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)10.3.20.0/23

network10.3.20.0/23

broadcast10.3.21.255

first host10.3.20.1

last host10.3.21.254

subnet mask255.255.254.0

wildcard0.0.1.255

addresses512

usable hosts510

classA

ipcalc 10.3.20.0/23

address00001010.00000011.00010100.00000000

subnet mask11111111.11111111.11111110.00000000

network00001010.00000011.00010100.00000000

broadcast00001010.00000011.00010101.11111111

green = network part, grey = host part

hex0x0a031400

decimal167973888

reverse dns0.20.3.10.in-addr.arpa

ipv4-mapped::ffff:a03:1400

/23 split into /30 · 128 subnets

close ×

#	network	host range	broadcast
1	10.3.20.0/30	10.3.20.1 – 10.3.20.2	10.3.20.3
2	10.3.20.4/30	10.3.20.5 – 10.3.20.6	10.3.20.7
3	10.3.20.8/30	10.3.20.9 – 10.3.20.10	10.3.20.11
4	10.3.20.12/30	10.3.20.13 – 10.3.20.14	10.3.20.15
5	10.3.20.16/30	10.3.20.17 – 10.3.20.18	10.3.20.19
6	10.3.20.20/30	10.3.20.21 – 10.3.20.22	10.3.20.23
7	10.3.20.24/30	10.3.20.25 – 10.3.20.26	10.3.20.27
8	10.3.20.28/30	10.3.20.29 – 10.3.20.30	10.3.20.31
9	10.3.20.32/30	10.3.20.33 – 10.3.20.34	10.3.20.35
10	10.3.20.36/30	10.3.20.37 – 10.3.20.38	10.3.20.39
11	10.3.20.40/30	10.3.20.41 – 10.3.20.42	10.3.20.43
12	10.3.20.44/30	10.3.20.45 – 10.3.20.46	10.3.20.47
13	10.3.20.48/30	10.3.20.49 – 10.3.20.50	10.3.20.51
14	10.3.20.52/30	10.3.20.53 – 10.3.20.54	10.3.20.55
15	10.3.20.56/30	10.3.20.57 – 10.3.20.58	10.3.20.59
16	10.3.20.60/30	10.3.20.61 – 10.3.20.62	10.3.20.63
17	10.3.20.64/30	10.3.20.65 – 10.3.20.66	10.3.20.67
18	10.3.20.68/30	10.3.20.69 – 10.3.20.70	10.3.20.71
19	10.3.20.72/30	10.3.20.73 – 10.3.20.74	10.3.20.75
20	10.3.20.76/30	10.3.20.77 – 10.3.20.78	10.3.20.79
21	10.3.20.80/30	10.3.20.81 – 10.3.20.82	10.3.20.83
22	10.3.20.84/30	10.3.20.85 – 10.3.20.86	10.3.20.87
23	10.3.20.88/30	10.3.20.89 – 10.3.20.90	10.3.20.91
24	10.3.20.92/30	10.3.20.93 – 10.3.20.94	10.3.20.95
25	10.3.20.96/30	10.3.20.97 – 10.3.20.98	10.3.20.99
26	10.3.20.100/30	10.3.20.101 – 10.3.20.102	10.3.20.103
27	10.3.20.104/30	10.3.20.105 – 10.3.20.106	10.3.20.107
28	10.3.20.108/30	10.3.20.109 – 10.3.20.110	10.3.20.111
29	10.3.20.112/30	10.3.20.113 – 10.3.20.114	10.3.20.115
30	10.3.20.116/30	10.3.20.117 – 10.3.20.118	10.3.20.119
31	10.3.20.120/30	10.3.20.121 – 10.3.20.122	10.3.20.123
32	10.3.20.124/30	10.3.20.125 – 10.3.20.126	10.3.20.127
33	10.3.20.128/30	10.3.20.129 – 10.3.20.130	10.3.20.131
34	10.3.20.132/30	10.3.20.133 – 10.3.20.134	10.3.20.135
35	10.3.20.136/30	10.3.20.137 – 10.3.20.138	10.3.20.139
36	10.3.20.140/30	10.3.20.141 – 10.3.20.142	10.3.20.143
