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)10.2.129.0/25

network10.2.129.0/25

broadcast10.2.129.127

first host10.2.129.1

last host10.2.129.126

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.2.129.0/25

address00001010.00000010.10000001.00000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000010.10000001.00000000

broadcast00001010.00000010.10000001.01111111

green = network part, grey = host part

hex0x0a028100

decimal167936256

reverse dns0.129.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:8100

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.129.0/32	10.2.129.0 – 10.2.129.0	10.2.129.0
2	10.2.129.1/32	10.2.129.1 – 10.2.129.1	10.2.129.1
3	10.2.129.2/32	10.2.129.2 – 10.2.129.2	10.2.129.2
4	10.2.129.3/32	10.2.129.3 – 10.2.129.3	10.2.129.3
5	10.2.129.4/32	10.2.129.4 – 10.2.129.4	10.2.129.4
6	10.2.129.5/32	10.2.129.5 – 10.2.129.5	10.2.129.5
7	10.2.129.6/32	10.2.129.6 – 10.2.129.6	10.2.129.6
8	10.2.129.7/32	10.2.129.7 – 10.2.129.7	10.2.129.7
9	10.2.129.8/32	10.2.129.8 – 10.2.129.8	10.2.129.8
10	10.2.129.9/32	10.2.129.9 – 10.2.129.9	10.2.129.9
11	10.2.129.10/32	10.2.129.10 – 10.2.129.10	10.2.129.10
12	10.2.129.11/32	10.2.129.11 – 10.2.129.11	10.2.129.11
13	10.2.129.12/32	10.2.129.12 – 10.2.129.12	10.2.129.12
14	10.2.129.13/32	10.2.129.13 – 10.2.129.13	10.2.129.13
15	10.2.129.14/32	10.2.129.14 – 10.2.129.14	10.2.129.14
16	10.2.129.15/32	10.2.129.15 – 10.2.129.15	10.2.129.15
17	10.2.129.16/32	10.2.129.16 – 10.2.129.16	10.2.129.16
18	10.2.129.17/32	10.2.129.17 – 10.2.129.17	10.2.129.17
19	10.2.129.18/32	10.2.129.18 – 10.2.129.18	10.2.129.18
20	10.2.129.19/32	10.2.129.19 – 10.2.129.19	10.2.129.19
21	10.2.129.20/32	10.2.129.20 – 10.2.129.20	10.2.129.20
22	10.2.129.21/32	10.2.129.21 – 10.2.129.21	10.2.129.21
23	10.2.129.22/32	10.2.129.22 – 10.2.129.22	10.2.129.22
24	10.2.129.23/32	10.2.129.23 – 10.2.129.23	10.2.129.23
25	10.2.129.24/32	10.2.129.24 – 10.2.129.24	10.2.129.24
26	10.2.129.25/32	10.2.129.25 – 10.2.129.25	10.2.129.25
27	10.2.129.26/32	10.2.129.26 – 10.2.129.26	10.2.129.26
28	10.2.129.27/32	10.2.129.27 – 10.2.129.27	10.2.129.27
29	10.2.129.28/32	10.2.129.28 – 10.2.129.28	10.2.129.28
30	10.2.129.29/32	10.2.129.29 – 10.2.129.29	10.2.129.29
31	10.2.129.30/32	10.2.129.30 – 10.2.129.30	10.2.129.30
32	10.2.129.31/32	10.2.129.31 – 10.2.129.31	10.2.129.31
33	10.2.129.32/32	10.2.129.32 – 10.2.129.32	10.2.129.32
34	10.2.129.33/32	10.2.129.33 – 10.2.129.33	10.2.129.33
35	10.2.129.34/32	10.2.129.34 – 10.2.129.34	10.2.129.34
36	10.2.129.35/32	10.2.129.35 – 10.2.129.35	10.2.129.35
37	10.2.129.36/32	10.2.129.36 – 10.2.129.36	10.2.129.36
