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)10.2.138.0/23

network10.2.138.0/23

broadcast10.2.139.255

first host10.2.138.1

last host10.2.139.254

subnet mask255.255.254.0

wildcard0.0.1.255

addresses512

usable hosts510

classA

ipcalc 10.2.138.0/23

address00001010.00000010.10001010.00000000

subnet mask11111111.11111111.11111110.00000000

network00001010.00000010.10001010.00000000

broadcast00001010.00000010.10001011.11111111

green = network part, grey = host part

hex0x0a028a00

decimal167938560

reverse dns0.138.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:8a00

/23 split into /30 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.138.0/30	10.2.138.1 – 10.2.138.2	10.2.138.3
2	10.2.138.4/30	10.2.138.5 – 10.2.138.6	10.2.138.7
3	10.2.138.8/30	10.2.138.9 – 10.2.138.10	10.2.138.11
4	10.2.138.12/30	10.2.138.13 – 10.2.138.14	10.2.138.15
5	10.2.138.16/30	10.2.138.17 – 10.2.138.18	10.2.138.19
6	10.2.138.20/30	10.2.138.21 – 10.2.138.22	10.2.138.23
7	10.2.138.24/30	10.2.138.25 – 10.2.138.26	10.2.138.27
8	10.2.138.28/30	10.2.138.29 – 10.2.138.30	10.2.138.31
9	10.2.138.32/30	10.2.138.33 – 10.2.138.34	10.2.138.35
10	10.2.138.36/30	10.2.138.37 – 10.2.138.38	10.2.138.39
11	10.2.138.40/30	10.2.138.41 – 10.2.138.42	10.2.138.43
12	10.2.138.44/30	10.2.138.45 – 10.2.138.46	10.2.138.47
13	10.2.138.48/30	10.2.138.49 – 10.2.138.50	10.2.138.51
14	10.2.138.52/30	10.2.138.53 – 10.2.138.54	10.2.138.55
15	10.2.138.56/30	10.2.138.57 – 10.2.138.58	10.2.138.59
16	10.2.138.60/30	10.2.138.61 – 10.2.138.62	10.2.138.63
17	10.2.138.64/30	10.2.138.65 – 10.2.138.66	10.2.138.67
18	10.2.138.68/30	10.2.138.69 – 10.2.138.70	10.2.138.71
19	10.2.138.72/30	10.2.138.73 – 10.2.138.74	10.2.138.75
20	10.2.138.76/30	10.2.138.77 – 10.2.138.78	10.2.138.79
21	10.2.138.80/30	10.2.138.81 – 10.2.138.82	10.2.138.83
22	10.2.138.84/30	10.2.138.85 – 10.2.138.86	10.2.138.87
23	10.2.138.88/30	10.2.138.89 – 10.2.138.90	10.2.138.91
24	10.2.138.92/30	10.2.138.93 – 10.2.138.94	10.2.138.95
25	10.2.138.96/30	10.2.138.97 – 10.2.138.98	10.2.138.99
26	10.2.138.100/30	10.2.138.101 – 10.2.138.102	10.2.138.103
27	10.2.138.104/30	10.2.138.105 – 10.2.138.106	10.2.138.107
28	10.2.138.108/30	10.2.138.109 – 10.2.138.110	10.2.138.111
29	10.2.138.112/30	10.2.138.113 – 10.2.138.114	10.2.138.115
30	10.2.138.116/30	10.2.138.117 – 10.2.138.118	10.2.138.119
31	10.2.138.120/30	10.2.138.121 – 10.2.138.122	10.2.138.123
32	10.2.138.124/30	10.2.138.125 – 10.2.138.126	10.2.138.127
33	10.2.138.128/30	10.2.138.129 – 10.2.138.130	10.2.138.131
34	10.2.138.132/30	10.2.138.133 – 10.2.138.134	10.2.138.135
35	10.2.138.136/30	10.2.138.137 – 10.2.138.138	10.2.138.139
36	10.2.138.140/30	10.2.138.141 – 10.2.138.142	10.2.138.143
