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)10.166.103.0/25

network10.166.103.0/25

broadcast10.166.103.127

first host10.166.103.1

last host10.166.103.126

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.166.103.0/25

address00001010.10100110.01100111.00000000

subnet mask11111111.11111111.11111111.10000000

network00001010.10100110.01100111.00000000

broadcast00001010.10100110.01100111.01111111

green = network part, grey = host part

hex0x0aa66700

decimal178677504

reverse dns0.103.166.10.in-addr.arpa

ipv4-mapped::ffff:aa6:6700

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.166.103.0/32	10.166.103.0 – 10.166.103.0	10.166.103.0
2	10.166.103.1/32	10.166.103.1 – 10.166.103.1	10.166.103.1
3	10.166.103.2/32	10.166.103.2 – 10.166.103.2	10.166.103.2
4	10.166.103.3/32	10.166.103.3 – 10.166.103.3	10.166.103.3
5	10.166.103.4/32	10.166.103.4 – 10.166.103.4	10.166.103.4
6	10.166.103.5/32	10.166.103.5 – 10.166.103.5	10.166.103.5
7	10.166.103.6/32	10.166.103.6 – 10.166.103.6	10.166.103.6
8	10.166.103.7/32	10.166.103.7 – 10.166.103.7	10.166.103.7
9	10.166.103.8/32	10.166.103.8 – 10.166.103.8	10.166.103.8
10	10.166.103.9/32	10.166.103.9 – 10.166.103.9	10.166.103.9
11	10.166.103.10/32	10.166.103.10 – 10.166.103.10	10.166.103.10
12	10.166.103.11/32	10.166.103.11 – 10.166.103.11	10.166.103.11
13	10.166.103.12/32	10.166.103.12 – 10.166.103.12	10.166.103.12
14	10.166.103.13/32	10.166.103.13 – 10.166.103.13	10.166.103.13
15	10.166.103.14/32	10.166.103.14 – 10.166.103.14	10.166.103.14
16	10.166.103.15/32	10.166.103.15 – 10.166.103.15	10.166.103.15
17	10.166.103.16/32	10.166.103.16 – 10.166.103.16	10.166.103.16
18	10.166.103.17/32	10.166.103.17 – 10.166.103.17	10.166.103.17
19	10.166.103.18/32	10.166.103.18 – 10.166.103.18	10.166.103.18
20	10.166.103.19/32	10.166.103.19 – 10.166.103.19	10.166.103.19
21	10.166.103.20/32	10.166.103.20 – 10.166.103.20	10.166.103.20
22	10.166.103.21/32	10.166.103.21 – 10.166.103.21	10.166.103.21
23	10.166.103.22/32	10.166.103.22 – 10.166.103.22	10.166.103.22
24	10.166.103.23/32	10.166.103.23 – 10.166.103.23	10.166.103.23
25	10.166.103.24/32	10.166.103.24 – 10.166.103.24	10.166.103.24
26	10.166.103.25/32	10.166.103.25 – 10.166.103.25	10.166.103.25
27	10.166.103.26/32	10.166.103.26 – 10.166.103.26	10.166.103.26
28	10.166.103.27/32	10.166.103.27 – 10.166.103.27	10.166.103.27
29	10.166.103.28/32	10.166.103.28 – 10.166.103.28	10.166.103.28
30	10.166.103.29/32	10.166.103.29 – 10.166.103.29	10.166.103.29
31	10.166.103.30/32	10.166.103.30 – 10.166.103.30	10.166.103.30
32	10.166.103.31/32	10.166.103.31 – 10.166.103.31	10.166.103.31
33	10.166.103.32/32	10.166.103.32 – 10.166.103.32	10.166.103.32
34	10.166.103.33/32	10.166.103.33 – 10.166.103.33	10.166.103.33
35	10.166.103.34/32	10.166.103.34 – 10.166.103.34	10.166.103.34
36	10.166.103.35/32	10.166.103.35 – 10.166.103.35	10.166.103.35
37	10.166.103.36/32	10.166.103.36 – 10.166.103.36	10.166.103.36
38	10.166.103.37/32	10.166.103.37 – 10.166.103.37	10.166.103.37
