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)10.2.19.0/25

network10.2.19.0/25

broadcast10.2.19.127

first host10.2.19.1

last host10.2.19.126

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.2.19.0/25

address00001010.00000010.00010011.00000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000010.00010011.00000000

broadcast00001010.00000010.00010011.01111111

green = network part, grey = host part

hex0x0a021300

decimal167908096

reverse dns0.19.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:1300

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.19.0/32	10.2.19.0 – 10.2.19.0	10.2.19.0
2	10.2.19.1/32	10.2.19.1 – 10.2.19.1	10.2.19.1
3	10.2.19.2/32	10.2.19.2 – 10.2.19.2	10.2.19.2
4	10.2.19.3/32	10.2.19.3 – 10.2.19.3	10.2.19.3
5	10.2.19.4/32	10.2.19.4 – 10.2.19.4	10.2.19.4
6	10.2.19.5/32	10.2.19.5 – 10.2.19.5	10.2.19.5
7	10.2.19.6/32	10.2.19.6 – 10.2.19.6	10.2.19.6
8	10.2.19.7/32	10.2.19.7 – 10.2.19.7	10.2.19.7
9	10.2.19.8/32	10.2.19.8 – 10.2.19.8	10.2.19.8
10	10.2.19.9/32	10.2.19.9 – 10.2.19.9	10.2.19.9
11	10.2.19.10/32	10.2.19.10 – 10.2.19.10	10.2.19.10
12	10.2.19.11/32	10.2.19.11 – 10.2.19.11	10.2.19.11
13	10.2.19.12/32	10.2.19.12 – 10.2.19.12	10.2.19.12
14	10.2.19.13/32	10.2.19.13 – 10.2.19.13	10.2.19.13
15	10.2.19.14/32	10.2.19.14 – 10.2.19.14	10.2.19.14
16	10.2.19.15/32	10.2.19.15 – 10.2.19.15	10.2.19.15
17	10.2.19.16/32	10.2.19.16 – 10.2.19.16	10.2.19.16
18	10.2.19.17/32	10.2.19.17 – 10.2.19.17	10.2.19.17
19	10.2.19.18/32	10.2.19.18 – 10.2.19.18	10.2.19.18
20	10.2.19.19/32	10.2.19.19 – 10.2.19.19	10.2.19.19
21	10.2.19.20/32	10.2.19.20 – 10.2.19.20	10.2.19.20
22	10.2.19.21/32	10.2.19.21 – 10.2.19.21	10.2.19.21
23	10.2.19.22/32	10.2.19.22 – 10.2.19.22	10.2.19.22
24	10.2.19.23/32	10.2.19.23 – 10.2.19.23	10.2.19.23
25	10.2.19.24/32	10.2.19.24 – 10.2.19.24	10.2.19.24
26	10.2.19.25/32	10.2.19.25 – 10.2.19.25	10.2.19.25
27	10.2.19.26/32	10.2.19.26 – 10.2.19.26	10.2.19.26
28	10.2.19.27/32	10.2.19.27 – 10.2.19.27	10.2.19.27
29	10.2.19.28/32	10.2.19.28 – 10.2.19.28	10.2.19.28
30	10.2.19.29/32	10.2.19.29 – 10.2.19.29	10.2.19.29
31	10.2.19.30/32	10.2.19.30 – 10.2.19.30	10.2.19.30
32	10.2.19.31/32	10.2.19.31 – 10.2.19.31	10.2.19.31
33	10.2.19.32/32	10.2.19.32 – 10.2.19.32	10.2.19.32
34	10.2.19.33/32	10.2.19.33 – 10.2.19.33	10.2.19.33
35	10.2.19.34/32	10.2.19.34 – 10.2.19.34	10.2.19.34
36	10.2.19.35/32	10.2.19.35 – 10.2.19.35	10.2.19.35
37	10.2.19.36/32	10.2.19.36 – 10.2.19.36	10.2.19.36
