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)10.167.51.128/25

network10.167.51.128/25

broadcast10.167.51.255

first host10.167.51.129

last host10.167.51.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.167.51.128/25

address00001010.10100111.00110011.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.10100111.00110011.10000000

broadcast00001010.10100111.00110011.11111111

green = network part, grey = host part

hex0x0aa73380

decimal178729856

reverse dns128.51.167.10.in-addr.arpa

ipv4-mapped::ffff:aa7:3380

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.167.51.128/32	10.167.51.128 – 10.167.51.128	10.167.51.128
2	10.167.51.129/32	10.167.51.129 – 10.167.51.129	10.167.51.129
3	10.167.51.130/32	10.167.51.130 – 10.167.51.130	10.167.51.130
4	10.167.51.131/32	10.167.51.131 – 10.167.51.131	10.167.51.131
5	10.167.51.132/32	10.167.51.132 – 10.167.51.132	10.167.51.132
6	10.167.51.133/32	10.167.51.133 – 10.167.51.133	10.167.51.133
7	10.167.51.134/32	10.167.51.134 – 10.167.51.134	10.167.51.134
8	10.167.51.135/32	10.167.51.135 – 10.167.51.135	10.167.51.135
9	10.167.51.136/32	10.167.51.136 – 10.167.51.136	10.167.51.136
10	10.167.51.137/32	10.167.51.137 – 10.167.51.137	10.167.51.137
11	10.167.51.138/32	10.167.51.138 – 10.167.51.138	10.167.51.138
12	10.167.51.139/32	10.167.51.139 – 10.167.51.139	10.167.51.139
13	10.167.51.140/32	10.167.51.140 – 10.167.51.140	10.167.51.140
14	10.167.51.141/32	10.167.51.141 – 10.167.51.141	10.167.51.141
15	10.167.51.142/32	10.167.51.142 – 10.167.51.142	10.167.51.142
16	10.167.51.143/32	10.167.51.143 – 10.167.51.143	10.167.51.143
17	10.167.51.144/32	10.167.51.144 – 10.167.51.144	10.167.51.144
18	10.167.51.145/32	10.167.51.145 – 10.167.51.145	10.167.51.145
19	10.167.51.146/32	10.167.51.146 – 10.167.51.146	10.167.51.146
20	10.167.51.147/32	10.167.51.147 – 10.167.51.147	10.167.51.147
21	10.167.51.148/32	10.167.51.148 – 10.167.51.148	10.167.51.148
22	10.167.51.149/32	10.167.51.149 – 10.167.51.149	10.167.51.149
23	10.167.51.150/32	10.167.51.150 – 10.167.51.150	10.167.51.150
24	10.167.51.151/32	10.167.51.151 – 10.167.51.151	10.167.51.151
25	10.167.51.152/32	10.167.51.152 – 10.167.51.152	10.167.51.152
26	10.167.51.153/32	10.167.51.153 – 10.167.51.153	10.167.51.153
27	10.167.51.154/32	10.167.51.154 – 10.167.51.154	10.167.51.154
28	10.167.51.155/32	10.167.51.155 – 10.167.51.155	10.167.51.155
29	10.167.51.156/32	10.167.51.156 – 10.167.51.156	10.167.51.156
30	10.167.51.157/32	10.167.51.157 – 10.167.51.157	10.167.51.157
31	10.167.51.158/32	10.167.51.158 – 10.167.51.158	10.167.51.158
32	10.167.51.159/32	10.167.51.159 – 10.167.51.159	10.167.51.159
33	10.167.51.160/32	10.167.51.160 – 10.167.51.160	10.167.51.160
34	10.167.51.161/32	10.167.51.161 – 10.167.51.161	10.167.51.161
35	10.167.51.162/32	10.167.51.162 – 10.167.51.162	10.167.51.162
36	10.167.51.163/32	10.167.51.163 – 10.167.51.163	10.167.51.163
37	10.167.51.164/32	10.167.51.164 – 10.167.51.164	10.167.51.164
38	10.167.51.165/32	10.167.51.165 – 10.167.51.165	10.167.51.165
39	10.167.51.166/32	10.167.51.166 – 10.167.51.166	10.167.51.166
40	10.167.51.167/32	10.167.51.167 – 10.167.51.167	10.167.51.167
