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)10.2.16.0/23

network10.2.16.0/23

broadcast10.2.17.255

first host10.2.16.1

last host10.2.17.254

subnet mask255.255.254.0

wildcard0.0.1.255

addresses512

usable hosts510

classA

ipcalc 10.2.16.0/23

address00001010.00000010.00010000.00000000

subnet mask11111111.11111111.11111110.00000000

network00001010.00000010.00010000.00000000

broadcast00001010.00000010.00010001.11111111

green = network part, grey = host part

hex0x0a021000

decimal167907328

reverse dns0.16.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:1000

/23 split into /29 · 64 subnets

close ×

#	network	host range	broadcast
1	10.2.16.0/29	10.2.16.1 – 10.2.16.6	10.2.16.7
2	10.2.16.8/29	10.2.16.9 – 10.2.16.14	10.2.16.15
3	10.2.16.16/29	10.2.16.17 – 10.2.16.22	10.2.16.23
4	10.2.16.24/29	10.2.16.25 – 10.2.16.30	10.2.16.31
5	10.2.16.32/29	10.2.16.33 – 10.2.16.38	10.2.16.39
6	10.2.16.40/29	10.2.16.41 – 10.2.16.46	10.2.16.47
7	10.2.16.48/29	10.2.16.49 – 10.2.16.54	10.2.16.55
8	10.2.16.56/29	10.2.16.57 – 10.2.16.62	10.2.16.63
9	10.2.16.64/29	10.2.16.65 – 10.2.16.70	10.2.16.71
10	10.2.16.72/29	10.2.16.73 – 10.2.16.78	10.2.16.79
11	10.2.16.80/29	10.2.16.81 – 10.2.16.86	10.2.16.87
12	10.2.16.88/29	10.2.16.89 – 10.2.16.94	10.2.16.95
13	10.2.16.96/29	10.2.16.97 – 10.2.16.102	10.2.16.103
14	10.2.16.104/29	10.2.16.105 – 10.2.16.110	10.2.16.111
15	10.2.16.112/29	10.2.16.113 – 10.2.16.118	10.2.16.119
16	10.2.16.120/29	10.2.16.121 – 10.2.16.126	10.2.16.127
17	10.2.16.128/29	10.2.16.129 – 10.2.16.134	10.2.16.135
18	10.2.16.136/29	10.2.16.137 – 10.2.16.142	10.2.16.143
19	10.2.16.144/29	10.2.16.145 – 10.2.16.150	10.2.16.151
20	10.2.16.152/29	10.2.16.153 – 10.2.16.158	10.2.16.159
21	10.2.16.160/29	10.2.16.161 – 10.2.16.166	10.2.16.167
22	10.2.16.168/29	10.2.16.169 – 10.2.16.174	10.2.16.175
23	10.2.16.176/29	10.2.16.177 – 10.2.16.182	10.2.16.183
24	10.2.16.184/29	10.2.16.185 – 10.2.16.190	10.2.16.191
25	10.2.16.192/29	10.2.16.193 – 10.2.16.198	10.2.16.199
26	10.2.16.200/29	10.2.16.201 – 10.2.16.206	10.2.16.207
27	10.2.16.208/29	10.2.16.209 – 10.2.16.214	10.2.16.215
28	10.2.16.216/29	10.2.16.217 – 10.2.16.222	10.2.16.223
29	10.2.16.224/29	10.2.16.225 – 10.2.16.230	10.2.16.231
30	10.2.16.232/29	10.2.16.233 – 10.2.16.238	10.2.16.239
31	10.2.16.240/29	10.2.16.241 – 10.2.16.246	10.2.16.247
32	10.2.16.248/29	10.2.16.249 – 10.2.16.254	10.2.16.255
33	10.2.17.0/29	10.2.17.1 – 10.2.17.6	10.2.17.7
34	10.2.17.8/29	10.2.17.9 – 10.2.17.14	10.2.17.15
35	10.2.17.16/29	10.2.17.17 – 10.2.17.22	10.2.17.23
36	10.2.17.24/29	10.2.17.25 – 10.2.17.30	10.2.17.31
37	10.2.17.32/29	10.2.17.33 – 10.2.17.38	10.2.17.39
38	10.2.17.40/29	10.2.17.41 – 10.2.17.46	10.2.17.47
39	10.2.17.48/29	10.2.17.49 – 10.2.17.54	10.2.17.55
40	10.2.17.56/29	10.2.17.57 – 10.2.17.62	10.2.17.63
41	10.2.17.64/29	10.2.17.65 – 10.2.17.70	10.2.17.71
42	10.2.17.72/29	10.2.17.73 – 10.2.17.78	10.2.17.79
43	10.2.17.80/29	10.2.17.81 – 10.2.17.86	10.2.17.87
44	10.2.17.88/29	10.2.17.89 – 10.2.17.94	10.2.17.95
45	10.2.17.96/29	10.2.17.97 – 10.2.17.102	10.2.17.103
46	10.2.17.104/29	10.2.17.105 – 10.2.17.110	10.2.17.111
47	10.2.17.112/29	10.2.17.113 – 10.2.17.118	10.2.17.119
48	10.2.17.120/29	10.2.17.121 – 10.2.17.126	10.2.17.127
49	10.2.17.128/29	10.2.17.129 – 10.2.17.134	10.2.17.135
50	10.2.17.136/29	10.2.17.137 – 10.2.17.142	10.2.17.143
51	10.2.17.144/29	10.2.17.145 – 10.2.17.150	10.2.17.151
52	10.2.17.152/29	10.2.17.153 – 10.2.17.158	10.2.17.159
53	10.2.17.160/29	10.2.17.161 – 10.2.17.166	10.2.17.167
54	10.2.17.168/29	10.2.17.169 – 10.2.17.174	10.2.17.175
55	10.2.17.176/29	10.2.17.177 – 10.2.17.182	10.2.17.183
56	10.2.17.184/29	10.2.17.185 – 10.2.17.190	10.2.17.191
57	10.2.17.192/29	10.2.17.193 – 10.2.17.198	10.2.17.199
58	10.2.17.200/29	10.2.17.201 – 10.2.17.206	10.2.17.207
59	10.2.17.208/29	10.2.17.209 – 10.2.17.214	10.2.17.215
60	10.2.17.216/29	10.2.17.217 – 10.2.17.222	10.2.17.223
61	10.2.17.224/29	10.2.17.225 – 10.2.17.230	10.2.17.231
62	10.2.17.232/29	10.2.17.233 – 10.2.17.238	10.2.17.239
63	10.2.17.240/29	10.2.17.241 – 10.2.17.246	10.2.17.247
64	10.2.17.248/29	10.2.17.249 – 10.2.17.254	10.2.17.255

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 /23
/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	1
/24	255.255.255.0	256	254	2 split →
/25	255.255.255.128	128	126	4 split →
/26	255.255.255.192	64	62	8 split →
/27	255.255.255.224	32	30	16 split →
/28	255.255.255.240	16	14	32 split →
/29	255.255.255.248	8	6	64 split →
/30	255.255.255.252	4	2	128 split →
/31	255.255.255.254	2	2	256 split →
/32	255.255.255.255	1	1	512 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 →