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)10.8.72.0/23

network10.8.72.0/23

broadcast10.8.73.255

first host10.8.72.1

last host10.8.73.254

subnet mask255.255.254.0

wildcard0.0.1.255

addresses512

usable hosts510

classA

ipcalc 10.8.72.0/23

address00001010.00001000.01001000.00000000

subnet mask11111111.11111111.11111110.00000000

network00001010.00001000.01001000.00000000

broadcast00001010.00001000.01001001.11111111

green = network part, grey = host part

hex0x0a084800

decimal168314880

reverse dns0.72.8.10.in-addr.arpa

ipv4-mapped::ffff:a08:4800

/23 split into /28 · 32 subnets

close ×

#	network	host range	broadcast
1	10.8.72.0/28	10.8.72.1 – 10.8.72.14	10.8.72.15
2	10.8.72.16/28	10.8.72.17 – 10.8.72.30	10.8.72.31
3	10.8.72.32/28	10.8.72.33 – 10.8.72.46	10.8.72.47
4	10.8.72.48/28	10.8.72.49 – 10.8.72.62	10.8.72.63
5	10.8.72.64/28	10.8.72.65 – 10.8.72.78	10.8.72.79
6	10.8.72.80/28	10.8.72.81 – 10.8.72.94	10.8.72.95
7	10.8.72.96/28	10.8.72.97 – 10.8.72.110	10.8.72.111
8	10.8.72.112/28	10.8.72.113 – 10.8.72.126	10.8.72.127
9	10.8.72.128/28	10.8.72.129 – 10.8.72.142	10.8.72.143
10	10.8.72.144/28	10.8.72.145 – 10.8.72.158	10.8.72.159
11	10.8.72.160/28	10.8.72.161 – 10.8.72.174	10.8.72.175
12	10.8.72.176/28	10.8.72.177 – 10.8.72.190	10.8.72.191
13	10.8.72.192/28	10.8.72.193 – 10.8.72.206	10.8.72.207
14	10.8.72.208/28	10.8.72.209 – 10.8.72.222	10.8.72.223
15	10.8.72.224/28	10.8.72.225 – 10.8.72.238	10.8.72.239
16	10.8.72.240/28	10.8.72.241 – 10.8.72.254	10.8.72.255
17	10.8.73.0/28	10.8.73.1 – 10.8.73.14	10.8.73.15
18	10.8.73.16/28	10.8.73.17 – 10.8.73.30	10.8.73.31
19	10.8.73.32/28	10.8.73.33 – 10.8.73.46	10.8.73.47
20	10.8.73.48/28	10.8.73.49 – 10.8.73.62	10.8.73.63
21	10.8.73.64/28	10.8.73.65 – 10.8.73.78	10.8.73.79
22	10.8.73.80/28	10.8.73.81 – 10.8.73.94	10.8.73.95
23	10.8.73.96/28	10.8.73.97 – 10.8.73.110	10.8.73.111
24	10.8.73.112/28	10.8.73.113 – 10.8.73.126	10.8.73.127
25	10.8.73.128/28	10.8.73.129 – 10.8.73.142	10.8.73.143
26	10.8.73.144/28	10.8.73.145 – 10.8.73.158	10.8.73.159
27	10.8.73.160/28	10.8.73.161 – 10.8.73.174	10.8.73.175
28	10.8.73.176/28	10.8.73.177 – 10.8.73.190	10.8.73.191
29	10.8.73.192/28	10.8.73.193 – 10.8.73.206	10.8.73.207
30	10.8.73.208/28	10.8.73.209 – 10.8.73.222	10.8.73.223
31	10.8.73.224/28	10.8.73.225 – 10.8.73.238	10.8.73.239
32	10.8.73.240/28	10.8.73.241 – 10.8.73.254	10.8.73.255

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