219	10.2.62.208/29	10.2.62.209 – 10.2.62.214	10.2.62.215
220	10.2.62.216/29	10.2.62.217 – 10.2.62.222	10.2.62.223
221	10.2.62.224/29	10.2.62.225 – 10.2.62.230	10.2.62.231
222	10.2.62.232/29	10.2.62.233 – 10.2.62.238	10.2.62.239
223	10.2.62.240/29	10.2.62.241 – 10.2.62.246	10.2.62.247
224	10.2.62.248/29	10.2.62.249 – 10.2.62.254	10.2.62.255
225	10.2.63.0/29	10.2.63.1 – 10.2.63.6	10.2.63.7
226	10.2.63.8/29	10.2.63.9 – 10.2.63.14	10.2.63.15
227	10.2.63.16/29	10.2.63.17 – 10.2.63.22	10.2.63.23
228	10.2.63.24/29	10.2.63.25 – 10.2.63.30	10.2.63.31
229	10.2.63.32/29	10.2.63.33 – 10.2.63.38	10.2.63.39
230	10.2.63.40/29	10.2.63.41 – 10.2.63.46	10.2.63.47
231	10.2.63.48/29	10.2.63.49 – 10.2.63.54	10.2.63.55
232	10.2.63.56/29	10.2.63.57 – 10.2.63.62	10.2.63.63
233	10.2.63.64/29	10.2.63.65 – 10.2.63.70	10.2.63.71
234	10.2.63.72/29	10.2.63.73 – 10.2.63.78	10.2.63.79
235	10.2.63.80/29	10.2.63.81 – 10.2.63.86	10.2.63.87
236	10.2.63.88/29	10.2.63.89 – 10.2.63.94	10.2.63.95
237	10.2.63.96/29	10.2.63.97 – 10.2.63.102	10.2.63.103
238	10.2.63.104/29	10.2.63.105 – 10.2.63.110	10.2.63.111
239	10.2.63.112/29	10.2.63.113 – 10.2.63.118	10.2.63.119
240	10.2.63.120/29	10.2.63.121 – 10.2.63.126	10.2.63.127
241	10.2.63.128/29	10.2.63.129 – 10.2.63.134	10.2.63.135
242	10.2.63.136/29	10.2.63.137 – 10.2.63.142	10.2.63.143
243	10.2.63.144/29	10.2.63.145 – 10.2.63.150	10.2.63.151
244	10.2.63.152/29	10.2.63.153 – 10.2.63.158	10.2.63.159
245	10.2.63.160/29	10.2.63.161 – 10.2.63.166	10.2.63.167
246	10.2.63.168/29	10.2.63.169 – 10.2.63.174	10.2.63.175
247	10.2.63.176/29	10.2.63.177 – 10.2.63.182	10.2.63.183
248	10.2.63.184/29	10.2.63.185 – 10.2.63.190	10.2.63.191
249	10.2.63.192/29	10.2.63.193 – 10.2.63.198	10.2.63.199
250	10.2.63.200/29	10.2.63.201 – 10.2.63.206	10.2.63.207
251	10.2.63.208/29	10.2.63.209 – 10.2.63.214	10.2.63.215
252	10.2.63.216/29	10.2.63.217 – 10.2.63.222	10.2.63.223
253	10.2.63.224/29	10.2.63.225 – 10.2.63.230	10.2.63.231
254	10.2.63.232/29	10.2.63.233 – 10.2.63.238	10.2.63.239
255	10.2.63.240/29	10.2.63.241 – 10.2.63.246	10.2.63.247
256	10.2.63.248/29	10.2.63.249 – 10.2.63.254	10.2.63.255

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 →