37	10.3.20.144/30	10.3.20.145 – 10.3.20.146	10.3.20.147
38	10.3.20.148/30	10.3.20.149 – 10.3.20.150	10.3.20.151
39	10.3.20.152/30	10.3.20.153 – 10.3.20.154	10.3.20.155
40	10.3.20.156/30	10.3.20.157 – 10.3.20.158	10.3.20.159
41	10.3.20.160/30	10.3.20.161 – 10.3.20.162	10.3.20.163
42	10.3.20.164/30	10.3.20.165 – 10.3.20.166	10.3.20.167
43	10.3.20.168/30	10.3.20.169 – 10.3.20.170	10.3.20.171
44	10.3.20.172/30	10.3.20.173 – 10.3.20.174	10.3.20.175
45	10.3.20.176/30	10.3.20.177 – 10.3.20.178	10.3.20.179
46	10.3.20.180/30	10.3.20.181 – 10.3.20.182	10.3.20.183
47	10.3.20.184/30	10.3.20.185 – 10.3.20.186	10.3.20.187
48	10.3.20.188/30	10.3.20.189 – 10.3.20.190	10.3.20.191
49	10.3.20.192/30	10.3.20.193 – 10.3.20.194	10.3.20.195
50	10.3.20.196/30	10.3.20.197 – 10.3.20.198	10.3.20.199
51	10.3.20.200/30	10.3.20.201 – 10.3.20.202	10.3.20.203
52	10.3.20.204/30	10.3.20.205 – 10.3.20.206	10.3.20.207
53	10.3.20.208/30	10.3.20.209 – 10.3.20.210	10.3.20.211
54	10.3.20.212/30	10.3.20.213 – 10.3.20.214	10.3.20.215
55	10.3.20.216/30	10.3.20.217 – 10.3.20.218	10.3.20.219
56	10.3.20.220/30	10.3.20.221 – 10.3.20.222	10.3.20.223
57	10.3.20.224/30	10.3.20.225 – 10.3.20.226	10.3.20.227
58	10.3.20.228/30	10.3.20.229 – 10.3.20.230	10.3.20.231
59	10.3.20.232/30	10.3.20.233 – 10.3.20.234	10.3.20.235
60	10.3.20.236/30	10.3.20.237 – 10.3.20.238	10.3.20.239
61	10.3.20.240/30	10.3.20.241 – 10.3.20.242	10.3.20.243
62	10.3.20.244/30	10.3.20.245 – 10.3.20.246	10.3.20.247
63	10.3.20.248/30	10.3.20.249 – 10.3.20.250	10.3.20.251
64	10.3.20.252/30	10.3.20.253 – 10.3.20.254	10.3.20.255
65	10.3.21.0/30	10.3.21.1 – 10.3.21.2	10.3.21.3
66	10.3.21.4/30	10.3.21.5 – 10.3.21.6	10.3.21.7
67	10.3.21.8/30	10.3.21.9 – 10.3.21.10	10.3.21.11
68	10.3.21.12/30	10.3.21.13 – 10.3.21.14	10.3.21.15
69	10.3.21.16/30	10.3.21.17 – 10.3.21.18	10.3.21.19
70	10.3.21.20/30	10.3.21.21 – 10.3.21.22	10.3.21.23
71	10.3.21.24/30	10.3.21.25 – 10.3.21.26	10.3.21.27
72	10.3.21.28/30	10.3.21.29 – 10.3.21.30	10.3.21.31
73	10.3.21.32/30	10.3.21.33 – 10.3.21.34	10.3.21.35
74	10.3.21.36/30	10.3.21.37 – 10.3.21.38	10.3.21.39
75	10.3.21.40/30	10.3.21.41 – 10.3.21.42	10.3.21.43
76	10.3.21.44/30	10.3.21.45 – 10.3.21.46	10.3.21.47
77	10.3.21.48/30	10.3.21.49 – 10.3.21.50	10.3.21.51
78	10.3.21.52/30	10.3.21.53 – 10.3.21.54	10.3.21.55
79	10.3.21.56/30	10.3.21.57 – 10.3.21.58	10.3.21.59
80	10.3.21.60/30	10.3.21.61 – 10.3.21.62	10.3.21.63
81	10.3.21.64/30	10.3.21.65 – 10.3.21.66	10.3.21.67
82	10.3.21.68/30	10.3.21.69 – 10.3.21.70	10.3.21.71
83	10.3.21.72/30	10.3.21.73 – 10.3.21.74	10.3.21.75
