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)10.2.161.0/25

network10.2.161.0/25

broadcast10.2.161.127

first host10.2.161.1

last host10.2.161.126

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.2.161.0/25

address00001010.00000010.10100001.00000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000010.10100001.00000000

broadcast00001010.00000010.10100001.01111111

green = network part, grey = host part

hex0x0a02a100

decimal167944448

reverse dns0.161.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:a100

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.161.0/32	10.2.161.0 – 10.2.161.0	10.2.161.0
2	10.2.161.1/32	10.2.161.1 – 10.2.161.1	10.2.161.1
3	10.2.161.2/32	10.2.161.2 – 10.2.161.2	10.2.161.2
4	10.2.161.3/32	10.2.161.3 – 10.2.161.3	10.2.161.3
5	10.2.161.4/32	10.2.161.4 – 10.2.161.4	10.2.161.4
6	10.2.161.5/32	10.2.161.5 – 10.2.161.5	10.2.161.5
7	10.2.161.6/32	10.2.161.6 – 10.2.161.6	10.2.161.6
8	10.2.161.7/32	10.2.161.7 – 10.2.161.7	10.2.161.7
9	10.2.161.8/32	10.2.161.8 – 10.2.161.8	10.2.161.8
10	10.2.161.9/32	10.2.161.9 – 10.2.161.9	10.2.161.9
11	10.2.161.10/32	10.2.161.10 – 10.2.161.10	10.2.161.10
12	10.2.161.11/32	10.2.161.11 – 10.2.161.11	10.2.161.11
13	10.2.161.12/32	10.2.161.12 – 10.2.161.12	10.2.161.12
14	10.2.161.13/32	10.2.161.13 – 10.2.161.13	10.2.161.13
15	10.2.161.14/32	10.2.161.14 – 10.2.161.14	10.2.161.14
16	10.2.161.15/32	10.2.161.15 – 10.2.161.15	10.2.161.15
17	10.2.161.16/32	10.2.161.16 – 10.2.161.16	10.2.161.16
18	10.2.161.17/32	10.2.161.17 – 10.2.161.17	10.2.161.17
19	10.2.161.18/32	10.2.161.18 – 10.2.161.18	10.2.161.18
20	10.2.161.19/32	10.2.161.19 – 10.2.161.19	10.2.161.19
21	10.2.161.20/32	10.2.161.20 – 10.2.161.20	10.2.161.20
22	10.2.161.21/32	10.2.161.21 – 10.2.161.21	10.2.161.21
23	10.2.161.22/32	10.2.161.22 – 10.2.161.22	10.2.161.22
24	10.2.161.23/32	10.2.161.23 – 10.2.161.23	10.2.161.23
25	10.2.161.24/32	10.2.161.24 – 10.2.161.24	10.2.161.24
26	10.2.161.25/32	10.2.161.25 – 10.2.161.25	10.2.161.25
27	10.2.161.26/32	10.2.161.26 – 10.2.161.26	10.2.161.26
28	10.2.161.27/32	10.2.161.27 – 10.2.161.27	10.2.161.27
29	10.2.161.28/32	10.2.161.28 – 10.2.161.28	10.2.161.28
30	10.2.161.29/32	10.2.161.29 – 10.2.161.29	10.2.161.29
31	10.2.161.30/32	10.2.161.30 – 10.2.161.30	10.2.161.30
32	10.2.161.31/32	10.2.161.31 – 10.2.161.31	10.2.161.31
33	10.2.161.32/32	10.2.161.32 – 10.2.161.32	10.2.161.32
34	10.2.161.33/32	10.2.161.33 – 10.2.161.33	10.2.161.33
35	10.2.161.34/32	10.2.161.34 – 10.2.161.34	10.2.161.34
36	10.2.161.35/32	10.2.161.35 – 10.2.161.35	10.2.161.35
37	10.2.161.36/32	10.2.161.36 – 10.2.161.36	10.2.161.36
