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)10.139.0.0/16

network10.139.0.0/16

broadcast10.139.255.255

first host10.139.0.1

last host10.139.255.254

subnet mask255.255.0.0

wildcard0.0.255.255

addresses65,536

usable hosts65,534

classA

ipcalc 10.139.0.0/16

address00001010.10001011.00000000.00000000

subnet mask11111111.11111111.00000000.00000000

network00001010.10001011.00000000.00000000

broadcast00001010.10001011.11111111.11111111

green = network part, grey = host part

hex0x0a8b0000

decimal176881664

reverse dns0.0.139.10.in-addr.arpa

ipv4-mapped::ffff:a8b:0

/16 split into /22 · 64 subnets

close ×

#	network	host range	broadcast
1	10.139.0.0/22	10.139.0.1 – 10.139.3.254	10.139.3.255
2	10.139.4.0/22	10.139.4.1 – 10.139.7.254	10.139.7.255
3	10.139.8.0/22	10.139.8.1 – 10.139.11.254	10.139.11.255
4	10.139.12.0/22	10.139.12.1 – 10.139.15.254	10.139.15.255
5	10.139.16.0/22	10.139.16.1 – 10.139.19.254	10.139.19.255
6	10.139.20.0/22	10.139.20.1 – 10.139.23.254	10.139.23.255
7	10.139.24.0/22	10.139.24.1 – 10.139.27.254	10.139.27.255
8	10.139.28.0/22	10.139.28.1 – 10.139.31.254	10.139.31.255
9	10.139.32.0/22	10.139.32.1 – 10.139.35.254	10.139.35.255
10	10.139.36.0/22	10.139.36.1 – 10.139.39.254	10.139.39.255
11	10.139.40.0/22	10.139.40.1 – 10.139.43.254	10.139.43.255
12	10.139.44.0/22	10.139.44.1 – 10.139.47.254	10.139.47.255
13	10.139.48.0/22	10.139.48.1 – 10.139.51.254	10.139.51.255
14	10.139.52.0/22	10.139.52.1 – 10.139.55.254	10.139.55.255
15	10.139.56.0/22	10.139.56.1 – 10.139.59.254	10.139.59.255
16	10.139.60.0/22	10.139.60.1 – 10.139.63.254	10.139.63.255
17	10.139.64.0/22	10.139.64.1 – 10.139.67.254	10.139.67.255
18	10.139.68.0/22	10.139.68.1 – 10.139.71.254	10.139.71.255
19	10.139.72.0/22	10.139.72.1 – 10.139.75.254	10.139.75.255
20	10.139.76.0/22	10.139.76.1 – 10.139.79.254	10.139.79.255
21	10.139.80.0/22	10.139.80.1 – 10.139.83.254	10.139.83.255
22	10.139.84.0/22	10.139.84.1 – 10.139.87.254	10.139.87.255
23	10.139.88.0/22	10.139.88.1 – 10.139.91.254	10.139.91.255
24	10.139.92.0/22	10.139.92.1 – 10.139.95.254	10.139.95.255
25	10.139.96.0/22	10.139.96.1 – 10.139.99.254	10.139.99.255
26	10.139.100.0/22	10.139.100.1 – 10.139.103.254	10.139.103.255
27	10.139.104.0/22	10.139.104.1 – 10.139.107.254	10.139.107.255
28	10.139.108.0/22	10.139.108.1 – 10.139.111.254	10.139.111.255
29	10.139.112.0/22	10.139.112.1 – 10.139.115.254	10.139.115.255
30	10.139.116.0/22	10.139.116.1 – 10.139.119.254	10.139.119.255
31	10.139.120.0/22	10.139.120.1 – 10.139.123.254	10.139.123.255
32	10.139.124.0/22	10.139.124.1 – 10.139.127.254	10.139.127.255
33	10.139.128.0/22	10.139.128.1 – 10.139.131.254	10.139.131.255
34	10.139.132.0/22	10.139.132.1 – 10.139.135.254	10.139.135.255
