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)10.18.166.0/25

network10.18.166.0/25

broadcast10.18.166.127

first host10.18.166.1

last host10.18.166.126

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.18.166.0/25

address00001010.00010010.10100110.00000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00010010.10100110.00000000

broadcast00001010.00010010.10100110.01111111

green = network part, grey = host part

hex0x0a12a600

decimal168994304

reverse dns0.166.18.10.in-addr.arpa

ipv4-mapped::ffff:a12:a600

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.18.166.0/32	10.18.166.0 – 10.18.166.0	10.18.166.0
2	10.18.166.1/32	10.18.166.1 – 10.18.166.1	10.18.166.1
3	10.18.166.2/32	10.18.166.2 – 10.18.166.2	10.18.166.2
4	10.18.166.3/32	10.18.166.3 – 10.18.166.3	10.18.166.3
5	10.18.166.4/32	10.18.166.4 – 10.18.166.4	10.18.166.4
6	10.18.166.5/32	10.18.166.5 – 10.18.166.5	10.18.166.5
7	10.18.166.6/32	10.18.166.6 – 10.18.166.6	10.18.166.6
8	10.18.166.7/32	10.18.166.7 – 10.18.166.7	10.18.166.7
9	10.18.166.8/32	10.18.166.8 – 10.18.166.8	10.18.166.8
10	10.18.166.9/32	10.18.166.9 – 10.18.166.9	10.18.166.9
11	10.18.166.10/32	10.18.166.10 – 10.18.166.10	10.18.166.10
12	10.18.166.11/32	10.18.166.11 – 10.18.166.11	10.18.166.11
13	10.18.166.12/32	10.18.166.12 – 10.18.166.12	10.18.166.12
14	10.18.166.13/32	10.18.166.13 – 10.18.166.13	10.18.166.13
15	10.18.166.14/32	10.18.166.14 – 10.18.166.14	10.18.166.14
16	10.18.166.15/32	10.18.166.15 – 10.18.166.15	10.18.166.15
17	10.18.166.16/32	10.18.166.16 – 10.18.166.16	10.18.166.16
18	10.18.166.17/32	10.18.166.17 – 10.18.166.17	10.18.166.17
19	10.18.166.18/32	10.18.166.18 – 10.18.166.18	10.18.166.18
20	10.18.166.19/32	10.18.166.19 – 10.18.166.19	10.18.166.19
21	10.18.166.20/32	10.18.166.20 – 10.18.166.20	10.18.166.20
22	10.18.166.21/32	10.18.166.21 – 10.18.166.21	10.18.166.21
23	10.18.166.22/32	10.18.166.22 – 10.18.166.22	10.18.166.22
24	10.18.166.23/32	10.18.166.23 – 10.18.166.23	10.18.166.23
25	10.18.166.24/32	10.18.166.24 – 10.18.166.24	10.18.166.24
26	10.18.166.25/32	10.18.166.25 – 10.18.166.25	10.18.166.25
27	10.18.166.26/32	10.18.166.26 – 10.18.166.26	10.18.166.26
28	10.18.166.27/32	10.18.166.27 – 10.18.166.27	10.18.166.27
29	10.18.166.28/32	10.18.166.28 – 10.18.166.28	10.18.166.28
30	10.18.166.29/32	10.18.166.29 – 10.18.166.29	10.18.166.29
31	10.18.166.30/32	10.18.166.30 – 10.18.166.30	10.18.166.30
32	10.18.166.31/32	10.18.166.31 – 10.18.166.31	10.18.166.31
33	10.18.166.32/32	10.18.166.32 – 10.18.166.32	10.18.166.32
34	10.18.166.33/32	10.18.166.33 – 10.18.166.33	10.18.166.33
35	10.18.166.34/32	10.18.166.34 – 10.18.166.34	10.18.166.34
36	10.18.166.35/32	10.18.166.35 – 10.18.166.35	10.18.166.35
37	10.18.166.36/32	10.18.166.36 – 10.18.166.36	10.18.166.36
38	10.18.166.37/32	10.18.166.37 – 10.18.166.37	10.18.166.37
