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)10.2.23.0/25

network10.2.23.0/25

broadcast10.2.23.127

first host10.2.23.1

last host10.2.23.126

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.2.23.0/25

address00001010.00000010.00010111.00000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000010.00010111.00000000

broadcast00001010.00000010.00010111.01111111

green = network part, grey = host part

hex0x0a021700

decimal167909120

reverse dns0.23.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:1700

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.23.0/32	10.2.23.0 – 10.2.23.0	10.2.23.0
2	10.2.23.1/32	10.2.23.1 – 10.2.23.1	10.2.23.1
3	10.2.23.2/32	10.2.23.2 – 10.2.23.2	10.2.23.2
4	10.2.23.3/32	10.2.23.3 – 10.2.23.3	10.2.23.3
5	10.2.23.4/32	10.2.23.4 – 10.2.23.4	10.2.23.4
6	10.2.23.5/32	10.2.23.5 – 10.2.23.5	10.2.23.5
7	10.2.23.6/32	10.2.23.6 – 10.2.23.6	10.2.23.6
8	10.2.23.7/32	10.2.23.7 – 10.2.23.7	10.2.23.7
9	10.2.23.8/32	10.2.23.8 – 10.2.23.8	10.2.23.8
10	10.2.23.9/32	10.2.23.9 – 10.2.23.9	10.2.23.9
11	10.2.23.10/32	10.2.23.10 – 10.2.23.10	10.2.23.10
12	10.2.23.11/32	10.2.23.11 – 10.2.23.11	10.2.23.11
13	10.2.23.12/32	10.2.23.12 – 10.2.23.12	10.2.23.12
14	10.2.23.13/32	10.2.23.13 – 10.2.23.13	10.2.23.13
15	10.2.23.14/32	10.2.23.14 – 10.2.23.14	10.2.23.14
16	10.2.23.15/32	10.2.23.15 – 10.2.23.15	10.2.23.15
17	10.2.23.16/32	10.2.23.16 – 10.2.23.16	10.2.23.16
18	10.2.23.17/32	10.2.23.17 – 10.2.23.17	10.2.23.17
19	10.2.23.18/32	10.2.23.18 – 10.2.23.18	10.2.23.18
20	10.2.23.19/32	10.2.23.19 – 10.2.23.19	10.2.23.19
21	10.2.23.20/32	10.2.23.20 – 10.2.23.20	10.2.23.20
22	10.2.23.21/32	10.2.23.21 – 10.2.23.21	10.2.23.21
23	10.2.23.22/32	10.2.23.22 – 10.2.23.22	10.2.23.22
24	10.2.23.23/32	10.2.23.23 – 10.2.23.23	10.2.23.23
25	10.2.23.24/32	10.2.23.24 – 10.2.23.24	10.2.23.24
26	10.2.23.25/32	10.2.23.25 – 10.2.23.25	10.2.23.25
27	10.2.23.26/32	10.2.23.26 – 10.2.23.26	10.2.23.26
28	10.2.23.27/32	10.2.23.27 – 10.2.23.27	10.2.23.27
29	10.2.23.28/32	10.2.23.28 – 10.2.23.28	10.2.23.28
30	10.2.23.29/32	10.2.23.29 – 10.2.23.29	10.2.23.29
31	10.2.23.30/32	10.2.23.30 – 10.2.23.30	10.2.23.30
32	10.2.23.31/32	10.2.23.31 – 10.2.23.31	10.2.23.31
33	10.2.23.32/32	10.2.23.32 – 10.2.23.32	10.2.23.32
34	10.2.23.33/32	10.2.23.33 – 10.2.23.33	10.2.23.33
35	10.2.23.34/32	10.2.23.34 – 10.2.23.34	10.2.23.34
36	10.2.23.35/32	10.2.23.35 – 10.2.23.35	10.2.23.35
37	10.2.23.36/32	10.2.23.36 – 10.2.23.36	10.2.23.36
