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)10.3.149.128/25

network10.3.149.128/25

broadcast10.3.149.255

first host10.3.149.129

last host10.3.149.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.3.149.128/25

address00001010.00000011.10010101.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000011.10010101.10000000

broadcast00001010.00000011.10010101.11111111

green = network part, grey = host part

hex0x0a039580

decimal168007040

reverse dns128.149.3.10.in-addr.arpa

ipv4-mapped::ffff:a03:9580

/25 split into /31 · 64 subnets

close ×

#	network	host range	broadcast
1	10.3.149.128/31	10.3.149.128 – 10.3.149.129	10.3.149.129
2	10.3.149.130/31	10.3.149.130 – 10.3.149.131	10.3.149.131
3	10.3.149.132/31	10.3.149.132 – 10.3.149.133	10.3.149.133
4	10.3.149.134/31	10.3.149.134 – 10.3.149.135	10.3.149.135
5	10.3.149.136/31	10.3.149.136 – 10.3.149.137	10.3.149.137
6	10.3.149.138/31	10.3.149.138 – 10.3.149.139	10.3.149.139
7	10.3.149.140/31	10.3.149.140 – 10.3.149.141	10.3.149.141
8	10.3.149.142/31	10.3.149.142 – 10.3.149.143	10.3.149.143
9	10.3.149.144/31	10.3.149.144 – 10.3.149.145	10.3.149.145
10	10.3.149.146/31	10.3.149.146 – 10.3.149.147	10.3.149.147
11	10.3.149.148/31	10.3.149.148 – 10.3.149.149	10.3.149.149
12	10.3.149.150/31	10.3.149.150 – 10.3.149.151	10.3.149.151
13	10.3.149.152/31	10.3.149.152 – 10.3.149.153	10.3.149.153
14	10.3.149.154/31	10.3.149.154 – 10.3.149.155	10.3.149.155
15	10.3.149.156/31	10.3.149.156 – 10.3.149.157	10.3.149.157
16	10.3.149.158/31	10.3.149.158 – 10.3.149.159	10.3.149.159
17	10.3.149.160/31	10.3.149.160 – 10.3.149.161	10.3.149.161
18	10.3.149.162/31	10.3.149.162 – 10.3.149.163	10.3.149.163
19	10.3.149.164/31	10.3.149.164 – 10.3.149.165	10.3.149.165
20	10.3.149.166/31	10.3.149.166 – 10.3.149.167	10.3.149.167
21	10.3.149.168/31	10.3.149.168 – 10.3.149.169	10.3.149.169
22	10.3.149.170/31	10.3.149.170 – 10.3.149.171	10.3.149.171
23	10.3.149.172/31	10.3.149.172 – 10.3.149.173	10.3.149.173
24	10.3.149.174/31	10.3.149.174 – 10.3.149.175	10.3.149.175
25	10.3.149.176/31	10.3.149.176 – 10.3.149.177	10.3.149.177
26	10.3.149.178/31	10.3.149.178 – 10.3.149.179	10.3.149.179
27	10.3.149.180/31	10.3.149.180 – 10.3.149.181	10.3.149.181
28	10.3.149.182/31	10.3.149.182 – 10.3.149.183	10.3.149.183
29	10.3.149.184/31	10.3.149.184 – 10.3.149.185	10.3.149.185
30	10.3.149.186/31	10.3.149.186 – 10.3.149.187	10.3.149.187
31	10.3.149.188/31	10.3.149.188 – 10.3.149.189	10.3.149.189
32	10.3.149.190/31	10.3.149.190 – 10.3.149.191	10.3.149.191
33	10.3.149.192/31	10.3.149.192 – 10.3.149.193	10.3.149.193
34	10.3.149.194/31	10.3.149.194 – 10.3.149.195	10.3.149.195
35	10.3.149.196/31	10.3.149.196 – 10.3.149.197	10.3.149.197
36	10.3.149.198/31	10.3.149.198 – 10.3.149.199	10.3.149.199
37	10.3.149.200/31	10.3.149.200 – 10.3.149.201	10.3.149.201
38	10.3.149.202/31	10.3.149.202 – 10.3.149.203	10.3.149.203
39	10.3.149.204/31	10.3.149.204 – 10.3.149.205	10.3.149.205
40	10.3.149.206/31	10.3.149.206 – 10.3.149.207	10.3.149.207
41	10.3.149.208/31	10.3.149.208 – 10.3.149.209	10.3.149.209
42	10.3.149.210/31	10.3.149.210 – 10.3.149.211	10.3.149.211
43	10.3.149.212/31	10.3.149.212 – 10.3.149.213	10.3.149.213
44	10.3.149.214/31	10.3.149.214 – 10.3.149.215	10.3.149.215
45	10.3.149.216/31	10.3.149.216 – 10.3.149.217	10.3.149.217
46	10.3.149.218/31	10.3.149.218 – 10.3.149.219	10.3.149.219
47	10.3.149.220/31	10.3.149.220 – 10.3.149.221	10.3.149.221
48	10.3.149.222/31	10.3.149.222 – 10.3.149.223	10.3.149.223
49	10.3.149.224/31	10.3.149.224 – 10.3.149.225	10.3.149.225
50	10.3.149.226/31	10.3.149.226 – 10.3.149.227	10.3.149.227
51	10.3.149.228/31	10.3.149.228 – 10.3.149.229	10.3.149.229
52	10.3.149.230/31	10.3.149.230 – 10.3.149.231	10.3.149.231
53	10.3.149.232/31	10.3.149.232 – 10.3.149.233	10.3.149.233
54	10.3.149.234/31	10.3.149.234 – 10.3.149.235	10.3.149.235
55	10.3.149.236/31	10.3.149.236 – 10.3.149.237	10.3.149.237
56	10.3.149.238/31	10.3.149.238 – 10.3.149.239	10.3.149.239
57	10.3.149.240/31	10.3.149.240 – 10.3.149.241	10.3.149.241
58	10.3.149.242/31	10.3.149.242 – 10.3.149.243	10.3.149.243
59	10.3.149.244/31	10.3.149.244 – 10.3.149.245	10.3.149.245
60	10.3.149.246/31	10.3.149.246 – 10.3.149.247	10.3.149.247
61	10.3.149.248/31	10.3.149.248 – 10.3.149.249	10.3.149.249
62	10.3.149.250/31	10.3.149.250 – 10.3.149.251	10.3.149.251
63	10.3.149.252/31	10.3.149.252 – 10.3.149.253	10.3.149.253
64	10.3.149.254/31	10.3.149.254 – 10.3.149.255	10.3.149.255

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 →