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)10.3.172.0/24

network10.3.172.0/24

broadcast10.3.172.255

first host10.3.172.1

last host10.3.172.254

subnet mask255.255.255.0

wildcard0.0.0.255

addresses256

usable hosts254

classA

ipcalc 10.3.172.0/24

address00001010.00000011.10101100.00000000

subnet mask11111111.11111111.11111111.00000000

network00001010.00000011.10101100.00000000

broadcast00001010.00000011.10101100.11111111

green = network part, grey = host part

hex0x0a03ac00

decimal168012800

reverse dns0.172.3.10.in-addr.arpa

ipv4-mapped::ffff:a03:ac00

/24 split into /30 · 64 subnets

close ×

#	network	host range	broadcast
1	10.3.172.0/30	10.3.172.1 – 10.3.172.2	10.3.172.3
2	10.3.172.4/30	10.3.172.5 – 10.3.172.6	10.3.172.7
3	10.3.172.8/30	10.3.172.9 – 10.3.172.10	10.3.172.11
4	10.3.172.12/30	10.3.172.13 – 10.3.172.14	10.3.172.15
5	10.3.172.16/30	10.3.172.17 – 10.3.172.18	10.3.172.19
6	10.3.172.20/30	10.3.172.21 – 10.3.172.22	10.3.172.23
7	10.3.172.24/30	10.3.172.25 – 10.3.172.26	10.3.172.27
8	10.3.172.28/30	10.3.172.29 – 10.3.172.30	10.3.172.31
9	10.3.172.32/30	10.3.172.33 – 10.3.172.34	10.3.172.35
10	10.3.172.36/30	10.3.172.37 – 10.3.172.38	10.3.172.39
11	10.3.172.40/30	10.3.172.41 – 10.3.172.42	10.3.172.43
12	10.3.172.44/30	10.3.172.45 – 10.3.172.46	10.3.172.47
13	10.3.172.48/30	10.3.172.49 – 10.3.172.50	10.3.172.51
14	10.3.172.52/30	10.3.172.53 – 10.3.172.54	10.3.172.55
15	10.3.172.56/30	10.3.172.57 – 10.3.172.58	10.3.172.59
16	10.3.172.60/30	10.3.172.61 – 10.3.172.62	10.3.172.63
17	10.3.172.64/30	10.3.172.65 – 10.3.172.66	10.3.172.67
18	10.3.172.68/30	10.3.172.69 – 10.3.172.70	10.3.172.71
19	10.3.172.72/30	10.3.172.73 – 10.3.172.74	10.3.172.75
20	10.3.172.76/30	10.3.172.77 – 10.3.172.78	10.3.172.79
21	10.3.172.80/30	10.3.172.81 – 10.3.172.82	10.3.172.83
22	10.3.172.84/30	10.3.172.85 – 10.3.172.86	10.3.172.87
23	10.3.172.88/30	10.3.172.89 – 10.3.172.90	10.3.172.91
24	10.3.172.92/30	10.3.172.93 – 10.3.172.94	10.3.172.95
25	10.3.172.96/30	10.3.172.97 – 10.3.172.98	10.3.172.99
26	10.3.172.100/30	10.3.172.101 – 10.3.172.102	10.3.172.103
27	10.3.172.104/30	10.3.172.105 – 10.3.172.106	10.3.172.107
28	10.3.172.108/30	10.3.172.109 – 10.3.172.110	10.3.172.111
29	10.3.172.112/30	10.3.172.113 – 10.3.172.114	10.3.172.115
30	10.3.172.116/30	10.3.172.117 – 10.3.172.118	10.3.172.119
31	10.3.172.120/30	10.3.172.121 – 10.3.172.122	10.3.172.123
32	10.3.172.124/30	10.3.172.125 – 10.3.172.126	10.3.172.127
33	10.3.172.128/30	10.3.172.129 – 10.3.172.130	10.3.172.131
34	10.3.172.132/30	10.3.172.133 – 10.3.172.134	10.3.172.135
35	10.3.172.136/30	10.3.172.137 – 10.3.172.138	10.3.172.139
36	10.3.172.140/30	10.3.172.141 – 10.3.172.142	10.3.172.143
37	10.3.172.144/30	10.3.172.145 – 10.3.172.146	10.3.172.147
38	10.3.172.148/30	10.3.172.149 – 10.3.172.150	10.3.172.151
39	10.3.172.152/30	10.3.172.153 – 10.3.172.154	10.3.172.155
40	10.3.172.156/30	10.3.172.157 – 10.3.172.158	10.3.172.159
41	10.3.172.160/30	10.3.172.161 – 10.3.172.162	10.3.172.163
42	10.3.172.164/30	10.3.172.165 – 10.3.172.166	10.3.172.167
43	10.3.172.168/30	10.3.172.169 – 10.3.172.170	10.3.172.171
44	10.3.172.172/30	10.3.172.173 – 10.3.172.174	10.3.172.175
45	10.3.172.176/30	10.3.172.177 – 10.3.172.178	10.3.172.179
46	10.3.172.180/30	10.3.172.181 – 10.3.172.182	10.3.172.183
47	10.3.172.184/30	10.3.172.185 – 10.3.172.186	10.3.172.187
48	10.3.172.188/30	10.3.172.189 – 10.3.172.190	10.3.172.191
49	10.3.172.192/30	10.3.172.193 – 10.3.172.194	10.3.172.195
50	10.3.172.196/30	10.3.172.197 – 10.3.172.198	10.3.172.199
51	10.3.172.200/30	10.3.172.201 – 10.3.172.202	10.3.172.203
52	10.3.172.204/30	10.3.172.205 – 10.3.172.206	10.3.172.207
53	10.3.172.208/30	10.3.172.209 – 10.3.172.210	10.3.172.211
54	10.3.172.212/30	10.3.172.213 – 10.3.172.214	10.3.172.215
55	10.3.172.216/30	10.3.172.217 – 10.3.172.218	10.3.172.219
56	10.3.172.220/30	10.3.172.221 – 10.3.172.222	10.3.172.223
57	10.3.172.224/30	10.3.172.225 – 10.3.172.226	10.3.172.227
58	10.3.172.228/30	10.3.172.229 – 10.3.172.230	10.3.172.231
59	10.3.172.232/30	10.3.172.233 – 10.3.172.234	10.3.172.235
60	10.3.172.236/30	10.3.172.237 – 10.3.172.238	10.3.172.239
61	10.3.172.240/30	10.3.172.241 – 10.3.172.242	10.3.172.243
62	10.3.172.244/30	10.3.172.245 – 10.3.172.246	10.3.172.247
63	10.3.172.248/30	10.3.172.249 – 10.3.172.250	10.3.172.251
64	10.3.172.252/30	10.3.172.253 – 10.3.172.254	10.3.172.255

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 →