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)10.0.99.0/27

network10.0.99.0/27

broadcast10.0.99.31

first host10.0.99.1

last host10.0.99.30

subnet mask255.255.255.224

wildcard0.0.0.31

addresses32

usable hosts30

classA

ipcalc 10.0.99.0/27

address00001010.00000000.01100011.00000000

subnet mask11111111.11111111.11111111.11100000

network00001010.00000000.01100011.00000000

broadcast00001010.00000000.01100011.00011111

green = network part, grey = host part

hex0x0a006300

decimal167797504

reverse dns0.99.0.10.in-addr.arpa

ipv4-mapped::ffff:a00:6300

/27 split into /32 · 32 subnets

close ×

#	network	host range	broadcast
1	10.0.99.0/32	10.0.99.0 – 10.0.99.0	10.0.99.0
2	10.0.99.1/32	10.0.99.1 – 10.0.99.1	10.0.99.1
3	10.0.99.2/32	10.0.99.2 – 10.0.99.2	10.0.99.2
4	10.0.99.3/32	10.0.99.3 – 10.0.99.3	10.0.99.3
5	10.0.99.4/32	10.0.99.4 – 10.0.99.4	10.0.99.4
6	10.0.99.5/32	10.0.99.5 – 10.0.99.5	10.0.99.5
7	10.0.99.6/32	10.0.99.6 – 10.0.99.6	10.0.99.6
8	10.0.99.7/32	10.0.99.7 – 10.0.99.7	10.0.99.7
9	10.0.99.8/32	10.0.99.8 – 10.0.99.8	10.0.99.8
10	10.0.99.9/32	10.0.99.9 – 10.0.99.9	10.0.99.9
11	10.0.99.10/32	10.0.99.10 – 10.0.99.10	10.0.99.10
12	10.0.99.11/32	10.0.99.11 – 10.0.99.11	10.0.99.11
13	10.0.99.12/32	10.0.99.12 – 10.0.99.12	10.0.99.12
14	10.0.99.13/32	10.0.99.13 – 10.0.99.13	10.0.99.13
15	10.0.99.14/32	10.0.99.14 – 10.0.99.14	10.0.99.14
16	10.0.99.15/32	10.0.99.15 – 10.0.99.15	10.0.99.15
17	10.0.99.16/32	10.0.99.16 – 10.0.99.16	10.0.99.16
18	10.0.99.17/32	10.0.99.17 – 10.0.99.17	10.0.99.17
19	10.0.99.18/32	10.0.99.18 – 10.0.99.18	10.0.99.18
20	10.0.99.19/32	10.0.99.19 – 10.0.99.19	10.0.99.19
21	10.0.99.20/32	10.0.99.20 – 10.0.99.20	10.0.99.20
22	10.0.99.21/32	10.0.99.21 – 10.0.99.21	10.0.99.21
23	10.0.99.22/32	10.0.99.22 – 10.0.99.22	10.0.99.22
24	10.0.99.23/32	10.0.99.23 – 10.0.99.23	10.0.99.23
25	10.0.99.24/32	10.0.99.24 – 10.0.99.24	10.0.99.24
26	10.0.99.25/32	10.0.99.25 – 10.0.99.25	10.0.99.25
27	10.0.99.26/32	10.0.99.26 – 10.0.99.26	10.0.99.26
28	10.0.99.27/32	10.0.99.27 – 10.0.99.27	10.0.99.27
29	10.0.99.28/32	10.0.99.28 – 10.0.99.28	10.0.99.28
30	10.0.99.29/32	10.0.99.29 – 10.0.99.29	10.0.99.29
31	10.0.99.30/32	10.0.99.30 – 10.0.99.30	10.0.99.30
32	10.0.99.31/32	10.0.99.31 – 10.0.99.31	10.0.99.31

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 /27
/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	-
/24	255.255.255.0	256	254	-
/25	255.255.255.128	128	126	-
/26	255.255.255.192	64	62	-
/27	255.255.255.224	32	30	1
/28	255.255.255.240	16	14	2 split →
/29	255.255.255.248	8	6	4 split →
/30	255.255.255.252	4	2	8 split →
/31	255.255.255.254	2	2	16 split →
/32	255.255.255.255	1	1	32 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 →