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)10.167.18.128/25

network10.167.18.128/25

broadcast10.167.18.255

first host10.167.18.129

last host10.167.18.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.167.18.128/25

address00001010.10100111.00010010.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.10100111.00010010.10000000

broadcast00001010.10100111.00010010.11111111

green = network part, grey = host part

hex0x0aa71280

decimal178721408

reverse dns128.18.167.10.in-addr.arpa

ipv4-mapped::ffff:aa7:1280

/25 split into /31 · 64 subnets

close ×

#	network	host range	broadcast
1	10.167.18.128/31	10.167.18.128 – 10.167.18.129	10.167.18.129
2	10.167.18.130/31	10.167.18.130 – 10.167.18.131	10.167.18.131
3	10.167.18.132/31	10.167.18.132 – 10.167.18.133	10.167.18.133
4	10.167.18.134/31	10.167.18.134 – 10.167.18.135	10.167.18.135
5	10.167.18.136/31	10.167.18.136 – 10.167.18.137	10.167.18.137
6	10.167.18.138/31	10.167.18.138 – 10.167.18.139	10.167.18.139
7	10.167.18.140/31	10.167.18.140 – 10.167.18.141	10.167.18.141
8	10.167.18.142/31	10.167.18.142 – 10.167.18.143	10.167.18.143
9	10.167.18.144/31	10.167.18.144 – 10.167.18.145	10.167.18.145
10	10.167.18.146/31	10.167.18.146 – 10.167.18.147	10.167.18.147
11	10.167.18.148/31	10.167.18.148 – 10.167.18.149	10.167.18.149
12	10.167.18.150/31	10.167.18.150 – 10.167.18.151	10.167.18.151
13	10.167.18.152/31	10.167.18.152 – 10.167.18.153	10.167.18.153
14	10.167.18.154/31	10.167.18.154 – 10.167.18.155	10.167.18.155
15	10.167.18.156/31	10.167.18.156 – 10.167.18.157	10.167.18.157
16	10.167.18.158/31	10.167.18.158 – 10.167.18.159	10.167.18.159
17	10.167.18.160/31	10.167.18.160 – 10.167.18.161	10.167.18.161
18	10.167.18.162/31	10.167.18.162 – 10.167.18.163	10.167.18.163
19	10.167.18.164/31	10.167.18.164 – 10.167.18.165	10.167.18.165
20	10.167.18.166/31	10.167.18.166 – 10.167.18.167	10.167.18.167
21	10.167.18.168/31	10.167.18.168 – 10.167.18.169	10.167.18.169
22	10.167.18.170/31	10.167.18.170 – 10.167.18.171	10.167.18.171
23	10.167.18.172/31	10.167.18.172 – 10.167.18.173	10.167.18.173
24	10.167.18.174/31	10.167.18.174 – 10.167.18.175	10.167.18.175
25	10.167.18.176/31	10.167.18.176 – 10.167.18.177	10.167.18.177
26	10.167.18.178/31	10.167.18.178 – 10.167.18.179	10.167.18.179
27	10.167.18.180/31	10.167.18.180 – 10.167.18.181	10.167.18.181
28	10.167.18.182/31	10.167.18.182 – 10.167.18.183	10.167.18.183
29	10.167.18.184/31	10.167.18.184 – 10.167.18.185	10.167.18.185
30	10.167.18.186/31	10.167.18.186 – 10.167.18.187	10.167.18.187
31	10.167.18.188/31	10.167.18.188 – 10.167.18.189	10.167.18.189
32	10.167.18.190/31	10.167.18.190 – 10.167.18.191	10.167.18.191
33	10.167.18.192/31	10.167.18.192 – 10.167.18.193	10.167.18.193
34	10.167.18.194/31	10.167.18.194 – 10.167.18.195	10.167.18.195
35	10.167.18.196/31	10.167.18.196 – 10.167.18.197	10.167.18.197
36	10.167.18.198/31	10.167.18.198 – 10.167.18.199	10.167.18.199
37	10.167.18.200/31	10.167.18.200 – 10.167.18.201	10.167.18.201
38	10.167.18.202/31	10.167.18.202 – 10.167.18.203	10.167.18.203
39	10.167.18.204/31	10.167.18.204 – 10.167.18.205	10.167.18.205
40	10.167.18.206/31	10.167.18.206 – 10.167.18.207	10.167.18.207
41	10.167.18.208/31	10.167.18.208 – 10.167.18.209	10.167.18.209
42	10.167.18.210/31	10.167.18.210 – 10.167.18.211	10.167.18.211
43	10.167.18.212/31	10.167.18.212 – 10.167.18.213	10.167.18.213
44	10.167.18.214/31	10.167.18.214 – 10.167.18.215	10.167.18.215
45	10.167.18.216/31	10.167.18.216 – 10.167.18.217	10.167.18.217
46	10.167.18.218/31	10.167.18.218 – 10.167.18.219	10.167.18.219
47	10.167.18.220/31	10.167.18.220 – 10.167.18.221	10.167.18.221
48	10.167.18.222/31	10.167.18.222 – 10.167.18.223	10.167.18.223
49	10.167.18.224/31	10.167.18.224 – 10.167.18.225	10.167.18.225
50	10.167.18.226/31	10.167.18.226 – 10.167.18.227	10.167.18.227
51	10.167.18.228/31	10.167.18.228 – 10.167.18.229	10.167.18.229
52	10.167.18.230/31	10.167.18.230 – 10.167.18.231	10.167.18.231
53	10.167.18.232/31	10.167.18.232 – 10.167.18.233	10.167.18.233
54	10.167.18.234/31	10.167.18.234 – 10.167.18.235	10.167.18.235
55	10.167.18.236/31	10.167.18.236 – 10.167.18.237	10.167.18.237
56	10.167.18.238/31	10.167.18.238 – 10.167.18.239	10.167.18.239
57	10.167.18.240/31	10.167.18.240 – 10.167.18.241	10.167.18.241
58	10.167.18.242/31	10.167.18.242 – 10.167.18.243	10.167.18.243
59	10.167.18.244/31	10.167.18.244 – 10.167.18.245	10.167.18.245
60	10.167.18.246/31	10.167.18.246 – 10.167.18.247	10.167.18.247
61	10.167.18.248/31	10.167.18.248 – 10.167.18.249	10.167.18.249
62	10.167.18.250/31	10.167.18.250 – 10.167.18.251	10.167.18.251
63	10.167.18.252/31	10.167.18.252 – 10.167.18.253	10.167.18.253
64	10.167.18.254/31	10.167.18.254 – 10.167.18.255	10.167.18.255

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 →