35	10.139.136.0/22	10.139.136.1 – 10.139.139.254	10.139.139.255
36	10.139.140.0/22	10.139.140.1 – 10.139.143.254	10.139.143.255
37	10.139.144.0/22	10.139.144.1 – 10.139.147.254	10.139.147.255
38	10.139.148.0/22	10.139.148.1 – 10.139.151.254	10.139.151.255
39	10.139.152.0/22	10.139.152.1 – 10.139.155.254	10.139.155.255
40	10.139.156.0/22	10.139.156.1 – 10.139.159.254	10.139.159.255
41	10.139.160.0/22	10.139.160.1 – 10.139.163.254	10.139.163.255
42	10.139.164.0/22	10.139.164.1 – 10.139.167.254	10.139.167.255
43	10.139.168.0/22	10.139.168.1 – 10.139.171.254	10.139.171.255
44	10.139.172.0/22	10.139.172.1 – 10.139.175.254	10.139.175.255
45	10.139.176.0/22	10.139.176.1 – 10.139.179.254	10.139.179.255
46	10.139.180.0/22	10.139.180.1 – 10.139.183.254	10.139.183.255
47	10.139.184.0/22	10.139.184.1 – 10.139.187.254	10.139.187.255
48	10.139.188.0/22	10.139.188.1 – 10.139.191.254	10.139.191.255
49	10.139.192.0/22	10.139.192.1 – 10.139.195.254	10.139.195.255
50	10.139.196.0/22	10.139.196.1 – 10.139.199.254	10.139.199.255
51	10.139.200.0/22	10.139.200.1 – 10.139.203.254	10.139.203.255
52	10.139.204.0/22	10.139.204.1 – 10.139.207.254	10.139.207.255
53	10.139.208.0/22	10.139.208.1 – 10.139.211.254	10.139.211.255
54	10.139.212.0/22	10.139.212.1 – 10.139.215.254	10.139.215.255
55	10.139.216.0/22	10.139.216.1 – 10.139.219.254	10.139.219.255
56	10.139.220.0/22	10.139.220.1 – 10.139.223.254	10.139.223.255
57	10.139.224.0/22	10.139.224.1 – 10.139.227.254	10.139.227.255
58	10.139.228.0/22	10.139.228.1 – 10.139.231.254	10.139.231.255
59	10.139.232.0/22	10.139.232.1 – 10.139.235.254	10.139.235.255
60	10.139.236.0/22	10.139.236.1 – 10.139.239.254	10.139.239.255
61	10.139.240.0/22	10.139.240.1 – 10.139.243.254	10.139.243.255
62	10.139.244.0/22	10.139.244.1 – 10.139.247.254	10.139.247.255
63	10.139.248.0/22	10.139.248.1 – 10.139.251.254	10.139.251.255
64	10.139.252.0/22	10.139.252.1 – 10.139.255.254	10.139.255.255

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 /16
/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	1
/17	255.255.128.0	32,768	32,766	2 split →
/18	255.255.192.0	16,384	16,382	4 split →
/19	255.255.224.0	8,192	8,190	8 split →
/20	255.255.240.0	4,096	4,094	16 split →
/21	255.255.248.0	2,048	2,046	32 split →
/22	255.255.252.0	1,024	1,022	64 split →
/23	255.255.254.0	512	510	128 split →
/24	255.255.255.0	256	254	256 split →
/25	255.255.255.128	128	126	512 split →
/26	255.255.255.192	64	62	1,024 split →
/27	255.255.255.224	32	30	2,048 split →
/28	255.255.255.240	16	14	4,096 split →
/29	255.255.255.248	8	6	8,192 split →
/30	255.255.255.252	4	2	16,384 split →
/31	255.255.255.254	2	2	32,768 split →
/32	255.255.255.255	1	1	65,536 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 →