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)10.2.16.0/23

network10.2.16.0/23

broadcast10.2.17.255

first host10.2.16.1

last host10.2.17.254

subnet mask255.255.254.0

wildcard0.0.1.255

addresses512

usable hosts510

classA

ipcalc 10.2.16.0/23

address00001010.00000010.00010000.00000000

subnet mask11111111.11111111.11111110.00000000

network00001010.00000010.00010000.00000000

broadcast00001010.00000010.00010001.11111111

green = network part, grey = host part

hex0x0a021000

decimal167907328

reverse dns0.16.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:1000

/23 split into /30 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.16.0/30	10.2.16.1 – 10.2.16.2	10.2.16.3
2	10.2.16.4/30	10.2.16.5 – 10.2.16.6	10.2.16.7
3	10.2.16.8/30	10.2.16.9 – 10.2.16.10	10.2.16.11
4	10.2.16.12/30	10.2.16.13 – 10.2.16.14	10.2.16.15
5	10.2.16.16/30	10.2.16.17 – 10.2.16.18	10.2.16.19
6	10.2.16.20/30	10.2.16.21 – 10.2.16.22	10.2.16.23
7	10.2.16.24/30	10.2.16.25 – 10.2.16.26	10.2.16.27
8	10.2.16.28/30	10.2.16.29 – 10.2.16.30	10.2.16.31
9	10.2.16.32/30	10.2.16.33 – 10.2.16.34	10.2.16.35
10	10.2.16.36/30	10.2.16.37 – 10.2.16.38	10.2.16.39
11	10.2.16.40/30	10.2.16.41 – 10.2.16.42	10.2.16.43
12	10.2.16.44/30	10.2.16.45 – 10.2.16.46	10.2.16.47
13	10.2.16.48/30	10.2.16.49 – 10.2.16.50	10.2.16.51
14	10.2.16.52/30	10.2.16.53 – 10.2.16.54	10.2.16.55
15	10.2.16.56/30	10.2.16.57 – 10.2.16.58	10.2.16.59
16	10.2.16.60/30	10.2.16.61 – 10.2.16.62	10.2.16.63
17	10.2.16.64/30	10.2.16.65 – 10.2.16.66	10.2.16.67
18	10.2.16.68/30	10.2.16.69 – 10.2.16.70	10.2.16.71
19	10.2.16.72/30	10.2.16.73 – 10.2.16.74	10.2.16.75
20	10.2.16.76/30	10.2.16.77 – 10.2.16.78	10.2.16.79
21	10.2.16.80/30	10.2.16.81 – 10.2.16.82	10.2.16.83
22	10.2.16.84/30	10.2.16.85 – 10.2.16.86	10.2.16.87
23	10.2.16.88/30	10.2.16.89 – 10.2.16.90	10.2.16.91
24	10.2.16.92/30	10.2.16.93 – 10.2.16.94	10.2.16.95
25	10.2.16.96/30	10.2.16.97 – 10.2.16.98	10.2.16.99
26	10.2.16.100/30	10.2.16.101 – 10.2.16.102	10.2.16.103
27	10.2.16.104/30	10.2.16.105 – 10.2.16.106	10.2.16.107
28	10.2.16.108/30	10.2.16.109 – 10.2.16.110	10.2.16.111
29	10.2.16.112/30	10.2.16.113 – 10.2.16.114	10.2.16.115
30	10.2.16.116/30	10.2.16.117 – 10.2.16.118	10.2.16.119
31	10.2.16.120/30	10.2.16.121 – 10.2.16.122	10.2.16.123
32	10.2.16.124/30	10.2.16.125 – 10.2.16.126	10.2.16.127
33	10.2.16.128/30	10.2.16.129 – 10.2.16.130	10.2.16.131
34	10.2.16.132/30	10.2.16.133 – 10.2.16.134	10.2.16.135
35	10.2.16.136/30	10.2.16.137 – 10.2.16.138	10.2.16.139
36	10.2.16.140/30	10.2.16.141 – 10.2.16.142	10.2.16.143
