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)10.167.20.0/25

network10.167.20.0/25

broadcast10.167.20.127

first host10.167.20.1

last host10.167.20.126

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.167.20.0/25

address00001010.10100111.00010100.00000000

subnet mask11111111.11111111.11111111.10000000

network00001010.10100111.00010100.00000000

broadcast00001010.10100111.00010100.01111111

green = network part, grey = host part

hex0x0aa71400

decimal178721792

reverse dns0.20.167.10.in-addr.arpa

ipv4-mapped::ffff:aa7:1400

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.167.20.0/32	10.167.20.0 – 10.167.20.0	10.167.20.0
2	10.167.20.1/32	10.167.20.1 – 10.167.20.1	10.167.20.1
3	10.167.20.2/32	10.167.20.2 – 10.167.20.2	10.167.20.2
4	10.167.20.3/32	10.167.20.3 – 10.167.20.3	10.167.20.3
5	10.167.20.4/32	10.167.20.4 – 10.167.20.4	10.167.20.4
6	10.167.20.5/32	10.167.20.5 – 10.167.20.5	10.167.20.5
7	10.167.20.6/32	10.167.20.6 – 10.167.20.6	10.167.20.6
8	10.167.20.7/32	10.167.20.7 – 10.167.20.7	10.167.20.7
9	10.167.20.8/32	10.167.20.8 – 10.167.20.8	10.167.20.8
10	10.167.20.9/32	10.167.20.9 – 10.167.20.9	10.167.20.9
11	10.167.20.10/32	10.167.20.10 – 10.167.20.10	10.167.20.10
12	10.167.20.11/32	10.167.20.11 – 10.167.20.11	10.167.20.11
13	10.167.20.12/32	10.167.20.12 – 10.167.20.12	10.167.20.12
14	10.167.20.13/32	10.167.20.13 – 10.167.20.13	10.167.20.13
15	10.167.20.14/32	10.167.20.14 – 10.167.20.14	10.167.20.14
16	10.167.20.15/32	10.167.20.15 – 10.167.20.15	10.167.20.15
17	10.167.20.16/32	10.167.20.16 – 10.167.20.16	10.167.20.16
18	10.167.20.17/32	10.167.20.17 – 10.167.20.17	10.167.20.17
19	10.167.20.18/32	10.167.20.18 – 10.167.20.18	10.167.20.18
20	10.167.20.19/32	10.167.20.19 – 10.167.20.19	10.167.20.19
21	10.167.20.20/32	10.167.20.20 – 10.167.20.20	10.167.20.20
22	10.167.20.21/32	10.167.20.21 – 10.167.20.21	10.167.20.21
23	10.167.20.22/32	10.167.20.22 – 10.167.20.22	10.167.20.22
24	10.167.20.23/32	10.167.20.23 – 10.167.20.23	10.167.20.23
25	10.167.20.24/32	10.167.20.24 – 10.167.20.24	10.167.20.24
26	10.167.20.25/32	10.167.20.25 – 10.167.20.25	10.167.20.25
27	10.167.20.26/32	10.167.20.26 – 10.167.20.26	10.167.20.26
28	10.167.20.27/32	10.167.20.27 – 10.167.20.27	10.167.20.27
29	10.167.20.28/32	10.167.20.28 – 10.167.20.28	10.167.20.28
30	10.167.20.29/32	10.167.20.29 – 10.167.20.29	10.167.20.29
31	10.167.20.30/32	10.167.20.30 – 10.167.20.30	10.167.20.30
32	10.167.20.31/32	10.167.20.31 – 10.167.20.31	10.167.20.31
33	10.167.20.32/32	10.167.20.32 – 10.167.20.32	10.167.20.32
34	10.167.20.33/32	10.167.20.33 – 10.167.20.33	10.167.20.33
35	10.167.20.34/32	10.167.20.34 – 10.167.20.34	10.167.20.34
36	10.167.20.35/32	10.167.20.35 – 10.167.20.35	10.167.20.35
37	10.167.20.36/32	10.167.20.36 – 10.167.20.36	10.167.20.36
38	10.167.20.37/32	10.167.20.37 – 10.167.20.37	10.167.20.37
