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)10.0.10.128/25

network10.0.10.128/25

broadcast10.0.10.255

first host10.0.10.129

last host10.0.10.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.0.10.128/25

address00001010.00000000.00001010.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000000.00001010.10000000

broadcast00001010.00000000.00001010.11111111

green = network part, grey = host part

hex0x0a000a80

decimal167774848

reverse dns128.10.0.10.in-addr.arpa

ipv4-mapped::ffff:a00:a80

/25 split into /31 · 64 subnets

close ×

#	network	host range	broadcast
1	10.0.10.128/31	10.0.10.128 – 10.0.10.129	10.0.10.129
2	10.0.10.130/31	10.0.10.130 – 10.0.10.131	10.0.10.131
3	10.0.10.132/31	10.0.10.132 – 10.0.10.133	10.0.10.133
4	10.0.10.134/31	10.0.10.134 – 10.0.10.135	10.0.10.135
5	10.0.10.136/31	10.0.10.136 – 10.0.10.137	10.0.10.137
6	10.0.10.138/31	10.0.10.138 – 10.0.10.139	10.0.10.139
7	10.0.10.140/31	10.0.10.140 – 10.0.10.141	10.0.10.141
8	10.0.10.142/31	10.0.10.142 – 10.0.10.143	10.0.10.143
9	10.0.10.144/31	10.0.10.144 – 10.0.10.145	10.0.10.145
10	10.0.10.146/31	10.0.10.146 – 10.0.10.147	10.0.10.147
11	10.0.10.148/31	10.0.10.148 – 10.0.10.149	10.0.10.149
12	10.0.10.150/31	10.0.10.150 – 10.0.10.151	10.0.10.151
13	10.0.10.152/31	10.0.10.152 – 10.0.10.153	10.0.10.153
14	10.0.10.154/31	10.0.10.154 – 10.0.10.155	10.0.10.155
15	10.0.10.156/31	10.0.10.156 – 10.0.10.157	10.0.10.157
16	10.0.10.158/31	10.0.10.158 – 10.0.10.159	10.0.10.159
17	10.0.10.160/31	10.0.10.160 – 10.0.10.161	10.0.10.161
18	10.0.10.162/31	10.0.10.162 – 10.0.10.163	10.0.10.163
19	10.0.10.164/31	10.0.10.164 – 10.0.10.165	10.0.10.165
20	10.0.10.166/31	10.0.10.166 – 10.0.10.167	10.0.10.167
21	10.0.10.168/31	10.0.10.168 – 10.0.10.169	10.0.10.169
22	10.0.10.170/31	10.0.10.170 – 10.0.10.171	10.0.10.171
23	10.0.10.172/31	10.0.10.172 – 10.0.10.173	10.0.10.173
24	10.0.10.174/31	10.0.10.174 – 10.0.10.175	10.0.10.175
25	10.0.10.176/31	10.0.10.176 – 10.0.10.177	10.0.10.177
26	10.0.10.178/31	10.0.10.178 – 10.0.10.179	10.0.10.179
27	10.0.10.180/31	10.0.10.180 – 10.0.10.181	10.0.10.181
28	10.0.10.182/31	10.0.10.182 – 10.0.10.183	10.0.10.183
29	10.0.10.184/31	10.0.10.184 – 10.0.10.185	10.0.10.185
30	10.0.10.186/31	10.0.10.186 – 10.0.10.187	10.0.10.187
31	10.0.10.188/31	10.0.10.188 – 10.0.10.189	10.0.10.189
32	10.0.10.190/31	10.0.10.190 – 10.0.10.191	10.0.10.191
33	10.0.10.192/31	10.0.10.192 – 10.0.10.193	10.0.10.193
34	10.0.10.194/31	10.0.10.194 – 10.0.10.195	10.0.10.195
35	10.0.10.196/31	10.0.10.196 – 10.0.10.197	10.0.10.197
36	10.0.10.198/31	10.0.10.198 – 10.0.10.199	10.0.10.199
37	10.0.10.200/31	10.0.10.200 – 10.0.10.201	10.0.10.201
38	10.0.10.202/31	10.0.10.202 – 10.0.10.203	10.0.10.203
39	10.0.10.204/31	10.0.10.204 – 10.0.10.205	10.0.10.205
40	10.0.10.206/31	10.0.10.206 – 10.0.10.207	10.0.10.207
41	10.0.10.208/31	10.0.10.208 – 10.0.10.209	10.0.10.209
42	10.0.10.210/31	10.0.10.210 – 10.0.10.211	10.0.10.211
43	10.0.10.212/31	10.0.10.212 – 10.0.10.213	10.0.10.213
44	10.0.10.214/31	10.0.10.214 – 10.0.10.215	10.0.10.215
45	10.0.10.216/31	10.0.10.216 – 10.0.10.217	10.0.10.217
46	10.0.10.218/31	10.0.10.218 – 10.0.10.219	10.0.10.219
47	10.0.10.220/31	10.0.10.220 – 10.0.10.221	10.0.10.221
48	10.0.10.222/31	10.0.10.222 – 10.0.10.223	10.0.10.223
49	10.0.10.224/31	10.0.10.224 – 10.0.10.225	10.0.10.225
50	10.0.10.226/31	10.0.10.226 – 10.0.10.227	10.0.10.227
51	10.0.10.228/31	10.0.10.228 – 10.0.10.229	10.0.10.229
52	10.0.10.230/31	10.0.10.230 – 10.0.10.231	10.0.10.231
53	10.0.10.232/31	10.0.10.232 – 10.0.10.233	10.0.10.233
54	10.0.10.234/31	10.0.10.234 – 10.0.10.235	10.0.10.235
55	10.0.10.236/31	10.0.10.236 – 10.0.10.237	10.0.10.237
56	10.0.10.238/31	10.0.10.238 – 10.0.10.239	10.0.10.239
57	10.0.10.240/31	10.0.10.240 – 10.0.10.241	10.0.10.241
58	10.0.10.242/31	10.0.10.242 – 10.0.10.243	10.0.10.243
59	10.0.10.244/31	10.0.10.244 – 10.0.10.245	10.0.10.245
60	10.0.10.246/31	10.0.10.246 – 10.0.10.247	10.0.10.247
61	10.0.10.248/31	10.0.10.248 – 10.0.10.249	10.0.10.249
62	10.0.10.250/31	10.0.10.250 – 10.0.10.251	10.0.10.251
63	10.0.10.252/31	10.0.10.252 – 10.0.10.253	10.0.10.253
64	10.0.10.254/31	10.0.10.254 – 10.0.10.255	10.0.10.255

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 →