37	10.2.138.144/30	10.2.138.145 – 10.2.138.146	10.2.138.147
38	10.2.138.148/30	10.2.138.149 – 10.2.138.150	10.2.138.151
39	10.2.138.152/30	10.2.138.153 – 10.2.138.154	10.2.138.155
40	10.2.138.156/30	10.2.138.157 – 10.2.138.158	10.2.138.159
41	10.2.138.160/30	10.2.138.161 – 10.2.138.162	10.2.138.163
42	10.2.138.164/30	10.2.138.165 – 10.2.138.166	10.2.138.167
43	10.2.138.168/30	10.2.138.169 – 10.2.138.170	10.2.138.171
44	10.2.138.172/30	10.2.138.173 – 10.2.138.174	10.2.138.175
45	10.2.138.176/30	10.2.138.177 – 10.2.138.178	10.2.138.179
46	10.2.138.180/30	10.2.138.181 – 10.2.138.182	10.2.138.183
47	10.2.138.184/30	10.2.138.185 – 10.2.138.186	10.2.138.187
48	10.2.138.188/30	10.2.138.189 – 10.2.138.190	10.2.138.191
49	10.2.138.192/30	10.2.138.193 – 10.2.138.194	10.2.138.195
50	10.2.138.196/30	10.2.138.197 – 10.2.138.198	10.2.138.199
51	10.2.138.200/30	10.2.138.201 – 10.2.138.202	10.2.138.203
52	10.2.138.204/30	10.2.138.205 – 10.2.138.206	10.2.138.207
53	10.2.138.208/30	10.2.138.209 – 10.2.138.210	10.2.138.211
54	10.2.138.212/30	10.2.138.213 – 10.2.138.214	10.2.138.215
55	10.2.138.216/30	10.2.138.217 – 10.2.138.218	10.2.138.219
56	10.2.138.220/30	10.2.138.221 – 10.2.138.222	10.2.138.223
57	10.2.138.224/30	10.2.138.225 – 10.2.138.226	10.2.138.227
58	10.2.138.228/30	10.2.138.229 – 10.2.138.230	10.2.138.231
59	10.2.138.232/30	10.2.138.233 – 10.2.138.234	10.2.138.235
60	10.2.138.236/30	10.2.138.237 – 10.2.138.238	10.2.138.239
61	10.2.138.240/30	10.2.138.241 – 10.2.138.242	10.2.138.243
62	10.2.138.244/30	10.2.138.245 – 10.2.138.246	10.2.138.247
63	10.2.138.248/30	10.2.138.249 – 10.2.138.250	10.2.138.251
64	10.2.138.252/30	10.2.138.253 – 10.2.138.254	10.2.138.255
65	10.2.139.0/30	10.2.139.1 – 10.2.139.2	10.2.139.3
66	10.2.139.4/30	10.2.139.5 – 10.2.139.6	10.2.139.7
67	10.2.139.8/30	10.2.139.9 – 10.2.139.10	10.2.139.11
68	10.2.139.12/30	10.2.139.13 – 10.2.139.14	10.2.139.15
69	10.2.139.16/30	10.2.139.17 – 10.2.139.18	10.2.139.19
70	10.2.139.20/30	10.2.139.21 – 10.2.139.22	10.2.139.23
71	10.2.139.24/30	10.2.139.25 – 10.2.139.26	10.2.139.27
72	10.2.139.28/30	10.2.139.29 – 10.2.139.30	10.2.139.31
73	10.2.139.32/30	10.2.139.33 – 10.2.139.34	10.2.139.35
74	10.2.139.36/30	10.2.139.37 – 10.2.139.38	10.2.139.39
75	10.2.139.40/30	10.2.139.41 – 10.2.139.42	10.2.139.43
76	10.2.139.44/30	10.2.139.45 – 10.2.139.46	10.2.139.47
77	10.2.139.48/30	10.2.139.49 – 10.2.139.50	10.2.139.51
78	10.2.139.52/30	10.2.139.53 – 10.2.139.54	10.2.139.55
79	10.2.139.56/30	10.2.139.57 – 10.2.139.58	10.2.139.59
80	10.2.139.60/30	10.2.139.61 – 10.2.139.62	10.2.139.63
81	10.2.139.64/30	10.2.139.65 – 10.2.139.66	10.2.139.67
82	10.2.139.68/30	10.2.139.69 – 10.2.139.70	10.2.139.71
83	10.2.139.72/30	10.2.139.73 – 10.2.139.74	10.2.139.75
