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)10.2.165.0/25

network10.2.165.0/25

broadcast10.2.165.127

first host10.2.165.1

last host10.2.165.126

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.2.165.0/25

address00001010.00000010.10100101.00000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000010.10100101.00000000

broadcast00001010.00000010.10100101.01111111

green = network part, grey = host part

hex0x0a02a500

decimal167945472

reverse dns0.165.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:a500

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.165.0/32	10.2.165.0 – 10.2.165.0	10.2.165.0
2	10.2.165.1/32	10.2.165.1 – 10.2.165.1	10.2.165.1
3	10.2.165.2/32	10.2.165.2 – 10.2.165.2	10.2.165.2
4	10.2.165.3/32	10.2.165.3 – 10.2.165.3	10.2.165.3
5	10.2.165.4/32	10.2.165.4 – 10.2.165.4	10.2.165.4
6	10.2.165.5/32	10.2.165.5 – 10.2.165.5	10.2.165.5
7	10.2.165.6/32	10.2.165.6 – 10.2.165.6	10.2.165.6
8	10.2.165.7/32	10.2.165.7 – 10.2.165.7	10.2.165.7
9	10.2.165.8/32	10.2.165.8 – 10.2.165.8	10.2.165.8
10	10.2.165.9/32	10.2.165.9 – 10.2.165.9	10.2.165.9
11	10.2.165.10/32	10.2.165.10 – 10.2.165.10	10.2.165.10
12	10.2.165.11/32	10.2.165.11 – 10.2.165.11	10.2.165.11
13	10.2.165.12/32	10.2.165.12 – 10.2.165.12	10.2.165.12
14	10.2.165.13/32	10.2.165.13 – 10.2.165.13	10.2.165.13
15	10.2.165.14/32	10.2.165.14 – 10.2.165.14	10.2.165.14
16	10.2.165.15/32	10.2.165.15 – 10.2.165.15	10.2.165.15
17	10.2.165.16/32	10.2.165.16 – 10.2.165.16	10.2.165.16
18	10.2.165.17/32	10.2.165.17 – 10.2.165.17	10.2.165.17
19	10.2.165.18/32	10.2.165.18 – 10.2.165.18	10.2.165.18
20	10.2.165.19/32	10.2.165.19 – 10.2.165.19	10.2.165.19
21	10.2.165.20/32	10.2.165.20 – 10.2.165.20	10.2.165.20
22	10.2.165.21/32	10.2.165.21 – 10.2.165.21	10.2.165.21
23	10.2.165.22/32	10.2.165.22 – 10.2.165.22	10.2.165.22
24	10.2.165.23/32	10.2.165.23 – 10.2.165.23	10.2.165.23
25	10.2.165.24/32	10.2.165.24 – 10.2.165.24	10.2.165.24
26	10.2.165.25/32	10.2.165.25 – 10.2.165.25	10.2.165.25
27	10.2.165.26/32	10.2.165.26 – 10.2.165.26	10.2.165.26
28	10.2.165.27/32	10.2.165.27 – 10.2.165.27	10.2.165.27
29	10.2.165.28/32	10.2.165.28 – 10.2.165.28	10.2.165.28
30	10.2.165.29/32	10.2.165.29 – 10.2.165.29	10.2.165.29
31	10.2.165.30/32	10.2.165.30 – 10.2.165.30	10.2.165.30
32	10.2.165.31/32	10.2.165.31 – 10.2.165.31	10.2.165.31
33	10.2.165.32/32	10.2.165.32 – 10.2.165.32	10.2.165.32
34	10.2.165.33/32	10.2.165.33 – 10.2.165.33	10.2.165.33
35	10.2.165.34/32	10.2.165.34 – 10.2.165.34	10.2.165.34
36	10.2.165.35/32	10.2.165.35 – 10.2.165.35	10.2.165.35
37	10.2.165.36/32	10.2.165.36 – 10.2.165.36	10.2.165.36