38	10.2.129.37/32	10.2.129.37 – 10.2.129.37	10.2.129.37
39	10.2.129.38/32	10.2.129.38 – 10.2.129.38	10.2.129.38
40	10.2.129.39/32	10.2.129.39 – 10.2.129.39	10.2.129.39
41	10.2.129.40/32	10.2.129.40 – 10.2.129.40	10.2.129.40
42	10.2.129.41/32	10.2.129.41 – 10.2.129.41	10.2.129.41
43	10.2.129.42/32	10.2.129.42 – 10.2.129.42	10.2.129.42
44	10.2.129.43/32	10.2.129.43 – 10.2.129.43	10.2.129.43
45	10.2.129.44/32	10.2.129.44 – 10.2.129.44	10.2.129.44
46	10.2.129.45/32	10.2.129.45 – 10.2.129.45	10.2.129.45
47	10.2.129.46/32	10.2.129.46 – 10.2.129.46	10.2.129.46
48	10.2.129.47/32	10.2.129.47 – 10.2.129.47	10.2.129.47
49	10.2.129.48/32	10.2.129.48 – 10.2.129.48	10.2.129.48
50	10.2.129.49/32	10.2.129.49 – 10.2.129.49	10.2.129.49
51	10.2.129.50/32	10.2.129.50 – 10.2.129.50	10.2.129.50
52	10.2.129.51/32	10.2.129.51 – 10.2.129.51	10.2.129.51
53	10.2.129.52/32	10.2.129.52 – 10.2.129.52	10.2.129.52
54	10.2.129.53/32	10.2.129.53 – 10.2.129.53	10.2.129.53
55	10.2.129.54/32	10.2.129.54 – 10.2.129.54	10.2.129.54
56	10.2.129.55/32	10.2.129.55 – 10.2.129.55	10.2.129.55
57	10.2.129.56/32	10.2.129.56 – 10.2.129.56	10.2.129.56
58	10.2.129.57/32	10.2.129.57 – 10.2.129.57	10.2.129.57
59	10.2.129.58/32	10.2.129.58 – 10.2.129.58	10.2.129.58
60	10.2.129.59/32	10.2.129.59 – 10.2.129.59	10.2.129.59
61	10.2.129.60/32	10.2.129.60 – 10.2.129.60	10.2.129.60
62	10.2.129.61/32	10.2.129.61 – 10.2.129.61	10.2.129.61
63	10.2.129.62/32	10.2.129.62 – 10.2.129.62	10.2.129.62
64	10.2.129.63/32	10.2.129.63 – 10.2.129.63	10.2.129.63
65	10.2.129.64/32	10.2.129.64 – 10.2.129.64	10.2.129.64
66	10.2.129.65/32	10.2.129.65 – 10.2.129.65	10.2.129.65
67	10.2.129.66/32	10.2.129.66 – 10.2.129.66	10.2.129.66
68	10.2.129.67/32	10.2.129.67 – 10.2.129.67	10.2.129.67
69	10.2.129.68/32	10.2.129.68 – 10.2.129.68	10.2.129.68
70	10.2.129.69/32	10.2.129.69 – 10.2.129.69	10.2.129.69
71	10.2.129.70/32	10.2.129.70 – 10.2.129.70	10.2.129.70
72	10.2.129.71/32	10.2.129.71 – 10.2.129.71	10.2.129.71
73	10.2.129.72/32	10.2.129.72 – 10.2.129.72	10.2.129.72
74	10.2.129.73/32	10.2.129.73 – 10.2.129.73	10.2.129.73
75	10.2.129.74/32	10.2.129.74 – 10.2.129.74	10.2.129.74
76	10.2.129.75/32	10.2.129.75 – 10.2.129.75	10.2.129.75
77	10.2.129.76/32	10.2.129.76 – 10.2.129.76	10.2.129.76
78	10.2.129.77/32	10.2.129.77 – 10.2.129.77	10.2.129.77
79	10.2.129.78/32	10.2.129.78 – 10.2.129.78	10.2.129.78
80	10.2.129.79/32	10.2.129.79 – 10.2.129.79	10.2.129.79
81	10.2.129.80/32	10.2.129.80 – 10.2.129.80	10.2.129.80
82	10.2.129.81/32	10.2.129.81 – 10.2.129.81	10.2.129.81
83	10.2.129.82/32	10.2.129.82 – 10.2.129.82	10.2.129.82
84	10.2.129.83/32	10.2.129.83 – 10.2.129.83	10.2.129.83
