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)10.166.5.0/24

network10.166.5.0/24

broadcast10.166.5.255

first host10.166.5.1

last host10.166.5.254

subnet mask255.255.255.0

wildcard0.0.0.255

addresses256

usable hosts254

classA

ipcalc 10.166.5.0/24

address00001010.10100110.00000101.00000000

subnet mask11111111.11111111.11111111.00000000

network00001010.10100110.00000101.00000000

broadcast00001010.10100110.00000101.11111111

green = network part, grey = host part

hex0x0aa60500

decimal178652416

reverse dns0.5.166.10.in-addr.arpa

ipv4-mapped::ffff:aa6:500

/24 split into /30 · 64 subnets

close ×

#	network	host range	broadcast
1	10.166.5.0/30	10.166.5.1 – 10.166.5.2	10.166.5.3
2	10.166.5.4/30	10.166.5.5 – 10.166.5.6	10.166.5.7
3	10.166.5.8/30	10.166.5.9 – 10.166.5.10	10.166.5.11
4	10.166.5.12/30	10.166.5.13 – 10.166.5.14	10.166.5.15
5	10.166.5.16/30	10.166.5.17 – 10.166.5.18	10.166.5.19
6	10.166.5.20/30	10.166.5.21 – 10.166.5.22	10.166.5.23
7	10.166.5.24/30	10.166.5.25 – 10.166.5.26	10.166.5.27
8	10.166.5.28/30	10.166.5.29 – 10.166.5.30	10.166.5.31
9	10.166.5.32/30	10.166.5.33 – 10.166.5.34	10.166.5.35
10	10.166.5.36/30	10.166.5.37 – 10.166.5.38	10.166.5.39
11	10.166.5.40/30	10.166.5.41 – 10.166.5.42	10.166.5.43
12	10.166.5.44/30	10.166.5.45 – 10.166.5.46	10.166.5.47
13	10.166.5.48/30	10.166.5.49 – 10.166.5.50	10.166.5.51
14	10.166.5.52/30	10.166.5.53 – 10.166.5.54	10.166.5.55
15	10.166.5.56/30	10.166.5.57 – 10.166.5.58	10.166.5.59
16	10.166.5.60/30	10.166.5.61 – 10.166.5.62	10.166.5.63
17	10.166.5.64/30	10.166.5.65 – 10.166.5.66	10.166.5.67
18	10.166.5.68/30	10.166.5.69 – 10.166.5.70	10.166.5.71
19	10.166.5.72/30	10.166.5.73 – 10.166.5.74	10.166.5.75
20	10.166.5.76/30	10.166.5.77 – 10.166.5.78	10.166.5.79
21	10.166.5.80/30	10.166.5.81 – 10.166.5.82	10.166.5.83
22	10.166.5.84/30	10.166.5.85 – 10.166.5.86	10.166.5.87
23	10.166.5.88/30	10.166.5.89 – 10.166.5.90	10.166.5.91
24	10.166.5.92/30	10.166.5.93 – 10.166.5.94	10.166.5.95
25	10.166.5.96/30	10.166.5.97 – 10.166.5.98	10.166.5.99
26	10.166.5.100/30	10.166.5.101 – 10.166.5.102	10.166.5.103
27	10.166.5.104/30	10.166.5.105 – 10.166.5.106	10.166.5.107
28	10.166.5.108/30	10.166.5.109 – 10.166.5.110	10.166.5.111
29	10.166.5.112/30	10.166.5.113 – 10.166.5.114	10.166.5.115
30	10.166.5.116/30	10.166.5.117 – 10.166.5.118	10.166.5.119
31	10.166.5.120/30	10.166.5.121 – 10.166.5.122	10.166.5.123
32	10.166.5.124/30	10.166.5.125 – 10.166.5.126	10.166.5.127
33	10.166.5.128/30	10.166.5.129 – 10.166.5.130	10.166.5.131
34	10.166.5.132/30	10.166.5.133 – 10.166.5.134	10.166.5.135
35	10.166.5.136/30	10.166.5.137 – 10.166.5.138	10.166.5.139
36	10.166.5.140/30	10.166.5.141 – 10.166.5.142	10.166.5.143
37	10.166.5.144/30	10.166.5.145 – 10.166.5.146	10.166.5.147
38	10.166.5.148/30	10.166.5.149 – 10.166.5.150	10.166.5.151
39	10.166.5.152/30	10.166.5.153 – 10.166.5.154	10.166.5.155
40	10.166.5.156/30	10.166.5.157 – 10.166.5.158	10.166.5.159
41	10.166.5.160/30	10.166.5.161 – 10.166.5.162	10.166.5.163
42	10.166.5.164/30	10.166.5.165 – 10.166.5.166	10.166.5.167
43	10.166.5.168/30	10.166.5.169 – 10.166.5.170	10.166.5.171
44	10.166.5.172/30	10.166.5.173 – 10.166.5.174	10.166.5.175
45	10.166.5.176/30	10.166.5.177 – 10.166.5.178	10.166.5.179
46	10.166.5.180/30	10.166.5.181 – 10.166.5.182	10.166.5.183
47	10.166.5.184/30	10.166.5.185 – 10.166.5.186	10.166.5.187
48	10.166.5.188/30	10.166.5.189 – 10.166.5.190	10.166.5.191
49	10.166.5.192/30	10.166.5.193 – 10.166.5.194	10.166.5.195
50	10.166.5.196/30	10.166.5.197 – 10.166.5.198	10.166.5.199
51	10.166.5.200/30	10.166.5.201 – 10.166.5.202	10.166.5.203
52	10.166.5.204/30	10.166.5.205 – 10.166.5.206	10.166.5.207
53	10.166.5.208/30	10.166.5.209 – 10.166.5.210	10.166.5.211
54	10.166.5.212/30	10.166.5.213 – 10.166.5.214	10.166.5.215
55	10.166.5.216/30	10.166.5.217 – 10.166.5.218	10.166.5.219
56	10.166.5.220/30	10.166.5.221 – 10.166.5.222	10.166.5.223
57	10.166.5.224/30	10.166.5.225 – 10.166.5.226	10.166.5.227
58	10.166.5.228/30	10.166.5.229 – 10.166.5.230	10.166.5.231
59	10.166.5.232/30	10.166.5.233 – 10.166.5.234	10.166.5.235
60	10.166.5.236/30	10.166.5.237 – 10.166.5.238	10.166.5.239
61	10.166.5.240/30	10.166.5.241 – 10.166.5.242	10.166.5.243
62	10.166.5.244/30	10.166.5.245 – 10.166.5.246	10.166.5.247
63	10.166.5.248/30	10.166.5.249 – 10.166.5.250	10.166.5.251
64	10.166.5.252/30	10.166.5.253 – 10.166.5.254	10.166.5.255

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 →