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)10.167.31.128/25

network10.167.31.128/25

broadcast10.167.31.255

first host10.167.31.129

last host10.167.31.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.167.31.128/25

address00001010.10100111.00011111.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.10100111.00011111.10000000

broadcast00001010.10100111.00011111.11111111

green = network part, grey = host part

hex0x0aa71f80

decimal178724736

reverse dns128.31.167.10.in-addr.arpa

ipv4-mapped::ffff:aa7:1f80

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.167.31.128/32	10.167.31.128 – 10.167.31.128	10.167.31.128
2	10.167.31.129/32	10.167.31.129 – 10.167.31.129	10.167.31.129
3	10.167.31.130/32	10.167.31.130 – 10.167.31.130	10.167.31.130
4	10.167.31.131/32	10.167.31.131 – 10.167.31.131	10.167.31.131
5	10.167.31.132/32	10.167.31.132 – 10.167.31.132	10.167.31.132
6	10.167.31.133/32	10.167.31.133 – 10.167.31.133	10.167.31.133
7	10.167.31.134/32	10.167.31.134 – 10.167.31.134	10.167.31.134
8	10.167.31.135/32	10.167.31.135 – 10.167.31.135	10.167.31.135
9	10.167.31.136/32	10.167.31.136 – 10.167.31.136	10.167.31.136
10	10.167.31.137/32	10.167.31.137 – 10.167.31.137	10.167.31.137
11	10.167.31.138/32	10.167.31.138 – 10.167.31.138	10.167.31.138
12	10.167.31.139/32	10.167.31.139 – 10.167.31.139	10.167.31.139
13	10.167.31.140/32	10.167.31.140 – 10.167.31.140	10.167.31.140
14	10.167.31.141/32	10.167.31.141 – 10.167.31.141	10.167.31.141
15	10.167.31.142/32	10.167.31.142 – 10.167.31.142	10.167.31.142
16	10.167.31.143/32	10.167.31.143 – 10.167.31.143	10.167.31.143
17	10.167.31.144/32	10.167.31.144 – 10.167.31.144	10.167.31.144
18	10.167.31.145/32	10.167.31.145 – 10.167.31.145	10.167.31.145
19	10.167.31.146/32	10.167.31.146 – 10.167.31.146	10.167.31.146
20	10.167.31.147/32	10.167.31.147 – 10.167.31.147	10.167.31.147
21	10.167.31.148/32	10.167.31.148 – 10.167.31.148	10.167.31.148
22	10.167.31.149/32	10.167.31.149 – 10.167.31.149	10.167.31.149
23	10.167.31.150/32	10.167.31.150 – 10.167.31.150	10.167.31.150
24	10.167.31.151/32	10.167.31.151 – 10.167.31.151	10.167.31.151
25	10.167.31.152/32	10.167.31.152 – 10.167.31.152	10.167.31.152
26	10.167.31.153/32	10.167.31.153 – 10.167.31.153	10.167.31.153
27	10.167.31.154/32	10.167.31.154 – 10.167.31.154	10.167.31.154
28	10.167.31.155/32	10.167.31.155 – 10.167.31.155	10.167.31.155
29	10.167.31.156/32	10.167.31.156 – 10.167.31.156	10.167.31.156
30	10.167.31.157/32	10.167.31.157 – 10.167.31.157	10.167.31.157
31	10.167.31.158/32	10.167.31.158 – 10.167.31.158	10.167.31.158
32	10.167.31.159/32	10.167.31.159 – 10.167.31.159	10.167.31.159
33	10.167.31.160/32	10.167.31.160 – 10.167.31.160	10.167.31.160
34	10.167.31.161/32	10.167.31.161 – 10.167.31.161	10.167.31.161
35	10.167.31.162/32	10.167.31.162 – 10.167.31.162	10.167.31.162
36	10.167.31.163/32	10.167.31.163 – 10.167.31.163	10.167.31.163
37	10.167.31.164/32	10.167.31.164 – 10.167.31.164	10.167.31.164