85	10.2.129.84/32	10.2.129.84 – 10.2.129.84	10.2.129.84
86	10.2.129.85/32	10.2.129.85 – 10.2.129.85	10.2.129.85
87	10.2.129.86/32	10.2.129.86 – 10.2.129.86	10.2.129.86
88	10.2.129.87/32	10.2.129.87 – 10.2.129.87	10.2.129.87
89	10.2.129.88/32	10.2.129.88 – 10.2.129.88	10.2.129.88
90	10.2.129.89/32	10.2.129.89 – 10.2.129.89	10.2.129.89
91	10.2.129.90/32	10.2.129.90 – 10.2.129.90	10.2.129.90
92	10.2.129.91/32	10.2.129.91 – 10.2.129.91	10.2.129.91
93	10.2.129.92/32	10.2.129.92 – 10.2.129.92	10.2.129.92
94	10.2.129.93/32	10.2.129.93 – 10.2.129.93	10.2.129.93
95	10.2.129.94/32	10.2.129.94 – 10.2.129.94	10.2.129.94
96	10.2.129.95/32	10.2.129.95 – 10.2.129.95	10.2.129.95
97	10.2.129.96/32	10.2.129.96 – 10.2.129.96	10.2.129.96
98	10.2.129.97/32	10.2.129.97 – 10.2.129.97	10.2.129.97
99	10.2.129.98/32	10.2.129.98 – 10.2.129.98	10.2.129.98
100	10.2.129.99/32	10.2.129.99 – 10.2.129.99	10.2.129.99
101	10.2.129.100/32	10.2.129.100 – 10.2.129.100	10.2.129.100
102	10.2.129.101/32	10.2.129.101 – 10.2.129.101	10.2.129.101
103	10.2.129.102/32	10.2.129.102 – 10.2.129.102	10.2.129.102
104	10.2.129.103/32	10.2.129.103 – 10.2.129.103	10.2.129.103
105	10.2.129.104/32	10.2.129.104 – 10.2.129.104	10.2.129.104
106	10.2.129.105/32	10.2.129.105 – 10.2.129.105	10.2.129.105
107	10.2.129.106/32	10.2.129.106 – 10.2.129.106	10.2.129.106
108	10.2.129.107/32	10.2.129.107 – 10.2.129.107	10.2.129.107
109	10.2.129.108/32	10.2.129.108 – 10.2.129.108	10.2.129.108
110	10.2.129.109/32	10.2.129.109 – 10.2.129.109	10.2.129.109
111	10.2.129.110/32	10.2.129.110 – 10.2.129.110	10.2.129.110
112	10.2.129.111/32	10.2.129.111 – 10.2.129.111	10.2.129.111
113	10.2.129.112/32	10.2.129.112 – 10.2.129.112	10.2.129.112
114	10.2.129.113/32	10.2.129.113 – 10.2.129.113	10.2.129.113
115	10.2.129.114/32	10.2.129.114 – 10.2.129.114	10.2.129.114
116	10.2.129.115/32	10.2.129.115 – 10.2.129.115	10.2.129.115
117	10.2.129.116/32	10.2.129.116 – 10.2.129.116	10.2.129.116
118	10.2.129.117/32	10.2.129.117 – 10.2.129.117	10.2.129.117
119	10.2.129.118/32	10.2.129.118 – 10.2.129.118	10.2.129.118
120	10.2.129.119/32	10.2.129.119 – 10.2.129.119	10.2.129.119
121	10.2.129.120/32	10.2.129.120 – 10.2.129.120	10.2.129.120
122	10.2.129.121/32	10.2.129.121 – 10.2.129.121	10.2.129.121
123	10.2.129.122/32	10.2.129.122 – 10.2.129.122	10.2.129.122
124	10.2.129.123/32	10.2.129.123 – 10.2.129.123	10.2.129.123
125	10.2.129.124/32	10.2.129.124 – 10.2.129.124	10.2.129.124
126	10.2.129.125/32	10.2.129.125 – 10.2.129.125	10.2.129.125
127	10.2.129.126/32	10.2.129.126 – 10.2.129.126	10.2.129.126
128	10.2.129.127/32	10.2.129.127 – 10.2.129.127	10.2.129.127

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 →