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)10.15.224.0/20

network10.15.224.0/20

broadcast10.15.239.255

first host10.15.224.1

last host10.15.239.254

subnet mask255.255.240.0

wildcard0.0.15.255

addresses4,096

usable hosts4,094

classA

ipcalc 10.15.224.0/20

address00001010.00001111.11100000.00000000

subnet mask11111111.11111111.11110000.00000000

network00001010.00001111.11100000.00000000

broadcast00001010.00001111.11101111.11111111

green = network part, grey = host part

hex0x0a0fe000

decimal168812544

reverse dns0.224.15.10.in-addr.arpa

ipv4-mapped::ffff:a0f:e000

/20 split into /26 · 64 subnets

close ×

#	network	host range	broadcast
1	10.15.224.0/26	10.15.224.1 – 10.15.224.62	10.15.224.63
2	10.15.224.64/26	10.15.224.65 – 10.15.224.126	10.15.224.127
3	10.15.224.128/26	10.15.224.129 – 10.15.224.190	10.15.224.191
4	10.15.224.192/26	10.15.224.193 – 10.15.224.254	10.15.224.255
5	10.15.225.0/26	10.15.225.1 – 10.15.225.62	10.15.225.63
6	10.15.225.64/26	10.15.225.65 – 10.15.225.126	10.15.225.127
7	10.15.225.128/26	10.15.225.129 – 10.15.225.190	10.15.225.191
8	10.15.225.192/26	10.15.225.193 – 10.15.225.254	10.15.225.255
9	10.15.226.0/26	10.15.226.1 – 10.15.226.62	10.15.226.63
10	10.15.226.64/26	10.15.226.65 – 10.15.226.126	10.15.226.127
11	10.15.226.128/26	10.15.226.129 – 10.15.226.190	10.15.226.191
12	10.15.226.192/26	10.15.226.193 – 10.15.226.254	10.15.226.255
13	10.15.227.0/26	10.15.227.1 – 10.15.227.62	10.15.227.63
14	10.15.227.64/26	10.15.227.65 – 10.15.227.126	10.15.227.127
15	10.15.227.128/26	10.15.227.129 – 10.15.227.190	10.15.227.191
16	10.15.227.192/26	10.15.227.193 – 10.15.227.254	10.15.227.255
17	10.15.228.0/26	10.15.228.1 – 10.15.228.62	10.15.228.63
18	10.15.228.64/26	10.15.228.65 – 10.15.228.126	10.15.228.127
19	10.15.228.128/26	10.15.228.129 – 10.15.228.190	10.15.228.191
20	10.15.228.192/26	10.15.228.193 – 10.15.228.254	10.15.228.255
21	10.15.229.0/26	10.15.229.1 – 10.15.229.62	10.15.229.63
22	10.15.229.64/26	10.15.229.65 – 10.15.229.126	10.15.229.127
23	10.15.229.128/26	10.15.229.129 – 10.15.229.190	10.15.229.191
24	10.15.229.192/26	10.15.229.193 – 10.15.229.254	10.15.229.255
25	10.15.230.0/26	10.15.230.1 – 10.15.230.62	10.15.230.63
26	10.15.230.64/26	10.15.230.65 – 10.15.230.126	10.15.230.127
27	10.15.230.128/26	10.15.230.129 – 10.15.230.190	10.15.230.191
28	10.15.230.192/26	10.15.230.193 – 10.15.230.254	10.15.230.255
29	10.15.231.0/26	10.15.231.1 – 10.15.231.62	10.15.231.63
30	10.15.231.64/26	10.15.231.65 – 10.15.231.126	10.15.231.127
31	10.15.231.128/26	10.15.231.129 – 10.15.231.190	10.15.231.191
32	10.15.231.192/26	10.15.231.193 – 10.15.231.254	10.15.231.255
33	10.15.232.0/26	10.15.232.1 – 10.15.232.62	10.15.232.63
34	10.15.232.64/26	10.15.232.65 – 10.15.232.126	10.15.232.127
35	10.15.232.128/26	10.15.232.129 – 10.15.232.190	10.15.232.191
36	10.15.232.192/26	10.15.232.193 – 10.15.232.254	10.15.232.255
37	10.15.233.0/26	10.15.233.1 – 10.15.233.62	10.15.233.63
38	10.15.233.64/26	10.15.233.65 – 10.15.233.126	10.15.233.127
39	10.15.233.128/26	10.15.233.129 – 10.15.233.190	10.15.233.191
40	10.15.233.192/26	10.15.233.193 – 10.15.233.254	10.15.233.255
41	10.15.234.0/26	10.15.234.1 – 10.15.234.62	10.15.234.63
42	10.15.234.64/26	10.15.234.65 – 10.15.234.126	10.15.234.127
43	10.15.234.128/26	10.15.234.129 – 10.15.234.190	10.15.234.191
44	10.15.234.192/26	10.15.234.193 – 10.15.234.254	10.15.234.255
45	10.15.235.0/26	10.15.235.1 – 10.15.235.62	10.15.235.63
46	10.15.235.64/26	10.15.235.65 – 10.15.235.126	10.15.235.127
47	10.15.235.128/26	10.15.235.129 – 10.15.235.190	10.15.235.191
48	10.15.235.192/26	10.15.235.193 – 10.15.235.254	10.15.235.255
49	10.15.236.0/26	10.15.236.1 – 10.15.236.62	10.15.236.63
50	10.15.236.64/26	10.15.236.65 – 10.15.236.126	10.15.236.127
51	10.15.236.128/26	10.15.236.129 – 10.15.236.190	10.15.236.191
52	10.15.236.192/26	10.15.236.193 – 10.15.236.254	10.15.236.255
53	10.15.237.0/26	10.15.237.1 – 10.15.237.62	10.15.237.63
54	10.15.237.64/26	10.15.237.65 – 10.15.237.126	10.15.237.127
55	10.15.237.128/26	10.15.237.129 – 10.15.237.190	10.15.237.191
56	10.15.237.192/26	10.15.237.193 – 10.15.237.254	10.15.237.255
57	10.15.238.0/26	10.15.238.1 – 10.15.238.62	10.15.238.63
58	10.15.238.64/26	10.15.238.65 – 10.15.238.126	10.15.238.127
59	10.15.238.128/26	10.15.238.129 – 10.15.238.190	10.15.238.191
60	10.15.238.192/26	10.15.238.193 – 10.15.238.254	10.15.238.255
61	10.15.239.0/26	10.15.239.1 – 10.15.239.62	10.15.239.63
62	10.15.239.64/26	10.15.239.65 – 10.15.239.126	10.15.239.127
63	10.15.239.128/26	10.15.239.129 – 10.15.239.190	10.15.239.191
64	10.15.239.192/26	10.15.239.193 – 10.15.239.254	10.15.239.255

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 →