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)10.0.91.0/24

network10.0.91.0/24

broadcast10.0.91.255

first host10.0.91.1

last host10.0.91.254

subnet mask255.255.255.0

wildcard0.0.0.255

addresses256

usable hosts254

classA

ipcalc 10.0.91.0/24

address00001010.00000000.01011011.00000000

subnet mask11111111.11111111.11111111.00000000

network00001010.00000000.01011011.00000000

broadcast00001010.00000000.01011011.11111111

green = network part, grey = host part

hex0x0a005b00

decimal167795456

reverse dns0.91.0.10.in-addr.arpa

ipv4-mapped::ffff:a00:5b00

/24 split into /30 · 64 subnets

close ×

#	network	host range	broadcast
1	10.0.91.0/30	10.0.91.1 – 10.0.91.2	10.0.91.3
2	10.0.91.4/30	10.0.91.5 – 10.0.91.6	10.0.91.7
3	10.0.91.8/30	10.0.91.9 – 10.0.91.10	10.0.91.11
4	10.0.91.12/30	10.0.91.13 – 10.0.91.14	10.0.91.15
5	10.0.91.16/30	10.0.91.17 – 10.0.91.18	10.0.91.19
6	10.0.91.20/30	10.0.91.21 – 10.0.91.22	10.0.91.23
7	10.0.91.24/30	10.0.91.25 – 10.0.91.26	10.0.91.27
8	10.0.91.28/30	10.0.91.29 – 10.0.91.30	10.0.91.31
9	10.0.91.32/30	10.0.91.33 – 10.0.91.34	10.0.91.35
10	10.0.91.36/30	10.0.91.37 – 10.0.91.38	10.0.91.39
11	10.0.91.40/30	10.0.91.41 – 10.0.91.42	10.0.91.43
12	10.0.91.44/30	10.0.91.45 – 10.0.91.46	10.0.91.47
13	10.0.91.48/30	10.0.91.49 – 10.0.91.50	10.0.91.51
14	10.0.91.52/30	10.0.91.53 – 10.0.91.54	10.0.91.55
15	10.0.91.56/30	10.0.91.57 – 10.0.91.58	10.0.91.59
16	10.0.91.60/30	10.0.91.61 – 10.0.91.62	10.0.91.63
17	10.0.91.64/30	10.0.91.65 – 10.0.91.66	10.0.91.67
18	10.0.91.68/30	10.0.91.69 – 10.0.91.70	10.0.91.71
19	10.0.91.72/30	10.0.91.73 – 10.0.91.74	10.0.91.75
20	10.0.91.76/30	10.0.91.77 – 10.0.91.78	10.0.91.79
21	10.0.91.80/30	10.0.91.81 – 10.0.91.82	10.0.91.83
22	10.0.91.84/30	10.0.91.85 – 10.0.91.86	10.0.91.87
23	10.0.91.88/30	10.0.91.89 – 10.0.91.90	10.0.91.91
24	10.0.91.92/30	10.0.91.93 – 10.0.91.94	10.0.91.95
25	10.0.91.96/30	10.0.91.97 – 10.0.91.98	10.0.91.99
26	10.0.91.100/30	10.0.91.101 – 10.0.91.102	10.0.91.103
27	10.0.91.104/30	10.0.91.105 – 10.0.91.106	10.0.91.107
28	10.0.91.108/30	10.0.91.109 – 10.0.91.110	10.0.91.111
29	10.0.91.112/30	10.0.91.113 – 10.0.91.114	10.0.91.115
30	10.0.91.116/30	10.0.91.117 – 10.0.91.118	10.0.91.119
31	10.0.91.120/30	10.0.91.121 – 10.0.91.122	10.0.91.123
32	10.0.91.124/30	10.0.91.125 – 10.0.91.126	10.0.91.127
33	10.0.91.128/30	10.0.91.129 – 10.0.91.130	10.0.91.131
34	10.0.91.132/30	10.0.91.133 – 10.0.91.134	10.0.91.135
35	10.0.91.136/30	10.0.91.137 – 10.0.91.138	10.0.91.139
36	10.0.91.140/30	10.0.91.141 – 10.0.91.142	10.0.91.143
37	10.0.91.144/30	10.0.91.145 – 10.0.91.146	10.0.91.147
38	10.0.91.148/30	10.0.91.149 – 10.0.91.150	10.0.91.151
39	10.0.91.152/30	10.0.91.153 – 10.0.91.154	10.0.91.155
40	10.0.91.156/30	10.0.91.157 – 10.0.91.158	10.0.91.159
41	10.0.91.160/30	10.0.91.161 – 10.0.91.162	10.0.91.163
42	10.0.91.164/30	10.0.91.165 – 10.0.91.166	10.0.91.167
43	10.0.91.168/30	10.0.91.169 – 10.0.91.170	10.0.91.171
44	10.0.91.172/30	10.0.91.173 – 10.0.91.174	10.0.91.175
45	10.0.91.176/30	10.0.91.177 – 10.0.91.178	10.0.91.179
46	10.0.91.180/30	10.0.91.181 – 10.0.91.182	10.0.91.183
47	10.0.91.184/30	10.0.91.185 – 10.0.91.186	10.0.91.187
48	10.0.91.188/30	10.0.91.189 – 10.0.91.190	10.0.91.191
49	10.0.91.192/30	10.0.91.193 – 10.0.91.194	10.0.91.195
50	10.0.91.196/30	10.0.91.197 – 10.0.91.198	10.0.91.199
51	10.0.91.200/30	10.0.91.201 – 10.0.91.202	10.0.91.203
52	10.0.91.204/30	10.0.91.205 – 10.0.91.206	10.0.91.207
53	10.0.91.208/30	10.0.91.209 – 10.0.91.210	10.0.91.211
54	10.0.91.212/30	10.0.91.213 – 10.0.91.214	10.0.91.215
55	10.0.91.216/30	10.0.91.217 – 10.0.91.218	10.0.91.219
56	10.0.91.220/30	10.0.91.221 – 10.0.91.222	10.0.91.223
57	10.0.91.224/30	10.0.91.225 – 10.0.91.226	10.0.91.227
58	10.0.91.228/30	10.0.91.229 – 10.0.91.230	10.0.91.231
59	10.0.91.232/30	10.0.91.233 – 10.0.91.234	10.0.91.235
60	10.0.91.236/30	10.0.91.237 – 10.0.91.238	10.0.91.239
61	10.0.91.240/30	10.0.91.241 – 10.0.91.242	10.0.91.243
62	10.0.91.244/30	10.0.91.245 – 10.0.91.246	10.0.91.247
63	10.0.91.248/30	10.0.91.249 – 10.0.91.250	10.0.91.251
64	10.0.91.252/30	10.0.91.253 – 10.0.91.254	10.0.91.255

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 →