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)10.167.81.128/25

network10.167.81.128/25

broadcast10.167.81.255

first host10.167.81.129

last host10.167.81.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.167.81.128/25

address00001010.10100111.01010001.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.10100111.01010001.10000000

broadcast00001010.10100111.01010001.11111111

green = network part, grey = host part

hex0x0aa75180

decimal178737536

reverse dns128.81.167.10.in-addr.arpa

ipv4-mapped::ffff:aa7:5180

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.167.81.128/32	10.167.81.128 – 10.167.81.128	10.167.81.128
2	10.167.81.129/32	10.167.81.129 – 10.167.81.129	10.167.81.129
3	10.167.81.130/32	10.167.81.130 – 10.167.81.130	10.167.81.130
4	10.167.81.131/32	10.167.81.131 – 10.167.81.131	10.167.81.131
5	10.167.81.132/32	10.167.81.132 – 10.167.81.132	10.167.81.132
6	10.167.81.133/32	10.167.81.133 – 10.167.81.133	10.167.81.133
7	10.167.81.134/32	10.167.81.134 – 10.167.81.134	10.167.81.134
8	10.167.81.135/32	10.167.81.135 – 10.167.81.135	10.167.81.135
9	10.167.81.136/32	10.167.81.136 – 10.167.81.136	10.167.81.136
10	10.167.81.137/32	10.167.81.137 – 10.167.81.137	10.167.81.137
11	10.167.81.138/32	10.167.81.138 – 10.167.81.138	10.167.81.138
12	10.167.81.139/32	10.167.81.139 – 10.167.81.139	10.167.81.139
13	10.167.81.140/32	10.167.81.140 – 10.167.81.140	10.167.81.140
14	10.167.81.141/32	10.167.81.141 – 10.167.81.141	10.167.81.141
15	10.167.81.142/32	10.167.81.142 – 10.167.81.142	10.167.81.142
16	10.167.81.143/32	10.167.81.143 – 10.167.81.143	10.167.81.143
17	10.167.81.144/32	10.167.81.144 – 10.167.81.144	10.167.81.144
18	10.167.81.145/32	10.167.81.145 – 10.167.81.145	10.167.81.145
19	10.167.81.146/32	10.167.81.146 – 10.167.81.146	10.167.81.146
20	10.167.81.147/32	10.167.81.147 – 10.167.81.147	10.167.81.147
21	10.167.81.148/32	10.167.81.148 – 10.167.81.148	10.167.81.148
22	10.167.81.149/32	10.167.81.149 – 10.167.81.149	10.167.81.149
23	10.167.81.150/32	10.167.81.150 – 10.167.81.150	10.167.81.150
24	10.167.81.151/32	10.167.81.151 – 10.167.81.151	10.167.81.151
25	10.167.81.152/32	10.167.81.152 – 10.167.81.152	10.167.81.152
26	10.167.81.153/32	10.167.81.153 – 10.167.81.153	10.167.81.153
27	10.167.81.154/32	10.167.81.154 – 10.167.81.154	10.167.81.154
28	10.167.81.155/32	10.167.81.155 – 10.167.81.155	10.167.81.155
29	10.167.81.156/32	10.167.81.156 – 10.167.81.156	10.167.81.156
30	10.167.81.157/32	10.167.81.157 – 10.167.81.157	10.167.81.157
31	10.167.81.158/32	10.167.81.158 – 10.167.81.158	10.167.81.158
32	10.167.81.159/32	10.167.81.159 – 10.167.81.159	10.167.81.159
33	10.167.81.160/32	10.167.81.160 – 10.167.81.160	10.167.81.160
34	10.167.81.161/32	10.167.81.161 – 10.167.81.161	10.167.81.161
35	10.167.81.162/32	10.167.81.162 – 10.167.81.162	10.167.81.162
36	10.167.81.163/32	10.167.81.163 – 10.167.81.163	10.167.81.163
37	10.167.81.164/32	10.167.81.164 – 10.167.81.164	10.167.81.164