37	10.2.16.144/30	10.2.16.145 – 10.2.16.146	10.2.16.147
38	10.2.16.148/30	10.2.16.149 – 10.2.16.150	10.2.16.151
39	10.2.16.152/30	10.2.16.153 – 10.2.16.154	10.2.16.155
40	10.2.16.156/30	10.2.16.157 – 10.2.16.158	10.2.16.159
41	10.2.16.160/30	10.2.16.161 – 10.2.16.162	10.2.16.163
42	10.2.16.164/30	10.2.16.165 – 10.2.16.166	10.2.16.167
43	10.2.16.168/30	10.2.16.169 – 10.2.16.170	10.2.16.171
44	10.2.16.172/30	10.2.16.173 – 10.2.16.174	10.2.16.175
45	10.2.16.176/30	10.2.16.177 – 10.2.16.178	10.2.16.179
46	10.2.16.180/30	10.2.16.181 – 10.2.16.182	10.2.16.183
47	10.2.16.184/30	10.2.16.185 – 10.2.16.186	10.2.16.187
48	10.2.16.188/30	10.2.16.189 – 10.2.16.190	10.2.16.191
49	10.2.16.192/30	10.2.16.193 – 10.2.16.194	10.2.16.195
50	10.2.16.196/30	10.2.16.197 – 10.2.16.198	10.2.16.199
51	10.2.16.200/30	10.2.16.201 – 10.2.16.202	10.2.16.203
52	10.2.16.204/30	10.2.16.205 – 10.2.16.206	10.2.16.207
53	10.2.16.208/30	10.2.16.209 – 10.2.16.210	10.2.16.211
54	10.2.16.212/30	10.2.16.213 – 10.2.16.214	10.2.16.215
55	10.2.16.216/30	10.2.16.217 – 10.2.16.218	10.2.16.219
56	10.2.16.220/30	10.2.16.221 – 10.2.16.222	10.2.16.223
57	10.2.16.224/30	10.2.16.225 – 10.2.16.226	10.2.16.227
58	10.2.16.228/30	10.2.16.229 – 10.2.16.230	10.2.16.231
59	10.2.16.232/30	10.2.16.233 – 10.2.16.234	10.2.16.235
60	10.2.16.236/30	10.2.16.237 – 10.2.16.238	10.2.16.239
61	10.2.16.240/30	10.2.16.241 – 10.2.16.242	10.2.16.243
62	10.2.16.244/30	10.2.16.245 – 10.2.16.246	10.2.16.247
63	10.2.16.248/30	10.2.16.249 – 10.2.16.250	10.2.16.251
64	10.2.16.252/30	10.2.16.253 – 10.2.16.254	10.2.16.255
65	10.2.17.0/30	10.2.17.1 – 10.2.17.2	10.2.17.3
66	10.2.17.4/30	10.2.17.5 – 10.2.17.6	10.2.17.7
67	10.2.17.8/30	10.2.17.9 – 10.2.17.10	10.2.17.11
68	10.2.17.12/30	10.2.17.13 – 10.2.17.14	10.2.17.15
69	10.2.17.16/30	10.2.17.17 – 10.2.17.18	10.2.17.19
70	10.2.17.20/30	10.2.17.21 – 10.2.17.22	10.2.17.23
71	10.2.17.24/30	10.2.17.25 – 10.2.17.26	10.2.17.27
72	10.2.17.28/30	10.2.17.29 – 10.2.17.30	10.2.17.31
73	10.2.17.32/30	10.2.17.33 – 10.2.17.34	10.2.17.35
74	10.2.17.36/30	10.2.17.37 – 10.2.17.38	10.2.17.39
75	10.2.17.40/30	10.2.17.41 – 10.2.17.42	10.2.17.43
76	10.2.17.44/30	10.2.17.45 – 10.2.17.46	10.2.17.47
77	10.2.17.48/30	10.2.17.49 – 10.2.17.50	10.2.17.51
78	10.2.17.52/30	10.2.17.53 – 10.2.17.54	10.2.17.55
79	10.2.17.56/30	10.2.17.57 – 10.2.17.58	10.2.17.59
80	10.2.17.60/30	10.2.17.61 – 10.2.17.62	10.2.17.63
81	10.2.17.64/30	10.2.17.65 – 10.2.17.66	10.2.17.67
82	10.2.17.68/30	10.2.17.69 – 10.2.17.70	10.2.17.71
83	10.2.17.72/30	10.2.17.73 – 10.2.17.74	10.2.17.75
