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)10.3.248.0/23

network10.3.248.0/23

broadcast10.3.249.255

first host10.3.248.1

last host10.3.249.254

subnet mask255.255.254.0

wildcard0.0.1.255

addresses512

usable hosts510

classA

ipcalc 10.3.248.0/23

address00001010.00000011.11111000.00000000

subnet mask11111111.11111111.11111110.00000000

network00001010.00000011.11111000.00000000

broadcast00001010.00000011.11111001.11111111

green = network part, grey = host part

hex0x0a03f800

decimal168032256

reverse dns0.248.3.10.in-addr.arpa

ipv4-mapped::ffff:a03:f800

/23 split into /30 · 128 subnets

close ×

#	network	host range	broadcast
1	10.3.248.0/30	10.3.248.1 – 10.3.248.2	10.3.248.3
2	10.3.248.4/30	10.3.248.5 – 10.3.248.6	10.3.248.7
3	10.3.248.8/30	10.3.248.9 – 10.3.248.10	10.3.248.11
4	10.3.248.12/30	10.3.248.13 – 10.3.248.14	10.3.248.15
5	10.3.248.16/30	10.3.248.17 – 10.3.248.18	10.3.248.19
6	10.3.248.20/30	10.3.248.21 – 10.3.248.22	10.3.248.23
7	10.3.248.24/30	10.3.248.25 – 10.3.248.26	10.3.248.27
8	10.3.248.28/30	10.3.248.29 – 10.3.248.30	10.3.248.31
9	10.3.248.32/30	10.3.248.33 – 10.3.248.34	10.3.248.35
10	10.3.248.36/30	10.3.248.37 – 10.3.248.38	10.3.248.39
11	10.3.248.40/30	10.3.248.41 – 10.3.248.42	10.3.248.43
12	10.3.248.44/30	10.3.248.45 – 10.3.248.46	10.3.248.47
13	10.3.248.48/30	10.3.248.49 – 10.3.248.50	10.3.248.51
14	10.3.248.52/30	10.3.248.53 – 10.3.248.54	10.3.248.55
15	10.3.248.56/30	10.3.248.57 – 10.3.248.58	10.3.248.59
16	10.3.248.60/30	10.3.248.61 – 10.3.248.62	10.3.248.63
17	10.3.248.64/30	10.3.248.65 – 10.3.248.66	10.3.248.67
18	10.3.248.68/30	10.3.248.69 – 10.3.248.70	10.3.248.71
19	10.3.248.72/30	10.3.248.73 – 10.3.248.74	10.3.248.75
20	10.3.248.76/30	10.3.248.77 – 10.3.248.78	10.3.248.79
21	10.3.248.80/30	10.3.248.81 – 10.3.248.82	10.3.248.83
22	10.3.248.84/30	10.3.248.85 – 10.3.248.86	10.3.248.87
23	10.3.248.88/30	10.3.248.89 – 10.3.248.90	10.3.248.91
24	10.3.248.92/30	10.3.248.93 – 10.3.248.94	10.3.248.95
25	10.3.248.96/30	10.3.248.97 – 10.3.248.98	10.3.248.99
26	10.3.248.100/30	10.3.248.101 – 10.3.248.102	10.3.248.103
27	10.3.248.104/30	10.3.248.105 – 10.3.248.106	10.3.248.107
28	10.3.248.108/30	10.3.248.109 – 10.3.248.110	10.3.248.111
29	10.3.248.112/30	10.3.248.113 – 10.3.248.114	10.3.248.115
30	10.3.248.116/30	10.3.248.117 – 10.3.248.118	10.3.248.119
31	10.3.248.120/30	10.3.248.121 – 10.3.248.122	10.3.248.123
32	10.3.248.124/30	10.3.248.125 – 10.3.248.126	10.3.248.127
33	10.3.248.128/30	10.3.248.129 – 10.3.248.130	10.3.248.131
34	10.3.248.132/30	10.3.248.133 – 10.3.248.134	10.3.248.135
35	10.3.248.136/30	10.3.248.137 – 10.3.248.138	10.3.248.139
36	10.3.248.140/30	10.3.248.141 – 10.3.248.142	10.3.248.143
37	10.3.248.144/30	10.3.248.145 – 10.3.248.146	10.3.248.147