38	10.2.165.37/32	10.2.165.37 – 10.2.165.37	10.2.165.37
39	10.2.165.38/32	10.2.165.38 – 10.2.165.38	10.2.165.38
40	10.2.165.39/32	10.2.165.39 – 10.2.165.39	10.2.165.39
41	10.2.165.40/32	10.2.165.40 – 10.2.165.40	10.2.165.40
42	10.2.165.41/32	10.2.165.41 – 10.2.165.41	10.2.165.41
43	10.2.165.42/32	10.2.165.42 – 10.2.165.42	10.2.165.42
44	10.2.165.43/32	10.2.165.43 – 10.2.165.43	10.2.165.43
45	10.2.165.44/32	10.2.165.44 – 10.2.165.44	10.2.165.44
46	10.2.165.45/32	10.2.165.45 – 10.2.165.45	10.2.165.45
47	10.2.165.46/32	10.2.165.46 – 10.2.165.46	10.2.165.46
48	10.2.165.47/32	10.2.165.47 – 10.2.165.47	10.2.165.47
49	10.2.165.48/32	10.2.165.48 – 10.2.165.48	10.2.165.48
50	10.2.165.49/32	10.2.165.49 – 10.2.165.49	10.2.165.49
51	10.2.165.50/32	10.2.165.50 – 10.2.165.50	10.2.165.50
52	10.2.165.51/32	10.2.165.51 – 10.2.165.51	10.2.165.51
53	10.2.165.52/32	10.2.165.52 – 10.2.165.52	10.2.165.52
54	10.2.165.53/32	10.2.165.53 – 10.2.165.53	10.2.165.53
55	10.2.165.54/32	10.2.165.54 – 10.2.165.54	10.2.165.54
56	10.2.165.55/32	10.2.165.55 – 10.2.165.55	10.2.165.55
57	10.2.165.56/32	10.2.165.56 – 10.2.165.56	10.2.165.56
58	10.2.165.57/32	10.2.165.57 – 10.2.165.57	10.2.165.57
59	10.2.165.58/32	10.2.165.58 – 10.2.165.58	10.2.165.58
60	10.2.165.59/32	10.2.165.59 – 10.2.165.59	10.2.165.59
61	10.2.165.60/32	10.2.165.60 – 10.2.165.60	10.2.165.60
62	10.2.165.61/32	10.2.165.61 – 10.2.165.61	10.2.165.61
63	10.2.165.62/32	10.2.165.62 – 10.2.165.62	10.2.165.62
64	10.2.165.63/32	10.2.165.63 – 10.2.165.63	10.2.165.63
65	10.2.165.64/32	10.2.165.64 – 10.2.165.64	10.2.165.64
66	10.2.165.65/32	10.2.165.65 – 10.2.165.65	10.2.165.65
67	10.2.165.66/32	10.2.165.66 – 10.2.165.66	10.2.165.66
68	10.2.165.67/32	10.2.165.67 – 10.2.165.67	10.2.165.67
69	10.2.165.68/32	10.2.165.68 – 10.2.165.68	10.2.165.68
70	10.2.165.69/32	10.2.165.69 – 10.2.165.69	10.2.165.69
71	10.2.165.70/32	10.2.165.70 – 10.2.165.70	10.2.165.70
72	10.2.165.71/32	10.2.165.71 – 10.2.165.71	10.2.165.71
73	10.2.165.72/32	10.2.165.72 – 10.2.165.72	10.2.165.72
74	10.2.165.73/32	10.2.165.73 – 10.2.165.73	10.2.165.73
75	10.2.165.74/32	10.2.165.74 – 10.2.165.74	10.2.165.74
76	10.2.165.75/32	10.2.165.75 – 10.2.165.75	10.2.165.75
77	10.2.165.76/32	10.2.165.76 – 10.2.165.76	10.2.165.76
78	10.2.165.77/32	10.2.165.77 – 10.2.165.77	10.2.165.77
79	10.2.165.78/32	10.2.165.78 – 10.2.165.78	10.2.165.78
80	10.2.165.79/32	10.2.165.79 – 10.2.165.79	10.2.165.79
81	10.2.165.80/32	10.2.165.80 – 10.2.165.80	10.2.165.80
82	10.2.165.81/32	10.2.165.81 – 10.2.165.81	10.2.165.81
83	10.2.165.82/32	10.2.165.82 – 10.2.165.82	10.2.165.82
84	10.2.165.83/32	10.2.165.83 – 10.2.165.83	10.2.165.83