39	10.18.166.38/32	10.18.166.38 – 10.18.166.38	10.18.166.38
40	10.18.166.39/32	10.18.166.39 – 10.18.166.39	10.18.166.39
41	10.18.166.40/32	10.18.166.40 – 10.18.166.40	10.18.166.40
42	10.18.166.41/32	10.18.166.41 – 10.18.166.41	10.18.166.41
43	10.18.166.42/32	10.18.166.42 – 10.18.166.42	10.18.166.42
44	10.18.166.43/32	10.18.166.43 – 10.18.166.43	10.18.166.43
45	10.18.166.44/32	10.18.166.44 – 10.18.166.44	10.18.166.44
46	10.18.166.45/32	10.18.166.45 – 10.18.166.45	10.18.166.45
47	10.18.166.46/32	10.18.166.46 – 10.18.166.46	10.18.166.46
48	10.18.166.47/32	10.18.166.47 – 10.18.166.47	10.18.166.47
49	10.18.166.48/32	10.18.166.48 – 10.18.166.48	10.18.166.48
50	10.18.166.49/32	10.18.166.49 – 10.18.166.49	10.18.166.49
51	10.18.166.50/32	10.18.166.50 – 10.18.166.50	10.18.166.50
52	10.18.166.51/32	10.18.166.51 – 10.18.166.51	10.18.166.51
53	10.18.166.52/32	10.18.166.52 – 10.18.166.52	10.18.166.52
54	10.18.166.53/32	10.18.166.53 – 10.18.166.53	10.18.166.53
55	10.18.166.54/32	10.18.166.54 – 10.18.166.54	10.18.166.54
56	10.18.166.55/32	10.18.166.55 – 10.18.166.55	10.18.166.55
57	10.18.166.56/32	10.18.166.56 – 10.18.166.56	10.18.166.56
58	10.18.166.57/32	10.18.166.57 – 10.18.166.57	10.18.166.57
59	10.18.166.58/32	10.18.166.58 – 10.18.166.58	10.18.166.58
60	10.18.166.59/32	10.18.166.59 – 10.18.166.59	10.18.166.59
61	10.18.166.60/32	10.18.166.60 – 10.18.166.60	10.18.166.60
62	10.18.166.61/32	10.18.166.61 – 10.18.166.61	10.18.166.61
63	10.18.166.62/32	10.18.166.62 – 10.18.166.62	10.18.166.62
64	10.18.166.63/32	10.18.166.63 – 10.18.166.63	10.18.166.63
65	10.18.166.64/32	10.18.166.64 – 10.18.166.64	10.18.166.64
66	10.18.166.65/32	10.18.166.65 – 10.18.166.65	10.18.166.65
67	10.18.166.66/32	10.18.166.66 – 10.18.166.66	10.18.166.66
68	10.18.166.67/32	10.18.166.67 – 10.18.166.67	10.18.166.67
69	10.18.166.68/32	10.18.166.68 – 10.18.166.68	10.18.166.68
70	10.18.166.69/32	10.18.166.69 – 10.18.166.69	10.18.166.69
71	10.18.166.70/32	10.18.166.70 – 10.18.166.70	10.18.166.70
72	10.18.166.71/32	10.18.166.71 – 10.18.166.71	10.18.166.71
73	10.18.166.72/32	10.18.166.72 – 10.18.166.72	10.18.166.72
74	10.18.166.73/32	10.18.166.73 – 10.18.166.73	10.18.166.73
75	10.18.166.74/32	10.18.166.74 – 10.18.166.74	10.18.166.74
76	10.18.166.75/32	10.18.166.75 – 10.18.166.75	10.18.166.75
77	10.18.166.76/32	10.18.166.76 – 10.18.166.76	10.18.166.76
78	10.18.166.77/32	10.18.166.77 – 10.18.166.77	10.18.166.77
79	10.18.166.78/32	10.18.166.78 – 10.18.166.78	10.18.166.78
80	10.18.166.79/32	10.18.166.79 – 10.18.166.79	10.18.166.79
81	10.18.166.80/32	10.18.166.80 – 10.18.166.80	10.18.166.80
82	10.18.166.81/32	10.18.166.81 – 10.18.166.81	10.18.166.81
83	10.18.166.82/32	10.18.166.82 – 10.18.166.82	10.18.166.82
84	10.18.166.83/32	10.18.166.83 – 10.18.166.83	10.18.166.83
85	10.18.166.84/32	10.18.166.84 – 10.18.166.84	10.18.166.84