38	10.167.81.165/32	10.167.81.165 – 10.167.81.165	10.167.81.165
39	10.167.81.166/32	10.167.81.166 – 10.167.81.166	10.167.81.166
40	10.167.81.167/32	10.167.81.167 – 10.167.81.167	10.167.81.167
41	10.167.81.168/32	10.167.81.168 – 10.167.81.168	10.167.81.168
42	10.167.81.169/32	10.167.81.169 – 10.167.81.169	10.167.81.169
43	10.167.81.170/32	10.167.81.170 – 10.167.81.170	10.167.81.170
44	10.167.81.171/32	10.167.81.171 – 10.167.81.171	10.167.81.171
45	10.167.81.172/32	10.167.81.172 – 10.167.81.172	10.167.81.172
46	10.167.81.173/32	10.167.81.173 – 10.167.81.173	10.167.81.173
47	10.167.81.174/32	10.167.81.174 – 10.167.81.174	10.167.81.174
48	10.167.81.175/32	10.167.81.175 – 10.167.81.175	10.167.81.175
49	10.167.81.176/32	10.167.81.176 – 10.167.81.176	10.167.81.176
50	10.167.81.177/32	10.167.81.177 – 10.167.81.177	10.167.81.177
51	10.167.81.178/32	10.167.81.178 – 10.167.81.178	10.167.81.178
52	10.167.81.179/32	10.167.81.179 – 10.167.81.179	10.167.81.179
53	10.167.81.180/32	10.167.81.180 – 10.167.81.180	10.167.81.180
54	10.167.81.181/32	10.167.81.181 – 10.167.81.181	10.167.81.181
55	10.167.81.182/32	10.167.81.182 – 10.167.81.182	10.167.81.182
56	10.167.81.183/32	10.167.81.183 – 10.167.81.183	10.167.81.183
57	10.167.81.184/32	10.167.81.184 – 10.167.81.184	10.167.81.184
58	10.167.81.185/32	10.167.81.185 – 10.167.81.185	10.167.81.185
59	10.167.81.186/32	10.167.81.186 – 10.167.81.186	10.167.81.186
60	10.167.81.187/32	10.167.81.187 – 10.167.81.187	10.167.81.187
61	10.167.81.188/32	10.167.81.188 – 10.167.81.188	10.167.81.188
62	10.167.81.189/32	10.167.81.189 – 10.167.81.189	10.167.81.189
63	10.167.81.190/32	10.167.81.190 – 10.167.81.190	10.167.81.190
64	10.167.81.191/32	10.167.81.191 – 10.167.81.191	10.167.81.191
65	10.167.81.192/32	10.167.81.192 – 10.167.81.192	10.167.81.192
66	10.167.81.193/32	10.167.81.193 – 10.167.81.193	10.167.81.193
67	10.167.81.194/32	10.167.81.194 – 10.167.81.194	10.167.81.194
68	10.167.81.195/32	10.167.81.195 – 10.167.81.195	10.167.81.195
69	10.167.81.196/32	10.167.81.196 – 10.167.81.196	10.167.81.196
70	10.167.81.197/32	10.167.81.197 – 10.167.81.197	10.167.81.197
71	10.167.81.198/32	10.167.81.198 – 10.167.81.198	10.167.81.198
72	10.167.81.199/32	10.167.81.199 – 10.167.81.199	10.167.81.199
73	10.167.81.200/32	10.167.81.200 – 10.167.81.200	10.167.81.200
74	10.167.81.201/32	10.167.81.201 – 10.167.81.201	10.167.81.201
75	10.167.81.202/32	10.167.81.202 – 10.167.81.202	10.167.81.202
76	10.167.81.203/32	10.167.81.203 – 10.167.81.203	10.167.81.203
77	10.167.81.204/32	10.167.81.204 – 10.167.81.204	10.167.81.204
78	10.167.81.205/32	10.167.81.205 – 10.167.81.205	10.167.81.205
79	10.167.81.206/32	10.167.81.206 – 10.167.81.206	10.167.81.206
80	10.167.81.207/32	10.167.81.207 – 10.167.81.207	10.167.81.207
81	10.167.81.208/32	10.167.81.208 – 10.167.81.208	10.167.81.208
82	10.167.81.209/32	10.167.81.209 – 10.167.81.209	10.167.81.209
83	10.167.81.210/32	10.167.81.210 – 10.167.81.210	10.167.81.210
