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)10.239.78.128/25

network10.239.78.128/25

broadcast10.239.78.255

first host10.239.78.129

last host10.239.78.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.239.78.128/25

address00001010.11101111.01001110.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.11101111.01001110.10000000

broadcast00001010.11101111.01001110.11111111

green = network part, grey = host part

hex0x0aef4e80

decimal183455360

reverse dns128.78.239.10.in-addr.arpa

ipv4-mapped::ffff:aef:4e80

/25 split into /31 · 64 subnets

close ×

#	network	host range	broadcast
1	10.239.78.128/31	10.239.78.128 – 10.239.78.129	10.239.78.129
2	10.239.78.130/31	10.239.78.130 – 10.239.78.131	10.239.78.131
3	10.239.78.132/31	10.239.78.132 – 10.239.78.133	10.239.78.133
4	10.239.78.134/31	10.239.78.134 – 10.239.78.135	10.239.78.135
5	10.239.78.136/31	10.239.78.136 – 10.239.78.137	10.239.78.137
6	10.239.78.138/31	10.239.78.138 – 10.239.78.139	10.239.78.139
7	10.239.78.140/31	10.239.78.140 – 10.239.78.141	10.239.78.141
8	10.239.78.142/31	10.239.78.142 – 10.239.78.143	10.239.78.143
9	10.239.78.144/31	10.239.78.144 – 10.239.78.145	10.239.78.145
10	10.239.78.146/31	10.239.78.146 – 10.239.78.147	10.239.78.147
11	10.239.78.148/31	10.239.78.148 – 10.239.78.149	10.239.78.149
12	10.239.78.150/31	10.239.78.150 – 10.239.78.151	10.239.78.151
13	10.239.78.152/31	10.239.78.152 – 10.239.78.153	10.239.78.153
14	10.239.78.154/31	10.239.78.154 – 10.239.78.155	10.239.78.155
15	10.239.78.156/31	10.239.78.156 – 10.239.78.157	10.239.78.157
16	10.239.78.158/31	10.239.78.158 – 10.239.78.159	10.239.78.159
17	10.239.78.160/31	10.239.78.160 – 10.239.78.161	10.239.78.161
18	10.239.78.162/31	10.239.78.162 – 10.239.78.163	10.239.78.163
19	10.239.78.164/31	10.239.78.164 – 10.239.78.165	10.239.78.165
20	10.239.78.166/31	10.239.78.166 – 10.239.78.167	10.239.78.167
21	10.239.78.168/31	10.239.78.168 – 10.239.78.169	10.239.78.169
22	10.239.78.170/31	10.239.78.170 – 10.239.78.171	10.239.78.171
23	10.239.78.172/31	10.239.78.172 – 10.239.78.173	10.239.78.173
24	10.239.78.174/31	10.239.78.174 – 10.239.78.175	10.239.78.175
25	10.239.78.176/31	10.239.78.176 – 10.239.78.177	10.239.78.177
26	10.239.78.178/31	10.239.78.178 – 10.239.78.179	10.239.78.179
27	10.239.78.180/31	10.239.78.180 – 10.239.78.181	10.239.78.181
28	10.239.78.182/31	10.239.78.182 – 10.239.78.183	10.239.78.183
29	10.239.78.184/31	10.239.78.184 – 10.239.78.185	10.239.78.185
30	10.239.78.186/31	10.239.78.186 – 10.239.78.187	10.239.78.187
31	10.239.78.188/31	10.239.78.188 – 10.239.78.189	10.239.78.189
32	10.239.78.190/31	10.239.78.190 – 10.239.78.191	10.239.78.191
33	10.239.78.192/31	10.239.78.192 – 10.239.78.193	10.239.78.193
34	10.239.78.194/31	10.239.78.194 – 10.239.78.195	10.239.78.195
35	10.239.78.196/31	10.239.78.196 – 10.239.78.197	10.239.78.197
36	10.239.78.198/31	10.239.78.198 – 10.239.78.199	10.239.78.199
37	10.239.78.200/31	10.239.78.200 – 10.239.78.201	10.239.78.201
38	10.239.78.202/31	10.239.78.202 – 10.239.78.203	10.239.78.203
39	10.239.78.204/31	10.239.78.204 – 10.239.78.205	10.239.78.205
40	10.239.78.206/31	10.239.78.206 – 10.239.78.207	10.239.78.207
41	10.239.78.208/31	10.239.78.208 – 10.239.78.209	10.239.78.209
42	10.239.78.210/31	10.239.78.210 – 10.239.78.211	10.239.78.211
43	10.239.78.212/31	10.239.78.212 – 10.239.78.213	10.239.78.213
44	10.239.78.214/31	10.239.78.214 – 10.239.78.215	10.239.78.215
45	10.239.78.216/31	10.239.78.216 – 10.239.78.217	10.239.78.217
46	10.239.78.218/31	10.239.78.218 – 10.239.78.219	10.239.78.219
47	10.239.78.220/31	10.239.78.220 – 10.239.78.221	10.239.78.221
48	10.239.78.222/31	10.239.78.222 – 10.239.78.223	10.239.78.223
49	10.239.78.224/31	10.239.78.224 – 10.239.78.225	10.239.78.225
50	10.239.78.226/31	10.239.78.226 – 10.239.78.227	10.239.78.227
51	10.239.78.228/31	10.239.78.228 – 10.239.78.229	10.239.78.229
52	10.239.78.230/31	10.239.78.230 – 10.239.78.231	10.239.78.231
53	10.239.78.232/31	10.239.78.232 – 10.239.78.233	10.239.78.233
54	10.239.78.234/31	10.239.78.234 – 10.239.78.235	10.239.78.235
55	10.239.78.236/31	10.239.78.236 – 10.239.78.237	10.239.78.237
56	10.239.78.238/31	10.239.78.238 – 10.239.78.239	10.239.78.239
57	10.239.78.240/31	10.239.78.240 – 10.239.78.241	10.239.78.241
58	10.239.78.242/31	10.239.78.242 – 10.239.78.243	10.239.78.243
59	10.239.78.244/31	10.239.78.244 – 10.239.78.245	10.239.78.245
60	10.239.78.246/31	10.239.78.246 – 10.239.78.247	10.239.78.247
61	10.239.78.248/31	10.239.78.248 – 10.239.78.249	10.239.78.249
62	10.239.78.250/31	10.239.78.250 – 10.239.78.251	10.239.78.251
63	10.239.78.252/31	10.239.78.252 – 10.239.78.253	10.239.78.253
64	10.239.78.254/31	10.239.78.254 – 10.239.78.255	10.239.78.255

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 →