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)10.91.65.0/24

network10.91.65.0/24

broadcast10.91.65.255

first host10.91.65.1

last host10.91.65.254

subnet mask255.255.255.0

wildcard0.0.0.255

addresses256

usable hosts254

classA

ipcalc 10.91.65.0/24

address00001010.01011011.01000001.00000000

subnet mask11111111.11111111.11111111.00000000

network00001010.01011011.01000001.00000000

broadcast00001010.01011011.01000001.11111111

green = network part, grey = host part

hex0x0a5b4100

decimal173752576

reverse dns0.65.91.10.in-addr.arpa

ipv4-mapped::ffff:a5b:4100

/24 split into /30 · 64 subnets

close ×

#	network	host range	broadcast
1	10.91.65.0/30	10.91.65.1 – 10.91.65.2	10.91.65.3
2	10.91.65.4/30	10.91.65.5 – 10.91.65.6	10.91.65.7
3	10.91.65.8/30	10.91.65.9 – 10.91.65.10	10.91.65.11
4	10.91.65.12/30	10.91.65.13 – 10.91.65.14	10.91.65.15
5	10.91.65.16/30	10.91.65.17 – 10.91.65.18	10.91.65.19
6	10.91.65.20/30	10.91.65.21 – 10.91.65.22	10.91.65.23
7	10.91.65.24/30	10.91.65.25 – 10.91.65.26	10.91.65.27
8	10.91.65.28/30	10.91.65.29 – 10.91.65.30	10.91.65.31
9	10.91.65.32/30	10.91.65.33 – 10.91.65.34	10.91.65.35
10	10.91.65.36/30	10.91.65.37 – 10.91.65.38	10.91.65.39
11	10.91.65.40/30	10.91.65.41 – 10.91.65.42	10.91.65.43
12	10.91.65.44/30	10.91.65.45 – 10.91.65.46	10.91.65.47
13	10.91.65.48/30	10.91.65.49 – 10.91.65.50	10.91.65.51
14	10.91.65.52/30	10.91.65.53 – 10.91.65.54	10.91.65.55
15	10.91.65.56/30	10.91.65.57 – 10.91.65.58	10.91.65.59
16	10.91.65.60/30	10.91.65.61 – 10.91.65.62	10.91.65.63
17	10.91.65.64/30	10.91.65.65 – 10.91.65.66	10.91.65.67
18	10.91.65.68/30	10.91.65.69 – 10.91.65.70	10.91.65.71
19	10.91.65.72/30	10.91.65.73 – 10.91.65.74	10.91.65.75
20	10.91.65.76/30	10.91.65.77 – 10.91.65.78	10.91.65.79
21	10.91.65.80/30	10.91.65.81 – 10.91.65.82	10.91.65.83
22	10.91.65.84/30	10.91.65.85 – 10.91.65.86	10.91.65.87
23	10.91.65.88/30	10.91.65.89 – 10.91.65.90	10.91.65.91
24	10.91.65.92/30	10.91.65.93 – 10.91.65.94	10.91.65.95
25	10.91.65.96/30	10.91.65.97 – 10.91.65.98	10.91.65.99
26	10.91.65.100/30	10.91.65.101 – 10.91.65.102	10.91.65.103
27	10.91.65.104/30	10.91.65.105 – 10.91.65.106	10.91.65.107
28	10.91.65.108/30	10.91.65.109 – 10.91.65.110	10.91.65.111
29	10.91.65.112/30	10.91.65.113 – 10.91.65.114	10.91.65.115
30	10.91.65.116/30	10.91.65.117 – 10.91.65.118	10.91.65.119
31	10.91.65.120/30	10.91.65.121 – 10.91.65.122	10.91.65.123
32	10.91.65.124/30	10.91.65.125 – 10.91.65.126	10.91.65.127
33	10.91.65.128/30	10.91.65.129 – 10.91.65.130	10.91.65.131
34	10.91.65.132/30	10.91.65.133 – 10.91.65.134	10.91.65.135
35	10.91.65.136/30	10.91.65.137 – 10.91.65.138	10.91.65.139
36	10.91.65.140/30	10.91.65.141 – 10.91.65.142	10.91.65.143
37	10.91.65.144/30	10.91.65.145 – 10.91.65.146	10.91.65.147
38	10.91.65.148/30	10.91.65.149 – 10.91.65.150	10.91.65.151
39	10.91.65.152/30	10.91.65.153 – 10.91.65.154	10.91.65.155
40	10.91.65.156/30	10.91.65.157 – 10.91.65.158	10.91.65.159
41	10.91.65.160/30	10.91.65.161 – 10.91.65.162	10.91.65.163
42	10.91.65.164/30	10.91.65.165 – 10.91.65.166	10.91.65.167
43	10.91.65.168/30	10.91.65.169 – 10.91.65.170	10.91.65.171
44	10.91.65.172/30	10.91.65.173 – 10.91.65.174	10.91.65.175
45	10.91.65.176/30	10.91.65.177 – 10.91.65.178	10.91.65.179
46	10.91.65.180/30	10.91.65.181 – 10.91.65.182	10.91.65.183
47	10.91.65.184/30	10.91.65.185 – 10.91.65.186	10.91.65.187
48	10.91.65.188/30	10.91.65.189 – 10.91.65.190	10.91.65.191
49	10.91.65.192/30	10.91.65.193 – 10.91.65.194	10.91.65.195
50	10.91.65.196/30	10.91.65.197 – 10.91.65.198	10.91.65.199
51	10.91.65.200/30	10.91.65.201 – 10.91.65.202	10.91.65.203
52	10.91.65.204/30	10.91.65.205 – 10.91.65.206	10.91.65.207
53	10.91.65.208/30	10.91.65.209 – 10.91.65.210	10.91.65.211
54	10.91.65.212/30	10.91.65.213 – 10.91.65.214	10.91.65.215
55	10.91.65.216/30	10.91.65.217 – 10.91.65.218	10.91.65.219
56	10.91.65.220/30	10.91.65.221 – 10.91.65.222	10.91.65.223
57	10.91.65.224/30	10.91.65.225 – 10.91.65.226	10.91.65.227
58	10.91.65.228/30	10.91.65.229 – 10.91.65.230	10.91.65.231
59	10.91.65.232/30	10.91.65.233 – 10.91.65.234	10.91.65.235
60	10.91.65.236/30	10.91.65.237 – 10.91.65.238	10.91.65.239
61	10.91.65.240/30	10.91.65.241 – 10.91.65.242	10.91.65.243
62	10.91.65.244/30	10.91.65.245 – 10.91.65.246	10.91.65.247
63	10.91.65.248/30	10.91.65.249 – 10.91.65.250	10.91.65.251
64	10.91.65.252/30	10.91.65.253 – 10.91.65.254	10.91.65.255

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 →