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)10.2.97.128/25

network10.2.97.128/25

broadcast10.2.97.255

first host10.2.97.129

last host10.2.97.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.2.97.128/25

address00001010.00000010.01100001.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000010.01100001.10000000

broadcast00001010.00000010.01100001.11111111

green = network part, grey = host part

hex0x0a026180

decimal167928192

reverse dns128.97.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:6180

/25 split into /31 · 64 subnets

close ×

#	network	host range	broadcast
1	10.2.97.128/31	10.2.97.128 – 10.2.97.129	10.2.97.129
2	10.2.97.130/31	10.2.97.130 – 10.2.97.131	10.2.97.131
3	10.2.97.132/31	10.2.97.132 – 10.2.97.133	10.2.97.133
4	10.2.97.134/31	10.2.97.134 – 10.2.97.135	10.2.97.135
5	10.2.97.136/31	10.2.97.136 – 10.2.97.137	10.2.97.137
6	10.2.97.138/31	10.2.97.138 – 10.2.97.139	10.2.97.139
7	10.2.97.140/31	10.2.97.140 – 10.2.97.141	10.2.97.141
8	10.2.97.142/31	10.2.97.142 – 10.2.97.143	10.2.97.143
9	10.2.97.144/31	10.2.97.144 – 10.2.97.145	10.2.97.145
10	10.2.97.146/31	10.2.97.146 – 10.2.97.147	10.2.97.147
11	10.2.97.148/31	10.2.97.148 – 10.2.97.149	10.2.97.149
12	10.2.97.150/31	10.2.97.150 – 10.2.97.151	10.2.97.151
13	10.2.97.152/31	10.2.97.152 – 10.2.97.153	10.2.97.153
14	10.2.97.154/31	10.2.97.154 – 10.2.97.155	10.2.97.155
15	10.2.97.156/31	10.2.97.156 – 10.2.97.157	10.2.97.157
16	10.2.97.158/31	10.2.97.158 – 10.2.97.159	10.2.97.159
17	10.2.97.160/31	10.2.97.160 – 10.2.97.161	10.2.97.161
18	10.2.97.162/31	10.2.97.162 – 10.2.97.163	10.2.97.163
19	10.2.97.164/31	10.2.97.164 – 10.2.97.165	10.2.97.165
20	10.2.97.166/31	10.2.97.166 – 10.2.97.167	10.2.97.167
21	10.2.97.168/31	10.2.97.168 – 10.2.97.169	10.2.97.169
22	10.2.97.170/31	10.2.97.170 – 10.2.97.171	10.2.97.171
23	10.2.97.172/31	10.2.97.172 – 10.2.97.173	10.2.97.173
24	10.2.97.174/31	10.2.97.174 – 10.2.97.175	10.2.97.175
25	10.2.97.176/31	10.2.97.176 – 10.2.97.177	10.2.97.177
26	10.2.97.178/31	10.2.97.178 – 10.2.97.179	10.2.97.179
27	10.2.97.180/31	10.2.97.180 – 10.2.97.181	10.2.97.181
28	10.2.97.182/31	10.2.97.182 – 10.2.97.183	10.2.97.183
29	10.2.97.184/31	10.2.97.184 – 10.2.97.185	10.2.97.185
30	10.2.97.186/31	10.2.97.186 – 10.2.97.187	10.2.97.187
31	10.2.97.188/31	10.2.97.188 – 10.2.97.189	10.2.97.189
32	10.2.97.190/31	10.2.97.190 – 10.2.97.191	10.2.97.191
33	10.2.97.192/31	10.2.97.192 – 10.2.97.193	10.2.97.193
34	10.2.97.194/31	10.2.97.194 – 10.2.97.195	10.2.97.195
35	10.2.97.196/31	10.2.97.196 – 10.2.97.197	10.2.97.197
36	10.2.97.198/31	10.2.97.198 – 10.2.97.199	10.2.97.199
37	10.2.97.200/31	10.2.97.200 – 10.2.97.201	10.2.97.201
38	10.2.97.202/31	10.2.97.202 – 10.2.97.203	10.2.97.203
39	10.2.97.204/31	10.2.97.204 – 10.2.97.205	10.2.97.205
40	10.2.97.206/31	10.2.97.206 – 10.2.97.207	10.2.97.207
41	10.2.97.208/31	10.2.97.208 – 10.2.97.209	10.2.97.209
42	10.2.97.210/31	10.2.97.210 – 10.2.97.211	10.2.97.211
43	10.2.97.212/31	10.2.97.212 – 10.2.97.213	10.2.97.213
44	10.2.97.214/31	10.2.97.214 – 10.2.97.215	10.2.97.215
45	10.2.97.216/31	10.2.97.216 – 10.2.97.217	10.2.97.217
46	10.2.97.218/31	10.2.97.218 – 10.2.97.219	10.2.97.219
47	10.2.97.220/31	10.2.97.220 – 10.2.97.221	10.2.97.221
48	10.2.97.222/31	10.2.97.222 – 10.2.97.223	10.2.97.223
49	10.2.97.224/31	10.2.97.224 – 10.2.97.225	10.2.97.225
50	10.2.97.226/31	10.2.97.226 – 10.2.97.227	10.2.97.227
51	10.2.97.228/31	10.2.97.228 – 10.2.97.229	10.2.97.229
52	10.2.97.230/31	10.2.97.230 – 10.2.97.231	10.2.97.231
53	10.2.97.232/31	10.2.97.232 – 10.2.97.233	10.2.97.233
54	10.2.97.234/31	10.2.97.234 – 10.2.97.235	10.2.97.235
55	10.2.97.236/31	10.2.97.236 – 10.2.97.237	10.2.97.237
56	10.2.97.238/31	10.2.97.238 – 10.2.97.239	10.2.97.239
57	10.2.97.240/31	10.2.97.240 – 10.2.97.241	10.2.97.241
58	10.2.97.242/31	10.2.97.242 – 10.2.97.243	10.2.97.243
59	10.2.97.244/31	10.2.97.244 – 10.2.97.245	10.2.97.245
60	10.2.97.246/31	10.2.97.246 – 10.2.97.247	10.2.97.247
61	10.2.97.248/31	10.2.97.248 – 10.2.97.249	10.2.97.249
62	10.2.97.250/31	10.2.97.250 – 10.2.97.251	10.2.97.251
63	10.2.97.252/31	10.2.97.252 – 10.2.97.253	10.2.97.253
64	10.2.97.254/31	10.2.97.254 – 10.2.97.255	10.2.97.255

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 →