84	10.3.21.76/30	10.3.21.77 – 10.3.21.78	10.3.21.79
85	10.3.21.80/30	10.3.21.81 – 10.3.21.82	10.3.21.83
86	10.3.21.84/30	10.3.21.85 – 10.3.21.86	10.3.21.87
87	10.3.21.88/30	10.3.21.89 – 10.3.21.90	10.3.21.91
88	10.3.21.92/30	10.3.21.93 – 10.3.21.94	10.3.21.95
89	10.3.21.96/30	10.3.21.97 – 10.3.21.98	10.3.21.99
90	10.3.21.100/30	10.3.21.101 – 10.3.21.102	10.3.21.103
91	10.3.21.104/30	10.3.21.105 – 10.3.21.106	10.3.21.107
92	10.3.21.108/30	10.3.21.109 – 10.3.21.110	10.3.21.111
93	10.3.21.112/30	10.3.21.113 – 10.3.21.114	10.3.21.115
94	10.3.21.116/30	10.3.21.117 – 10.3.21.118	10.3.21.119
95	10.3.21.120/30	10.3.21.121 – 10.3.21.122	10.3.21.123
96	10.3.21.124/30	10.3.21.125 – 10.3.21.126	10.3.21.127
97	10.3.21.128/30	10.3.21.129 – 10.3.21.130	10.3.21.131
98	10.3.21.132/30	10.3.21.133 – 10.3.21.134	10.3.21.135
99	10.3.21.136/30	10.3.21.137 – 10.3.21.138	10.3.21.139
100	10.3.21.140/30	10.3.21.141 – 10.3.21.142	10.3.21.143
101	10.3.21.144/30	10.3.21.145 – 10.3.21.146	10.3.21.147
102	10.3.21.148/30	10.3.21.149 – 10.3.21.150	10.3.21.151
103	10.3.21.152/30	10.3.21.153 – 10.3.21.154	10.3.21.155
104	10.3.21.156/30	10.3.21.157 – 10.3.21.158	10.3.21.159
105	10.3.21.160/30	10.3.21.161 – 10.3.21.162	10.3.21.163
106	10.3.21.164/30	10.3.21.165 – 10.3.21.166	10.3.21.167
107	10.3.21.168/30	10.3.21.169 – 10.3.21.170	10.3.21.171
108	10.3.21.172/30	10.3.21.173 – 10.3.21.174	10.3.21.175
109	10.3.21.176/30	10.3.21.177 – 10.3.21.178	10.3.21.179
110	10.3.21.180/30	10.3.21.181 – 10.3.21.182	10.3.21.183
111	10.3.21.184/30	10.3.21.185 – 10.3.21.186	10.3.21.187
112	10.3.21.188/30	10.3.21.189 – 10.3.21.190	10.3.21.191
113	10.3.21.192/30	10.3.21.193 – 10.3.21.194	10.3.21.195
114	10.3.21.196/30	10.3.21.197 – 10.3.21.198	10.3.21.199
115	10.3.21.200/30	10.3.21.201 – 10.3.21.202	10.3.21.203
116	10.3.21.204/30	10.3.21.205 – 10.3.21.206	10.3.21.207
117	10.3.21.208/30	10.3.21.209 – 10.3.21.210	10.3.21.211
118	10.3.21.212/30	10.3.21.213 – 10.3.21.214	10.3.21.215
119	10.3.21.216/30	10.3.21.217 – 10.3.21.218	10.3.21.219
120	10.3.21.220/30	10.3.21.221 – 10.3.21.222	10.3.21.223
121	10.3.21.224/30	10.3.21.225 – 10.3.21.226	10.3.21.227
122	10.3.21.228/30	10.3.21.229 – 10.3.21.230	10.3.21.231
123	10.3.21.232/30	10.3.21.233 – 10.3.21.234	10.3.21.235
124	10.3.21.236/30	10.3.21.237 – 10.3.21.238	10.3.21.239
125	10.3.21.240/30	10.3.21.241 – 10.3.21.242	10.3.21.243
126	10.3.21.244/30	10.3.21.245 – 10.3.21.246	10.3.21.247
127	10.3.21.248/30	10.3.21.249 – 10.3.21.250	10.3.21.251
128	10.3.21.252/30	10.3.21.253 – 10.3.21.254	10.3.21.255

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 →