38	10.2.19.37/32	10.2.19.37 – 10.2.19.37	10.2.19.37
39	10.2.19.38/32	10.2.19.38 – 10.2.19.38	10.2.19.38
40	10.2.19.39/32	10.2.19.39 – 10.2.19.39	10.2.19.39
41	10.2.19.40/32	10.2.19.40 – 10.2.19.40	10.2.19.40
42	10.2.19.41/32	10.2.19.41 – 10.2.19.41	10.2.19.41
43	10.2.19.42/32	10.2.19.42 – 10.2.19.42	10.2.19.42
44	10.2.19.43/32	10.2.19.43 – 10.2.19.43	10.2.19.43
45	10.2.19.44/32	10.2.19.44 – 10.2.19.44	10.2.19.44
46	10.2.19.45/32	10.2.19.45 – 10.2.19.45	10.2.19.45
47	10.2.19.46/32	10.2.19.46 – 10.2.19.46	10.2.19.46
48	10.2.19.47/32	10.2.19.47 – 10.2.19.47	10.2.19.47
49	10.2.19.48/32	10.2.19.48 – 10.2.19.48	10.2.19.48
50	10.2.19.49/32	10.2.19.49 – 10.2.19.49	10.2.19.49
51	10.2.19.50/32	10.2.19.50 – 10.2.19.50	10.2.19.50
52	10.2.19.51/32	10.2.19.51 – 10.2.19.51	10.2.19.51
53	10.2.19.52/32	10.2.19.52 – 10.2.19.52	10.2.19.52
54	10.2.19.53/32	10.2.19.53 – 10.2.19.53	10.2.19.53
55	10.2.19.54/32	10.2.19.54 – 10.2.19.54	10.2.19.54
56	10.2.19.55/32	10.2.19.55 – 10.2.19.55	10.2.19.55
57	10.2.19.56/32	10.2.19.56 – 10.2.19.56	10.2.19.56
58	10.2.19.57/32	10.2.19.57 – 10.2.19.57	10.2.19.57
59	10.2.19.58/32	10.2.19.58 – 10.2.19.58	10.2.19.58
60	10.2.19.59/32	10.2.19.59 – 10.2.19.59	10.2.19.59
61	10.2.19.60/32	10.2.19.60 – 10.2.19.60	10.2.19.60
62	10.2.19.61/32	10.2.19.61 – 10.2.19.61	10.2.19.61
63	10.2.19.62/32	10.2.19.62 – 10.2.19.62	10.2.19.62
64	10.2.19.63/32	10.2.19.63 – 10.2.19.63	10.2.19.63
65	10.2.19.64/32	10.2.19.64 – 10.2.19.64	10.2.19.64
66	10.2.19.65/32	10.2.19.65 – 10.2.19.65	10.2.19.65
67	10.2.19.66/32	10.2.19.66 – 10.2.19.66	10.2.19.66
68	10.2.19.67/32	10.2.19.67 – 10.2.19.67	10.2.19.67
69	10.2.19.68/32	10.2.19.68 – 10.2.19.68	10.2.19.68
70	10.2.19.69/32	10.2.19.69 – 10.2.19.69	10.2.19.69
71	10.2.19.70/32	10.2.19.70 – 10.2.19.70	10.2.19.70
72	10.2.19.71/32	10.2.19.71 – 10.2.19.71	10.2.19.71
73	10.2.19.72/32	10.2.19.72 – 10.2.19.72	10.2.19.72
74	10.2.19.73/32	10.2.19.73 – 10.2.19.73	10.2.19.73
75	10.2.19.74/32	10.2.19.74 – 10.2.19.74	10.2.19.74
76	10.2.19.75/32	10.2.19.75 – 10.2.19.75	10.2.19.75
77	10.2.19.76/32	10.2.19.76 – 10.2.19.76	10.2.19.76
78	10.2.19.77/32	10.2.19.77 – 10.2.19.77	10.2.19.77
79	10.2.19.78/32	10.2.19.78 – 10.2.19.78	10.2.19.78
80	10.2.19.79/32	10.2.19.79 – 10.2.19.79	10.2.19.79
81	10.2.19.80/32	10.2.19.80 – 10.2.19.80	10.2.19.80
82	10.2.19.81/32	10.2.19.81 – 10.2.19.81	10.2.19.81
83	10.2.19.82/32	10.2.19.82 – 10.2.19.82	10.2.19.82
84	10.2.19.83/32	10.2.19.83 – 10.2.19.83	10.2.19.83