39	10.167.20.38/32	10.167.20.38 – 10.167.20.38	10.167.20.38
40	10.167.20.39/32	10.167.20.39 – 10.167.20.39	10.167.20.39
41	10.167.20.40/32	10.167.20.40 – 10.167.20.40	10.167.20.40
42	10.167.20.41/32	10.167.20.41 – 10.167.20.41	10.167.20.41
43	10.167.20.42/32	10.167.20.42 – 10.167.20.42	10.167.20.42
44	10.167.20.43/32	10.167.20.43 – 10.167.20.43	10.167.20.43
45	10.167.20.44/32	10.167.20.44 – 10.167.20.44	10.167.20.44
46	10.167.20.45/32	10.167.20.45 – 10.167.20.45	10.167.20.45
47	10.167.20.46/32	10.167.20.46 – 10.167.20.46	10.167.20.46
48	10.167.20.47/32	10.167.20.47 – 10.167.20.47	10.167.20.47
49	10.167.20.48/32	10.167.20.48 – 10.167.20.48	10.167.20.48
50	10.167.20.49/32	10.167.20.49 – 10.167.20.49	10.167.20.49
51	10.167.20.50/32	10.167.20.50 – 10.167.20.50	10.167.20.50
52	10.167.20.51/32	10.167.20.51 – 10.167.20.51	10.167.20.51
53	10.167.20.52/32	10.167.20.52 – 10.167.20.52	10.167.20.52
54	10.167.20.53/32	10.167.20.53 – 10.167.20.53	10.167.20.53
55	10.167.20.54/32	10.167.20.54 – 10.167.20.54	10.167.20.54
56	10.167.20.55/32	10.167.20.55 – 10.167.20.55	10.167.20.55
57	10.167.20.56/32	10.167.20.56 – 10.167.20.56	10.167.20.56
58	10.167.20.57/32	10.167.20.57 – 10.167.20.57	10.167.20.57
59	10.167.20.58/32	10.167.20.58 – 10.167.20.58	10.167.20.58
60	10.167.20.59/32	10.167.20.59 – 10.167.20.59	10.167.20.59
61	10.167.20.60/32	10.167.20.60 – 10.167.20.60	10.167.20.60
62	10.167.20.61/32	10.167.20.61 – 10.167.20.61	10.167.20.61
63	10.167.20.62/32	10.167.20.62 – 10.167.20.62	10.167.20.62
64	10.167.20.63/32	10.167.20.63 – 10.167.20.63	10.167.20.63
65	10.167.20.64/32	10.167.20.64 – 10.167.20.64	10.167.20.64
66	10.167.20.65/32	10.167.20.65 – 10.167.20.65	10.167.20.65
67	10.167.20.66/32	10.167.20.66 – 10.167.20.66	10.167.20.66
68	10.167.20.67/32	10.167.20.67 – 10.167.20.67	10.167.20.67
69	10.167.20.68/32	10.167.20.68 – 10.167.20.68	10.167.20.68
70	10.167.20.69/32	10.167.20.69 – 10.167.20.69	10.167.20.69
71	10.167.20.70/32	10.167.20.70 – 10.167.20.70	10.167.20.70
72	10.167.20.71/32	10.167.20.71 – 10.167.20.71	10.167.20.71
73	10.167.20.72/32	10.167.20.72 – 10.167.20.72	10.167.20.72
74	10.167.20.73/32	10.167.20.73 – 10.167.20.73	10.167.20.73
75	10.167.20.74/32	10.167.20.74 – 10.167.20.74	10.167.20.74
76	10.167.20.75/32	10.167.20.75 – 10.167.20.75	10.167.20.75
77	10.167.20.76/32	10.167.20.76 – 10.167.20.76	10.167.20.76
78	10.167.20.77/32	10.167.20.77 – 10.167.20.77	10.167.20.77
79	10.167.20.78/32	10.167.20.78 – 10.167.20.78	10.167.20.78
80	10.167.20.79/32	10.167.20.79 – 10.167.20.79	10.167.20.79
81	10.167.20.80/32	10.167.20.80 – 10.167.20.80	10.167.20.80
82	10.167.20.81/32	10.167.20.81 – 10.167.20.81	10.167.20.81
83	10.167.20.82/32	10.167.20.82 – 10.167.20.82	10.167.20.82
84	10.167.20.83/32	10.167.20.83 – 10.167.20.83	10.167.20.83
