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)172.16.3.0/24

network172.16.3.0/24

broadcast172.16.3.255

first host172.16.3.1

last host172.16.3.254

subnet mask255.255.255.0

wildcard0.0.0.255

addresses256

usable hosts254

classB

ipcalc 172.16.3.0/24

address10101100.00010000.00000011.00000000

subnet mask11111111.11111111.11111111.00000000

network10101100.00010000.00000011.00000000

broadcast10101100.00010000.00000011.11111111

green = network part, grey = host part

hex0xac100300

decimal2886730496

reverse dns0.3.16.172.in-addr.arpa

ipv4-mapped::ffff:ac10:300

/24 split into /30 · 64 subnets

close ×

#	network	host range	broadcast
1	172.16.3.0/30	172.16.3.1 – 172.16.3.2	172.16.3.3
2	172.16.3.4/30	172.16.3.5 – 172.16.3.6	172.16.3.7
3	172.16.3.8/30	172.16.3.9 – 172.16.3.10	172.16.3.11
4	172.16.3.12/30	172.16.3.13 – 172.16.3.14	172.16.3.15
5	172.16.3.16/30	172.16.3.17 – 172.16.3.18	172.16.3.19
6	172.16.3.20/30	172.16.3.21 – 172.16.3.22	172.16.3.23
7	172.16.3.24/30	172.16.3.25 – 172.16.3.26	172.16.3.27
8	172.16.3.28/30	172.16.3.29 – 172.16.3.30	172.16.3.31
9	172.16.3.32/30	172.16.3.33 – 172.16.3.34	172.16.3.35
10	172.16.3.36/30	172.16.3.37 – 172.16.3.38	172.16.3.39
11	172.16.3.40/30	172.16.3.41 – 172.16.3.42	172.16.3.43
12	172.16.3.44/30	172.16.3.45 – 172.16.3.46	172.16.3.47
13	172.16.3.48/30	172.16.3.49 – 172.16.3.50	172.16.3.51
14	172.16.3.52/30	172.16.3.53 – 172.16.3.54	172.16.3.55
15	172.16.3.56/30	172.16.3.57 – 172.16.3.58	172.16.3.59
16	172.16.3.60/30	172.16.3.61 – 172.16.3.62	172.16.3.63
17	172.16.3.64/30	172.16.3.65 – 172.16.3.66	172.16.3.67
18	172.16.3.68/30	172.16.3.69 – 172.16.3.70	172.16.3.71
19	172.16.3.72/30	172.16.3.73 – 172.16.3.74	172.16.3.75
20	172.16.3.76/30	172.16.3.77 – 172.16.3.78	172.16.3.79
21	172.16.3.80/30	172.16.3.81 – 172.16.3.82	172.16.3.83
22	172.16.3.84/30	172.16.3.85 – 172.16.3.86	172.16.3.87
23	172.16.3.88/30	172.16.3.89 – 172.16.3.90	172.16.3.91
24	172.16.3.92/30	172.16.3.93 – 172.16.3.94	172.16.3.95
25	172.16.3.96/30	172.16.3.97 – 172.16.3.98	172.16.3.99
26	172.16.3.100/30	172.16.3.101 – 172.16.3.102	172.16.3.103
27	172.16.3.104/30	172.16.3.105 – 172.16.3.106	172.16.3.107
28	172.16.3.108/30	172.16.3.109 – 172.16.3.110	172.16.3.111
29	172.16.3.112/30	172.16.3.113 – 172.16.3.114	172.16.3.115
30	172.16.3.116/30	172.16.3.117 – 172.16.3.118	172.16.3.119
31	172.16.3.120/30	172.16.3.121 – 172.16.3.122	172.16.3.123
32	172.16.3.124/30	172.16.3.125 – 172.16.3.126	172.16.3.127
33	172.16.3.128/30	172.16.3.129 – 172.16.3.130	172.16.3.131
34	172.16.3.132/30	172.16.3.133 – 172.16.3.134	172.16.3.135
35	172.16.3.136/30	172.16.3.137 – 172.16.3.138	172.16.3.139
36	172.16.3.140/30	172.16.3.141 – 172.16.3.142	172.16.3.143
37	172.16.3.144/30	172.16.3.145 – 172.16.3.146	172.16.3.147
38	172.16.3.148/30	172.16.3.149 – 172.16.3.150	172.16.3.151
39	172.16.3.152/30	172.16.3.153 – 172.16.3.154	172.16.3.155
40	172.16.3.156/30	172.16.3.157 – 172.16.3.158	172.16.3.159
41	172.16.3.160/30	172.16.3.161 – 172.16.3.162	172.16.3.163
42	172.16.3.164/30	172.16.3.165 – 172.16.3.166	172.16.3.167
43	172.16.3.168/30	172.16.3.169 – 172.16.3.170	172.16.3.171
44	172.16.3.172/30	172.16.3.173 – 172.16.3.174	172.16.3.175
45	172.16.3.176/30	172.16.3.177 – 172.16.3.178	172.16.3.179
46	172.16.3.180/30	172.16.3.181 – 172.16.3.182	172.16.3.183
47	172.16.3.184/30	172.16.3.185 – 172.16.3.186	172.16.3.187
48	172.16.3.188/30	172.16.3.189 – 172.16.3.190	172.16.3.191
49	172.16.3.192/30	172.16.3.193 – 172.16.3.194	172.16.3.195
50	172.16.3.196/30	172.16.3.197 – 172.16.3.198	172.16.3.199
51	172.16.3.200/30	172.16.3.201 – 172.16.3.202	172.16.3.203
52	172.16.3.204/30	172.16.3.205 – 172.16.3.206	172.16.3.207
53	172.16.3.208/30	172.16.3.209 – 172.16.3.210	172.16.3.211
54	172.16.3.212/30	172.16.3.213 – 172.16.3.214	172.16.3.215
55	172.16.3.216/30	172.16.3.217 – 172.16.3.218	172.16.3.219
56	172.16.3.220/30	172.16.3.221 – 172.16.3.222	172.16.3.223
57	172.16.3.224/30	172.16.3.225 – 172.16.3.226	172.16.3.227
58	172.16.3.228/30	172.16.3.229 – 172.16.3.230	172.16.3.231
59	172.16.3.232/30	172.16.3.233 – 172.16.3.234	172.16.3.235
60	172.16.3.236/30	172.16.3.237 – 172.16.3.238	172.16.3.239
61	172.16.3.240/30	172.16.3.241 – 172.16.3.242	172.16.3.243
62	172.16.3.244/30	172.16.3.245 – 172.16.3.246	172.16.3.247
63	172.16.3.248/30	172.16.3.249 – 172.16.3.250	172.16.3.251
64	172.16.3.252/30	172.16.3.253 – 172.16.3.254	172.16.3.255

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 →