85	10.2.19.84/32	10.2.19.84 – 10.2.19.84	10.2.19.84
86	10.2.19.85/32	10.2.19.85 – 10.2.19.85	10.2.19.85
87	10.2.19.86/32	10.2.19.86 – 10.2.19.86	10.2.19.86
88	10.2.19.87/32	10.2.19.87 – 10.2.19.87	10.2.19.87
89	10.2.19.88/32	10.2.19.88 – 10.2.19.88	10.2.19.88
90	10.2.19.89/32	10.2.19.89 – 10.2.19.89	10.2.19.89
91	10.2.19.90/32	10.2.19.90 – 10.2.19.90	10.2.19.90
92	10.2.19.91/32	10.2.19.91 – 10.2.19.91	10.2.19.91
93	10.2.19.92/32	10.2.19.92 – 10.2.19.92	10.2.19.92
94	10.2.19.93/32	10.2.19.93 – 10.2.19.93	10.2.19.93
95	10.2.19.94/32	10.2.19.94 – 10.2.19.94	10.2.19.94
96	10.2.19.95/32	10.2.19.95 – 10.2.19.95	10.2.19.95
97	10.2.19.96/32	10.2.19.96 – 10.2.19.96	10.2.19.96
98	10.2.19.97/32	10.2.19.97 – 10.2.19.97	10.2.19.97
99	10.2.19.98/32	10.2.19.98 – 10.2.19.98	10.2.19.98
100	10.2.19.99/32	10.2.19.99 – 10.2.19.99	10.2.19.99
101	10.2.19.100/32	10.2.19.100 – 10.2.19.100	10.2.19.100
102	10.2.19.101/32	10.2.19.101 – 10.2.19.101	10.2.19.101
103	10.2.19.102/32	10.2.19.102 – 10.2.19.102	10.2.19.102
104	10.2.19.103/32	10.2.19.103 – 10.2.19.103	10.2.19.103
105	10.2.19.104/32	10.2.19.104 – 10.2.19.104	10.2.19.104
106	10.2.19.105/32	10.2.19.105 – 10.2.19.105	10.2.19.105
107	10.2.19.106/32	10.2.19.106 – 10.2.19.106	10.2.19.106
108	10.2.19.107/32	10.2.19.107 – 10.2.19.107	10.2.19.107
109	10.2.19.108/32	10.2.19.108 – 10.2.19.108	10.2.19.108
110	10.2.19.109/32	10.2.19.109 – 10.2.19.109	10.2.19.109
111	10.2.19.110/32	10.2.19.110 – 10.2.19.110	10.2.19.110
112	10.2.19.111/32	10.2.19.111 – 10.2.19.111	10.2.19.111
113	10.2.19.112/32	10.2.19.112 – 10.2.19.112	10.2.19.112
114	10.2.19.113/32	10.2.19.113 – 10.2.19.113	10.2.19.113
115	10.2.19.114/32	10.2.19.114 – 10.2.19.114	10.2.19.114
116	10.2.19.115/32	10.2.19.115 – 10.2.19.115	10.2.19.115
117	10.2.19.116/32	10.2.19.116 – 10.2.19.116	10.2.19.116
118	10.2.19.117/32	10.2.19.117 – 10.2.19.117	10.2.19.117
119	10.2.19.118/32	10.2.19.118 – 10.2.19.118	10.2.19.118
120	10.2.19.119/32	10.2.19.119 – 10.2.19.119	10.2.19.119
121	10.2.19.120/32	10.2.19.120 – 10.2.19.120	10.2.19.120
122	10.2.19.121/32	10.2.19.121 – 10.2.19.121	10.2.19.121
123	10.2.19.122/32	10.2.19.122 – 10.2.19.122	10.2.19.122
124	10.2.19.123/32	10.2.19.123 – 10.2.19.123	10.2.19.123
125	10.2.19.124/32	10.2.19.124 – 10.2.19.124	10.2.19.124
126	10.2.19.125/32	10.2.19.125 – 10.2.19.125	10.2.19.125
127	10.2.19.126/32	10.2.19.126 – 10.2.19.126	10.2.19.126
128	10.2.19.127/32	10.2.19.127 – 10.2.19.127	10.2.19.127

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 →