38	10.167.31.165/32	10.167.31.165 – 10.167.31.165	10.167.31.165
39	10.167.31.166/32	10.167.31.166 – 10.167.31.166	10.167.31.166
40	10.167.31.167/32	10.167.31.167 – 10.167.31.167	10.167.31.167
41	10.167.31.168/32	10.167.31.168 – 10.167.31.168	10.167.31.168
42	10.167.31.169/32	10.167.31.169 – 10.167.31.169	10.167.31.169
43	10.167.31.170/32	10.167.31.170 – 10.167.31.170	10.167.31.170
44	10.167.31.171/32	10.167.31.171 – 10.167.31.171	10.167.31.171
45	10.167.31.172/32	10.167.31.172 – 10.167.31.172	10.167.31.172
46	10.167.31.173/32	10.167.31.173 – 10.167.31.173	10.167.31.173
47	10.167.31.174/32	10.167.31.174 – 10.167.31.174	10.167.31.174
48	10.167.31.175/32	10.167.31.175 – 10.167.31.175	10.167.31.175
49	10.167.31.176/32	10.167.31.176 – 10.167.31.176	10.167.31.176
50	10.167.31.177/32	10.167.31.177 – 10.167.31.177	10.167.31.177
51	10.167.31.178/32	10.167.31.178 – 10.167.31.178	10.167.31.178
52	10.167.31.179/32	10.167.31.179 – 10.167.31.179	10.167.31.179
53	10.167.31.180/32	10.167.31.180 – 10.167.31.180	10.167.31.180
54	10.167.31.181/32	10.167.31.181 – 10.167.31.181	10.167.31.181
55	10.167.31.182/32	10.167.31.182 – 10.167.31.182	10.167.31.182
56	10.167.31.183/32	10.167.31.183 – 10.167.31.183	10.167.31.183
57	10.167.31.184/32	10.167.31.184 – 10.167.31.184	10.167.31.184
58	10.167.31.185/32	10.167.31.185 – 10.167.31.185	10.167.31.185
59	10.167.31.186/32	10.167.31.186 – 10.167.31.186	10.167.31.186
60	10.167.31.187/32	10.167.31.187 – 10.167.31.187	10.167.31.187
61	10.167.31.188/32	10.167.31.188 – 10.167.31.188	10.167.31.188
62	10.167.31.189/32	10.167.31.189 – 10.167.31.189	10.167.31.189
63	10.167.31.190/32	10.167.31.190 – 10.167.31.190	10.167.31.190
64	10.167.31.191/32	10.167.31.191 – 10.167.31.191	10.167.31.191
65	10.167.31.192/32	10.167.31.192 – 10.167.31.192	10.167.31.192
66	10.167.31.193/32	10.167.31.193 – 10.167.31.193	10.167.31.193
67	10.167.31.194/32	10.167.31.194 – 10.167.31.194	10.167.31.194
68	10.167.31.195/32	10.167.31.195 – 10.167.31.195	10.167.31.195
69	10.167.31.196/32	10.167.31.196 – 10.167.31.196	10.167.31.196
70	10.167.31.197/32	10.167.31.197 – 10.167.31.197	10.167.31.197
71	10.167.31.198/32	10.167.31.198 – 10.167.31.198	10.167.31.198
72	10.167.31.199/32	10.167.31.199 – 10.167.31.199	10.167.31.199
73	10.167.31.200/32	10.167.31.200 – 10.167.31.200	10.167.31.200
74	10.167.31.201/32	10.167.31.201 – 10.167.31.201	10.167.31.201
75	10.167.31.202/32	10.167.31.202 – 10.167.31.202	10.167.31.202
76	10.167.31.203/32	10.167.31.203 – 10.167.31.203	10.167.31.203
77	10.167.31.204/32	10.167.31.204 – 10.167.31.204	10.167.31.204
78	10.167.31.205/32	10.167.31.205 – 10.167.31.205	10.167.31.205
79	10.167.31.206/32	10.167.31.206 – 10.167.31.206	10.167.31.206
80	10.167.31.207/32	10.167.31.207 – 10.167.31.207	10.167.31.207
81	10.167.31.208/32	10.167.31.208 – 10.167.31.208	10.167.31.208
82	10.167.31.209/32	10.167.31.209 – 10.167.31.209	10.167.31.209
83	10.167.31.210/32	10.167.31.210 – 10.167.31.210	10.167.31.210