41	10.167.51.168/32	10.167.51.168 – 10.167.51.168	10.167.51.168
42	10.167.51.169/32	10.167.51.169 – 10.167.51.169	10.167.51.169
43	10.167.51.170/32	10.167.51.170 – 10.167.51.170	10.167.51.170
44	10.167.51.171/32	10.167.51.171 – 10.167.51.171	10.167.51.171
45	10.167.51.172/32	10.167.51.172 – 10.167.51.172	10.167.51.172
46	10.167.51.173/32	10.167.51.173 – 10.167.51.173	10.167.51.173
47	10.167.51.174/32	10.167.51.174 – 10.167.51.174	10.167.51.174
48	10.167.51.175/32	10.167.51.175 – 10.167.51.175	10.167.51.175
49	10.167.51.176/32	10.167.51.176 – 10.167.51.176	10.167.51.176
50	10.167.51.177/32	10.167.51.177 – 10.167.51.177	10.167.51.177
51	10.167.51.178/32	10.167.51.178 – 10.167.51.178	10.167.51.178
52	10.167.51.179/32	10.167.51.179 – 10.167.51.179	10.167.51.179
53	10.167.51.180/32	10.167.51.180 – 10.167.51.180	10.167.51.180
54	10.167.51.181/32	10.167.51.181 – 10.167.51.181	10.167.51.181
55	10.167.51.182/32	10.167.51.182 – 10.167.51.182	10.167.51.182
56	10.167.51.183/32	10.167.51.183 – 10.167.51.183	10.167.51.183
57	10.167.51.184/32	10.167.51.184 – 10.167.51.184	10.167.51.184
58	10.167.51.185/32	10.167.51.185 – 10.167.51.185	10.167.51.185
59	10.167.51.186/32	10.167.51.186 – 10.167.51.186	10.167.51.186
60	10.167.51.187/32	10.167.51.187 – 10.167.51.187	10.167.51.187
61	10.167.51.188/32	10.167.51.188 – 10.167.51.188	10.167.51.188
62	10.167.51.189/32	10.167.51.189 – 10.167.51.189	10.167.51.189
63	10.167.51.190/32	10.167.51.190 – 10.167.51.190	10.167.51.190
64	10.167.51.191/32	10.167.51.191 – 10.167.51.191	10.167.51.191
65	10.167.51.192/32	10.167.51.192 – 10.167.51.192	10.167.51.192
66	10.167.51.193/32	10.167.51.193 – 10.167.51.193	10.167.51.193
67	10.167.51.194/32	10.167.51.194 – 10.167.51.194	10.167.51.194
68	10.167.51.195/32	10.167.51.195 – 10.167.51.195	10.167.51.195
69	10.167.51.196/32	10.167.51.196 – 10.167.51.196	10.167.51.196
70	10.167.51.197/32	10.167.51.197 – 10.167.51.197	10.167.51.197
71	10.167.51.198/32	10.167.51.198 – 10.167.51.198	10.167.51.198
72	10.167.51.199/32	10.167.51.199 – 10.167.51.199	10.167.51.199
73	10.167.51.200/32	10.167.51.200 – 10.167.51.200	10.167.51.200
74	10.167.51.201/32	10.167.51.201 – 10.167.51.201	10.167.51.201
75	10.167.51.202/32	10.167.51.202 – 10.167.51.202	10.167.51.202
76	10.167.51.203/32	10.167.51.203 – 10.167.51.203	10.167.51.203
77	10.167.51.204/32	10.167.51.204 – 10.167.51.204	10.167.51.204
78	10.167.51.205/32	10.167.51.205 – 10.167.51.205	10.167.51.205
79	10.167.51.206/32	10.167.51.206 – 10.167.51.206	10.167.51.206
80	10.167.51.207/32	10.167.51.207 – 10.167.51.207	10.167.51.207
81	10.167.51.208/32	10.167.51.208 – 10.167.51.208	10.167.51.208
82	10.167.51.209/32	10.167.51.209 – 10.167.51.209	10.167.51.209
83	10.167.51.210/32	10.167.51.210 – 10.167.51.210	10.167.51.210
84	10.167.51.211/32	10.167.51.211 – 10.167.51.211	10.167.51.211
85	10.167.51.212/32	10.167.51.212 – 10.167.51.212	10.167.51.212
86	10.167.51.213/32	10.167.51.213 – 10.167.51.213	10.167.51.213
87	10.167.51.214/32	10.167.51.214 – 10.167.51.214	10.167.51.214
88	10.167.51.215/32	10.167.51.215 – 10.167.51.215	10.167.51.215
