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)10.167.221.0/25

network10.167.221.0/25

broadcast10.167.221.127

first host10.167.221.1

last host10.167.221.126

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.167.221.0/25

address00001010.10100111.11011101.00000000

subnet mask11111111.11111111.11111111.10000000

network00001010.10100111.11011101.00000000

broadcast00001010.10100111.11011101.01111111

green = network part, grey = host part

hex0x0aa7dd00

decimal178773248

reverse dns0.221.167.10.in-addr.arpa

ipv4-mapped::ffff:aa7:dd00

/25 split into /31 · 64 subnets

close ×

#	network	host range	broadcast
1	10.167.221.0/31	10.167.221.0 – 10.167.221.1	10.167.221.1
2	10.167.221.2/31	10.167.221.2 – 10.167.221.3	10.167.221.3
3	10.167.221.4/31	10.167.221.4 – 10.167.221.5	10.167.221.5
4	10.167.221.6/31	10.167.221.6 – 10.167.221.7	10.167.221.7
5	10.167.221.8/31	10.167.221.8 – 10.167.221.9	10.167.221.9
6	10.167.221.10/31	10.167.221.10 – 10.167.221.11	10.167.221.11
7	10.167.221.12/31	10.167.221.12 – 10.167.221.13	10.167.221.13
8	10.167.221.14/31	10.167.221.14 – 10.167.221.15	10.167.221.15
9	10.167.221.16/31	10.167.221.16 – 10.167.221.17	10.167.221.17
10	10.167.221.18/31	10.167.221.18 – 10.167.221.19	10.167.221.19
11	10.167.221.20/31	10.167.221.20 – 10.167.221.21	10.167.221.21
12	10.167.221.22/31	10.167.221.22 – 10.167.221.23	10.167.221.23
13	10.167.221.24/31	10.167.221.24 – 10.167.221.25	10.167.221.25
14	10.167.221.26/31	10.167.221.26 – 10.167.221.27	10.167.221.27
15	10.167.221.28/31	10.167.221.28 – 10.167.221.29	10.167.221.29
16	10.167.221.30/31	10.167.221.30 – 10.167.221.31	10.167.221.31
17	10.167.221.32/31	10.167.221.32 – 10.167.221.33	10.167.221.33
18	10.167.221.34/31	10.167.221.34 – 10.167.221.35	10.167.221.35
19	10.167.221.36/31	10.167.221.36 – 10.167.221.37	10.167.221.37
20	10.167.221.38/31	10.167.221.38 – 10.167.221.39	10.167.221.39
21	10.167.221.40/31	10.167.221.40 – 10.167.221.41	10.167.221.41
22	10.167.221.42/31	10.167.221.42 – 10.167.221.43	10.167.221.43
23	10.167.221.44/31	10.167.221.44 – 10.167.221.45	10.167.221.45
24	10.167.221.46/31	10.167.221.46 – 10.167.221.47	10.167.221.47
25	10.167.221.48/31	10.167.221.48 – 10.167.221.49	10.167.221.49
26	10.167.221.50/31	10.167.221.50 – 10.167.221.51	10.167.221.51
27	10.167.221.52/31	10.167.221.52 – 10.167.221.53	10.167.221.53
28	10.167.221.54/31	10.167.221.54 – 10.167.221.55	10.167.221.55
29	10.167.221.56/31	10.167.221.56 – 10.167.221.57	10.167.221.57
30	10.167.221.58/31	10.167.221.58 – 10.167.221.59	10.167.221.59
31	10.167.221.60/31	10.167.221.60 – 10.167.221.61	10.167.221.61
32	10.167.221.62/31	10.167.221.62 – 10.167.221.63	10.167.221.63
33	10.167.221.64/31	10.167.221.64 – 10.167.221.65	10.167.221.65
34	10.167.221.66/31	10.167.221.66 – 10.167.221.67	10.167.221.67
35	10.167.221.68/31	10.167.221.68 – 10.167.221.69	10.167.221.69
36	10.167.221.70/31	10.167.221.70 – 10.167.221.71	10.167.221.71
37	10.167.221.72/31	10.167.221.72 – 10.167.221.73	10.167.221.73
38	10.167.221.74/31	10.167.221.74 – 10.167.221.75	10.167.221.75
39	10.167.221.76/31	10.167.221.76 – 10.167.221.77	10.167.221.77
40	10.167.221.78/31	10.167.221.78 – 10.167.221.79	10.167.221.79
41	10.167.221.80/31	10.167.221.80 – 10.167.221.81	10.167.221.81
42	10.167.221.82/31	10.167.221.82 – 10.167.221.83	10.167.221.83
43	10.167.221.84/31	10.167.221.84 – 10.167.221.85	10.167.221.85
44	10.167.221.86/31	10.167.221.86 – 10.167.221.87	10.167.221.87
45	10.167.221.88/31	10.167.221.88 – 10.167.221.89	10.167.221.89
46	10.167.221.90/31	10.167.221.90 – 10.167.221.91	10.167.221.91
47	10.167.221.92/31	10.167.221.92 – 10.167.221.93	10.167.221.93
48	10.167.221.94/31	10.167.221.94 – 10.167.221.95	10.167.221.95
49	10.167.221.96/31	10.167.221.96 – 10.167.221.97	10.167.221.97
50	10.167.221.98/31	10.167.221.98 – 10.167.221.99	10.167.221.99
51	10.167.221.100/31	10.167.221.100 – 10.167.221.101	10.167.221.101
52	10.167.221.102/31	10.167.221.102 – 10.167.221.103	10.167.221.103
53	10.167.221.104/31	10.167.221.104 – 10.167.221.105	10.167.221.105
54	10.167.221.106/31	10.167.221.106 – 10.167.221.107	10.167.221.107
55	10.167.221.108/31	10.167.221.108 – 10.167.221.109	10.167.221.109
56	10.167.221.110/31	10.167.221.110 – 10.167.221.111	10.167.221.111
57	10.167.221.112/31	10.167.221.112 – 10.167.221.113	10.167.221.113
58	10.167.221.114/31	10.167.221.114 – 10.167.221.115	10.167.221.115
59	10.167.221.116/31	10.167.221.116 – 10.167.221.117	10.167.221.117
60	10.167.221.118/31	10.167.221.118 – 10.167.221.119	10.167.221.119
61	10.167.221.120/31	10.167.221.120 – 10.167.221.121	10.167.221.121
62	10.167.221.122/31	10.167.221.122 – 10.167.221.123	10.167.221.123
63	10.167.221.124/31	10.167.221.124 – 10.167.221.125	10.167.221.125
64	10.167.221.126/31	10.167.221.126 – 10.167.221.127	10.167.221.127

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 →