38	10.2.161.37/32	10.2.161.37 – 10.2.161.37	10.2.161.37
39	10.2.161.38/32	10.2.161.38 – 10.2.161.38	10.2.161.38
40	10.2.161.39/32	10.2.161.39 – 10.2.161.39	10.2.161.39
41	10.2.161.40/32	10.2.161.40 – 10.2.161.40	10.2.161.40
42	10.2.161.41/32	10.2.161.41 – 10.2.161.41	10.2.161.41
43	10.2.161.42/32	10.2.161.42 – 10.2.161.42	10.2.161.42
44	10.2.161.43/32	10.2.161.43 – 10.2.161.43	10.2.161.43
45	10.2.161.44/32	10.2.161.44 – 10.2.161.44	10.2.161.44
46	10.2.161.45/32	10.2.161.45 – 10.2.161.45	10.2.161.45
47	10.2.161.46/32	10.2.161.46 – 10.2.161.46	10.2.161.46
48	10.2.161.47/32	10.2.161.47 – 10.2.161.47	10.2.161.47
49	10.2.161.48/32	10.2.161.48 – 10.2.161.48	10.2.161.48
50	10.2.161.49/32	10.2.161.49 – 10.2.161.49	10.2.161.49
51	10.2.161.50/32	10.2.161.50 – 10.2.161.50	10.2.161.50
52	10.2.161.51/32	10.2.161.51 – 10.2.161.51	10.2.161.51
53	10.2.161.52/32	10.2.161.52 – 10.2.161.52	10.2.161.52
54	10.2.161.53/32	10.2.161.53 – 10.2.161.53	10.2.161.53
55	10.2.161.54/32	10.2.161.54 – 10.2.161.54	10.2.161.54
56	10.2.161.55/32	10.2.161.55 – 10.2.161.55	10.2.161.55
57	10.2.161.56/32	10.2.161.56 – 10.2.161.56	10.2.161.56
58	10.2.161.57/32	10.2.161.57 – 10.2.161.57	10.2.161.57
59	10.2.161.58/32	10.2.161.58 – 10.2.161.58	10.2.161.58
60	10.2.161.59/32	10.2.161.59 – 10.2.161.59	10.2.161.59
61	10.2.161.60/32	10.2.161.60 – 10.2.161.60	10.2.161.60
62	10.2.161.61/32	10.2.161.61 – 10.2.161.61	10.2.161.61
63	10.2.161.62/32	10.2.161.62 – 10.2.161.62	10.2.161.62
64	10.2.161.63/32	10.2.161.63 – 10.2.161.63	10.2.161.63
65	10.2.161.64/32	10.2.161.64 – 10.2.161.64	10.2.161.64
66	10.2.161.65/32	10.2.161.65 – 10.2.161.65	10.2.161.65
67	10.2.161.66/32	10.2.161.66 – 10.2.161.66	10.2.161.66
68	10.2.161.67/32	10.2.161.67 – 10.2.161.67	10.2.161.67
69	10.2.161.68/32	10.2.161.68 – 10.2.161.68	10.2.161.68
70	10.2.161.69/32	10.2.161.69 – 10.2.161.69	10.2.161.69
71	10.2.161.70/32	10.2.161.70 – 10.2.161.70	10.2.161.70
72	10.2.161.71/32	10.2.161.71 – 10.2.161.71	10.2.161.71
73	10.2.161.72/32	10.2.161.72 – 10.2.161.72	10.2.161.72
74	10.2.161.73/32	10.2.161.73 – 10.2.161.73	10.2.161.73
75	10.2.161.74/32	10.2.161.74 – 10.2.161.74	10.2.161.74
76	10.2.161.75/32	10.2.161.75 – 10.2.161.75	10.2.161.75
77	10.2.161.76/32	10.2.161.76 – 10.2.161.76	10.2.161.76
78	10.2.161.77/32	10.2.161.77 – 10.2.161.77	10.2.161.77
79	10.2.161.78/32	10.2.161.78 – 10.2.161.78	10.2.161.78
80	10.2.161.79/32	10.2.161.79 – 10.2.161.79	10.2.161.79
81	10.2.161.80/32	10.2.161.80 – 10.2.161.80	10.2.161.80
82	10.2.161.81/32	10.2.161.81 – 10.2.161.81	10.2.161.81
83	10.2.161.82/32	10.2.161.82 – 10.2.161.82	10.2.161.82
84	10.2.161.83/32	10.2.161.83 – 10.2.161.83	10.2.161.83
