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)10.15.176.0/20

network10.15.176.0/20

broadcast10.15.191.255

first host10.15.176.1

last host10.15.191.254

subnet mask255.255.240.0

wildcard0.0.15.255

addresses4,096

usable hosts4,094

classA

ipcalc 10.15.176.0/20

address00001010.00001111.10110000.00000000

subnet mask11111111.11111111.11110000.00000000

network00001010.00001111.10110000.00000000

broadcast00001010.00001111.10111111.11111111

green = network part, grey = host part

hex0x0a0fb000

decimal168800256

reverse dns0.176.15.10.in-addr.arpa

ipv4-mapped::ffff:a0f:b000

/20 split into /26 · 64 subnets

close ×

#	network	host range	broadcast
1	10.15.176.0/26	10.15.176.1 – 10.15.176.62	10.15.176.63
2	10.15.176.64/26	10.15.176.65 – 10.15.176.126	10.15.176.127
3	10.15.176.128/26	10.15.176.129 – 10.15.176.190	10.15.176.191
4	10.15.176.192/26	10.15.176.193 – 10.15.176.254	10.15.176.255
5	10.15.177.0/26	10.15.177.1 – 10.15.177.62	10.15.177.63
6	10.15.177.64/26	10.15.177.65 – 10.15.177.126	10.15.177.127
7	10.15.177.128/26	10.15.177.129 – 10.15.177.190	10.15.177.191
8	10.15.177.192/26	10.15.177.193 – 10.15.177.254	10.15.177.255
9	10.15.178.0/26	10.15.178.1 – 10.15.178.62	10.15.178.63
10	10.15.178.64/26	10.15.178.65 – 10.15.178.126	10.15.178.127
11	10.15.178.128/26	10.15.178.129 – 10.15.178.190	10.15.178.191
12	10.15.178.192/26	10.15.178.193 – 10.15.178.254	10.15.178.255
13	10.15.179.0/26	10.15.179.1 – 10.15.179.62	10.15.179.63
14	10.15.179.64/26	10.15.179.65 – 10.15.179.126	10.15.179.127
15	10.15.179.128/26	10.15.179.129 – 10.15.179.190	10.15.179.191
16	10.15.179.192/26	10.15.179.193 – 10.15.179.254	10.15.179.255
17	10.15.180.0/26	10.15.180.1 – 10.15.180.62	10.15.180.63
18	10.15.180.64/26	10.15.180.65 – 10.15.180.126	10.15.180.127
19	10.15.180.128/26	10.15.180.129 – 10.15.180.190	10.15.180.191
20	10.15.180.192/26	10.15.180.193 – 10.15.180.254	10.15.180.255
21	10.15.181.0/26	10.15.181.1 – 10.15.181.62	10.15.181.63
22	10.15.181.64/26	10.15.181.65 – 10.15.181.126	10.15.181.127
23	10.15.181.128/26	10.15.181.129 – 10.15.181.190	10.15.181.191
24	10.15.181.192/26	10.15.181.193 – 10.15.181.254	10.15.181.255
25	10.15.182.0/26	10.15.182.1 – 10.15.182.62	10.15.182.63
26	10.15.182.64/26	10.15.182.65 – 10.15.182.126	10.15.182.127
27	10.15.182.128/26	10.15.182.129 – 10.15.182.190	10.15.182.191
28	10.15.182.192/26	10.15.182.193 – 10.15.182.254	10.15.182.255
29	10.15.183.0/26	10.15.183.1 – 10.15.183.62	10.15.183.63
30	10.15.183.64/26	10.15.183.65 – 10.15.183.126	10.15.183.127
31	10.15.183.128/26	10.15.183.129 – 10.15.183.190	10.15.183.191
32	10.15.183.192/26	10.15.183.193 – 10.15.183.254	10.15.183.255
33	10.15.184.0/26	10.15.184.1 – 10.15.184.62	10.15.184.63
34	10.15.184.64/26	10.15.184.65 – 10.15.184.126	10.15.184.127
35	10.15.184.128/26	10.15.184.129 – 10.15.184.190	10.15.184.191
36	10.15.184.192/26	10.15.184.193 – 10.15.184.254	10.15.184.255
37	10.15.185.0/26	10.15.185.1 – 10.15.185.62	10.15.185.63
38	10.15.185.64/26	10.15.185.65 – 10.15.185.126	10.15.185.127
39	10.15.185.128/26	10.15.185.129 – 10.15.185.190	10.15.185.191
40	10.15.185.192/26	10.15.185.193 – 10.15.185.254	10.15.185.255
41	10.15.186.0/26	10.15.186.1 – 10.15.186.62	10.15.186.63
42	10.15.186.64/26	10.15.186.65 – 10.15.186.126	10.15.186.127
43	10.15.186.128/26	10.15.186.129 – 10.15.186.190	10.15.186.191
44	10.15.186.192/26	10.15.186.193 – 10.15.186.254	10.15.186.255
45	10.15.187.0/26	10.15.187.1 – 10.15.187.62	10.15.187.63
46	10.15.187.64/26	10.15.187.65 – 10.15.187.126	10.15.187.127
47	10.15.187.128/26	10.15.187.129 – 10.15.187.190	10.15.187.191
48	10.15.187.192/26	10.15.187.193 – 10.15.187.254	10.15.187.255
49	10.15.188.0/26	10.15.188.1 – 10.15.188.62	10.15.188.63
50	10.15.188.64/26	10.15.188.65 – 10.15.188.126	10.15.188.127
51	10.15.188.128/26	10.15.188.129 – 10.15.188.190	10.15.188.191
52	10.15.188.192/26	10.15.188.193 – 10.15.188.254	10.15.188.255
53	10.15.189.0/26	10.15.189.1 – 10.15.189.62	10.15.189.63
54	10.15.189.64/26	10.15.189.65 – 10.15.189.126	10.15.189.127
55	10.15.189.128/26	10.15.189.129 – 10.15.189.190	10.15.189.191
56	10.15.189.192/26	10.15.189.193 – 10.15.189.254	10.15.189.255
57	10.15.190.0/26	10.15.190.1 – 10.15.190.62	10.15.190.63
58	10.15.190.64/26	10.15.190.65 – 10.15.190.126	10.15.190.127
59	10.15.190.128/26	10.15.190.129 – 10.15.190.190	10.15.190.191
60	10.15.190.192/26	10.15.190.193 – 10.15.190.254	10.15.190.255
61	10.15.191.0/26	10.15.191.1 – 10.15.191.62	10.15.191.63
62	10.15.191.64/26	10.15.191.65 – 10.15.191.126	10.15.191.127
63	10.15.191.128/26	10.15.191.129 – 10.15.191.190	10.15.191.191
64	10.15.191.192/26	10.15.191.193 – 10.15.191.254	10.15.191.255

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 /20
/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	1
/21	255.255.248.0	2,048	2,046	2 split →
/22	255.255.252.0	1,024	1,022	4 split →
/23	255.255.254.0	512	510	8 split →
/24	255.255.255.0	256	254	16 split →
/25	255.255.255.128	128	126	32 split →
/26	255.255.255.192	64	62	64 split →
/27	255.255.255.224	32	30	128 split →
/28	255.255.255.240	16	14	256 split →
/29	255.255.255.248	8	6	512 split →
/30	255.255.255.252	4	2	1,024 split →
/31	255.255.255.254	2	2	2,048 split →
/32	255.255.255.255	1	1	4,096 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 →