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)10.71.97.0/25

network10.71.97.0/25

broadcast10.71.97.127

first host10.71.97.1

last host10.71.97.126

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.71.97.0/25

address00001010.01000111.01100001.00000000

subnet mask11111111.11111111.11111111.10000000

network00001010.01000111.01100001.00000000

broadcast00001010.01000111.01100001.01111111

green = network part, grey = host part

hex0x0a476100

decimal172450048

reverse dns0.97.71.10.in-addr.arpa

ipv4-mapped::ffff:a47:6100

/25 split into /30 · 32 subnets

close ×

#	network	host range	broadcast
1	10.71.97.0/30	10.71.97.1 – 10.71.97.2	10.71.97.3
2	10.71.97.4/30	10.71.97.5 – 10.71.97.6	10.71.97.7
3	10.71.97.8/30	10.71.97.9 – 10.71.97.10	10.71.97.11
4	10.71.97.12/30	10.71.97.13 – 10.71.97.14	10.71.97.15
5	10.71.97.16/30	10.71.97.17 – 10.71.97.18	10.71.97.19
6	10.71.97.20/30	10.71.97.21 – 10.71.97.22	10.71.97.23
7	10.71.97.24/30	10.71.97.25 – 10.71.97.26	10.71.97.27
8	10.71.97.28/30	10.71.97.29 – 10.71.97.30	10.71.97.31
9	10.71.97.32/30	10.71.97.33 – 10.71.97.34	10.71.97.35
10	10.71.97.36/30	10.71.97.37 – 10.71.97.38	10.71.97.39
11	10.71.97.40/30	10.71.97.41 – 10.71.97.42	10.71.97.43
12	10.71.97.44/30	10.71.97.45 – 10.71.97.46	10.71.97.47
13	10.71.97.48/30	10.71.97.49 – 10.71.97.50	10.71.97.51
14	10.71.97.52/30	10.71.97.53 – 10.71.97.54	10.71.97.55
15	10.71.97.56/30	10.71.97.57 – 10.71.97.58	10.71.97.59
16	10.71.97.60/30	10.71.97.61 – 10.71.97.62	10.71.97.63
17	10.71.97.64/30	10.71.97.65 – 10.71.97.66	10.71.97.67
18	10.71.97.68/30	10.71.97.69 – 10.71.97.70	10.71.97.71
19	10.71.97.72/30	10.71.97.73 – 10.71.97.74	10.71.97.75
20	10.71.97.76/30	10.71.97.77 – 10.71.97.78	10.71.97.79
21	10.71.97.80/30	10.71.97.81 – 10.71.97.82	10.71.97.83
22	10.71.97.84/30	10.71.97.85 – 10.71.97.86	10.71.97.87
23	10.71.97.88/30	10.71.97.89 – 10.71.97.90	10.71.97.91
24	10.71.97.92/30	10.71.97.93 – 10.71.97.94	10.71.97.95
25	10.71.97.96/30	10.71.97.97 – 10.71.97.98	10.71.97.99
26	10.71.97.100/30	10.71.97.101 – 10.71.97.102	10.71.97.103
27	10.71.97.104/30	10.71.97.105 – 10.71.97.106	10.71.97.107
28	10.71.97.108/30	10.71.97.109 – 10.71.97.110	10.71.97.111
29	10.71.97.112/30	10.71.97.113 – 10.71.97.114	10.71.97.115
30	10.71.97.116/30	10.71.97.117 – 10.71.97.118	10.71.97.119
31	10.71.97.120/30	10.71.97.121 – 10.71.97.122	10.71.97.123
32	10.71.97.124/30	10.71.97.125 – 10.71.97.126	10.71.97.127

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