39	10.166.103.38/32	10.166.103.38 – 10.166.103.38	10.166.103.38
40	10.166.103.39/32	10.166.103.39 – 10.166.103.39	10.166.103.39
41	10.166.103.40/32	10.166.103.40 – 10.166.103.40	10.166.103.40
42	10.166.103.41/32	10.166.103.41 – 10.166.103.41	10.166.103.41
43	10.166.103.42/32	10.166.103.42 – 10.166.103.42	10.166.103.42
44	10.166.103.43/32	10.166.103.43 – 10.166.103.43	10.166.103.43
45	10.166.103.44/32	10.166.103.44 – 10.166.103.44	10.166.103.44
46	10.166.103.45/32	10.166.103.45 – 10.166.103.45	10.166.103.45
47	10.166.103.46/32	10.166.103.46 – 10.166.103.46	10.166.103.46
48	10.166.103.47/32	10.166.103.47 – 10.166.103.47	10.166.103.47
49	10.166.103.48/32	10.166.103.48 – 10.166.103.48	10.166.103.48
50	10.166.103.49/32	10.166.103.49 – 10.166.103.49	10.166.103.49
51	10.166.103.50/32	10.166.103.50 – 10.166.103.50	10.166.103.50
52	10.166.103.51/32	10.166.103.51 – 10.166.103.51	10.166.103.51
53	10.166.103.52/32	10.166.103.52 – 10.166.103.52	10.166.103.52
54	10.166.103.53/32	10.166.103.53 – 10.166.103.53	10.166.103.53
55	10.166.103.54/32	10.166.103.54 – 10.166.103.54	10.166.103.54
56	10.166.103.55/32	10.166.103.55 – 10.166.103.55	10.166.103.55
57	10.166.103.56/32	10.166.103.56 – 10.166.103.56	10.166.103.56
58	10.166.103.57/32	10.166.103.57 – 10.166.103.57	10.166.103.57
59	10.166.103.58/32	10.166.103.58 – 10.166.103.58	10.166.103.58
60	10.166.103.59/32	10.166.103.59 – 10.166.103.59	10.166.103.59
61	10.166.103.60/32	10.166.103.60 – 10.166.103.60	10.166.103.60
62	10.166.103.61/32	10.166.103.61 – 10.166.103.61	10.166.103.61
63	10.166.103.62/32	10.166.103.62 – 10.166.103.62	10.166.103.62
64	10.166.103.63/32	10.166.103.63 – 10.166.103.63	10.166.103.63
65	10.166.103.64/32	10.166.103.64 – 10.166.103.64	10.166.103.64
66	10.166.103.65/32	10.166.103.65 – 10.166.103.65	10.166.103.65
67	10.166.103.66/32	10.166.103.66 – 10.166.103.66	10.166.103.66
68	10.166.103.67/32	10.166.103.67 – 10.166.103.67	10.166.103.67
69	10.166.103.68/32	10.166.103.68 – 10.166.103.68	10.166.103.68
70	10.166.103.69/32	10.166.103.69 – 10.166.103.69	10.166.103.69
71	10.166.103.70/32	10.166.103.70 – 10.166.103.70	10.166.103.70
72	10.166.103.71/32	10.166.103.71 – 10.166.103.71	10.166.103.71
73	10.166.103.72/32	10.166.103.72 – 10.166.103.72	10.166.103.72
74	10.166.103.73/32	10.166.103.73 – 10.166.103.73	10.166.103.73
75	10.166.103.74/32	10.166.103.74 – 10.166.103.74	10.166.103.74
76	10.166.103.75/32	10.166.103.75 – 10.166.103.75	10.166.103.75
77	10.166.103.76/32	10.166.103.76 – 10.166.103.76	10.166.103.76
78	10.166.103.77/32	10.166.103.77 – 10.166.103.77	10.166.103.77
79	10.166.103.78/32	10.166.103.78 – 10.166.103.78	10.166.103.78
80	10.166.103.79/32	10.166.103.79 – 10.166.103.79	10.166.103.79
81	10.166.103.80/32	10.166.103.80 – 10.166.103.80	10.166.103.80
82	10.166.103.81/32	10.166.103.81 – 10.166.103.81	10.166.103.81
83	10.166.103.82/32	10.166.103.82 – 10.166.103.82	10.166.103.82
84	10.166.103.83/32	10.166.103.83 – 10.166.103.83	10.166.103.83
