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)10.3.240.0/23

network10.3.240.0/23

broadcast10.3.241.255

first host10.3.240.1

last host10.3.241.254

subnet mask255.255.254.0

wildcard0.0.1.255

addresses512

usable hosts510

classA

ipcalc 10.3.240.0/23

address00001010.00000011.11110000.00000000

subnet mask11111111.11111111.11111110.00000000

network00001010.00000011.11110000.00000000

broadcast00001010.00000011.11110001.11111111

green = network part, grey = host part

hex0x0a03f000

decimal168030208

reverse dns0.240.3.10.in-addr.arpa

ipv4-mapped::ffff:a03:f000

/23 split into /30 · 128 subnets

close ×

#	network	host range	broadcast
1	10.3.240.0/30	10.3.240.1 – 10.3.240.2	10.3.240.3
2	10.3.240.4/30	10.3.240.5 – 10.3.240.6	10.3.240.7
3	10.3.240.8/30	10.3.240.9 – 10.3.240.10	10.3.240.11
4	10.3.240.12/30	10.3.240.13 – 10.3.240.14	10.3.240.15
5	10.3.240.16/30	10.3.240.17 – 10.3.240.18	10.3.240.19
6	10.3.240.20/30	10.3.240.21 – 10.3.240.22	10.3.240.23
7	10.3.240.24/30	10.3.240.25 – 10.3.240.26	10.3.240.27
8	10.3.240.28/30	10.3.240.29 – 10.3.240.30	10.3.240.31
9	10.3.240.32/30	10.3.240.33 – 10.3.240.34	10.3.240.35
10	10.3.240.36/30	10.3.240.37 – 10.3.240.38	10.3.240.39
11	10.3.240.40/30	10.3.240.41 – 10.3.240.42	10.3.240.43
12	10.3.240.44/30	10.3.240.45 – 10.3.240.46	10.3.240.47
13	10.3.240.48/30	10.3.240.49 – 10.3.240.50	10.3.240.51
14	10.3.240.52/30	10.3.240.53 – 10.3.240.54	10.3.240.55
15	10.3.240.56/30	10.3.240.57 – 10.3.240.58	10.3.240.59
16	10.3.240.60/30	10.3.240.61 – 10.3.240.62	10.3.240.63
17	10.3.240.64/30	10.3.240.65 – 10.3.240.66	10.3.240.67
18	10.3.240.68/30	10.3.240.69 – 10.3.240.70	10.3.240.71
19	10.3.240.72/30	10.3.240.73 – 10.3.240.74	10.3.240.75
20	10.3.240.76/30	10.3.240.77 – 10.3.240.78	10.3.240.79
21	10.3.240.80/30	10.3.240.81 – 10.3.240.82	10.3.240.83
22	10.3.240.84/30	10.3.240.85 – 10.3.240.86	10.3.240.87
23	10.3.240.88/30	10.3.240.89 – 10.3.240.90	10.3.240.91
24	10.3.240.92/30	10.3.240.93 – 10.3.240.94	10.3.240.95
25	10.3.240.96/30	10.3.240.97 – 10.3.240.98	10.3.240.99
26	10.3.240.100/30	10.3.240.101 – 10.3.240.102	10.3.240.103
27	10.3.240.104/30	10.3.240.105 – 10.3.240.106	10.3.240.107
28	10.3.240.108/30	10.3.240.109 – 10.3.240.110	10.3.240.111
29	10.3.240.112/30	10.3.240.113 – 10.3.240.114	10.3.240.115
30	10.3.240.116/30	10.3.240.117 – 10.3.240.118	10.3.240.119
31	10.3.240.120/30	10.3.240.121 – 10.3.240.122	10.3.240.123
32	10.3.240.124/30	10.3.240.125 – 10.3.240.126	10.3.240.127
33	10.3.240.128/30	10.3.240.129 – 10.3.240.130	10.3.240.131
34	10.3.240.132/30	10.3.240.133 – 10.3.240.134	10.3.240.135
35	10.3.240.136/30	10.3.240.137 – 10.3.240.138	10.3.240.139
36	10.3.240.140/30	10.3.240.141 – 10.3.240.142	10.3.240.143
37	10.3.240.144/30	10.3.240.145 – 10.3.240.146	10.3.240.147
