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)172.16.10.128/25

network172.16.10.128/25

broadcast172.16.10.255

first host172.16.10.129

last host172.16.10.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classB

ipcalc 172.16.10.128/25

address10101100.00010000.00001010.10000000

subnet mask11111111.11111111.11111111.10000000

network10101100.00010000.00001010.10000000

broadcast10101100.00010000.00001010.11111111

green = network part, grey = host part

hex0xac100a80

decimal2886732416

reverse dns128.10.16.172.in-addr.arpa

ipv4-mapped::ffff:ac10:a80

/25 split into /31 · 64 subnets

close ×

#	network	host range	broadcast
1	172.16.10.128/31	172.16.10.128 – 172.16.10.129	172.16.10.129
2	172.16.10.130/31	172.16.10.130 – 172.16.10.131	172.16.10.131
3	172.16.10.132/31	172.16.10.132 – 172.16.10.133	172.16.10.133
4	172.16.10.134/31	172.16.10.134 – 172.16.10.135	172.16.10.135
5	172.16.10.136/31	172.16.10.136 – 172.16.10.137	172.16.10.137
6	172.16.10.138/31	172.16.10.138 – 172.16.10.139	172.16.10.139
7	172.16.10.140/31	172.16.10.140 – 172.16.10.141	172.16.10.141
8	172.16.10.142/31	172.16.10.142 – 172.16.10.143	172.16.10.143
9	172.16.10.144/31	172.16.10.144 – 172.16.10.145	172.16.10.145
10	172.16.10.146/31	172.16.10.146 – 172.16.10.147	172.16.10.147
11	172.16.10.148/31	172.16.10.148 – 172.16.10.149	172.16.10.149
12	172.16.10.150/31	172.16.10.150 – 172.16.10.151	172.16.10.151
13	172.16.10.152/31	172.16.10.152 – 172.16.10.153	172.16.10.153
14	172.16.10.154/31	172.16.10.154 – 172.16.10.155	172.16.10.155
15	172.16.10.156/31	172.16.10.156 – 172.16.10.157	172.16.10.157
16	172.16.10.158/31	172.16.10.158 – 172.16.10.159	172.16.10.159
17	172.16.10.160/31	172.16.10.160 – 172.16.10.161	172.16.10.161
18	172.16.10.162/31	172.16.10.162 – 172.16.10.163	172.16.10.163
19	172.16.10.164/31	172.16.10.164 – 172.16.10.165	172.16.10.165
20	172.16.10.166/31	172.16.10.166 – 172.16.10.167	172.16.10.167
21	172.16.10.168/31	172.16.10.168 – 172.16.10.169	172.16.10.169
22	172.16.10.170/31	172.16.10.170 – 172.16.10.171	172.16.10.171
23	172.16.10.172/31	172.16.10.172 – 172.16.10.173	172.16.10.173
24	172.16.10.174/31	172.16.10.174 – 172.16.10.175	172.16.10.175
25	172.16.10.176/31	172.16.10.176 – 172.16.10.177	172.16.10.177
26	172.16.10.178/31	172.16.10.178 – 172.16.10.179	172.16.10.179
27	172.16.10.180/31	172.16.10.180 – 172.16.10.181	172.16.10.181
28	172.16.10.182/31	172.16.10.182 – 172.16.10.183	172.16.10.183
29	172.16.10.184/31	172.16.10.184 – 172.16.10.185	172.16.10.185
30	172.16.10.186/31	172.16.10.186 – 172.16.10.187	172.16.10.187
31	172.16.10.188/31	172.16.10.188 – 172.16.10.189	172.16.10.189
32	172.16.10.190/31	172.16.10.190 – 172.16.10.191	172.16.10.191
33	172.16.10.192/31	172.16.10.192 – 172.16.10.193	172.16.10.193
34	172.16.10.194/31	172.16.10.194 – 172.16.10.195	172.16.10.195
35	172.16.10.196/31	172.16.10.196 – 172.16.10.197	172.16.10.197
36	172.16.10.198/31	172.16.10.198 – 172.16.10.199	172.16.10.199
37	172.16.10.200/31	172.16.10.200 – 172.16.10.201	172.16.10.201
38	172.16.10.202/31	172.16.10.202 – 172.16.10.203	172.16.10.203
39	172.16.10.204/31	172.16.10.204 – 172.16.10.205	172.16.10.205
40	172.16.10.206/31	172.16.10.206 – 172.16.10.207	172.16.10.207
41	172.16.10.208/31	172.16.10.208 – 172.16.10.209	172.16.10.209
42	172.16.10.210/31	172.16.10.210 – 172.16.10.211	172.16.10.211
43	172.16.10.212/31	172.16.10.212 – 172.16.10.213	172.16.10.213
44	172.16.10.214/31	172.16.10.214 – 172.16.10.215	172.16.10.215
45	172.16.10.216/31	172.16.10.216 – 172.16.10.217	172.16.10.217
46	172.16.10.218/31	172.16.10.218 – 172.16.10.219	172.16.10.219
47	172.16.10.220/31	172.16.10.220 – 172.16.10.221	172.16.10.221
48	172.16.10.222/31	172.16.10.222 – 172.16.10.223	172.16.10.223
49	172.16.10.224/31	172.16.10.224 – 172.16.10.225	172.16.10.225
50	172.16.10.226/31	172.16.10.226 – 172.16.10.227	172.16.10.227
51	172.16.10.228/31	172.16.10.228 – 172.16.10.229	172.16.10.229
52	172.16.10.230/31	172.16.10.230 – 172.16.10.231	172.16.10.231
53	172.16.10.232/31	172.16.10.232 – 172.16.10.233	172.16.10.233
54	172.16.10.234/31	172.16.10.234 – 172.16.10.235	172.16.10.235
55	172.16.10.236/31	172.16.10.236 – 172.16.10.237	172.16.10.237
56	172.16.10.238/31	172.16.10.238 – 172.16.10.239	172.16.10.239
57	172.16.10.240/31	172.16.10.240 – 172.16.10.241	172.16.10.241
58	172.16.10.242/31	172.16.10.242 – 172.16.10.243	172.16.10.243
59	172.16.10.244/31	172.16.10.244 – 172.16.10.245	172.16.10.245
60	172.16.10.246/31	172.16.10.246 – 172.16.10.247	172.16.10.247
61	172.16.10.248/31	172.16.10.248 – 172.16.10.249	172.16.10.249
62	172.16.10.250/31	172.16.10.250 – 172.16.10.251	172.16.10.251
63	172.16.10.252/31	172.16.10.252 – 172.16.10.253	172.16.10.253
64	172.16.10.254/31	172.16.10.254 – 172.16.10.255	172.16.10.255

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 →