38	10.3.248.148/30	10.3.248.149 – 10.3.248.150	10.3.248.151
39	10.3.248.152/30	10.3.248.153 – 10.3.248.154	10.3.248.155
40	10.3.248.156/30	10.3.248.157 – 10.3.248.158	10.3.248.159
41	10.3.248.160/30	10.3.248.161 – 10.3.248.162	10.3.248.163
42	10.3.248.164/30	10.3.248.165 – 10.3.248.166	10.3.248.167
43	10.3.248.168/30	10.3.248.169 – 10.3.248.170	10.3.248.171
44	10.3.248.172/30	10.3.248.173 – 10.3.248.174	10.3.248.175
45	10.3.248.176/30	10.3.248.177 – 10.3.248.178	10.3.248.179
46	10.3.248.180/30	10.3.248.181 – 10.3.248.182	10.3.248.183
47	10.3.248.184/30	10.3.248.185 – 10.3.248.186	10.3.248.187
48	10.3.248.188/30	10.3.248.189 – 10.3.248.190	10.3.248.191
49	10.3.248.192/30	10.3.248.193 – 10.3.248.194	10.3.248.195
50	10.3.248.196/30	10.3.248.197 – 10.3.248.198	10.3.248.199
51	10.3.248.200/30	10.3.248.201 – 10.3.248.202	10.3.248.203
52	10.3.248.204/30	10.3.248.205 – 10.3.248.206	10.3.248.207
53	10.3.248.208/30	10.3.248.209 – 10.3.248.210	10.3.248.211
54	10.3.248.212/30	10.3.248.213 – 10.3.248.214	10.3.248.215
55	10.3.248.216/30	10.3.248.217 – 10.3.248.218	10.3.248.219
56	10.3.248.220/30	10.3.248.221 – 10.3.248.222	10.3.248.223
57	10.3.248.224/30	10.3.248.225 – 10.3.248.226	10.3.248.227
58	10.3.248.228/30	10.3.248.229 – 10.3.248.230	10.3.248.231
59	10.3.248.232/30	10.3.248.233 – 10.3.248.234	10.3.248.235
60	10.3.248.236/30	10.3.248.237 – 10.3.248.238	10.3.248.239
61	10.3.248.240/30	10.3.248.241 – 10.3.248.242	10.3.248.243
62	10.3.248.244/30	10.3.248.245 – 10.3.248.246	10.3.248.247
63	10.3.248.248/30	10.3.248.249 – 10.3.248.250	10.3.248.251
64	10.3.248.252/30	10.3.248.253 – 10.3.248.254	10.3.248.255
65	10.3.249.0/30	10.3.249.1 – 10.3.249.2	10.3.249.3
66	10.3.249.4/30	10.3.249.5 – 10.3.249.6	10.3.249.7
67	10.3.249.8/30	10.3.249.9 – 10.3.249.10	10.3.249.11
68	10.3.249.12/30	10.3.249.13 – 10.3.249.14	10.3.249.15
69	10.3.249.16/30	10.3.249.17 – 10.3.249.18	10.3.249.19
70	10.3.249.20/30	10.3.249.21 – 10.3.249.22	10.3.249.23
71	10.3.249.24/30	10.3.249.25 – 10.3.249.26	10.3.249.27
72	10.3.249.28/30	10.3.249.29 – 10.3.249.30	10.3.249.31
73	10.3.249.32/30	10.3.249.33 – 10.3.249.34	10.3.249.35
74	10.3.249.36/30	10.3.249.37 – 10.3.249.38	10.3.249.39
75	10.3.249.40/30	10.3.249.41 – 10.3.249.42	10.3.249.43
76	10.3.249.44/30	10.3.249.45 – 10.3.249.46	10.3.249.47
77	10.3.249.48/30	10.3.249.49 – 10.3.249.50	10.3.249.51
78	10.3.249.52/30	10.3.249.53 – 10.3.249.54	10.3.249.55
79	10.3.249.56/30	10.3.249.57 – 10.3.249.58	10.3.249.59
80	10.3.249.60/30	10.3.249.61 – 10.3.249.62	10.3.249.63
81	10.3.249.64/30	10.3.249.65 – 10.3.249.66	10.3.249.67
82	10.3.249.68/30	10.3.249.69 – 10.3.249.70	10.3.249.71
83	10.3.249.72/30	10.3.249.73 – 10.3.249.74	10.3.249.75
84	10.3.249.76/30	10.3.249.77 – 10.3.249.78	10.3.249.79