86	10.18.166.85/32	10.18.166.85 – 10.18.166.85	10.18.166.85
87	10.18.166.86/32	10.18.166.86 – 10.18.166.86	10.18.166.86
88	10.18.166.87/32	10.18.166.87 – 10.18.166.87	10.18.166.87
89	10.18.166.88/32	10.18.166.88 – 10.18.166.88	10.18.166.88
90	10.18.166.89/32	10.18.166.89 – 10.18.166.89	10.18.166.89
91	10.18.166.90/32	10.18.166.90 – 10.18.166.90	10.18.166.90
92	10.18.166.91/32	10.18.166.91 – 10.18.166.91	10.18.166.91
93	10.18.166.92/32	10.18.166.92 – 10.18.166.92	10.18.166.92
94	10.18.166.93/32	10.18.166.93 – 10.18.166.93	10.18.166.93
95	10.18.166.94/32	10.18.166.94 – 10.18.166.94	10.18.166.94
96	10.18.166.95/32	10.18.166.95 – 10.18.166.95	10.18.166.95
97	10.18.166.96/32	10.18.166.96 – 10.18.166.96	10.18.166.96
98	10.18.166.97/32	10.18.166.97 – 10.18.166.97	10.18.166.97
99	10.18.166.98/32	10.18.166.98 – 10.18.166.98	10.18.166.98
100	10.18.166.99/32	10.18.166.99 – 10.18.166.99	10.18.166.99
101	10.18.166.100/32	10.18.166.100 – 10.18.166.100	10.18.166.100
102	10.18.166.101/32	10.18.166.101 – 10.18.166.101	10.18.166.101
103	10.18.166.102/32	10.18.166.102 – 10.18.166.102	10.18.166.102
104	10.18.166.103/32	10.18.166.103 – 10.18.166.103	10.18.166.103
105	10.18.166.104/32	10.18.166.104 – 10.18.166.104	10.18.166.104
106	10.18.166.105/32	10.18.166.105 – 10.18.166.105	10.18.166.105
107	10.18.166.106/32	10.18.166.106 – 10.18.166.106	10.18.166.106
108	10.18.166.107/32	10.18.166.107 – 10.18.166.107	10.18.166.107
109	10.18.166.108/32	10.18.166.108 – 10.18.166.108	10.18.166.108
110	10.18.166.109/32	10.18.166.109 – 10.18.166.109	10.18.166.109
111	10.18.166.110/32	10.18.166.110 – 10.18.166.110	10.18.166.110
112	10.18.166.111/32	10.18.166.111 – 10.18.166.111	10.18.166.111
113	10.18.166.112/32	10.18.166.112 – 10.18.166.112	10.18.166.112
114	10.18.166.113/32	10.18.166.113 – 10.18.166.113	10.18.166.113
115	10.18.166.114/32	10.18.166.114 – 10.18.166.114	10.18.166.114
116	10.18.166.115/32	10.18.166.115 – 10.18.166.115	10.18.166.115
117	10.18.166.116/32	10.18.166.116 – 10.18.166.116	10.18.166.116
118	10.18.166.117/32	10.18.166.117 – 10.18.166.117	10.18.166.117
119	10.18.166.118/32	10.18.166.118 – 10.18.166.118	10.18.166.118
120	10.18.166.119/32	10.18.166.119 – 10.18.166.119	10.18.166.119
121	10.18.166.120/32	10.18.166.120 – 10.18.166.120	10.18.166.120
122	10.18.166.121/32	10.18.166.121 – 10.18.166.121	10.18.166.121
123	10.18.166.122/32	10.18.166.122 – 10.18.166.122	10.18.166.122
124	10.18.166.123/32	10.18.166.123 – 10.18.166.123	10.18.166.123
125	10.18.166.124/32	10.18.166.124 – 10.18.166.124	10.18.166.124
126	10.18.166.125/32	10.18.166.125 – 10.18.166.125	10.18.166.125
127	10.18.166.126/32	10.18.166.126 – 10.18.166.126	10.18.166.126
128	10.18.166.127/32	10.18.166.127 – 10.18.166.127	10.18.166.127

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 →