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)10.167.81.0/24

network10.167.81.0/24

broadcast10.167.81.255

first host10.167.81.1

last host10.167.81.254

subnet mask255.255.255.0

wildcard0.0.0.255

addresses256

usable hosts254

classA

ipcalc 10.167.81.0/24

address00001010.10100111.01010001.00000000

subnet mask11111111.11111111.11111111.00000000

network00001010.10100111.01010001.00000000

broadcast00001010.10100111.01010001.11111111

green = network part, grey = host part

hex0x0aa75100

decimal178737408

reverse dns0.81.167.10.in-addr.arpa

ipv4-mapped::ffff:aa7:5100

/24 split into /30 · 64 subnets

close ×

#	network	host range	broadcast
1	10.167.81.0/30	10.167.81.1 – 10.167.81.2	10.167.81.3
2	10.167.81.4/30	10.167.81.5 – 10.167.81.6	10.167.81.7
3	10.167.81.8/30	10.167.81.9 – 10.167.81.10	10.167.81.11
4	10.167.81.12/30	10.167.81.13 – 10.167.81.14	10.167.81.15
5	10.167.81.16/30	10.167.81.17 – 10.167.81.18	10.167.81.19
6	10.167.81.20/30	10.167.81.21 – 10.167.81.22	10.167.81.23
7	10.167.81.24/30	10.167.81.25 – 10.167.81.26	10.167.81.27
8	10.167.81.28/30	10.167.81.29 – 10.167.81.30	10.167.81.31
9	10.167.81.32/30	10.167.81.33 – 10.167.81.34	10.167.81.35
10	10.167.81.36/30	10.167.81.37 – 10.167.81.38	10.167.81.39
11	10.167.81.40/30	10.167.81.41 – 10.167.81.42	10.167.81.43
12	10.167.81.44/30	10.167.81.45 – 10.167.81.46	10.167.81.47
13	10.167.81.48/30	10.167.81.49 – 10.167.81.50	10.167.81.51
14	10.167.81.52/30	10.167.81.53 – 10.167.81.54	10.167.81.55
15	10.167.81.56/30	10.167.81.57 – 10.167.81.58	10.167.81.59
16	10.167.81.60/30	10.167.81.61 – 10.167.81.62	10.167.81.63
17	10.167.81.64/30	10.167.81.65 – 10.167.81.66	10.167.81.67
18	10.167.81.68/30	10.167.81.69 – 10.167.81.70	10.167.81.71
19	10.167.81.72/30	10.167.81.73 – 10.167.81.74	10.167.81.75
20	10.167.81.76/30	10.167.81.77 – 10.167.81.78	10.167.81.79
21	10.167.81.80/30	10.167.81.81 – 10.167.81.82	10.167.81.83
22	10.167.81.84/30	10.167.81.85 – 10.167.81.86	10.167.81.87
23	10.167.81.88/30	10.167.81.89 – 10.167.81.90	10.167.81.91
24	10.167.81.92/30	10.167.81.93 – 10.167.81.94	10.167.81.95
25	10.167.81.96/30	10.167.81.97 – 10.167.81.98	10.167.81.99
26	10.167.81.100/30	10.167.81.101 – 10.167.81.102	10.167.81.103
27	10.167.81.104/30	10.167.81.105 – 10.167.81.106	10.167.81.107
28	10.167.81.108/30	10.167.81.109 – 10.167.81.110	10.167.81.111
29	10.167.81.112/30	10.167.81.113 – 10.167.81.114	10.167.81.115
30	10.167.81.116/30	10.167.81.117 – 10.167.81.118	10.167.81.119
31	10.167.81.120/30	10.167.81.121 – 10.167.81.122	10.167.81.123
32	10.167.81.124/30	10.167.81.125 – 10.167.81.126	10.167.81.127
33	10.167.81.128/30	10.167.81.129 – 10.167.81.130	10.167.81.131
34	10.167.81.132/30	10.167.81.133 – 10.167.81.134	10.167.81.135
35	10.167.81.136/30	10.167.81.137 – 10.167.81.138	10.167.81.139
36	10.167.81.140/30	10.167.81.141 – 10.167.81.142	10.167.81.143
37	10.167.81.144/30	10.167.81.145 – 10.167.81.146	10.167.81.147
38	10.167.81.148/30	10.167.81.149 – 10.167.81.150	10.167.81.151
39	10.167.81.152/30	10.167.81.153 – 10.167.81.154	10.167.81.155
40	10.167.81.156/30	10.167.81.157 – 10.167.81.158	10.167.81.159
41	10.167.81.160/30	10.167.81.161 – 10.167.81.162	10.167.81.163
42	10.167.81.164/30	10.167.81.165 – 10.167.81.166	10.167.81.167
43	10.167.81.168/30	10.167.81.169 – 10.167.81.170	10.167.81.171
44	10.167.81.172/30	10.167.81.173 – 10.167.81.174	10.167.81.175
45	10.167.81.176/30	10.167.81.177 – 10.167.81.178	10.167.81.179
46	10.167.81.180/30	10.167.81.181 – 10.167.81.182	10.167.81.183
47	10.167.81.184/30	10.167.81.185 – 10.167.81.186	10.167.81.187
48	10.167.81.188/30	10.167.81.189 – 10.167.81.190	10.167.81.191
49	10.167.81.192/30	10.167.81.193 – 10.167.81.194	10.167.81.195
50	10.167.81.196/30	10.167.81.197 – 10.167.81.198	10.167.81.199
51	10.167.81.200/30	10.167.81.201 – 10.167.81.202	10.167.81.203
52	10.167.81.204/30	10.167.81.205 – 10.167.81.206	10.167.81.207
53	10.167.81.208/30	10.167.81.209 – 10.167.81.210	10.167.81.211
54	10.167.81.212/30	10.167.81.213 – 10.167.81.214	10.167.81.215
55	10.167.81.216/30	10.167.81.217 – 10.167.81.218	10.167.81.219
56	10.167.81.220/30	10.167.81.221 – 10.167.81.222	10.167.81.223
57	10.167.81.224/30	10.167.81.225 – 10.167.81.226	10.167.81.227
58	10.167.81.228/30	10.167.81.229 – 10.167.81.230	10.167.81.231
59	10.167.81.232/30	10.167.81.233 – 10.167.81.234	10.167.81.235
60	10.167.81.236/30	10.167.81.237 – 10.167.81.238	10.167.81.239
61	10.167.81.240/30	10.167.81.241 – 10.167.81.242	10.167.81.243
62	10.167.81.244/30	10.167.81.245 – 10.167.81.246	10.167.81.247
63	10.167.81.248/30	10.167.81.249 – 10.167.81.250	10.167.81.251
64	10.167.81.252/30	10.167.81.253 – 10.167.81.254	10.167.81.255

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 /24
/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	-
/24	255.255.255.0	256	254	1
/25	255.255.255.128	128	126	2 split →
/26	255.255.255.192	64	62	4 split →
/27	255.255.255.224	32	30	8 split →
/28	255.255.255.240	16	14	16 split →
/29	255.255.255.248	8	6	32 split →
/30	255.255.255.252	4	2	64 split →
/31	255.255.255.254	2	2	128 split →
/32	255.255.255.255	1	1	256 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 →