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)10.2.12.0/23

network10.2.12.0/23

broadcast10.2.13.255

first host10.2.12.1

last host10.2.13.254

subnet mask255.255.254.0

wildcard0.0.1.255

addresses512

usable hosts510

classA

ipcalc 10.2.12.0/23

address00001010.00000010.00001100.00000000

subnet mask11111111.11111111.11111110.00000000

network00001010.00000010.00001100.00000000

broadcast00001010.00000010.00001101.11111111

green = network part, grey = host part

hex0x0a020c00

decimal167906304

reverse dns0.12.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:c00

/23 split into /30 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.12.0/30	10.2.12.1 – 10.2.12.2	10.2.12.3
2	10.2.12.4/30	10.2.12.5 – 10.2.12.6	10.2.12.7
3	10.2.12.8/30	10.2.12.9 – 10.2.12.10	10.2.12.11
4	10.2.12.12/30	10.2.12.13 – 10.2.12.14	10.2.12.15
5	10.2.12.16/30	10.2.12.17 – 10.2.12.18	10.2.12.19
6	10.2.12.20/30	10.2.12.21 – 10.2.12.22	10.2.12.23
7	10.2.12.24/30	10.2.12.25 – 10.2.12.26	10.2.12.27
8	10.2.12.28/30	10.2.12.29 – 10.2.12.30	10.2.12.31
9	10.2.12.32/30	10.2.12.33 – 10.2.12.34	10.2.12.35
10	10.2.12.36/30	10.2.12.37 – 10.2.12.38	10.2.12.39
11	10.2.12.40/30	10.2.12.41 – 10.2.12.42	10.2.12.43
12	10.2.12.44/30	10.2.12.45 – 10.2.12.46	10.2.12.47
13	10.2.12.48/30	10.2.12.49 – 10.2.12.50	10.2.12.51
14	10.2.12.52/30	10.2.12.53 – 10.2.12.54	10.2.12.55
15	10.2.12.56/30	10.2.12.57 – 10.2.12.58	10.2.12.59
16	10.2.12.60/30	10.2.12.61 – 10.2.12.62	10.2.12.63
17	10.2.12.64/30	10.2.12.65 – 10.2.12.66	10.2.12.67
18	10.2.12.68/30	10.2.12.69 – 10.2.12.70	10.2.12.71
19	10.2.12.72/30	10.2.12.73 – 10.2.12.74	10.2.12.75
20	10.2.12.76/30	10.2.12.77 – 10.2.12.78	10.2.12.79
21	10.2.12.80/30	10.2.12.81 – 10.2.12.82	10.2.12.83
22	10.2.12.84/30	10.2.12.85 – 10.2.12.86	10.2.12.87
23	10.2.12.88/30	10.2.12.89 – 10.2.12.90	10.2.12.91
24	10.2.12.92/30	10.2.12.93 – 10.2.12.94	10.2.12.95
25	10.2.12.96/30	10.2.12.97 – 10.2.12.98	10.2.12.99
26	10.2.12.100/30	10.2.12.101 – 10.2.12.102	10.2.12.103
27	10.2.12.104/30	10.2.12.105 – 10.2.12.106	10.2.12.107
28	10.2.12.108/30	10.2.12.109 – 10.2.12.110	10.2.12.111
29	10.2.12.112/30	10.2.12.113 – 10.2.12.114	10.2.12.115
30	10.2.12.116/30	10.2.12.117 – 10.2.12.118	10.2.12.119
31	10.2.12.120/30	10.2.12.121 – 10.2.12.122	10.2.12.123
32	10.2.12.124/30	10.2.12.125 – 10.2.12.126	10.2.12.127
33	10.2.12.128/30	10.2.12.129 – 10.2.12.130	10.2.12.131
34	10.2.12.132/30	10.2.12.133 – 10.2.12.134	10.2.12.135
35	10.2.12.136/30	10.2.12.137 – 10.2.12.138	10.2.12.139
36	10.2.12.140/30	10.2.12.141 – 10.2.12.142	10.2.12.143
37	10.2.12.144/30	10.2.12.145 – 10.2.12.146	10.2.12.147
38	10.2.12.148/30	10.2.12.149 – 10.2.12.150	10.2.12.151
39	10.2.12.152/30	10.2.12.153 – 10.2.12.154	10.2.12.155
