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)10.1.160.0/21

network10.1.160.0/21

broadcast10.1.167.255

first host10.1.160.1

last host10.1.167.254

subnet mask255.255.248.0

wildcard0.0.7.255

addresses2,048

usable hosts2,046

classA

ipcalc 10.1.160.0/21

address00001010.00000001.10100000.00000000

subnet mask11111111.11111111.11111000.00000000

network00001010.00000001.10100000.00000000

broadcast00001010.00000001.10100111.11111111

green = network part, grey = host part

hex0x0a01a000

decimal167878656

reverse dns0.160.1.10.in-addr.arpa

ipv4-mapped::ffff:a01:a000

/21 split into /27 · 64 subnets

close ×

#	network	host range	broadcast
1	10.1.160.0/27	10.1.160.1 – 10.1.160.30	10.1.160.31
2	10.1.160.32/27	10.1.160.33 – 10.1.160.62	10.1.160.63
3	10.1.160.64/27	10.1.160.65 – 10.1.160.94	10.1.160.95
4	10.1.160.96/27	10.1.160.97 – 10.1.160.126	10.1.160.127
5	10.1.160.128/27	10.1.160.129 – 10.1.160.158	10.1.160.159
6	10.1.160.160/27	10.1.160.161 – 10.1.160.190	10.1.160.191
7	10.1.160.192/27	10.1.160.193 – 10.1.160.222	10.1.160.223
8	10.1.160.224/27	10.1.160.225 – 10.1.160.254	10.1.160.255
9	10.1.161.0/27	10.1.161.1 – 10.1.161.30	10.1.161.31
10	10.1.161.32/27	10.1.161.33 – 10.1.161.62	10.1.161.63
11	10.1.161.64/27	10.1.161.65 – 10.1.161.94	10.1.161.95
12	10.1.161.96/27	10.1.161.97 – 10.1.161.126	10.1.161.127
13	10.1.161.128/27	10.1.161.129 – 10.1.161.158	10.1.161.159
14	10.1.161.160/27	10.1.161.161 – 10.1.161.190	10.1.161.191
15	10.1.161.192/27	10.1.161.193 – 10.1.161.222	10.1.161.223
16	10.1.161.224/27	10.1.161.225 – 10.1.161.254	10.1.161.255
17	10.1.162.0/27	10.1.162.1 – 10.1.162.30	10.1.162.31
18	10.1.162.32/27	10.1.162.33 – 10.1.162.62	10.1.162.63
19	10.1.162.64/27	10.1.162.65 – 10.1.162.94	10.1.162.95
20	10.1.162.96/27	10.1.162.97 – 10.1.162.126	10.1.162.127
21	10.1.162.128/27	10.1.162.129 – 10.1.162.158	10.1.162.159
22	10.1.162.160/27	10.1.162.161 – 10.1.162.190	10.1.162.191
23	10.1.162.192/27	10.1.162.193 – 10.1.162.222	10.1.162.223
24	10.1.162.224/27	10.1.162.225 – 10.1.162.254	10.1.162.255
25	10.1.163.0/27	10.1.163.1 – 10.1.163.30	10.1.163.31
26	10.1.163.32/27	10.1.163.33 – 10.1.163.62	10.1.163.63
27	10.1.163.64/27	10.1.163.65 – 10.1.163.94	10.1.163.95
28	10.1.163.96/27	10.1.163.97 – 10.1.163.126	10.1.163.127
29	10.1.163.128/27	10.1.163.129 – 10.1.163.158	10.1.163.159
30	10.1.163.160/27	10.1.163.161 – 10.1.163.190	10.1.163.191
31	10.1.163.192/27	10.1.163.193 – 10.1.163.222	10.1.163.223
32	10.1.163.224/27	10.1.163.225 – 10.1.163.254	10.1.163.255
33	10.1.164.0/27	10.1.164.1 – 10.1.164.30	10.1.164.31
34	10.1.164.32/27	10.1.164.33 – 10.1.164.62	10.1.164.63
35	10.1.164.64/27	10.1.164.65 – 10.1.164.94	10.1.164.95
36	10.1.164.96/27	10.1.164.97 – 10.1.164.126	10.1.164.127
37	10.1.164.128/27	10.1.164.129 – 10.1.164.158	10.1.164.159
38	10.1.164.160/27	10.1.164.161 – 10.1.164.190	10.1.164.191
39	10.1.164.192/27	10.1.164.193 – 10.1.164.222	10.1.164.223
40	10.1.164.224/27	10.1.164.225 – 10.1.164.254	10.1.164.255
41	10.1.165.0/27	10.1.165.1 – 10.1.165.30	10.1.165.31
42	10.1.165.32/27	10.1.165.33 – 10.1.165.62	10.1.165.63
43	10.1.165.64/27	10.1.165.65 – 10.1.165.94	10.1.165.95
44	10.1.165.96/27	10.1.165.97 – 10.1.165.126	10.1.165.127
45	10.1.165.128/27	10.1.165.129 – 10.1.165.158	10.1.165.159
46	10.1.165.160/27	10.1.165.161 – 10.1.165.190	10.1.165.191
47	10.1.165.192/27	10.1.165.193 – 10.1.165.222	10.1.165.223
48	10.1.165.224/27	10.1.165.225 – 10.1.165.254	10.1.165.255
49	10.1.166.0/27	10.1.166.1 – 10.1.166.30	10.1.166.31
50	10.1.166.32/27	10.1.166.33 – 10.1.166.62	10.1.166.63
51	10.1.166.64/27	10.1.166.65 – 10.1.166.94	10.1.166.95
52	10.1.166.96/27	10.1.166.97 – 10.1.166.126	10.1.166.127
53	10.1.166.128/27	10.1.166.129 – 10.1.166.158	10.1.166.159
54	10.1.166.160/27	10.1.166.161 – 10.1.166.190	10.1.166.191
55	10.1.166.192/27	10.1.166.193 – 10.1.166.222	10.1.166.223
56	10.1.166.224/27	10.1.166.225 – 10.1.166.254	10.1.166.255
57	10.1.167.0/27	10.1.167.1 – 10.1.167.30	10.1.167.31
58	10.1.167.32/27	10.1.167.33 – 10.1.167.62	10.1.167.63
59	10.1.167.64/27	10.1.167.65 – 10.1.167.94	10.1.167.95
60	10.1.167.96/27	10.1.167.97 – 10.1.167.126	10.1.167.127
61	10.1.167.128/27	10.1.167.129 – 10.1.167.158	10.1.167.159
62	10.1.167.160/27	10.1.167.161 – 10.1.167.190	10.1.167.191
63	10.1.167.192/27	10.1.167.193 – 10.1.167.222	10.1.167.223
64	10.1.167.224/27	10.1.167.225 – 10.1.167.254	10.1.167.255

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 /21
/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	1
/22	255.255.252.0	1,024	1,022	2 split →
/23	255.255.254.0	512	510	4 split →
/24	255.255.255.0	256	254	8 split →
/25	255.255.255.128	128	126	16 split →
/26	255.255.255.192	64	62	32 split →
/27	255.255.255.224	32	30	64 split →
/28	255.255.255.240	16	14	128 split →
/29	255.255.255.248	8	6	256 split →
/30	255.255.255.252	4	2	512 split →
/31	255.255.255.254	2	2	1,024 split →
/32	255.255.255.255	1	1	2,048 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 →