38	10.2.23.37/32	10.2.23.37 – 10.2.23.37	10.2.23.37
39	10.2.23.38/32	10.2.23.38 – 10.2.23.38	10.2.23.38
40	10.2.23.39/32	10.2.23.39 – 10.2.23.39	10.2.23.39
41	10.2.23.40/32	10.2.23.40 – 10.2.23.40	10.2.23.40
42	10.2.23.41/32	10.2.23.41 – 10.2.23.41	10.2.23.41
43	10.2.23.42/32	10.2.23.42 – 10.2.23.42	10.2.23.42
44	10.2.23.43/32	10.2.23.43 – 10.2.23.43	10.2.23.43
45	10.2.23.44/32	10.2.23.44 – 10.2.23.44	10.2.23.44
46	10.2.23.45/32	10.2.23.45 – 10.2.23.45	10.2.23.45
47	10.2.23.46/32	10.2.23.46 – 10.2.23.46	10.2.23.46
48	10.2.23.47/32	10.2.23.47 – 10.2.23.47	10.2.23.47
49	10.2.23.48/32	10.2.23.48 – 10.2.23.48	10.2.23.48
50	10.2.23.49/32	10.2.23.49 – 10.2.23.49	10.2.23.49
51	10.2.23.50/32	10.2.23.50 – 10.2.23.50	10.2.23.50
52	10.2.23.51/32	10.2.23.51 – 10.2.23.51	10.2.23.51
53	10.2.23.52/32	10.2.23.52 – 10.2.23.52	10.2.23.52
54	10.2.23.53/32	10.2.23.53 – 10.2.23.53	10.2.23.53
55	10.2.23.54/32	10.2.23.54 – 10.2.23.54	10.2.23.54
56	10.2.23.55/32	10.2.23.55 – 10.2.23.55	10.2.23.55
57	10.2.23.56/32	10.2.23.56 – 10.2.23.56	10.2.23.56
58	10.2.23.57/32	10.2.23.57 – 10.2.23.57	10.2.23.57
59	10.2.23.58/32	10.2.23.58 – 10.2.23.58	10.2.23.58
60	10.2.23.59/32	10.2.23.59 – 10.2.23.59	10.2.23.59
61	10.2.23.60/32	10.2.23.60 – 10.2.23.60	10.2.23.60
62	10.2.23.61/32	10.2.23.61 – 10.2.23.61	10.2.23.61
63	10.2.23.62/32	10.2.23.62 – 10.2.23.62	10.2.23.62
64	10.2.23.63/32	10.2.23.63 – 10.2.23.63	10.2.23.63
65	10.2.23.64/32	10.2.23.64 – 10.2.23.64	10.2.23.64
66	10.2.23.65/32	10.2.23.65 – 10.2.23.65	10.2.23.65
67	10.2.23.66/32	10.2.23.66 – 10.2.23.66	10.2.23.66
68	10.2.23.67/32	10.2.23.67 – 10.2.23.67	10.2.23.67
69	10.2.23.68/32	10.2.23.68 – 10.2.23.68	10.2.23.68
70	10.2.23.69/32	10.2.23.69 – 10.2.23.69	10.2.23.69
71	10.2.23.70/32	10.2.23.70 – 10.2.23.70	10.2.23.70
72	10.2.23.71/32	10.2.23.71 – 10.2.23.71	10.2.23.71
73	10.2.23.72/32	10.2.23.72 – 10.2.23.72	10.2.23.72
74	10.2.23.73/32	10.2.23.73 – 10.2.23.73	10.2.23.73
75	10.2.23.74/32	10.2.23.74 – 10.2.23.74	10.2.23.74
76	10.2.23.75/32	10.2.23.75 – 10.2.23.75	10.2.23.75
77	10.2.23.76/32	10.2.23.76 – 10.2.23.76	10.2.23.76
78	10.2.23.77/32	10.2.23.77 – 10.2.23.77	10.2.23.77
79	10.2.23.78/32	10.2.23.78 – 10.2.23.78	10.2.23.78
80	10.2.23.79/32	10.2.23.79 – 10.2.23.79	10.2.23.79
81	10.2.23.80/32	10.2.23.80 – 10.2.23.80	10.2.23.80
82	10.2.23.81/32	10.2.23.81 – 10.2.23.81	10.2.23.81
83	10.2.23.82/32	10.2.23.82 – 10.2.23.82	10.2.23.82
84	10.2.23.83/32	10.2.23.83 – 10.2.23.83	10.2.23.83