85	10.167.20.84/32	10.167.20.84 – 10.167.20.84	10.167.20.84
86	10.167.20.85/32	10.167.20.85 – 10.167.20.85	10.167.20.85
87	10.167.20.86/32	10.167.20.86 – 10.167.20.86	10.167.20.86
88	10.167.20.87/32	10.167.20.87 – 10.167.20.87	10.167.20.87
89	10.167.20.88/32	10.167.20.88 – 10.167.20.88	10.167.20.88
90	10.167.20.89/32	10.167.20.89 – 10.167.20.89	10.167.20.89
91	10.167.20.90/32	10.167.20.90 – 10.167.20.90	10.167.20.90
92	10.167.20.91/32	10.167.20.91 – 10.167.20.91	10.167.20.91
93	10.167.20.92/32	10.167.20.92 – 10.167.20.92	10.167.20.92
94	10.167.20.93/32	10.167.20.93 – 10.167.20.93	10.167.20.93
95	10.167.20.94/32	10.167.20.94 – 10.167.20.94	10.167.20.94
96	10.167.20.95/32	10.167.20.95 – 10.167.20.95	10.167.20.95
97	10.167.20.96/32	10.167.20.96 – 10.167.20.96	10.167.20.96
98	10.167.20.97/32	10.167.20.97 – 10.167.20.97	10.167.20.97
99	10.167.20.98/32	10.167.20.98 – 10.167.20.98	10.167.20.98
100	10.167.20.99/32	10.167.20.99 – 10.167.20.99	10.167.20.99
101	10.167.20.100/32	10.167.20.100 – 10.167.20.100	10.167.20.100
102	10.167.20.101/32	10.167.20.101 – 10.167.20.101	10.167.20.101
103	10.167.20.102/32	10.167.20.102 – 10.167.20.102	10.167.20.102
104	10.167.20.103/32	10.167.20.103 – 10.167.20.103	10.167.20.103
105	10.167.20.104/32	10.167.20.104 – 10.167.20.104	10.167.20.104
106	10.167.20.105/32	10.167.20.105 – 10.167.20.105	10.167.20.105
107	10.167.20.106/32	10.167.20.106 – 10.167.20.106	10.167.20.106
108	10.167.20.107/32	10.167.20.107 – 10.167.20.107	10.167.20.107
109	10.167.20.108/32	10.167.20.108 – 10.167.20.108	10.167.20.108
110	10.167.20.109/32	10.167.20.109 – 10.167.20.109	10.167.20.109
111	10.167.20.110/32	10.167.20.110 – 10.167.20.110	10.167.20.110
112	10.167.20.111/32	10.167.20.111 – 10.167.20.111	10.167.20.111
113	10.167.20.112/32	10.167.20.112 – 10.167.20.112	10.167.20.112
114	10.167.20.113/32	10.167.20.113 – 10.167.20.113	10.167.20.113
115	10.167.20.114/32	10.167.20.114 – 10.167.20.114	10.167.20.114
116	10.167.20.115/32	10.167.20.115 – 10.167.20.115	10.167.20.115
117	10.167.20.116/32	10.167.20.116 – 10.167.20.116	10.167.20.116
118	10.167.20.117/32	10.167.20.117 – 10.167.20.117	10.167.20.117
119	10.167.20.118/32	10.167.20.118 – 10.167.20.118	10.167.20.118
120	10.167.20.119/32	10.167.20.119 – 10.167.20.119	10.167.20.119
121	10.167.20.120/32	10.167.20.120 – 10.167.20.120	10.167.20.120
122	10.167.20.121/32	10.167.20.121 – 10.167.20.121	10.167.20.121
123	10.167.20.122/32	10.167.20.122 – 10.167.20.122	10.167.20.122
124	10.167.20.123/32	10.167.20.123 – 10.167.20.123	10.167.20.123
125	10.167.20.124/32	10.167.20.124 – 10.167.20.124	10.167.20.124
126	10.167.20.125/32	10.167.20.125 – 10.167.20.125	10.167.20.125
127	10.167.20.126/32	10.167.20.126 – 10.167.20.126	10.167.20.126
128	10.167.20.127/32	10.167.20.127 – 10.167.20.127	10.167.20.127

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 →