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)10.3.181.0/24

network10.3.181.0/24

broadcast10.3.181.255

first host10.3.181.1

last host10.3.181.254

subnet mask255.255.255.0

wildcard0.0.0.255

addresses256

usable hosts254

classA

ipcalc 10.3.181.0/24

address00001010.00000011.10110101.00000000

subnet mask11111111.11111111.11111111.00000000

network00001010.00000011.10110101.00000000

broadcast00001010.00000011.10110101.11111111

green = network part, grey = host part

hex0x0a03b500

decimal168015104

reverse dns0.181.3.10.in-addr.arpa

ipv4-mapped::ffff:a03:b500

/24 split into /31 · 128 subnets

close ×

#	network	host range	broadcast
1	10.3.181.0/31	10.3.181.0 – 10.3.181.1	10.3.181.1
2	10.3.181.2/31	10.3.181.2 – 10.3.181.3	10.3.181.3
3	10.3.181.4/31	10.3.181.4 – 10.3.181.5	10.3.181.5
4	10.3.181.6/31	10.3.181.6 – 10.3.181.7	10.3.181.7
5	10.3.181.8/31	10.3.181.8 – 10.3.181.9	10.3.181.9
6	10.3.181.10/31	10.3.181.10 – 10.3.181.11	10.3.181.11
7	10.3.181.12/31	10.3.181.12 – 10.3.181.13	10.3.181.13
8	10.3.181.14/31	10.3.181.14 – 10.3.181.15	10.3.181.15
9	10.3.181.16/31	10.3.181.16 – 10.3.181.17	10.3.181.17
10	10.3.181.18/31	10.3.181.18 – 10.3.181.19	10.3.181.19
11	10.3.181.20/31	10.3.181.20 – 10.3.181.21	10.3.181.21
12	10.3.181.22/31	10.3.181.22 – 10.3.181.23	10.3.181.23
13	10.3.181.24/31	10.3.181.24 – 10.3.181.25	10.3.181.25
14	10.3.181.26/31	10.3.181.26 – 10.3.181.27	10.3.181.27
15	10.3.181.28/31	10.3.181.28 – 10.3.181.29	10.3.181.29
16	10.3.181.30/31	10.3.181.30 – 10.3.181.31	10.3.181.31
17	10.3.181.32/31	10.3.181.32 – 10.3.181.33	10.3.181.33
18	10.3.181.34/31	10.3.181.34 – 10.3.181.35	10.3.181.35
19	10.3.181.36/31	10.3.181.36 – 10.3.181.37	10.3.181.37
20	10.3.181.38/31	10.3.181.38 – 10.3.181.39	10.3.181.39
21	10.3.181.40/31	10.3.181.40 – 10.3.181.41	10.3.181.41
22	10.3.181.42/31	10.3.181.42 – 10.3.181.43	10.3.181.43
23	10.3.181.44/31	10.3.181.44 – 10.3.181.45	10.3.181.45
24	10.3.181.46/31	10.3.181.46 – 10.3.181.47	10.3.181.47
25	10.3.181.48/31	10.3.181.48 – 10.3.181.49	10.3.181.49
26	10.3.181.50/31	10.3.181.50 – 10.3.181.51	10.3.181.51
27	10.3.181.52/31	10.3.181.52 – 10.3.181.53	10.3.181.53
28	10.3.181.54/31	10.3.181.54 – 10.3.181.55	10.3.181.55
29	10.3.181.56/31	10.3.181.56 – 10.3.181.57	10.3.181.57
30	10.3.181.58/31	10.3.181.58 – 10.3.181.59	10.3.181.59
31	10.3.181.60/31	10.3.181.60 – 10.3.181.61	10.3.181.61
32	10.3.181.62/31	10.3.181.62 – 10.3.181.63	10.3.181.63
33	10.3.181.64/31	10.3.181.64 – 10.3.181.65	10.3.181.65
34	10.3.181.66/31	10.3.181.66 – 10.3.181.67	10.3.181.67
35	10.3.181.68/31	10.3.181.68 – 10.3.181.69	10.3.181.69
36	10.3.181.70/31	10.3.181.70 – 10.3.181.71	10.3.181.71
37	10.3.181.72/31	10.3.181.72 – 10.3.181.73	10.3.181.73
38	10.3.181.74/31	10.3.181.74 – 10.3.181.75	10.3.181.75
39	10.3.181.76/31	10.3.181.76 – 10.3.181.77	10.3.181.77
40	10.3.181.78/31	10.3.181.78 – 10.3.181.79	10.3.181.79
