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)10.31.167.128/25

network10.31.167.128/25

broadcast10.31.167.255

first host10.31.167.129

last host10.31.167.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.31.167.128/25

address00001010.00011111.10100111.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00011111.10100111.10000000

broadcast00001010.00011111.10100111.11111111

green = network part, grey = host part

hex0x0a1fa780

decimal169846656

reverse dns128.167.31.10.in-addr.arpa

ipv4-mapped::ffff:a1f:a780

/25 split into /31 · 64 subnets

close ×

#	network	host range	broadcast
1	10.31.167.128/31	10.31.167.128 – 10.31.167.129	10.31.167.129
2	10.31.167.130/31	10.31.167.130 – 10.31.167.131	10.31.167.131
3	10.31.167.132/31	10.31.167.132 – 10.31.167.133	10.31.167.133
4	10.31.167.134/31	10.31.167.134 – 10.31.167.135	10.31.167.135
5	10.31.167.136/31	10.31.167.136 – 10.31.167.137	10.31.167.137
6	10.31.167.138/31	10.31.167.138 – 10.31.167.139	10.31.167.139
7	10.31.167.140/31	10.31.167.140 – 10.31.167.141	10.31.167.141
8	10.31.167.142/31	10.31.167.142 – 10.31.167.143	10.31.167.143
9	10.31.167.144/31	10.31.167.144 – 10.31.167.145	10.31.167.145
10	10.31.167.146/31	10.31.167.146 – 10.31.167.147	10.31.167.147
11	10.31.167.148/31	10.31.167.148 – 10.31.167.149	10.31.167.149
12	10.31.167.150/31	10.31.167.150 – 10.31.167.151	10.31.167.151
13	10.31.167.152/31	10.31.167.152 – 10.31.167.153	10.31.167.153
14	10.31.167.154/31	10.31.167.154 – 10.31.167.155	10.31.167.155
15	10.31.167.156/31	10.31.167.156 – 10.31.167.157	10.31.167.157
16	10.31.167.158/31	10.31.167.158 – 10.31.167.159	10.31.167.159
17	10.31.167.160/31	10.31.167.160 – 10.31.167.161	10.31.167.161
18	10.31.167.162/31	10.31.167.162 – 10.31.167.163	10.31.167.163
19	10.31.167.164/31	10.31.167.164 – 10.31.167.165	10.31.167.165
20	10.31.167.166/31	10.31.167.166 – 10.31.167.167	10.31.167.167
21	10.31.167.168/31	10.31.167.168 – 10.31.167.169	10.31.167.169
22	10.31.167.170/31	10.31.167.170 – 10.31.167.171	10.31.167.171
23	10.31.167.172/31	10.31.167.172 – 10.31.167.173	10.31.167.173
24	10.31.167.174/31	10.31.167.174 – 10.31.167.175	10.31.167.175
25	10.31.167.176/31	10.31.167.176 – 10.31.167.177	10.31.167.177
26	10.31.167.178/31	10.31.167.178 – 10.31.167.179	10.31.167.179
27	10.31.167.180/31	10.31.167.180 – 10.31.167.181	10.31.167.181
28	10.31.167.182/31	10.31.167.182 – 10.31.167.183	10.31.167.183
29	10.31.167.184/31	10.31.167.184 – 10.31.167.185	10.31.167.185
30	10.31.167.186/31	10.31.167.186 – 10.31.167.187	10.31.167.187
31	10.31.167.188/31	10.31.167.188 – 10.31.167.189	10.31.167.189
32	10.31.167.190/31	10.31.167.190 – 10.31.167.191	10.31.167.191
33	10.31.167.192/31	10.31.167.192 – 10.31.167.193	10.31.167.193
34	10.31.167.194/31	10.31.167.194 – 10.31.167.195	10.31.167.195
35	10.31.167.196/31	10.31.167.196 – 10.31.167.197	10.31.167.197
36	10.31.167.198/31	10.31.167.198 – 10.31.167.199	10.31.167.199
37	10.31.167.200/31	10.31.167.200 – 10.31.167.201	10.31.167.201
38	10.31.167.202/31	10.31.167.202 – 10.31.167.203	10.31.167.203
39	10.31.167.204/31	10.31.167.204 – 10.31.167.205	10.31.167.205
40	10.31.167.206/31	10.31.167.206 – 10.31.167.207	10.31.167.207
41	10.31.167.208/31	10.31.167.208 – 10.31.167.209	10.31.167.209
42	10.31.167.210/31	10.31.167.210 – 10.31.167.211	10.31.167.211
43	10.31.167.212/31	10.31.167.212 – 10.31.167.213	10.31.167.213
44	10.31.167.214/31	10.31.167.214 – 10.31.167.215	10.31.167.215
45	10.31.167.216/31	10.31.167.216 – 10.31.167.217	10.31.167.217
46	10.31.167.218/31	10.31.167.218 – 10.31.167.219	10.31.167.219
47	10.31.167.220/31	10.31.167.220 – 10.31.167.221	10.31.167.221
48	10.31.167.222/31	10.31.167.222 – 10.31.167.223	10.31.167.223
49	10.31.167.224/31	10.31.167.224 – 10.31.167.225	10.31.167.225
50	10.31.167.226/31	10.31.167.226 – 10.31.167.227	10.31.167.227
51	10.31.167.228/31	10.31.167.228 – 10.31.167.229	10.31.167.229
52	10.31.167.230/31	10.31.167.230 – 10.31.167.231	10.31.167.231
53	10.31.167.232/31	10.31.167.232 – 10.31.167.233	10.31.167.233
54	10.31.167.234/31	10.31.167.234 – 10.31.167.235	10.31.167.235
55	10.31.167.236/31	10.31.167.236 – 10.31.167.237	10.31.167.237
56	10.31.167.238/31	10.31.167.238 – 10.31.167.239	10.31.167.239
57	10.31.167.240/31	10.31.167.240 – 10.31.167.241	10.31.167.241
58	10.31.167.242/31	10.31.167.242 – 10.31.167.243	10.31.167.243
59	10.31.167.244/31	10.31.167.244 – 10.31.167.245	10.31.167.245
60	10.31.167.246/31	10.31.167.246 – 10.31.167.247	10.31.167.247
61	10.31.167.248/31	10.31.167.248 – 10.31.167.249	10.31.167.249
62	10.31.167.250/31	10.31.167.250 – 10.31.167.251	10.31.167.251
63	10.31.167.252/31	10.31.167.252 – 10.31.167.253	10.31.167.253
64	10.31.167.254/31	10.31.167.254 – 10.31.167.255	10.31.167.255

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 →