85	10.2.23.84/32	10.2.23.84 – 10.2.23.84	10.2.23.84
86	10.2.23.85/32	10.2.23.85 – 10.2.23.85	10.2.23.85
87	10.2.23.86/32	10.2.23.86 – 10.2.23.86	10.2.23.86
88	10.2.23.87/32	10.2.23.87 – 10.2.23.87	10.2.23.87
89	10.2.23.88/32	10.2.23.88 – 10.2.23.88	10.2.23.88
90	10.2.23.89/32	10.2.23.89 – 10.2.23.89	10.2.23.89
91	10.2.23.90/32	10.2.23.90 – 10.2.23.90	10.2.23.90
92	10.2.23.91/32	10.2.23.91 – 10.2.23.91	10.2.23.91
93	10.2.23.92/32	10.2.23.92 – 10.2.23.92	10.2.23.92
94	10.2.23.93/32	10.2.23.93 – 10.2.23.93	10.2.23.93
95	10.2.23.94/32	10.2.23.94 – 10.2.23.94	10.2.23.94
96	10.2.23.95/32	10.2.23.95 – 10.2.23.95	10.2.23.95
97	10.2.23.96/32	10.2.23.96 – 10.2.23.96	10.2.23.96
98	10.2.23.97/32	10.2.23.97 – 10.2.23.97	10.2.23.97
99	10.2.23.98/32	10.2.23.98 – 10.2.23.98	10.2.23.98
100	10.2.23.99/32	10.2.23.99 – 10.2.23.99	10.2.23.99
101	10.2.23.100/32	10.2.23.100 – 10.2.23.100	10.2.23.100
102	10.2.23.101/32	10.2.23.101 – 10.2.23.101	10.2.23.101
103	10.2.23.102/32	10.2.23.102 – 10.2.23.102	10.2.23.102
104	10.2.23.103/32	10.2.23.103 – 10.2.23.103	10.2.23.103
105	10.2.23.104/32	10.2.23.104 – 10.2.23.104	10.2.23.104
106	10.2.23.105/32	10.2.23.105 – 10.2.23.105	10.2.23.105
107	10.2.23.106/32	10.2.23.106 – 10.2.23.106	10.2.23.106
108	10.2.23.107/32	10.2.23.107 – 10.2.23.107	10.2.23.107
109	10.2.23.108/32	10.2.23.108 – 10.2.23.108	10.2.23.108
110	10.2.23.109/32	10.2.23.109 – 10.2.23.109	10.2.23.109
111	10.2.23.110/32	10.2.23.110 – 10.2.23.110	10.2.23.110
112	10.2.23.111/32	10.2.23.111 – 10.2.23.111	10.2.23.111
113	10.2.23.112/32	10.2.23.112 – 10.2.23.112	10.2.23.112
114	10.2.23.113/32	10.2.23.113 – 10.2.23.113	10.2.23.113
115	10.2.23.114/32	10.2.23.114 – 10.2.23.114	10.2.23.114
116	10.2.23.115/32	10.2.23.115 – 10.2.23.115	10.2.23.115
117	10.2.23.116/32	10.2.23.116 – 10.2.23.116	10.2.23.116
118	10.2.23.117/32	10.2.23.117 – 10.2.23.117	10.2.23.117
119	10.2.23.118/32	10.2.23.118 – 10.2.23.118	10.2.23.118
120	10.2.23.119/32	10.2.23.119 – 10.2.23.119	10.2.23.119
121	10.2.23.120/32	10.2.23.120 – 10.2.23.120	10.2.23.120
122	10.2.23.121/32	10.2.23.121 – 10.2.23.121	10.2.23.121
123	10.2.23.122/32	10.2.23.122 – 10.2.23.122	10.2.23.122
124	10.2.23.123/32	10.2.23.123 – 10.2.23.123	10.2.23.123
125	10.2.23.124/32	10.2.23.124 – 10.2.23.124	10.2.23.124
126	10.2.23.125/32	10.2.23.125 – 10.2.23.125	10.2.23.125
127	10.2.23.126/32	10.2.23.126 – 10.2.23.126	10.2.23.126
128	10.2.23.127/32	10.2.23.127 – 10.2.23.127	10.2.23.127

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 →