38	10.3.240.148/30	10.3.240.149 – 10.3.240.150	10.3.240.151
39	10.3.240.152/30	10.3.240.153 – 10.3.240.154	10.3.240.155
40	10.3.240.156/30	10.3.240.157 – 10.3.240.158	10.3.240.159
41	10.3.240.160/30	10.3.240.161 – 10.3.240.162	10.3.240.163
42	10.3.240.164/30	10.3.240.165 – 10.3.240.166	10.3.240.167
43	10.3.240.168/30	10.3.240.169 – 10.3.240.170	10.3.240.171
44	10.3.240.172/30	10.3.240.173 – 10.3.240.174	10.3.240.175
45	10.3.240.176/30	10.3.240.177 – 10.3.240.178	10.3.240.179
46	10.3.240.180/30	10.3.240.181 – 10.3.240.182	10.3.240.183
47	10.3.240.184/30	10.3.240.185 – 10.3.240.186	10.3.240.187
48	10.3.240.188/30	10.3.240.189 – 10.3.240.190	10.3.240.191
49	10.3.240.192/30	10.3.240.193 – 10.3.240.194	10.3.240.195
50	10.3.240.196/30	10.3.240.197 – 10.3.240.198	10.3.240.199
51	10.3.240.200/30	10.3.240.201 – 10.3.240.202	10.3.240.203
52	10.3.240.204/30	10.3.240.205 – 10.3.240.206	10.3.240.207
53	10.3.240.208/30	10.3.240.209 – 10.3.240.210	10.3.240.211
54	10.3.240.212/30	10.3.240.213 – 10.3.240.214	10.3.240.215
55	10.3.240.216/30	10.3.240.217 – 10.3.240.218	10.3.240.219
56	10.3.240.220/30	10.3.240.221 – 10.3.240.222	10.3.240.223
57	10.3.240.224/30	10.3.240.225 – 10.3.240.226	10.3.240.227
58	10.3.240.228/30	10.3.240.229 – 10.3.240.230	10.3.240.231
59	10.3.240.232/30	10.3.240.233 – 10.3.240.234	10.3.240.235
60	10.3.240.236/30	10.3.240.237 – 10.3.240.238	10.3.240.239
61	10.3.240.240/30	10.3.240.241 – 10.3.240.242	10.3.240.243
62	10.3.240.244/30	10.3.240.245 – 10.3.240.246	10.3.240.247
63	10.3.240.248/30	10.3.240.249 – 10.3.240.250	10.3.240.251
64	10.3.240.252/30	10.3.240.253 – 10.3.240.254	10.3.240.255
65	10.3.241.0/30	10.3.241.1 – 10.3.241.2	10.3.241.3
66	10.3.241.4/30	10.3.241.5 – 10.3.241.6	10.3.241.7
67	10.3.241.8/30	10.3.241.9 – 10.3.241.10	10.3.241.11
68	10.3.241.12/30	10.3.241.13 – 10.3.241.14	10.3.241.15
69	10.3.241.16/30	10.3.241.17 – 10.3.241.18	10.3.241.19
70	10.3.241.20/30	10.3.241.21 – 10.3.241.22	10.3.241.23
71	10.3.241.24/30	10.3.241.25 – 10.3.241.26	10.3.241.27
72	10.3.241.28/30	10.3.241.29 – 10.3.241.30	10.3.241.31
73	10.3.241.32/30	10.3.241.33 – 10.3.241.34	10.3.241.35
74	10.3.241.36/30	10.3.241.37 – 10.3.241.38	10.3.241.39
75	10.3.241.40/30	10.3.241.41 – 10.3.241.42	10.3.241.43
76	10.3.241.44/30	10.3.241.45 – 10.3.241.46	10.3.241.47
77	10.3.241.48/30	10.3.241.49 – 10.3.241.50	10.3.241.51
78	10.3.241.52/30	10.3.241.53 – 10.3.241.54	10.3.241.55
79	10.3.241.56/30	10.3.241.57 – 10.3.241.58	10.3.241.59
80	10.3.241.60/30	10.3.241.61 – 10.3.241.62	10.3.241.63
81	10.3.241.64/30	10.3.241.65 – 10.3.241.66	10.3.241.67
82	10.3.241.68/30	10.3.241.69 – 10.3.241.70	10.3.241.71
83	10.3.241.72/30	10.3.241.73 – 10.3.241.74	10.3.241.75
84	10.3.241.76/30	10.3.241.77 – 10.3.241.78	10.3.241.79