41	10.3.181.80/31	10.3.181.80 – 10.3.181.81	10.3.181.81
42	10.3.181.82/31	10.3.181.82 – 10.3.181.83	10.3.181.83
43	10.3.181.84/31	10.3.181.84 – 10.3.181.85	10.3.181.85
44	10.3.181.86/31	10.3.181.86 – 10.3.181.87	10.3.181.87
45	10.3.181.88/31	10.3.181.88 – 10.3.181.89	10.3.181.89
46	10.3.181.90/31	10.3.181.90 – 10.3.181.91	10.3.181.91
47	10.3.181.92/31	10.3.181.92 – 10.3.181.93	10.3.181.93
48	10.3.181.94/31	10.3.181.94 – 10.3.181.95	10.3.181.95
49	10.3.181.96/31	10.3.181.96 – 10.3.181.97	10.3.181.97
50	10.3.181.98/31	10.3.181.98 – 10.3.181.99	10.3.181.99
51	10.3.181.100/31	10.3.181.100 – 10.3.181.101	10.3.181.101
52	10.3.181.102/31	10.3.181.102 – 10.3.181.103	10.3.181.103
53	10.3.181.104/31	10.3.181.104 – 10.3.181.105	10.3.181.105
54	10.3.181.106/31	10.3.181.106 – 10.3.181.107	10.3.181.107
55	10.3.181.108/31	10.3.181.108 – 10.3.181.109	10.3.181.109
56	10.3.181.110/31	10.3.181.110 – 10.3.181.111	10.3.181.111
57	10.3.181.112/31	10.3.181.112 – 10.3.181.113	10.3.181.113
58	10.3.181.114/31	10.3.181.114 – 10.3.181.115	10.3.181.115
59	10.3.181.116/31	10.3.181.116 – 10.3.181.117	10.3.181.117
60	10.3.181.118/31	10.3.181.118 – 10.3.181.119	10.3.181.119
61	10.3.181.120/31	10.3.181.120 – 10.3.181.121	10.3.181.121
62	10.3.181.122/31	10.3.181.122 – 10.3.181.123	10.3.181.123
63	10.3.181.124/31	10.3.181.124 – 10.3.181.125	10.3.181.125
64	10.3.181.126/31	10.3.181.126 – 10.3.181.127	10.3.181.127
65	10.3.181.128/31	10.3.181.128 – 10.3.181.129	10.3.181.129
66	10.3.181.130/31	10.3.181.130 – 10.3.181.131	10.3.181.131
67	10.3.181.132/31	10.3.181.132 – 10.3.181.133	10.3.181.133
68	10.3.181.134/31	10.3.181.134 – 10.3.181.135	10.3.181.135
69	10.3.181.136/31	10.3.181.136 – 10.3.181.137	10.3.181.137
70	10.3.181.138/31	10.3.181.138 – 10.3.181.139	10.3.181.139
71	10.3.181.140/31	10.3.181.140 – 10.3.181.141	10.3.181.141
72	10.3.181.142/31	10.3.181.142 – 10.3.181.143	10.3.181.143
73	10.3.181.144/31	10.3.181.144 – 10.3.181.145	10.3.181.145
74	10.3.181.146/31	10.3.181.146 – 10.3.181.147	10.3.181.147
75	10.3.181.148/31	10.3.181.148 – 10.3.181.149	10.3.181.149
76	10.3.181.150/31	10.3.181.150 – 10.3.181.151	10.3.181.151
77	10.3.181.152/31	10.3.181.152 – 10.3.181.153	10.3.181.153
78	10.3.181.154/31	10.3.181.154 – 10.3.181.155	10.3.181.155
79	10.3.181.156/31	10.3.181.156 – 10.3.181.157	10.3.181.157
80	10.3.181.158/31	10.3.181.158 – 10.3.181.159	10.3.181.159
81	10.3.181.160/31	10.3.181.160 – 10.3.181.161	10.3.181.161
82	10.3.181.162/31	10.3.181.162 – 10.3.181.163	10.3.181.163
83	10.3.181.164/31	10.3.181.164 – 10.3.181.165	10.3.181.165
84	10.3.181.166/31	10.3.181.166 – 10.3.181.167	10.3.181.167
85	10.3.181.168/31	10.3.181.168 – 10.3.181.169	10.3.181.169
86	10.3.181.170/31	10.3.181.170 – 10.3.181.171	10.3.181.171
87	10.3.181.172/31	10.3.181.172 – 10.3.181.173	10.3.181.173
88	10.3.181.174/31	10.3.181.174 – 10.3.181.175	10.3.181.175
