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)10.167.123.0/25

network10.167.123.0/25

broadcast10.167.123.127

first host10.167.123.1

last host10.167.123.126

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.167.123.0/25

address00001010.10100111.01111011.00000000

subnet mask11111111.11111111.11111111.10000000

network00001010.10100111.01111011.00000000

broadcast00001010.10100111.01111011.01111111

green = network part, grey = host part

hex0x0aa77b00

decimal178748160

reverse dns0.123.167.10.in-addr.arpa

ipv4-mapped::ffff:aa7:7b00

/25 split into /31 · 64 subnets

close ×

#	network	host range	broadcast
1	10.167.123.0/31	10.167.123.0 – 10.167.123.1	10.167.123.1
2	10.167.123.2/31	10.167.123.2 – 10.167.123.3	10.167.123.3
3	10.167.123.4/31	10.167.123.4 – 10.167.123.5	10.167.123.5
4	10.167.123.6/31	10.167.123.6 – 10.167.123.7	10.167.123.7
5	10.167.123.8/31	10.167.123.8 – 10.167.123.9	10.167.123.9
6	10.167.123.10/31	10.167.123.10 – 10.167.123.11	10.167.123.11
7	10.167.123.12/31	10.167.123.12 – 10.167.123.13	10.167.123.13
8	10.167.123.14/31	10.167.123.14 – 10.167.123.15	10.167.123.15
9	10.167.123.16/31	10.167.123.16 – 10.167.123.17	10.167.123.17
10	10.167.123.18/31	10.167.123.18 – 10.167.123.19	10.167.123.19
11	10.167.123.20/31	10.167.123.20 – 10.167.123.21	10.167.123.21
12	10.167.123.22/31	10.167.123.22 – 10.167.123.23	10.167.123.23
13	10.167.123.24/31	10.167.123.24 – 10.167.123.25	10.167.123.25
14	10.167.123.26/31	10.167.123.26 – 10.167.123.27	10.167.123.27
15	10.167.123.28/31	10.167.123.28 – 10.167.123.29	10.167.123.29
16	10.167.123.30/31	10.167.123.30 – 10.167.123.31	10.167.123.31
17	10.167.123.32/31	10.167.123.32 – 10.167.123.33	10.167.123.33
18	10.167.123.34/31	10.167.123.34 – 10.167.123.35	10.167.123.35
19	10.167.123.36/31	10.167.123.36 – 10.167.123.37	10.167.123.37
20	10.167.123.38/31	10.167.123.38 – 10.167.123.39	10.167.123.39
21	10.167.123.40/31	10.167.123.40 – 10.167.123.41	10.167.123.41
22	10.167.123.42/31	10.167.123.42 – 10.167.123.43	10.167.123.43
23	10.167.123.44/31	10.167.123.44 – 10.167.123.45	10.167.123.45
24	10.167.123.46/31	10.167.123.46 – 10.167.123.47	10.167.123.47
25	10.167.123.48/31	10.167.123.48 – 10.167.123.49	10.167.123.49
26	10.167.123.50/31	10.167.123.50 – 10.167.123.51	10.167.123.51
27	10.167.123.52/31	10.167.123.52 – 10.167.123.53	10.167.123.53
28	10.167.123.54/31	10.167.123.54 – 10.167.123.55	10.167.123.55
29	10.167.123.56/31	10.167.123.56 – 10.167.123.57	10.167.123.57
30	10.167.123.58/31	10.167.123.58 – 10.167.123.59	10.167.123.59
31	10.167.123.60/31	10.167.123.60 – 10.167.123.61	10.167.123.61
32	10.167.123.62/31	10.167.123.62 – 10.167.123.63	10.167.123.63
33	10.167.123.64/31	10.167.123.64 – 10.167.123.65	10.167.123.65
34	10.167.123.66/31	10.167.123.66 – 10.167.123.67	10.167.123.67
35	10.167.123.68/31	10.167.123.68 – 10.167.123.69	10.167.123.69
36	10.167.123.70/31	10.167.123.70 – 10.167.123.71	10.167.123.71
37	10.167.123.72/31	10.167.123.72 – 10.167.123.73	10.167.123.73
38	10.167.123.74/31	10.167.123.74 – 10.167.123.75	10.167.123.75
39	10.167.123.76/31	10.167.123.76 – 10.167.123.77	10.167.123.77
40	10.167.123.78/31	10.167.123.78 – 10.167.123.79	10.167.123.79
41	10.167.123.80/31	10.167.123.80 – 10.167.123.81	10.167.123.81
42	10.167.123.82/31	10.167.123.82 – 10.167.123.83	10.167.123.83
43	10.167.123.84/31	10.167.123.84 – 10.167.123.85	10.167.123.85
44	10.167.123.86/31	10.167.123.86 – 10.167.123.87	10.167.123.87
45	10.167.123.88/31	10.167.123.88 – 10.167.123.89	10.167.123.89
46	10.167.123.90/31	10.167.123.90 – 10.167.123.91	10.167.123.91
47	10.167.123.92/31	10.167.123.92 – 10.167.123.93	10.167.123.93
48	10.167.123.94/31	10.167.123.94 – 10.167.123.95	10.167.123.95
49	10.167.123.96/31	10.167.123.96 – 10.167.123.97	10.167.123.97
50	10.167.123.98/31	10.167.123.98 – 10.167.123.99	10.167.123.99
51	10.167.123.100/31	10.167.123.100 – 10.167.123.101	10.167.123.101
52	10.167.123.102/31	10.167.123.102 – 10.167.123.103	10.167.123.103
53	10.167.123.104/31	10.167.123.104 – 10.167.123.105	10.167.123.105
54	10.167.123.106/31	10.167.123.106 – 10.167.123.107	10.167.123.107
55	10.167.123.108/31	10.167.123.108 – 10.167.123.109	10.167.123.109
56	10.167.123.110/31	10.167.123.110 – 10.167.123.111	10.167.123.111
57	10.167.123.112/31	10.167.123.112 – 10.167.123.113	10.167.123.113
58	10.167.123.114/31	10.167.123.114 – 10.167.123.115	10.167.123.115
59	10.167.123.116/31	10.167.123.116 – 10.167.123.117	10.167.123.117
60	10.167.123.118/31	10.167.123.118 – 10.167.123.119	10.167.123.119
61	10.167.123.120/31	10.167.123.120 – 10.167.123.121	10.167.123.121
62	10.167.123.122/31	10.167.123.122 – 10.167.123.123	10.167.123.123
63	10.167.123.124/31	10.167.123.124 – 10.167.123.125	10.167.123.125
64	10.167.123.126/31	10.167.123.126 – 10.167.123.127	10.167.123.127

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 →