85	10.3.241.80/30	10.3.241.81 – 10.3.241.82	10.3.241.83
86	10.3.241.84/30	10.3.241.85 – 10.3.241.86	10.3.241.87
87	10.3.241.88/30	10.3.241.89 – 10.3.241.90	10.3.241.91
88	10.3.241.92/30	10.3.241.93 – 10.3.241.94	10.3.241.95
89	10.3.241.96/30	10.3.241.97 – 10.3.241.98	10.3.241.99
90	10.3.241.100/30	10.3.241.101 – 10.3.241.102	10.3.241.103
91	10.3.241.104/30	10.3.241.105 – 10.3.241.106	10.3.241.107
92	10.3.241.108/30	10.3.241.109 – 10.3.241.110	10.3.241.111
93	10.3.241.112/30	10.3.241.113 – 10.3.241.114	10.3.241.115
94	10.3.241.116/30	10.3.241.117 – 10.3.241.118	10.3.241.119
95	10.3.241.120/30	10.3.241.121 – 10.3.241.122	10.3.241.123
96	10.3.241.124/30	10.3.241.125 – 10.3.241.126	10.3.241.127
97	10.3.241.128/30	10.3.241.129 – 10.3.241.130	10.3.241.131
98	10.3.241.132/30	10.3.241.133 – 10.3.241.134	10.3.241.135
99	10.3.241.136/30	10.3.241.137 – 10.3.241.138	10.3.241.139
100	10.3.241.140/30	10.3.241.141 – 10.3.241.142	10.3.241.143
101	10.3.241.144/30	10.3.241.145 – 10.3.241.146	10.3.241.147
102	10.3.241.148/30	10.3.241.149 – 10.3.241.150	10.3.241.151
103	10.3.241.152/30	10.3.241.153 – 10.3.241.154	10.3.241.155
104	10.3.241.156/30	10.3.241.157 – 10.3.241.158	10.3.241.159
105	10.3.241.160/30	10.3.241.161 – 10.3.241.162	10.3.241.163
106	10.3.241.164/30	10.3.241.165 – 10.3.241.166	10.3.241.167
107	10.3.241.168/30	10.3.241.169 – 10.3.241.170	10.3.241.171
108	10.3.241.172/30	10.3.241.173 – 10.3.241.174	10.3.241.175
109	10.3.241.176/30	10.3.241.177 – 10.3.241.178	10.3.241.179
110	10.3.241.180/30	10.3.241.181 – 10.3.241.182	10.3.241.183
111	10.3.241.184/30	10.3.241.185 – 10.3.241.186	10.3.241.187
112	10.3.241.188/30	10.3.241.189 – 10.3.241.190	10.3.241.191
113	10.3.241.192/30	10.3.241.193 – 10.3.241.194	10.3.241.195
114	10.3.241.196/30	10.3.241.197 – 10.3.241.198	10.3.241.199
115	10.3.241.200/30	10.3.241.201 – 10.3.241.202	10.3.241.203
116	10.3.241.204/30	10.3.241.205 – 10.3.241.206	10.3.241.207
117	10.3.241.208/30	10.3.241.209 – 10.3.241.210	10.3.241.211
118	10.3.241.212/30	10.3.241.213 – 10.3.241.214	10.3.241.215
119	10.3.241.216/30	10.3.241.217 – 10.3.241.218	10.3.241.219
120	10.3.241.220/30	10.3.241.221 – 10.3.241.222	10.3.241.223
121	10.3.241.224/30	10.3.241.225 – 10.3.241.226	10.3.241.227
122	10.3.241.228/30	10.3.241.229 – 10.3.241.230	10.3.241.231
123	10.3.241.232/30	10.3.241.233 – 10.3.241.234	10.3.241.235
124	10.3.241.236/30	10.3.241.237 – 10.3.241.238	10.3.241.239
125	10.3.241.240/30	10.3.241.241 – 10.3.241.242	10.3.241.243
126	10.3.241.244/30	10.3.241.245 – 10.3.241.246	10.3.241.247
127	10.3.241.248/30	10.3.241.249 – 10.3.241.250	10.3.241.251
128	10.3.241.252/30	10.3.241.253 – 10.3.241.254	10.3.241.255

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 →