89	10.167.51.216/32	10.167.51.216 – 10.167.51.216	10.167.51.216
90	10.167.51.217/32	10.167.51.217 – 10.167.51.217	10.167.51.217
91	10.167.51.218/32	10.167.51.218 – 10.167.51.218	10.167.51.218
92	10.167.51.219/32	10.167.51.219 – 10.167.51.219	10.167.51.219
93	10.167.51.220/32	10.167.51.220 – 10.167.51.220	10.167.51.220
94	10.167.51.221/32	10.167.51.221 – 10.167.51.221	10.167.51.221
95	10.167.51.222/32	10.167.51.222 – 10.167.51.222	10.167.51.222
96	10.167.51.223/32	10.167.51.223 – 10.167.51.223	10.167.51.223
97	10.167.51.224/32	10.167.51.224 – 10.167.51.224	10.167.51.224
98	10.167.51.225/32	10.167.51.225 – 10.167.51.225	10.167.51.225
99	10.167.51.226/32	10.167.51.226 – 10.167.51.226	10.167.51.226
100	10.167.51.227/32	10.167.51.227 – 10.167.51.227	10.167.51.227
101	10.167.51.228/32	10.167.51.228 – 10.167.51.228	10.167.51.228
102	10.167.51.229/32	10.167.51.229 – 10.167.51.229	10.167.51.229
103	10.167.51.230/32	10.167.51.230 – 10.167.51.230	10.167.51.230
104	10.167.51.231/32	10.167.51.231 – 10.167.51.231	10.167.51.231
105	10.167.51.232/32	10.167.51.232 – 10.167.51.232	10.167.51.232
106	10.167.51.233/32	10.167.51.233 – 10.167.51.233	10.167.51.233
107	10.167.51.234/32	10.167.51.234 – 10.167.51.234	10.167.51.234
108	10.167.51.235/32	10.167.51.235 – 10.167.51.235	10.167.51.235
109	10.167.51.236/32	10.167.51.236 – 10.167.51.236	10.167.51.236
110	10.167.51.237/32	10.167.51.237 – 10.167.51.237	10.167.51.237
111	10.167.51.238/32	10.167.51.238 – 10.167.51.238	10.167.51.238
112	10.167.51.239/32	10.167.51.239 – 10.167.51.239	10.167.51.239
113	10.167.51.240/32	10.167.51.240 – 10.167.51.240	10.167.51.240
114	10.167.51.241/32	10.167.51.241 – 10.167.51.241	10.167.51.241
115	10.167.51.242/32	10.167.51.242 – 10.167.51.242	10.167.51.242
116	10.167.51.243/32	10.167.51.243 – 10.167.51.243	10.167.51.243
117	10.167.51.244/32	10.167.51.244 – 10.167.51.244	10.167.51.244
118	10.167.51.245/32	10.167.51.245 – 10.167.51.245	10.167.51.245
119	10.167.51.246/32	10.167.51.246 – 10.167.51.246	10.167.51.246
120	10.167.51.247/32	10.167.51.247 – 10.167.51.247	10.167.51.247
121	10.167.51.248/32	10.167.51.248 – 10.167.51.248	10.167.51.248
122	10.167.51.249/32	10.167.51.249 – 10.167.51.249	10.167.51.249
123	10.167.51.250/32	10.167.51.250 – 10.167.51.250	10.167.51.250
124	10.167.51.251/32	10.167.51.251 – 10.167.51.251	10.167.51.251
125	10.167.51.252/32	10.167.51.252 – 10.167.51.252	10.167.51.252
126	10.167.51.253/32	10.167.51.253 – 10.167.51.253	10.167.51.253
127	10.167.51.254/32	10.167.51.254 – 10.167.51.254	10.167.51.254
128	10.167.51.255/32	10.167.51.255 – 10.167.51.255	10.167.51.255

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 /25
/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	-
/22	255.255.252.0	1,024	1,022	-
/23	255.255.254.0	512	510	-
/24	255.255.255.0	256	254	-
/25	255.255.255.128	128	126	1
/26	255.255.255.192	64	62	2 split →
/27	255.255.255.224	32	30	4 split →
/28	255.255.255.240	16	14	8 split →
/29	255.255.255.248	8	6	16 split →
/30	255.255.255.252	4	2	32 split →
/31	255.255.255.254	2	2	64 split →
/32	255.255.255.255	1	1	128 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 →