84	10.2.17.76/30	10.2.17.77 – 10.2.17.78	10.2.17.79
85	10.2.17.80/30	10.2.17.81 – 10.2.17.82	10.2.17.83
86	10.2.17.84/30	10.2.17.85 – 10.2.17.86	10.2.17.87
87	10.2.17.88/30	10.2.17.89 – 10.2.17.90	10.2.17.91
88	10.2.17.92/30	10.2.17.93 – 10.2.17.94	10.2.17.95
89	10.2.17.96/30	10.2.17.97 – 10.2.17.98	10.2.17.99
90	10.2.17.100/30	10.2.17.101 – 10.2.17.102	10.2.17.103
91	10.2.17.104/30	10.2.17.105 – 10.2.17.106	10.2.17.107
92	10.2.17.108/30	10.2.17.109 – 10.2.17.110	10.2.17.111
93	10.2.17.112/30	10.2.17.113 – 10.2.17.114	10.2.17.115
94	10.2.17.116/30	10.2.17.117 – 10.2.17.118	10.2.17.119
95	10.2.17.120/30	10.2.17.121 – 10.2.17.122	10.2.17.123
96	10.2.17.124/30	10.2.17.125 – 10.2.17.126	10.2.17.127
97	10.2.17.128/30	10.2.17.129 – 10.2.17.130	10.2.17.131
98	10.2.17.132/30	10.2.17.133 – 10.2.17.134	10.2.17.135
99	10.2.17.136/30	10.2.17.137 – 10.2.17.138	10.2.17.139
100	10.2.17.140/30	10.2.17.141 – 10.2.17.142	10.2.17.143
101	10.2.17.144/30	10.2.17.145 – 10.2.17.146	10.2.17.147
102	10.2.17.148/30	10.2.17.149 – 10.2.17.150	10.2.17.151
103	10.2.17.152/30	10.2.17.153 – 10.2.17.154	10.2.17.155
104	10.2.17.156/30	10.2.17.157 – 10.2.17.158	10.2.17.159
105	10.2.17.160/30	10.2.17.161 – 10.2.17.162	10.2.17.163
106	10.2.17.164/30	10.2.17.165 – 10.2.17.166	10.2.17.167
107	10.2.17.168/30	10.2.17.169 – 10.2.17.170	10.2.17.171
108	10.2.17.172/30	10.2.17.173 – 10.2.17.174	10.2.17.175
109	10.2.17.176/30	10.2.17.177 – 10.2.17.178	10.2.17.179
110	10.2.17.180/30	10.2.17.181 – 10.2.17.182	10.2.17.183
111	10.2.17.184/30	10.2.17.185 – 10.2.17.186	10.2.17.187
112	10.2.17.188/30	10.2.17.189 – 10.2.17.190	10.2.17.191
113	10.2.17.192/30	10.2.17.193 – 10.2.17.194	10.2.17.195
114	10.2.17.196/30	10.2.17.197 – 10.2.17.198	10.2.17.199
115	10.2.17.200/30	10.2.17.201 – 10.2.17.202	10.2.17.203
116	10.2.17.204/30	10.2.17.205 – 10.2.17.206	10.2.17.207
117	10.2.17.208/30	10.2.17.209 – 10.2.17.210	10.2.17.211
118	10.2.17.212/30	10.2.17.213 – 10.2.17.214	10.2.17.215
119	10.2.17.216/30	10.2.17.217 – 10.2.17.218	10.2.17.219
120	10.2.17.220/30	10.2.17.221 – 10.2.17.222	10.2.17.223
121	10.2.17.224/30	10.2.17.225 – 10.2.17.226	10.2.17.227
122	10.2.17.228/30	10.2.17.229 – 10.2.17.230	10.2.17.231
123	10.2.17.232/30	10.2.17.233 – 10.2.17.234	10.2.17.235
124	10.2.17.236/30	10.2.17.237 – 10.2.17.238	10.2.17.239
125	10.2.17.240/30	10.2.17.241 – 10.2.17.242	10.2.17.243
126	10.2.17.244/30	10.2.17.245 – 10.2.17.246	10.2.17.247
127	10.2.17.248/30	10.2.17.249 – 10.2.17.250	10.2.17.251
128	10.2.17.252/30	10.2.17.253 – 10.2.17.254	10.2.17.255

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 →