84	10.2.139.76/30	10.2.139.77 – 10.2.139.78	10.2.139.79
85	10.2.139.80/30	10.2.139.81 – 10.2.139.82	10.2.139.83
86	10.2.139.84/30	10.2.139.85 – 10.2.139.86	10.2.139.87
87	10.2.139.88/30	10.2.139.89 – 10.2.139.90	10.2.139.91
88	10.2.139.92/30	10.2.139.93 – 10.2.139.94	10.2.139.95
89	10.2.139.96/30	10.2.139.97 – 10.2.139.98	10.2.139.99
90	10.2.139.100/30	10.2.139.101 – 10.2.139.102	10.2.139.103
91	10.2.139.104/30	10.2.139.105 – 10.2.139.106	10.2.139.107
92	10.2.139.108/30	10.2.139.109 – 10.2.139.110	10.2.139.111
93	10.2.139.112/30	10.2.139.113 – 10.2.139.114	10.2.139.115
94	10.2.139.116/30	10.2.139.117 – 10.2.139.118	10.2.139.119
95	10.2.139.120/30	10.2.139.121 – 10.2.139.122	10.2.139.123
96	10.2.139.124/30	10.2.139.125 – 10.2.139.126	10.2.139.127
97	10.2.139.128/30	10.2.139.129 – 10.2.139.130	10.2.139.131
98	10.2.139.132/30	10.2.139.133 – 10.2.139.134	10.2.139.135
99	10.2.139.136/30	10.2.139.137 – 10.2.139.138	10.2.139.139
100	10.2.139.140/30	10.2.139.141 – 10.2.139.142	10.2.139.143
101	10.2.139.144/30	10.2.139.145 – 10.2.139.146	10.2.139.147
102	10.2.139.148/30	10.2.139.149 – 10.2.139.150	10.2.139.151
103	10.2.139.152/30	10.2.139.153 – 10.2.139.154	10.2.139.155
104	10.2.139.156/30	10.2.139.157 – 10.2.139.158	10.2.139.159
105	10.2.139.160/30	10.2.139.161 – 10.2.139.162	10.2.139.163
106	10.2.139.164/30	10.2.139.165 – 10.2.139.166	10.2.139.167
107	10.2.139.168/30	10.2.139.169 – 10.2.139.170	10.2.139.171
108	10.2.139.172/30	10.2.139.173 – 10.2.139.174	10.2.139.175
109	10.2.139.176/30	10.2.139.177 – 10.2.139.178	10.2.139.179
110	10.2.139.180/30	10.2.139.181 – 10.2.139.182	10.2.139.183
111	10.2.139.184/30	10.2.139.185 – 10.2.139.186	10.2.139.187
112	10.2.139.188/30	10.2.139.189 – 10.2.139.190	10.2.139.191
113	10.2.139.192/30	10.2.139.193 – 10.2.139.194	10.2.139.195
114	10.2.139.196/30	10.2.139.197 – 10.2.139.198	10.2.139.199
115	10.2.139.200/30	10.2.139.201 – 10.2.139.202	10.2.139.203
116	10.2.139.204/30	10.2.139.205 – 10.2.139.206	10.2.139.207
117	10.2.139.208/30	10.2.139.209 – 10.2.139.210	10.2.139.211
118	10.2.139.212/30	10.2.139.213 – 10.2.139.214	10.2.139.215
119	10.2.139.216/30	10.2.139.217 – 10.2.139.218	10.2.139.219
120	10.2.139.220/30	10.2.139.221 – 10.2.139.222	10.2.139.223
121	10.2.139.224/30	10.2.139.225 – 10.2.139.226	10.2.139.227
122	10.2.139.228/30	10.2.139.229 – 10.2.139.230	10.2.139.231
123	10.2.139.232/30	10.2.139.233 – 10.2.139.234	10.2.139.235
124	10.2.139.236/30	10.2.139.237 – 10.2.139.238	10.2.139.239
125	10.2.139.240/30	10.2.139.241 – 10.2.139.242	10.2.139.243
126	10.2.139.244/30	10.2.139.245 – 10.2.139.246	10.2.139.247
127	10.2.139.248/30	10.2.139.249 – 10.2.139.250	10.2.139.251
128	10.2.139.252/30	10.2.139.253 – 10.2.139.254	10.2.139.255

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 →