85	10.3.249.80/30	10.3.249.81 – 10.3.249.82	10.3.249.83
86	10.3.249.84/30	10.3.249.85 – 10.3.249.86	10.3.249.87
87	10.3.249.88/30	10.3.249.89 – 10.3.249.90	10.3.249.91
88	10.3.249.92/30	10.3.249.93 – 10.3.249.94	10.3.249.95
89	10.3.249.96/30	10.3.249.97 – 10.3.249.98	10.3.249.99
90	10.3.249.100/30	10.3.249.101 – 10.3.249.102	10.3.249.103
91	10.3.249.104/30	10.3.249.105 – 10.3.249.106	10.3.249.107
92	10.3.249.108/30	10.3.249.109 – 10.3.249.110	10.3.249.111
93	10.3.249.112/30	10.3.249.113 – 10.3.249.114	10.3.249.115
94	10.3.249.116/30	10.3.249.117 – 10.3.249.118	10.3.249.119
95	10.3.249.120/30	10.3.249.121 – 10.3.249.122	10.3.249.123
96	10.3.249.124/30	10.3.249.125 – 10.3.249.126	10.3.249.127
97	10.3.249.128/30	10.3.249.129 – 10.3.249.130	10.3.249.131
98	10.3.249.132/30	10.3.249.133 – 10.3.249.134	10.3.249.135
99	10.3.249.136/30	10.3.249.137 – 10.3.249.138	10.3.249.139
100	10.3.249.140/30	10.3.249.141 – 10.3.249.142	10.3.249.143
101	10.3.249.144/30	10.3.249.145 – 10.3.249.146	10.3.249.147
102	10.3.249.148/30	10.3.249.149 – 10.3.249.150	10.3.249.151
103	10.3.249.152/30	10.3.249.153 – 10.3.249.154	10.3.249.155
104	10.3.249.156/30	10.3.249.157 – 10.3.249.158	10.3.249.159
105	10.3.249.160/30	10.3.249.161 – 10.3.249.162	10.3.249.163
106	10.3.249.164/30	10.3.249.165 – 10.3.249.166	10.3.249.167
107	10.3.249.168/30	10.3.249.169 – 10.3.249.170	10.3.249.171
108	10.3.249.172/30	10.3.249.173 – 10.3.249.174	10.3.249.175
109	10.3.249.176/30	10.3.249.177 – 10.3.249.178	10.3.249.179
110	10.3.249.180/30	10.3.249.181 – 10.3.249.182	10.3.249.183
111	10.3.249.184/30	10.3.249.185 – 10.3.249.186	10.3.249.187
112	10.3.249.188/30	10.3.249.189 – 10.3.249.190	10.3.249.191
113	10.3.249.192/30	10.3.249.193 – 10.3.249.194	10.3.249.195
114	10.3.249.196/30	10.3.249.197 – 10.3.249.198	10.3.249.199
115	10.3.249.200/30	10.3.249.201 – 10.3.249.202	10.3.249.203
116	10.3.249.204/30	10.3.249.205 – 10.3.249.206	10.3.249.207
117	10.3.249.208/30	10.3.249.209 – 10.3.249.210	10.3.249.211
118	10.3.249.212/30	10.3.249.213 – 10.3.249.214	10.3.249.215
119	10.3.249.216/30	10.3.249.217 – 10.3.249.218	10.3.249.219
120	10.3.249.220/30	10.3.249.221 – 10.3.249.222	10.3.249.223
121	10.3.249.224/30	10.3.249.225 – 10.3.249.226	10.3.249.227
122	10.3.249.228/30	10.3.249.229 – 10.3.249.230	10.3.249.231
123	10.3.249.232/30	10.3.249.233 – 10.3.249.234	10.3.249.235
124	10.3.249.236/30	10.3.249.237 – 10.3.249.238	10.3.249.239
125	10.3.249.240/30	10.3.249.241 – 10.3.249.242	10.3.249.243
126	10.3.249.244/30	10.3.249.245 – 10.3.249.246	10.3.249.247
127	10.3.249.248/30	10.3.249.249 – 10.3.249.250	10.3.249.251
128	10.3.249.252/30	10.3.249.253 – 10.3.249.254	10.3.249.255

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 →