85	10.2.161.84/32	10.2.161.84 – 10.2.161.84	10.2.161.84
86	10.2.161.85/32	10.2.161.85 – 10.2.161.85	10.2.161.85
87	10.2.161.86/32	10.2.161.86 – 10.2.161.86	10.2.161.86
88	10.2.161.87/32	10.2.161.87 – 10.2.161.87	10.2.161.87
89	10.2.161.88/32	10.2.161.88 – 10.2.161.88	10.2.161.88
90	10.2.161.89/32	10.2.161.89 – 10.2.161.89	10.2.161.89
91	10.2.161.90/32	10.2.161.90 – 10.2.161.90	10.2.161.90
92	10.2.161.91/32	10.2.161.91 – 10.2.161.91	10.2.161.91
93	10.2.161.92/32	10.2.161.92 – 10.2.161.92	10.2.161.92
94	10.2.161.93/32	10.2.161.93 – 10.2.161.93	10.2.161.93
95	10.2.161.94/32	10.2.161.94 – 10.2.161.94	10.2.161.94
96	10.2.161.95/32	10.2.161.95 – 10.2.161.95	10.2.161.95
97	10.2.161.96/32	10.2.161.96 – 10.2.161.96	10.2.161.96
98	10.2.161.97/32	10.2.161.97 – 10.2.161.97	10.2.161.97
99	10.2.161.98/32	10.2.161.98 – 10.2.161.98	10.2.161.98
100	10.2.161.99/32	10.2.161.99 – 10.2.161.99	10.2.161.99
101	10.2.161.100/32	10.2.161.100 – 10.2.161.100	10.2.161.100
102	10.2.161.101/32	10.2.161.101 – 10.2.161.101	10.2.161.101
103	10.2.161.102/32	10.2.161.102 – 10.2.161.102	10.2.161.102
104	10.2.161.103/32	10.2.161.103 – 10.2.161.103	10.2.161.103
105	10.2.161.104/32	10.2.161.104 – 10.2.161.104	10.2.161.104
106	10.2.161.105/32	10.2.161.105 – 10.2.161.105	10.2.161.105
107	10.2.161.106/32	10.2.161.106 – 10.2.161.106	10.2.161.106
108	10.2.161.107/32	10.2.161.107 – 10.2.161.107	10.2.161.107
109	10.2.161.108/32	10.2.161.108 – 10.2.161.108	10.2.161.108
110	10.2.161.109/32	10.2.161.109 – 10.2.161.109	10.2.161.109
111	10.2.161.110/32	10.2.161.110 – 10.2.161.110	10.2.161.110
112	10.2.161.111/32	10.2.161.111 – 10.2.161.111	10.2.161.111
113	10.2.161.112/32	10.2.161.112 – 10.2.161.112	10.2.161.112
114	10.2.161.113/32	10.2.161.113 – 10.2.161.113	10.2.161.113
115	10.2.161.114/32	10.2.161.114 – 10.2.161.114	10.2.161.114
116	10.2.161.115/32	10.2.161.115 – 10.2.161.115	10.2.161.115
117	10.2.161.116/32	10.2.161.116 – 10.2.161.116	10.2.161.116
118	10.2.161.117/32	10.2.161.117 – 10.2.161.117	10.2.161.117
119	10.2.161.118/32	10.2.161.118 – 10.2.161.118	10.2.161.118
120	10.2.161.119/32	10.2.161.119 – 10.2.161.119	10.2.161.119
121	10.2.161.120/32	10.2.161.120 – 10.2.161.120	10.2.161.120
122	10.2.161.121/32	10.2.161.121 – 10.2.161.121	10.2.161.121
123	10.2.161.122/32	10.2.161.122 – 10.2.161.122	10.2.161.122
124	10.2.161.123/32	10.2.161.123 – 10.2.161.123	10.2.161.123
125	10.2.161.124/32	10.2.161.124 – 10.2.161.124	10.2.161.124
126	10.2.161.125/32	10.2.161.125 – 10.2.161.125	10.2.161.125
127	10.2.161.126/32	10.2.161.126 – 10.2.161.126	10.2.161.126
128	10.2.161.127/32	10.2.161.127 – 10.2.161.127	10.2.161.127

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 →