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)10.240.3.0/24

network10.240.3.0/24

broadcast10.240.3.255

first host10.240.3.1

last host10.240.3.254

subnet mask255.255.255.0

wildcard0.0.0.255

addresses256

usable hosts254

classA

ipcalc 10.240.3.0/24

address00001010.11110000.00000011.00000000

subnet mask11111111.11111111.11111111.00000000

network00001010.11110000.00000011.00000000

broadcast00001010.11110000.00000011.11111111

green = network part, grey = host part

hex0x0af00300

decimal183501568

reverse dns0.3.240.10.in-addr.arpa

ipv4-mapped::ffff:af0:300

/24 split into /30 · 64 subnets

close ×

#	network	host range	broadcast
1	10.240.3.0/30	10.240.3.1 – 10.240.3.2	10.240.3.3
2	10.240.3.4/30	10.240.3.5 – 10.240.3.6	10.240.3.7
3	10.240.3.8/30	10.240.3.9 – 10.240.3.10	10.240.3.11
4	10.240.3.12/30	10.240.3.13 – 10.240.3.14	10.240.3.15
5	10.240.3.16/30	10.240.3.17 – 10.240.3.18	10.240.3.19
6	10.240.3.20/30	10.240.3.21 – 10.240.3.22	10.240.3.23
7	10.240.3.24/30	10.240.3.25 – 10.240.3.26	10.240.3.27
8	10.240.3.28/30	10.240.3.29 – 10.240.3.30	10.240.3.31
9	10.240.3.32/30	10.240.3.33 – 10.240.3.34	10.240.3.35
10	10.240.3.36/30	10.240.3.37 – 10.240.3.38	10.240.3.39
11	10.240.3.40/30	10.240.3.41 – 10.240.3.42	10.240.3.43
12	10.240.3.44/30	10.240.3.45 – 10.240.3.46	10.240.3.47
13	10.240.3.48/30	10.240.3.49 – 10.240.3.50	10.240.3.51
14	10.240.3.52/30	10.240.3.53 – 10.240.3.54	10.240.3.55
15	10.240.3.56/30	10.240.3.57 – 10.240.3.58	10.240.3.59
16	10.240.3.60/30	10.240.3.61 – 10.240.3.62	10.240.3.63
17	10.240.3.64/30	10.240.3.65 – 10.240.3.66	10.240.3.67
18	10.240.3.68/30	10.240.3.69 – 10.240.3.70	10.240.3.71
19	10.240.3.72/30	10.240.3.73 – 10.240.3.74	10.240.3.75
20	10.240.3.76/30	10.240.3.77 – 10.240.3.78	10.240.3.79
21	10.240.3.80/30	10.240.3.81 – 10.240.3.82	10.240.3.83
22	10.240.3.84/30	10.240.3.85 – 10.240.3.86	10.240.3.87
23	10.240.3.88/30	10.240.3.89 – 10.240.3.90	10.240.3.91
24	10.240.3.92/30	10.240.3.93 – 10.240.3.94	10.240.3.95
25	10.240.3.96/30	10.240.3.97 – 10.240.3.98	10.240.3.99
26	10.240.3.100/30	10.240.3.101 – 10.240.3.102	10.240.3.103
27	10.240.3.104/30	10.240.3.105 – 10.240.3.106	10.240.3.107
28	10.240.3.108/30	10.240.3.109 – 10.240.3.110	10.240.3.111
29	10.240.3.112/30	10.240.3.113 – 10.240.3.114	10.240.3.115
30	10.240.3.116/30	10.240.3.117 – 10.240.3.118	10.240.3.119
31	10.240.3.120/30	10.240.3.121 – 10.240.3.122	10.240.3.123
32	10.240.3.124/30	10.240.3.125 – 10.240.3.126	10.240.3.127
33	10.240.3.128/30	10.240.3.129 – 10.240.3.130	10.240.3.131
34	10.240.3.132/30	10.240.3.133 – 10.240.3.134	10.240.3.135
35	10.240.3.136/30	10.240.3.137 – 10.240.3.138	10.240.3.139
36	10.240.3.140/30	10.240.3.141 – 10.240.3.142	10.240.3.143
37	10.240.3.144/30	10.240.3.145 – 10.240.3.146	10.240.3.147
38	10.240.3.148/30	10.240.3.149 – 10.240.3.150	10.240.3.151
39	10.240.3.152/30	10.240.3.153 – 10.240.3.154	10.240.3.155
40	10.240.3.156/30	10.240.3.157 – 10.240.3.158	10.240.3.159
41	10.240.3.160/30	10.240.3.161 – 10.240.3.162	10.240.3.163
42	10.240.3.164/30	10.240.3.165 – 10.240.3.166	10.240.3.167
43	10.240.3.168/30	10.240.3.169 – 10.240.3.170	10.240.3.171
44	10.240.3.172/30	10.240.3.173 – 10.240.3.174	10.240.3.175
45	10.240.3.176/30	10.240.3.177 – 10.240.3.178	10.240.3.179
46	10.240.3.180/30	10.240.3.181 – 10.240.3.182	10.240.3.183
47	10.240.3.184/30	10.240.3.185 – 10.240.3.186	10.240.3.187
48	10.240.3.188/30	10.240.3.189 – 10.240.3.190	10.240.3.191
49	10.240.3.192/30	10.240.3.193 – 10.240.3.194	10.240.3.195
50	10.240.3.196/30	10.240.3.197 – 10.240.3.198	10.240.3.199
51	10.240.3.200/30	10.240.3.201 – 10.240.3.202	10.240.3.203
52	10.240.3.204/30	10.240.3.205 – 10.240.3.206	10.240.3.207
53	10.240.3.208/30	10.240.3.209 – 10.240.3.210	10.240.3.211
54	10.240.3.212/30	10.240.3.213 – 10.240.3.214	10.240.3.215
55	10.240.3.216/30	10.240.3.217 – 10.240.3.218	10.240.3.219
56	10.240.3.220/30	10.240.3.221 – 10.240.3.222	10.240.3.223
57	10.240.3.224/30	10.240.3.225 – 10.240.3.226	10.240.3.227
58	10.240.3.228/30	10.240.3.229 – 10.240.3.230	10.240.3.231
59	10.240.3.232/30	10.240.3.233 – 10.240.3.234	10.240.3.235
60	10.240.3.236/30	10.240.3.237 – 10.240.3.238	10.240.3.239
61	10.240.3.240/30	10.240.3.241 – 10.240.3.242	10.240.3.243
62	10.240.3.244/30	10.240.3.245 – 10.240.3.246	10.240.3.247
63	10.240.3.248/30	10.240.3.249 – 10.240.3.250	10.240.3.251
64	10.240.3.252/30	10.240.3.253 – 10.240.3.254	10.240.3.255

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 →