85	10.2.165.84/32	10.2.165.84 – 10.2.165.84	10.2.165.84
86	10.2.165.85/32	10.2.165.85 – 10.2.165.85	10.2.165.85
87	10.2.165.86/32	10.2.165.86 – 10.2.165.86	10.2.165.86
88	10.2.165.87/32	10.2.165.87 – 10.2.165.87	10.2.165.87
89	10.2.165.88/32	10.2.165.88 – 10.2.165.88	10.2.165.88
90	10.2.165.89/32	10.2.165.89 – 10.2.165.89	10.2.165.89
91	10.2.165.90/32	10.2.165.90 – 10.2.165.90	10.2.165.90
92	10.2.165.91/32	10.2.165.91 – 10.2.165.91	10.2.165.91
93	10.2.165.92/32	10.2.165.92 – 10.2.165.92	10.2.165.92
94	10.2.165.93/32	10.2.165.93 – 10.2.165.93	10.2.165.93
95	10.2.165.94/32	10.2.165.94 – 10.2.165.94	10.2.165.94
96	10.2.165.95/32	10.2.165.95 – 10.2.165.95	10.2.165.95
97	10.2.165.96/32	10.2.165.96 – 10.2.165.96	10.2.165.96
98	10.2.165.97/32	10.2.165.97 – 10.2.165.97	10.2.165.97
99	10.2.165.98/32	10.2.165.98 – 10.2.165.98	10.2.165.98
100	10.2.165.99/32	10.2.165.99 – 10.2.165.99	10.2.165.99
101	10.2.165.100/32	10.2.165.100 – 10.2.165.100	10.2.165.100
102	10.2.165.101/32	10.2.165.101 – 10.2.165.101	10.2.165.101
103	10.2.165.102/32	10.2.165.102 – 10.2.165.102	10.2.165.102
104	10.2.165.103/32	10.2.165.103 – 10.2.165.103	10.2.165.103
105	10.2.165.104/32	10.2.165.104 – 10.2.165.104	10.2.165.104
106	10.2.165.105/32	10.2.165.105 – 10.2.165.105	10.2.165.105
107	10.2.165.106/32	10.2.165.106 – 10.2.165.106	10.2.165.106
108	10.2.165.107/32	10.2.165.107 – 10.2.165.107	10.2.165.107
109	10.2.165.108/32	10.2.165.108 – 10.2.165.108	10.2.165.108
110	10.2.165.109/32	10.2.165.109 – 10.2.165.109	10.2.165.109
111	10.2.165.110/32	10.2.165.110 – 10.2.165.110	10.2.165.110
112	10.2.165.111/32	10.2.165.111 – 10.2.165.111	10.2.165.111
113	10.2.165.112/32	10.2.165.112 – 10.2.165.112	10.2.165.112
114	10.2.165.113/32	10.2.165.113 – 10.2.165.113	10.2.165.113
115	10.2.165.114/32	10.2.165.114 – 10.2.165.114	10.2.165.114
116	10.2.165.115/32	10.2.165.115 – 10.2.165.115	10.2.165.115
117	10.2.165.116/32	10.2.165.116 – 10.2.165.116	10.2.165.116
118	10.2.165.117/32	10.2.165.117 – 10.2.165.117	10.2.165.117
119	10.2.165.118/32	10.2.165.118 – 10.2.165.118	10.2.165.118
120	10.2.165.119/32	10.2.165.119 – 10.2.165.119	10.2.165.119
121	10.2.165.120/32	10.2.165.120 – 10.2.165.120	10.2.165.120
122	10.2.165.121/32	10.2.165.121 – 10.2.165.121	10.2.165.121
123	10.2.165.122/32	10.2.165.122 – 10.2.165.122	10.2.165.122
124	10.2.165.123/32	10.2.165.123 – 10.2.165.123	10.2.165.123
125	10.2.165.124/32	10.2.165.124 – 10.2.165.124	10.2.165.124
126	10.2.165.125/32	10.2.165.125 – 10.2.165.125	10.2.165.125
127	10.2.165.126/32	10.2.165.126 – 10.2.165.126	10.2.165.126
128	10.2.165.127/32	10.2.165.127 – 10.2.165.127	10.2.165.127

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 →