84	10.167.31.211/32	10.167.31.211 – 10.167.31.211	10.167.31.211
85	10.167.31.212/32	10.167.31.212 – 10.167.31.212	10.167.31.212
86	10.167.31.213/32	10.167.31.213 – 10.167.31.213	10.167.31.213
87	10.167.31.214/32	10.167.31.214 – 10.167.31.214	10.167.31.214
88	10.167.31.215/32	10.167.31.215 – 10.167.31.215	10.167.31.215
89	10.167.31.216/32	10.167.31.216 – 10.167.31.216	10.167.31.216
90	10.167.31.217/32	10.167.31.217 – 10.167.31.217	10.167.31.217
91	10.167.31.218/32	10.167.31.218 – 10.167.31.218	10.167.31.218
92	10.167.31.219/32	10.167.31.219 – 10.167.31.219	10.167.31.219
93	10.167.31.220/32	10.167.31.220 – 10.167.31.220	10.167.31.220
94	10.167.31.221/32	10.167.31.221 – 10.167.31.221	10.167.31.221
95	10.167.31.222/32	10.167.31.222 – 10.167.31.222	10.167.31.222
96	10.167.31.223/32	10.167.31.223 – 10.167.31.223	10.167.31.223
97	10.167.31.224/32	10.167.31.224 – 10.167.31.224	10.167.31.224
98	10.167.31.225/32	10.167.31.225 – 10.167.31.225	10.167.31.225
99	10.167.31.226/32	10.167.31.226 – 10.167.31.226	10.167.31.226
100	10.167.31.227/32	10.167.31.227 – 10.167.31.227	10.167.31.227
101	10.167.31.228/32	10.167.31.228 – 10.167.31.228	10.167.31.228
102	10.167.31.229/32	10.167.31.229 – 10.167.31.229	10.167.31.229
103	10.167.31.230/32	10.167.31.230 – 10.167.31.230	10.167.31.230
104	10.167.31.231/32	10.167.31.231 – 10.167.31.231	10.167.31.231
105	10.167.31.232/32	10.167.31.232 – 10.167.31.232	10.167.31.232
106	10.167.31.233/32	10.167.31.233 – 10.167.31.233	10.167.31.233
107	10.167.31.234/32	10.167.31.234 – 10.167.31.234	10.167.31.234
108	10.167.31.235/32	10.167.31.235 – 10.167.31.235	10.167.31.235
109	10.167.31.236/32	10.167.31.236 – 10.167.31.236	10.167.31.236
110	10.167.31.237/32	10.167.31.237 – 10.167.31.237	10.167.31.237
111	10.167.31.238/32	10.167.31.238 – 10.167.31.238	10.167.31.238
112	10.167.31.239/32	10.167.31.239 – 10.167.31.239	10.167.31.239
113	10.167.31.240/32	10.167.31.240 – 10.167.31.240	10.167.31.240
114	10.167.31.241/32	10.167.31.241 – 10.167.31.241	10.167.31.241
115	10.167.31.242/32	10.167.31.242 – 10.167.31.242	10.167.31.242
116	10.167.31.243/32	10.167.31.243 – 10.167.31.243	10.167.31.243
117	10.167.31.244/32	10.167.31.244 – 10.167.31.244	10.167.31.244
118	10.167.31.245/32	10.167.31.245 – 10.167.31.245	10.167.31.245
119	10.167.31.246/32	10.167.31.246 – 10.167.31.246	10.167.31.246
120	10.167.31.247/32	10.167.31.247 – 10.167.31.247	10.167.31.247
121	10.167.31.248/32	10.167.31.248 – 10.167.31.248	10.167.31.248
122	10.167.31.249/32	10.167.31.249 – 10.167.31.249	10.167.31.249
123	10.167.31.250/32	10.167.31.250 – 10.167.31.250	10.167.31.250
124	10.167.31.251/32	10.167.31.251 – 10.167.31.251	10.167.31.251
125	10.167.31.252/32	10.167.31.252 – 10.167.31.252	10.167.31.252
126	10.167.31.253/32	10.167.31.253 – 10.167.31.253	10.167.31.253
127	10.167.31.254/32	10.167.31.254 – 10.167.31.254	10.167.31.254
128	10.167.31.255/32	10.167.31.255 – 10.167.31.255	10.167.31.255

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 →