89	10.3.181.176/31	10.3.181.176 – 10.3.181.177	10.3.181.177
90	10.3.181.178/31	10.3.181.178 – 10.3.181.179	10.3.181.179
91	10.3.181.180/31	10.3.181.180 – 10.3.181.181	10.3.181.181
92	10.3.181.182/31	10.3.181.182 – 10.3.181.183	10.3.181.183
93	10.3.181.184/31	10.3.181.184 – 10.3.181.185	10.3.181.185
94	10.3.181.186/31	10.3.181.186 – 10.3.181.187	10.3.181.187
95	10.3.181.188/31	10.3.181.188 – 10.3.181.189	10.3.181.189
96	10.3.181.190/31	10.3.181.190 – 10.3.181.191	10.3.181.191
97	10.3.181.192/31	10.3.181.192 – 10.3.181.193	10.3.181.193
98	10.3.181.194/31	10.3.181.194 – 10.3.181.195	10.3.181.195
99	10.3.181.196/31	10.3.181.196 – 10.3.181.197	10.3.181.197
100	10.3.181.198/31	10.3.181.198 – 10.3.181.199	10.3.181.199
101	10.3.181.200/31	10.3.181.200 – 10.3.181.201	10.3.181.201
102	10.3.181.202/31	10.3.181.202 – 10.3.181.203	10.3.181.203
103	10.3.181.204/31	10.3.181.204 – 10.3.181.205	10.3.181.205
104	10.3.181.206/31	10.3.181.206 – 10.3.181.207	10.3.181.207
105	10.3.181.208/31	10.3.181.208 – 10.3.181.209	10.3.181.209
106	10.3.181.210/31	10.3.181.210 – 10.3.181.211	10.3.181.211
107	10.3.181.212/31	10.3.181.212 – 10.3.181.213	10.3.181.213
108	10.3.181.214/31	10.3.181.214 – 10.3.181.215	10.3.181.215
109	10.3.181.216/31	10.3.181.216 – 10.3.181.217	10.3.181.217
110	10.3.181.218/31	10.3.181.218 – 10.3.181.219	10.3.181.219
111	10.3.181.220/31	10.3.181.220 – 10.3.181.221	10.3.181.221
112	10.3.181.222/31	10.3.181.222 – 10.3.181.223	10.3.181.223
113	10.3.181.224/31	10.3.181.224 – 10.3.181.225	10.3.181.225
114	10.3.181.226/31	10.3.181.226 – 10.3.181.227	10.3.181.227
115	10.3.181.228/31	10.3.181.228 – 10.3.181.229	10.3.181.229
116	10.3.181.230/31	10.3.181.230 – 10.3.181.231	10.3.181.231
117	10.3.181.232/31	10.3.181.232 – 10.3.181.233	10.3.181.233
118	10.3.181.234/31	10.3.181.234 – 10.3.181.235	10.3.181.235
119	10.3.181.236/31	10.3.181.236 – 10.3.181.237	10.3.181.237
120	10.3.181.238/31	10.3.181.238 – 10.3.181.239	10.3.181.239
121	10.3.181.240/31	10.3.181.240 – 10.3.181.241	10.3.181.241
122	10.3.181.242/31	10.3.181.242 – 10.3.181.243	10.3.181.243
123	10.3.181.244/31	10.3.181.244 – 10.3.181.245	10.3.181.245
124	10.3.181.246/31	10.3.181.246 – 10.3.181.247	10.3.181.247
125	10.3.181.248/31	10.3.181.248 – 10.3.181.249	10.3.181.249
126	10.3.181.250/31	10.3.181.250 – 10.3.181.251	10.3.181.251
127	10.3.181.252/31	10.3.181.252 – 10.3.181.253	10.3.181.253
128	10.3.181.254/31	10.3.181.254 – 10.3.181.255	10.3.181.255

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 /24
/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	1
/25	255.255.255.128	128	126	2 split →
/26	255.255.255.192	64	62	4 split →
/27	255.255.255.224	32	30	8 split →
/28	255.255.255.240	16	14	16 split →
/29	255.255.255.248	8	6	32 split →
/30	255.255.255.252	4	2	64 split →
/31	255.255.255.254	2	2	128 split →
/32	255.255.255.255	1	1	256 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 →