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)10.15.192.0/20

network10.15.192.0/20

broadcast10.15.207.255

first host10.15.192.1

last host10.15.207.254

subnet mask255.255.240.0

wildcard0.0.15.255

addresses4,096

usable hosts4,094

classA

ipcalc 10.15.192.0/20

address00001010.00001111.11000000.00000000

subnet mask11111111.11111111.11110000.00000000

network00001010.00001111.11000000.00000000

broadcast00001010.00001111.11001111.11111111

green = network part, grey = host part

hex0x0a0fc000

decimal168804352

reverse dns0.192.15.10.in-addr.arpa

ipv4-mapped::ffff:a0f:c000

/20 split into /26 · 64 subnets

close ×

#	network	host range	broadcast
1	10.15.192.0/26	10.15.192.1 – 10.15.192.62	10.15.192.63
2	10.15.192.64/26	10.15.192.65 – 10.15.192.126	10.15.192.127
3	10.15.192.128/26	10.15.192.129 – 10.15.192.190	10.15.192.191
4	10.15.192.192/26	10.15.192.193 – 10.15.192.254	10.15.192.255
5	10.15.193.0/26	10.15.193.1 – 10.15.193.62	10.15.193.63
6	10.15.193.64/26	10.15.193.65 – 10.15.193.126	10.15.193.127
7	10.15.193.128/26	10.15.193.129 – 10.15.193.190	10.15.193.191
8	10.15.193.192/26	10.15.193.193 – 10.15.193.254	10.15.193.255
9	10.15.194.0/26	10.15.194.1 – 10.15.194.62	10.15.194.63
10	10.15.194.64/26	10.15.194.65 – 10.15.194.126	10.15.194.127
11	10.15.194.128/26	10.15.194.129 – 10.15.194.190	10.15.194.191
12	10.15.194.192/26	10.15.194.193 – 10.15.194.254	10.15.194.255
13	10.15.195.0/26	10.15.195.1 – 10.15.195.62	10.15.195.63
14	10.15.195.64/26	10.15.195.65 – 10.15.195.126	10.15.195.127
15	10.15.195.128/26	10.15.195.129 – 10.15.195.190	10.15.195.191
16	10.15.195.192/26	10.15.195.193 – 10.15.195.254	10.15.195.255
17	10.15.196.0/26	10.15.196.1 – 10.15.196.62	10.15.196.63
18	10.15.196.64/26	10.15.196.65 – 10.15.196.126	10.15.196.127
19	10.15.196.128/26	10.15.196.129 – 10.15.196.190	10.15.196.191
20	10.15.196.192/26	10.15.196.193 – 10.15.196.254	10.15.196.255
21	10.15.197.0/26	10.15.197.1 – 10.15.197.62	10.15.197.63
22	10.15.197.64/26	10.15.197.65 – 10.15.197.126	10.15.197.127
23	10.15.197.128/26	10.15.197.129 – 10.15.197.190	10.15.197.191
24	10.15.197.192/26	10.15.197.193 – 10.15.197.254	10.15.197.255
25	10.15.198.0/26	10.15.198.1 – 10.15.198.62	10.15.198.63
26	10.15.198.64/26	10.15.198.65 – 10.15.198.126	10.15.198.127
27	10.15.198.128/26	10.15.198.129 – 10.15.198.190	10.15.198.191
28	10.15.198.192/26	10.15.198.193 – 10.15.198.254	10.15.198.255
29	10.15.199.0/26	10.15.199.1 – 10.15.199.62	10.15.199.63
30	10.15.199.64/26	10.15.199.65 – 10.15.199.126	10.15.199.127
31	10.15.199.128/26	10.15.199.129 – 10.15.199.190	10.15.199.191
32	10.15.199.192/26	10.15.199.193 – 10.15.199.254	10.15.199.255
33	10.15.200.0/26	10.15.200.1 – 10.15.200.62	10.15.200.63
34	10.15.200.64/26	10.15.200.65 – 10.15.200.126	10.15.200.127
35	10.15.200.128/26	10.15.200.129 – 10.15.200.190	10.15.200.191
36	10.15.200.192/26	10.15.200.193 – 10.15.200.254	10.15.200.255
37	10.15.201.0/26	10.15.201.1 – 10.15.201.62	10.15.201.63
38	10.15.201.64/26	10.15.201.65 – 10.15.201.126	10.15.201.127
39	10.15.201.128/26	10.15.201.129 – 10.15.201.190	10.15.201.191
40	10.15.201.192/26	10.15.201.193 – 10.15.201.254	10.15.201.255
41	10.15.202.0/26	10.15.202.1 – 10.15.202.62	10.15.202.63
42	10.15.202.64/26	10.15.202.65 – 10.15.202.126	10.15.202.127
43	10.15.202.128/26	10.15.202.129 – 10.15.202.190	10.15.202.191
44	10.15.202.192/26	10.15.202.193 – 10.15.202.254	10.15.202.255
45	10.15.203.0/26	10.15.203.1 – 10.15.203.62	10.15.203.63
46	10.15.203.64/26	10.15.203.65 – 10.15.203.126	10.15.203.127
47	10.15.203.128/26	10.15.203.129 – 10.15.203.190	10.15.203.191
48	10.15.203.192/26	10.15.203.193 – 10.15.203.254	10.15.203.255
49	10.15.204.0/26	10.15.204.1 – 10.15.204.62	10.15.204.63
50	10.15.204.64/26	10.15.204.65 – 10.15.204.126	10.15.204.127
51	10.15.204.128/26	10.15.204.129 – 10.15.204.190	10.15.204.191
52	10.15.204.192/26	10.15.204.193 – 10.15.204.254	10.15.204.255
53	10.15.205.0/26	10.15.205.1 – 10.15.205.62	10.15.205.63
54	10.15.205.64/26	10.15.205.65 – 10.15.205.126	10.15.205.127
55	10.15.205.128/26	10.15.205.129 – 10.15.205.190	10.15.205.191
56	10.15.205.192/26	10.15.205.193 – 10.15.205.254	10.15.205.255
57	10.15.206.0/26	10.15.206.1 – 10.15.206.62	10.15.206.63
58	10.15.206.64/26	10.15.206.65 – 10.15.206.126	10.15.206.127
59	10.15.206.128/26	10.15.206.129 – 10.15.206.190	10.15.206.191
60	10.15.206.192/26	10.15.206.193 – 10.15.206.254	10.15.206.255
61	10.15.207.0/26	10.15.207.1 – 10.15.207.62	10.15.207.63
62	10.15.207.64/26	10.15.207.65 – 10.15.207.126	10.15.207.127
63	10.15.207.128/26	10.15.207.129 – 10.15.207.190	10.15.207.191
64	10.15.207.192/26	10.15.207.193 – 10.15.207.254	10.15.207.255

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 →