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)10.5.166.0/24

network10.5.166.0/24

broadcast10.5.166.255

first host10.5.166.1

last host10.5.166.254

subnet mask255.255.255.0

wildcard0.0.0.255

addresses256

usable hosts254

classA

ipcalc 10.5.166.0/24

address00001010.00000101.10100110.00000000

subnet mask11111111.11111111.11111111.00000000

network00001010.00000101.10100110.00000000

broadcast00001010.00000101.10100110.11111111

green = network part, grey = host part

hex0x0a05a600

decimal168142336

reverse dns0.166.5.10.in-addr.arpa

ipv4-mapped::ffff:a05:a600

/24 split into /30 · 64 subnets

close ×

#	network	host range	broadcast
1	10.5.166.0/30	10.5.166.1 – 10.5.166.2	10.5.166.3
2	10.5.166.4/30	10.5.166.5 – 10.5.166.6	10.5.166.7
3	10.5.166.8/30	10.5.166.9 – 10.5.166.10	10.5.166.11
4	10.5.166.12/30	10.5.166.13 – 10.5.166.14	10.5.166.15
5	10.5.166.16/30	10.5.166.17 – 10.5.166.18	10.5.166.19
6	10.5.166.20/30	10.5.166.21 – 10.5.166.22	10.5.166.23
7	10.5.166.24/30	10.5.166.25 – 10.5.166.26	10.5.166.27
8	10.5.166.28/30	10.5.166.29 – 10.5.166.30	10.5.166.31
9	10.5.166.32/30	10.5.166.33 – 10.5.166.34	10.5.166.35
10	10.5.166.36/30	10.5.166.37 – 10.5.166.38	10.5.166.39
11	10.5.166.40/30	10.5.166.41 – 10.5.166.42	10.5.166.43
12	10.5.166.44/30	10.5.166.45 – 10.5.166.46	10.5.166.47
13	10.5.166.48/30	10.5.166.49 – 10.5.166.50	10.5.166.51
14	10.5.166.52/30	10.5.166.53 – 10.5.166.54	10.5.166.55
15	10.5.166.56/30	10.5.166.57 – 10.5.166.58	10.5.166.59
16	10.5.166.60/30	10.5.166.61 – 10.5.166.62	10.5.166.63
17	10.5.166.64/30	10.5.166.65 – 10.5.166.66	10.5.166.67
18	10.5.166.68/30	10.5.166.69 – 10.5.166.70	10.5.166.71
19	10.5.166.72/30	10.5.166.73 – 10.5.166.74	10.5.166.75
20	10.5.166.76/30	10.5.166.77 – 10.5.166.78	10.5.166.79
21	10.5.166.80/30	10.5.166.81 – 10.5.166.82	10.5.166.83
22	10.5.166.84/30	10.5.166.85 – 10.5.166.86	10.5.166.87
23	10.5.166.88/30	10.5.166.89 – 10.5.166.90	10.5.166.91
24	10.5.166.92/30	10.5.166.93 – 10.5.166.94	10.5.166.95
25	10.5.166.96/30	10.5.166.97 – 10.5.166.98	10.5.166.99
26	10.5.166.100/30	10.5.166.101 – 10.5.166.102	10.5.166.103
27	10.5.166.104/30	10.5.166.105 – 10.5.166.106	10.5.166.107
28	10.5.166.108/30	10.5.166.109 – 10.5.166.110	10.5.166.111
29	10.5.166.112/30	10.5.166.113 – 10.5.166.114	10.5.166.115
30	10.5.166.116/30	10.5.166.117 – 10.5.166.118	10.5.166.119
31	10.5.166.120/30	10.5.166.121 – 10.5.166.122	10.5.166.123
32	10.5.166.124/30	10.5.166.125 – 10.5.166.126	10.5.166.127
33	10.5.166.128/30	10.5.166.129 – 10.5.166.130	10.5.166.131
34	10.5.166.132/30	10.5.166.133 – 10.5.166.134	10.5.166.135
35	10.5.166.136/30	10.5.166.137 – 10.5.166.138	10.5.166.139
36	10.5.166.140/30	10.5.166.141 – 10.5.166.142	10.5.166.143
37	10.5.166.144/30	10.5.166.145 – 10.5.166.146	10.5.166.147
38	10.5.166.148/30	10.5.166.149 – 10.5.166.150	10.5.166.151
39	10.5.166.152/30	10.5.166.153 – 10.5.166.154	10.5.166.155
40	10.5.166.156/30	10.5.166.157 – 10.5.166.158	10.5.166.159
41	10.5.166.160/30	10.5.166.161 – 10.5.166.162	10.5.166.163
42	10.5.166.164/30	10.5.166.165 – 10.5.166.166	10.5.166.167
43	10.5.166.168/30	10.5.166.169 – 10.5.166.170	10.5.166.171
44	10.5.166.172/30	10.5.166.173 – 10.5.166.174	10.5.166.175
45	10.5.166.176/30	10.5.166.177 – 10.5.166.178	10.5.166.179
46	10.5.166.180/30	10.5.166.181 – 10.5.166.182	10.5.166.183
47	10.5.166.184/30	10.5.166.185 – 10.5.166.186	10.5.166.187
48	10.5.166.188/30	10.5.166.189 – 10.5.166.190	10.5.166.191
49	10.5.166.192/30	10.5.166.193 – 10.5.166.194	10.5.166.195
50	10.5.166.196/30	10.5.166.197 – 10.5.166.198	10.5.166.199
51	10.5.166.200/30	10.5.166.201 – 10.5.166.202	10.5.166.203
52	10.5.166.204/30	10.5.166.205 – 10.5.166.206	10.5.166.207
53	10.5.166.208/30	10.5.166.209 – 10.5.166.210	10.5.166.211
54	10.5.166.212/30	10.5.166.213 – 10.5.166.214	10.5.166.215
55	10.5.166.216/30	10.5.166.217 – 10.5.166.218	10.5.166.219
56	10.5.166.220/30	10.5.166.221 – 10.5.166.222	10.5.166.223
57	10.5.166.224/30	10.5.166.225 – 10.5.166.226	10.5.166.227
58	10.5.166.228/30	10.5.166.229 – 10.5.166.230	10.5.166.231
59	10.5.166.232/30	10.5.166.233 – 10.5.166.234	10.5.166.235
60	10.5.166.236/30	10.5.166.237 – 10.5.166.238	10.5.166.239
61	10.5.166.240/30	10.5.166.241 – 10.5.166.242	10.5.166.243
62	10.5.166.244/30	10.5.166.245 – 10.5.166.246	10.5.166.247
63	10.5.166.248/30	10.5.166.249 – 10.5.166.250	10.5.166.251
64	10.5.166.252/30	10.5.166.253 – 10.5.166.254	10.5.166.255

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 →