85	10.166.103.84/32	10.166.103.84 – 10.166.103.84	10.166.103.84
86	10.166.103.85/32	10.166.103.85 – 10.166.103.85	10.166.103.85
87	10.166.103.86/32	10.166.103.86 – 10.166.103.86	10.166.103.86
88	10.166.103.87/32	10.166.103.87 – 10.166.103.87	10.166.103.87
89	10.166.103.88/32	10.166.103.88 – 10.166.103.88	10.166.103.88
90	10.166.103.89/32	10.166.103.89 – 10.166.103.89	10.166.103.89
91	10.166.103.90/32	10.166.103.90 – 10.166.103.90	10.166.103.90
92	10.166.103.91/32	10.166.103.91 – 10.166.103.91	10.166.103.91
93	10.166.103.92/32	10.166.103.92 – 10.166.103.92	10.166.103.92
94	10.166.103.93/32	10.166.103.93 – 10.166.103.93	10.166.103.93
95	10.166.103.94/32	10.166.103.94 – 10.166.103.94	10.166.103.94
96	10.166.103.95/32	10.166.103.95 – 10.166.103.95	10.166.103.95
97	10.166.103.96/32	10.166.103.96 – 10.166.103.96	10.166.103.96
98	10.166.103.97/32	10.166.103.97 – 10.166.103.97	10.166.103.97
99	10.166.103.98/32	10.166.103.98 – 10.166.103.98	10.166.103.98
100	10.166.103.99/32	10.166.103.99 – 10.166.103.99	10.166.103.99
101	10.166.103.100/32	10.166.103.100 – 10.166.103.100	10.166.103.100
102	10.166.103.101/32	10.166.103.101 – 10.166.103.101	10.166.103.101
103	10.166.103.102/32	10.166.103.102 – 10.166.103.102	10.166.103.102
104	10.166.103.103/32	10.166.103.103 – 10.166.103.103	10.166.103.103
105	10.166.103.104/32	10.166.103.104 – 10.166.103.104	10.166.103.104
106	10.166.103.105/32	10.166.103.105 – 10.166.103.105	10.166.103.105
107	10.166.103.106/32	10.166.103.106 – 10.166.103.106	10.166.103.106
108	10.166.103.107/32	10.166.103.107 – 10.166.103.107	10.166.103.107
109	10.166.103.108/32	10.166.103.108 – 10.166.103.108	10.166.103.108
110	10.166.103.109/32	10.166.103.109 – 10.166.103.109	10.166.103.109
111	10.166.103.110/32	10.166.103.110 – 10.166.103.110	10.166.103.110
112	10.166.103.111/32	10.166.103.111 – 10.166.103.111	10.166.103.111
113	10.166.103.112/32	10.166.103.112 – 10.166.103.112	10.166.103.112
114	10.166.103.113/32	10.166.103.113 – 10.166.103.113	10.166.103.113
115	10.166.103.114/32	10.166.103.114 – 10.166.103.114	10.166.103.114
116	10.166.103.115/32	10.166.103.115 – 10.166.103.115	10.166.103.115
117	10.166.103.116/32	10.166.103.116 – 10.166.103.116	10.166.103.116
118	10.166.103.117/32	10.166.103.117 – 10.166.103.117	10.166.103.117
119	10.166.103.118/32	10.166.103.118 – 10.166.103.118	10.166.103.118
120	10.166.103.119/32	10.166.103.119 – 10.166.103.119	10.166.103.119
121	10.166.103.120/32	10.166.103.120 – 10.166.103.120	10.166.103.120
122	10.166.103.121/32	10.166.103.121 – 10.166.103.121	10.166.103.121
123	10.166.103.122/32	10.166.103.122 – 10.166.103.122	10.166.103.122
124	10.166.103.123/32	10.166.103.123 – 10.166.103.123	10.166.103.123
125	10.166.103.124/32	10.166.103.124 – 10.166.103.124	10.166.103.124
126	10.166.103.125/32	10.166.103.125 – 10.166.103.125	10.166.103.125
127	10.166.103.126/32	10.166.103.126 – 10.166.103.126	10.166.103.126
128	10.166.103.127/32	10.166.103.127 – 10.166.103.127	10.166.103.127

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 →