84	10.167.81.211/32	10.167.81.211 – 10.167.81.211	10.167.81.211
85	10.167.81.212/32	10.167.81.212 – 10.167.81.212	10.167.81.212
86	10.167.81.213/32	10.167.81.213 – 10.167.81.213	10.167.81.213
87	10.167.81.214/32	10.167.81.214 – 10.167.81.214	10.167.81.214
88	10.167.81.215/32	10.167.81.215 – 10.167.81.215	10.167.81.215
89	10.167.81.216/32	10.167.81.216 – 10.167.81.216	10.167.81.216
90	10.167.81.217/32	10.167.81.217 – 10.167.81.217	10.167.81.217
91	10.167.81.218/32	10.167.81.218 – 10.167.81.218	10.167.81.218
92	10.167.81.219/32	10.167.81.219 – 10.167.81.219	10.167.81.219
93	10.167.81.220/32	10.167.81.220 – 10.167.81.220	10.167.81.220
94	10.167.81.221/32	10.167.81.221 – 10.167.81.221	10.167.81.221
95	10.167.81.222/32	10.167.81.222 – 10.167.81.222	10.167.81.222
96	10.167.81.223/32	10.167.81.223 – 10.167.81.223	10.167.81.223
97	10.167.81.224/32	10.167.81.224 – 10.167.81.224	10.167.81.224
98	10.167.81.225/32	10.167.81.225 – 10.167.81.225	10.167.81.225
99	10.167.81.226/32	10.167.81.226 – 10.167.81.226	10.167.81.226
100	10.167.81.227/32	10.167.81.227 – 10.167.81.227	10.167.81.227
101	10.167.81.228/32	10.167.81.228 – 10.167.81.228	10.167.81.228
102	10.167.81.229/32	10.167.81.229 – 10.167.81.229	10.167.81.229
103	10.167.81.230/32	10.167.81.230 – 10.167.81.230	10.167.81.230
104	10.167.81.231/32	10.167.81.231 – 10.167.81.231	10.167.81.231
105	10.167.81.232/32	10.167.81.232 – 10.167.81.232	10.167.81.232
106	10.167.81.233/32	10.167.81.233 – 10.167.81.233	10.167.81.233
107	10.167.81.234/32	10.167.81.234 – 10.167.81.234	10.167.81.234
108	10.167.81.235/32	10.167.81.235 – 10.167.81.235	10.167.81.235
109	10.167.81.236/32	10.167.81.236 – 10.167.81.236	10.167.81.236
110	10.167.81.237/32	10.167.81.237 – 10.167.81.237	10.167.81.237
111	10.167.81.238/32	10.167.81.238 – 10.167.81.238	10.167.81.238
112	10.167.81.239/32	10.167.81.239 – 10.167.81.239	10.167.81.239
113	10.167.81.240/32	10.167.81.240 – 10.167.81.240	10.167.81.240
114	10.167.81.241/32	10.167.81.241 – 10.167.81.241	10.167.81.241
115	10.167.81.242/32	10.167.81.242 – 10.167.81.242	10.167.81.242
116	10.167.81.243/32	10.167.81.243 – 10.167.81.243	10.167.81.243
117	10.167.81.244/32	10.167.81.244 – 10.167.81.244	10.167.81.244
118	10.167.81.245/32	10.167.81.245 – 10.167.81.245	10.167.81.245
119	10.167.81.246/32	10.167.81.246 – 10.167.81.246	10.167.81.246
120	10.167.81.247/32	10.167.81.247 – 10.167.81.247	10.167.81.247
121	10.167.81.248/32	10.167.81.248 – 10.167.81.248	10.167.81.248
122	10.167.81.249/32	10.167.81.249 – 10.167.81.249	10.167.81.249
123	10.167.81.250/32	10.167.81.250 – 10.167.81.250	10.167.81.250
124	10.167.81.251/32	10.167.81.251 – 10.167.81.251	10.167.81.251
125	10.167.81.252/32	10.167.81.252 – 10.167.81.252	10.167.81.252
126	10.167.81.253/32	10.167.81.253 – 10.167.81.253	10.167.81.253
127	10.167.81.254/32	10.167.81.254 – 10.167.81.254	10.167.81.254
128	10.167.81.255/32	10.167.81.255 – 10.167.81.255	10.167.81.255

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 →