40	10.2.12.156/30	10.2.12.157 – 10.2.12.158	10.2.12.159
41	10.2.12.160/30	10.2.12.161 – 10.2.12.162	10.2.12.163
42	10.2.12.164/30	10.2.12.165 – 10.2.12.166	10.2.12.167
43	10.2.12.168/30	10.2.12.169 – 10.2.12.170	10.2.12.171
44	10.2.12.172/30	10.2.12.173 – 10.2.12.174	10.2.12.175
45	10.2.12.176/30	10.2.12.177 – 10.2.12.178	10.2.12.179
46	10.2.12.180/30	10.2.12.181 – 10.2.12.182	10.2.12.183
47	10.2.12.184/30	10.2.12.185 – 10.2.12.186	10.2.12.187
48	10.2.12.188/30	10.2.12.189 – 10.2.12.190	10.2.12.191
49	10.2.12.192/30	10.2.12.193 – 10.2.12.194	10.2.12.195
50	10.2.12.196/30	10.2.12.197 – 10.2.12.198	10.2.12.199
51	10.2.12.200/30	10.2.12.201 – 10.2.12.202	10.2.12.203
52	10.2.12.204/30	10.2.12.205 – 10.2.12.206	10.2.12.207
53	10.2.12.208/30	10.2.12.209 – 10.2.12.210	10.2.12.211
54	10.2.12.212/30	10.2.12.213 – 10.2.12.214	10.2.12.215
55	10.2.12.216/30	10.2.12.217 – 10.2.12.218	10.2.12.219
56	10.2.12.220/30	10.2.12.221 – 10.2.12.222	10.2.12.223
57	10.2.12.224/30	10.2.12.225 – 10.2.12.226	10.2.12.227
58	10.2.12.228/30	10.2.12.229 – 10.2.12.230	10.2.12.231
59	10.2.12.232/30	10.2.12.233 – 10.2.12.234	10.2.12.235
60	10.2.12.236/30	10.2.12.237 – 10.2.12.238	10.2.12.239
61	10.2.12.240/30	10.2.12.241 – 10.2.12.242	10.2.12.243
62	10.2.12.244/30	10.2.12.245 – 10.2.12.246	10.2.12.247
63	10.2.12.248/30	10.2.12.249 – 10.2.12.250	10.2.12.251
64	10.2.12.252/30	10.2.12.253 – 10.2.12.254	10.2.12.255
65	10.2.13.0/30	10.2.13.1 – 10.2.13.2	10.2.13.3
66	10.2.13.4/30	10.2.13.5 – 10.2.13.6	10.2.13.7
67	10.2.13.8/30	10.2.13.9 – 10.2.13.10	10.2.13.11
68	10.2.13.12/30	10.2.13.13 – 10.2.13.14	10.2.13.15
69	10.2.13.16/30	10.2.13.17 – 10.2.13.18	10.2.13.19
70	10.2.13.20/30	10.2.13.21 – 10.2.13.22	10.2.13.23
71	10.2.13.24/30	10.2.13.25 – 10.2.13.26	10.2.13.27
72	10.2.13.28/30	10.2.13.29 – 10.2.13.30	10.2.13.31
73	10.2.13.32/30	10.2.13.33 – 10.2.13.34	10.2.13.35
74	10.2.13.36/30	10.2.13.37 – 10.2.13.38	10.2.13.39
75	10.2.13.40/30	10.2.13.41 – 10.2.13.42	10.2.13.43
76	10.2.13.44/30	10.2.13.45 – 10.2.13.46	10.2.13.47
77	10.2.13.48/30	10.2.13.49 – 10.2.13.50	10.2.13.51
78	10.2.13.52/30	10.2.13.53 – 10.2.13.54	10.2.13.55
79	10.2.13.56/30	10.2.13.57 – 10.2.13.58	10.2.13.59
80	10.2.13.60/30	10.2.13.61 – 10.2.13.62	10.2.13.63
81	10.2.13.64/30	10.2.13.65 – 10.2.13.66	10.2.13.67
82	10.2.13.68/30	10.2.13.69 – 10.2.13.70	10.2.13.71
83	10.2.13.72/30	10.2.13.73 – 10.2.13.74	10.2.13.75
84	10.2.13.76/30	10.2.13.77 – 10.2.13.78	10.2.13.79
85	10.2.13.80/30	10.2.13.81 – 10.2.13.82	10.2.13.83
86	10.2.13.84/30	10.2.13.85 – 10.2.13.86	10.2.13.87
87	10.2.13.88/30	10.2.13.89 – 10.2.13.90	10.2.13.91
88	10.2.13.92/30	10.2.13.93 – 10.2.13.94	10.2.13.95
89	10.2.13.96/30	10.2.13.97 – 10.2.13.98	10.2.13.99
