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)10.18.0.0/16

network10.18.0.0/16

broadcast10.18.255.255

first host10.18.0.1

last host10.18.255.254

subnet mask255.255.0.0

wildcard0.0.255.255

addresses65,536

usable hosts65,534

classA

ipcalc 10.18.0.0/16

address00001010.00010010.00000000.00000000

subnet mask11111111.11111111.00000000.00000000

network00001010.00010010.00000000.00000000

broadcast00001010.00010010.11111111.11111111

green = network part, grey = host part

hex0x0a120000

decimal168951808

reverse dns0.0.18.10.in-addr.arpa

ipv4-mapped::ffff:a12:0

/16 split into /22 · 64 subnets

close ×

#	network	host range	broadcast
1	10.18.0.0/22	10.18.0.1 – 10.18.3.254	10.18.3.255
2	10.18.4.0/22	10.18.4.1 – 10.18.7.254	10.18.7.255
3	10.18.8.0/22	10.18.8.1 – 10.18.11.254	10.18.11.255
4	10.18.12.0/22	10.18.12.1 – 10.18.15.254	10.18.15.255
5	10.18.16.0/22	10.18.16.1 – 10.18.19.254	10.18.19.255
6	10.18.20.0/22	10.18.20.1 – 10.18.23.254	10.18.23.255
7	10.18.24.0/22	10.18.24.1 – 10.18.27.254	10.18.27.255
8	10.18.28.0/22	10.18.28.1 – 10.18.31.254	10.18.31.255
9	10.18.32.0/22	10.18.32.1 – 10.18.35.254	10.18.35.255
10	10.18.36.0/22	10.18.36.1 – 10.18.39.254	10.18.39.255
11	10.18.40.0/22	10.18.40.1 – 10.18.43.254	10.18.43.255
12	10.18.44.0/22	10.18.44.1 – 10.18.47.254	10.18.47.255
13	10.18.48.0/22	10.18.48.1 – 10.18.51.254	10.18.51.255
14	10.18.52.0/22	10.18.52.1 – 10.18.55.254	10.18.55.255
15	10.18.56.0/22	10.18.56.1 – 10.18.59.254	10.18.59.255
16	10.18.60.0/22	10.18.60.1 – 10.18.63.254	10.18.63.255
17	10.18.64.0/22	10.18.64.1 – 10.18.67.254	10.18.67.255
18	10.18.68.0/22	10.18.68.1 – 10.18.71.254	10.18.71.255
19	10.18.72.0/22	10.18.72.1 – 10.18.75.254	10.18.75.255
20	10.18.76.0/22	10.18.76.1 – 10.18.79.254	10.18.79.255
21	10.18.80.0/22	10.18.80.1 – 10.18.83.254	10.18.83.255
22	10.18.84.0/22	10.18.84.1 – 10.18.87.254	10.18.87.255
23	10.18.88.0/22	10.18.88.1 – 10.18.91.254	10.18.91.255
24	10.18.92.0/22	10.18.92.1 – 10.18.95.254	10.18.95.255
25	10.18.96.0/22	10.18.96.1 – 10.18.99.254	10.18.99.255
26	10.18.100.0/22	10.18.100.1 – 10.18.103.254	10.18.103.255
27	10.18.104.0/22	10.18.104.1 – 10.18.107.254	10.18.107.255
28	10.18.108.0/22	10.18.108.1 – 10.18.111.254	10.18.111.255
29	10.18.112.0/22	10.18.112.1 – 10.18.115.254	10.18.115.255
30	10.18.116.0/22	10.18.116.1 – 10.18.119.254	10.18.119.255
31	10.18.120.0/22	10.18.120.1 – 10.18.123.254	10.18.123.255
32	10.18.124.0/22	10.18.124.1 – 10.18.127.254	10.18.127.255
33	10.18.128.0/22	10.18.128.1 – 10.18.131.254	10.18.131.255
34	10.18.132.0/22	10.18.132.1 – 10.18.135.254	10.18.135.255
35	10.18.136.0/22	10.18.136.1 – 10.18.139.254	10.18.139.255
36	10.18.140.0/22	10.18.140.1 – 10.18.143.254	10.18.143.255
37	10.18.144.0/22	10.18.144.1 – 10.18.147.254	10.18.147.255
38	10.18.148.0/22	10.18.148.1 – 10.18.151.254	10.18.151.255
39	10.18.152.0/22	10.18.152.1 – 10.18.155.254	10.18.155.255
40	10.18.156.0/22	10.18.156.1 – 10.18.159.254	10.18.159.255
41	10.18.160.0/22	10.18.160.1 – 10.18.163.254	10.18.163.255
42	10.18.164.0/22	10.18.164.1 – 10.18.167.254	10.18.167.255
43	10.18.168.0/22	10.18.168.1 – 10.18.171.254	10.18.171.255
44	10.18.172.0/22	10.18.172.1 – 10.18.175.254	10.18.175.255
45	10.18.176.0/22	10.18.176.1 – 10.18.179.254	10.18.179.255
46	10.18.180.0/22	10.18.180.1 – 10.18.183.254	10.18.183.255
47	10.18.184.0/22	10.18.184.1 – 10.18.187.254	10.18.187.255
48	10.18.188.0/22	10.18.188.1 – 10.18.191.254	10.18.191.255
49	10.18.192.0/22	10.18.192.1 – 10.18.195.254	10.18.195.255
50	10.18.196.0/22	10.18.196.1 – 10.18.199.254	10.18.199.255
51	10.18.200.0/22	10.18.200.1 – 10.18.203.254	10.18.203.255
52	10.18.204.0/22	10.18.204.1 – 10.18.207.254	10.18.207.255
53	10.18.208.0/22	10.18.208.1 – 10.18.211.254	10.18.211.255
54	10.18.212.0/22	10.18.212.1 – 10.18.215.254	10.18.215.255
55	10.18.216.0/22	10.18.216.1 – 10.18.219.254	10.18.219.255
56	10.18.220.0/22	10.18.220.1 – 10.18.223.254	10.18.223.255
57	10.18.224.0/22	10.18.224.1 – 10.18.227.254	10.18.227.255
58	10.18.228.0/22	10.18.228.1 – 10.18.231.254	10.18.231.255
59	10.18.232.0/22	10.18.232.1 – 10.18.235.254	10.18.235.255
60	10.18.236.0/22	10.18.236.1 – 10.18.239.254	10.18.239.255
61	10.18.240.0/22	10.18.240.1 – 10.18.243.254	10.18.243.255
62	10.18.244.0/22	10.18.244.1 – 10.18.247.254	10.18.247.255
63	10.18.248.0/22	10.18.248.1 – 10.18.251.254	10.18.251.255
64	10.18.252.0/22	10.18.252.1 – 10.18.255.254	10.18.255.255

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 →