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)10.3.243.0/24

network10.3.243.0/24

broadcast10.3.243.255

first host10.3.243.1

last host10.3.243.254

subnet mask255.255.255.0

wildcard0.0.0.255

addresses256

usable hosts254

classA

ipcalc 10.3.243.0/24

address00001010.00000011.11110011.00000000

subnet mask11111111.11111111.11111111.00000000

network00001010.00000011.11110011.00000000

broadcast00001010.00000011.11110011.11111111

green = network part, grey = host part

hex0x0a03f300

decimal168030976

reverse dns0.243.3.10.in-addr.arpa

ipv4-mapped::ffff:a03:f300

/24 split into /30 · 64 subnets

close ×

#	network	host range	broadcast
1	10.3.243.0/30	10.3.243.1 – 10.3.243.2	10.3.243.3
2	10.3.243.4/30	10.3.243.5 – 10.3.243.6	10.3.243.7
3	10.3.243.8/30	10.3.243.9 – 10.3.243.10	10.3.243.11
4	10.3.243.12/30	10.3.243.13 – 10.3.243.14	10.3.243.15
5	10.3.243.16/30	10.3.243.17 – 10.3.243.18	10.3.243.19
6	10.3.243.20/30	10.3.243.21 – 10.3.243.22	10.3.243.23
7	10.3.243.24/30	10.3.243.25 – 10.3.243.26	10.3.243.27
8	10.3.243.28/30	10.3.243.29 – 10.3.243.30	10.3.243.31
9	10.3.243.32/30	10.3.243.33 – 10.3.243.34	10.3.243.35
10	10.3.243.36/30	10.3.243.37 – 10.3.243.38	10.3.243.39
11	10.3.243.40/30	10.3.243.41 – 10.3.243.42	10.3.243.43
12	10.3.243.44/30	10.3.243.45 – 10.3.243.46	10.3.243.47
13	10.3.243.48/30	10.3.243.49 – 10.3.243.50	10.3.243.51
14	10.3.243.52/30	10.3.243.53 – 10.3.243.54	10.3.243.55
15	10.3.243.56/30	10.3.243.57 – 10.3.243.58	10.3.243.59
16	10.3.243.60/30	10.3.243.61 – 10.3.243.62	10.3.243.63
17	10.3.243.64/30	10.3.243.65 – 10.3.243.66	10.3.243.67
18	10.3.243.68/30	10.3.243.69 – 10.3.243.70	10.3.243.71
19	10.3.243.72/30	10.3.243.73 – 10.3.243.74	10.3.243.75
20	10.3.243.76/30	10.3.243.77 – 10.3.243.78	10.3.243.79
21	10.3.243.80/30	10.3.243.81 – 10.3.243.82	10.3.243.83
22	10.3.243.84/30	10.3.243.85 – 10.3.243.86	10.3.243.87
23	10.3.243.88/30	10.3.243.89 – 10.3.243.90	10.3.243.91
24	10.3.243.92/30	10.3.243.93 – 10.3.243.94	10.3.243.95
25	10.3.243.96/30	10.3.243.97 – 10.3.243.98	10.3.243.99
26	10.3.243.100/30	10.3.243.101 – 10.3.243.102	10.3.243.103
27	10.3.243.104/30	10.3.243.105 – 10.3.243.106	10.3.243.107
28	10.3.243.108/30	10.3.243.109 – 10.3.243.110	10.3.243.111
29	10.3.243.112/30	10.3.243.113 – 10.3.243.114	10.3.243.115
30	10.3.243.116/30	10.3.243.117 – 10.3.243.118	10.3.243.119
31	10.3.243.120/30	10.3.243.121 – 10.3.243.122	10.3.243.123
32	10.3.243.124/30	10.3.243.125 – 10.3.243.126	10.3.243.127
33	10.3.243.128/30	10.3.243.129 – 10.3.243.130	10.3.243.131
34	10.3.243.132/30	10.3.243.133 – 10.3.243.134	10.3.243.135
35	10.3.243.136/30	10.3.243.137 – 10.3.243.138	10.3.243.139
36	10.3.243.140/30	10.3.243.141 – 10.3.243.142	10.3.243.143
37	10.3.243.144/30	10.3.243.145 – 10.3.243.146	10.3.243.147
38	10.3.243.148/30	10.3.243.149 – 10.3.243.150	10.3.243.151
39	10.3.243.152/30	10.3.243.153 – 10.3.243.154	10.3.243.155
40	10.3.243.156/30	10.3.243.157 – 10.3.243.158	10.3.243.159
41	10.3.243.160/30	10.3.243.161 – 10.3.243.162	10.3.243.163
42	10.3.243.164/30	10.3.243.165 – 10.3.243.166	10.3.243.167
43	10.3.243.168/30	10.3.243.169 – 10.3.243.170	10.3.243.171
44	10.3.243.172/30	10.3.243.173 – 10.3.243.174	10.3.243.175
45	10.3.243.176/30	10.3.243.177 – 10.3.243.178	10.3.243.179
46	10.3.243.180/30	10.3.243.181 – 10.3.243.182	10.3.243.183
47	10.3.243.184/30	10.3.243.185 – 10.3.243.186	10.3.243.187
48	10.3.243.188/30	10.3.243.189 – 10.3.243.190	10.3.243.191
49	10.3.243.192/30	10.3.243.193 – 10.3.243.194	10.3.243.195
50	10.3.243.196/30	10.3.243.197 – 10.3.243.198	10.3.243.199
51	10.3.243.200/30	10.3.243.201 – 10.3.243.202	10.3.243.203
52	10.3.243.204/30	10.3.243.205 – 10.3.243.206	10.3.243.207
53	10.3.243.208/30	10.3.243.209 – 10.3.243.210	10.3.243.211
54	10.3.243.212/30	10.3.243.213 – 10.3.243.214	10.3.243.215
55	10.3.243.216/30	10.3.243.217 – 10.3.243.218	10.3.243.219
56	10.3.243.220/30	10.3.243.221 – 10.3.243.222	10.3.243.223
57	10.3.243.224/30	10.3.243.225 – 10.3.243.226	10.3.243.227
58	10.3.243.228/30	10.3.243.229 – 10.3.243.230	10.3.243.231
59	10.3.243.232/30	10.3.243.233 – 10.3.243.234	10.3.243.235
60	10.3.243.236/30	10.3.243.237 – 10.3.243.238	10.3.243.239
61	10.3.243.240/30	10.3.243.241 – 10.3.243.242	10.3.243.243
62	10.3.243.244/30	10.3.243.245 – 10.3.243.246	10.3.243.247
63	10.3.243.248/30	10.3.243.249 – 10.3.243.250	10.3.243.251
64	10.3.243.252/30	10.3.243.253 – 10.3.243.254	10.3.243.255

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 →