90	10.2.13.100/30	10.2.13.101 – 10.2.13.102	10.2.13.103
91	10.2.13.104/30	10.2.13.105 – 10.2.13.106	10.2.13.107
92	10.2.13.108/30	10.2.13.109 – 10.2.13.110	10.2.13.111
93	10.2.13.112/30	10.2.13.113 – 10.2.13.114	10.2.13.115
94	10.2.13.116/30	10.2.13.117 – 10.2.13.118	10.2.13.119
95	10.2.13.120/30	10.2.13.121 – 10.2.13.122	10.2.13.123
96	10.2.13.124/30	10.2.13.125 – 10.2.13.126	10.2.13.127
97	10.2.13.128/30	10.2.13.129 – 10.2.13.130	10.2.13.131
98	10.2.13.132/30	10.2.13.133 – 10.2.13.134	10.2.13.135
99	10.2.13.136/30	10.2.13.137 – 10.2.13.138	10.2.13.139
100	10.2.13.140/30	10.2.13.141 – 10.2.13.142	10.2.13.143
101	10.2.13.144/30	10.2.13.145 – 10.2.13.146	10.2.13.147
102	10.2.13.148/30	10.2.13.149 – 10.2.13.150	10.2.13.151
103	10.2.13.152/30	10.2.13.153 – 10.2.13.154	10.2.13.155
104	10.2.13.156/30	10.2.13.157 – 10.2.13.158	10.2.13.159
105	10.2.13.160/30	10.2.13.161 – 10.2.13.162	10.2.13.163
106	10.2.13.164/30	10.2.13.165 – 10.2.13.166	10.2.13.167
107	10.2.13.168/30	10.2.13.169 – 10.2.13.170	10.2.13.171
108	10.2.13.172/30	10.2.13.173 – 10.2.13.174	10.2.13.175
109	10.2.13.176/30	10.2.13.177 – 10.2.13.178	10.2.13.179
110	10.2.13.180/30	10.2.13.181 – 10.2.13.182	10.2.13.183
111	10.2.13.184/30	10.2.13.185 – 10.2.13.186	10.2.13.187
112	10.2.13.188/30	10.2.13.189 – 10.2.13.190	10.2.13.191
113	10.2.13.192/30	10.2.13.193 – 10.2.13.194	10.2.13.195
114	10.2.13.196/30	10.2.13.197 – 10.2.13.198	10.2.13.199
115	10.2.13.200/30	10.2.13.201 – 10.2.13.202	10.2.13.203
116	10.2.13.204/30	10.2.13.205 – 10.2.13.206	10.2.13.207
117	10.2.13.208/30	10.2.13.209 – 10.2.13.210	10.2.13.211
118	10.2.13.212/30	10.2.13.213 – 10.2.13.214	10.2.13.215
119	10.2.13.216/30	10.2.13.217 – 10.2.13.218	10.2.13.219
120	10.2.13.220/30	10.2.13.221 – 10.2.13.222	10.2.13.223
121	10.2.13.224/30	10.2.13.225 – 10.2.13.226	10.2.13.227
122	10.2.13.228/30	10.2.13.229 – 10.2.13.230	10.2.13.231
123	10.2.13.232/30	10.2.13.233 – 10.2.13.234	10.2.13.235
124	10.2.13.236/30	10.2.13.237 – 10.2.13.238	10.2.13.239
125	10.2.13.240/30	10.2.13.241 – 10.2.13.242	10.2.13.243
126	10.2.13.244/30	10.2.13.245 – 10.2.13.246	10.2.13.247
127	10.2.13.248/30	10.2.13.249 – 10.2.13.250	10.2.13.251
128	10.2.13.252/30	10.2.13.253 – 10.2.13.254	10.2.13.255

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 /23
/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	1
/24	255.255.255.0	256	254	2 split →
/25	255.255.255.128	128	126	4 split →
/26	255.255.255.192	64	62	8 split →
/27	255.255.255.224	32	30	16 split →
/28	255.255.255.240	16	14	32 split →
/29	255.255.255.248	8	6	64 split →
/30	255.255.255.252	4	2	128 split →
/31	255.255.255.254	2	2	256 split →
/32	255.255.255.255	1	1	512 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 →