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)10.2.255.0/25

network10.2.255.0/25

broadcast10.2.255.127

first host10.2.255.1

last host10.2.255.126

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.2.255.0/25

address00001010.00000010.11111111.00000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000010.11111111.00000000

broadcast00001010.00000010.11111111.01111111

green = network part, grey = host part

hex0x0a02ff00

decimal167968512

reverse dns0.255.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:ff00

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.255.0/32	10.2.255.0 – 10.2.255.0	10.2.255.0
2	10.2.255.1/32	10.2.255.1 – 10.2.255.1	10.2.255.1
3	10.2.255.2/32	10.2.255.2 – 10.2.255.2	10.2.255.2
4	10.2.255.3/32	10.2.255.3 – 10.2.255.3	10.2.255.3
5	10.2.255.4/32	10.2.255.4 – 10.2.255.4	10.2.255.4
6	10.2.255.5/32	10.2.255.5 – 10.2.255.5	10.2.255.5
7	10.2.255.6/32	10.2.255.6 – 10.2.255.6	10.2.255.6
8	10.2.255.7/32	10.2.255.7 – 10.2.255.7	10.2.255.7
9	10.2.255.8/32	10.2.255.8 – 10.2.255.8	10.2.255.8
10	10.2.255.9/32	10.2.255.9 – 10.2.255.9	10.2.255.9
11	10.2.255.10/32	10.2.255.10 – 10.2.255.10	10.2.255.10
12	10.2.255.11/32	10.2.255.11 – 10.2.255.11	10.2.255.11
13	10.2.255.12/32	10.2.255.12 – 10.2.255.12	10.2.255.12
14	10.2.255.13/32	10.2.255.13 – 10.2.255.13	10.2.255.13
15	10.2.255.14/32	10.2.255.14 – 10.2.255.14	10.2.255.14
16	10.2.255.15/32	10.2.255.15 – 10.2.255.15	10.2.255.15
17	10.2.255.16/32	10.2.255.16 – 10.2.255.16	10.2.255.16
18	10.2.255.17/32	10.2.255.17 – 10.2.255.17	10.2.255.17
19	10.2.255.18/32	10.2.255.18 – 10.2.255.18	10.2.255.18
20	10.2.255.19/32	10.2.255.19 – 10.2.255.19	10.2.255.19
21	10.2.255.20/32	10.2.255.20 – 10.2.255.20	10.2.255.20
22	10.2.255.21/32	10.2.255.21 – 10.2.255.21	10.2.255.21
23	10.2.255.22/32	10.2.255.22 – 10.2.255.22	10.2.255.22
24	10.2.255.23/32	10.2.255.23 – 10.2.255.23	10.2.255.23
25	10.2.255.24/32	10.2.255.24 – 10.2.255.24	10.2.255.24
26	10.2.255.25/32	10.2.255.25 – 10.2.255.25	10.2.255.25
27	10.2.255.26/32	10.2.255.26 – 10.2.255.26	10.2.255.26
28	10.2.255.27/32	10.2.255.27 – 10.2.255.27	10.2.255.27
29	10.2.255.28/32	10.2.255.28 – 10.2.255.28	10.2.255.28
30	10.2.255.29/32	10.2.255.29 – 10.2.255.29	10.2.255.29
31	10.2.255.30/32	10.2.255.30 – 10.2.255.30	10.2.255.30
32	10.2.255.31/32	10.2.255.31 – 10.2.255.31	10.2.255.31
33	10.2.255.32/32	10.2.255.32 – 10.2.255.32	10.2.255.32
34	10.2.255.33/32	10.2.255.33 – 10.2.255.33	10.2.255.33
35	10.2.255.34/32	10.2.255.34 – 10.2.255.34	10.2.255.34
36	10.2.255.35/32	10.2.255.35 – 10.2.255.35	10.2.255.35
37	10.2.255.36/32	10.2.255.36 – 10.2.255.36	10.2.255.36
38	10.2.255.37/32	10.2.255.37 – 10.2.255.37	10.2.255.37
39	10.2.255.38/32	10.2.255.38 – 10.2.255.38	10.2.255.38
40	10.2.255.39/32	10.2.255.39 – 10.2.255.39	10.2.255.39
41	10.2.255.40/32	10.2.255.40 – 10.2.255.40	10.2.255.40
42	10.2.255.41/32	10.2.255.41 – 10.2.255.41	10.2.255.41
43	10.2.255.42/32	10.2.255.42 – 10.2.255.42	10.2.255.42
44	10.2.255.43/32	10.2.255.43 – 10.2.255.43	10.2.255.43
45	10.2.255.44/32	10.2.255.44 – 10.2.255.44	10.2.255.44
46	10.2.255.45/32	10.2.255.45 – 10.2.255.45	10.2.255.45
47	10.2.255.46/32	10.2.255.46 – 10.2.255.46	10.2.255.46
48	10.2.255.47/32	10.2.255.47 – 10.2.255.47	10.2.255.47
49	10.2.255.48/32	10.2.255.48 – 10.2.255.48	10.2.255.48
50	10.2.255.49/32	10.2.255.49 – 10.2.255.49	10.2.255.49
51	10.2.255.50/32	10.2.255.50 – 10.2.255.50	10.2.255.50
52	10.2.255.51/32	10.2.255.51 – 10.2.255.51	10.2.255.51
53	10.2.255.52/32	10.2.255.52 – 10.2.255.52	10.2.255.52
54	10.2.255.53/32	10.2.255.53 – 10.2.255.53	10.2.255.53
55	10.2.255.54/32	10.2.255.54 – 10.2.255.54	10.2.255.54
56	10.2.255.55/32	10.2.255.55 – 10.2.255.55	10.2.255.55
57	10.2.255.56/32	10.2.255.56 – 10.2.255.56	10.2.255.56
58	10.2.255.57/32	10.2.255.57 – 10.2.255.57	10.2.255.57
59	10.2.255.58/32	10.2.255.58 – 10.2.255.58	10.2.255.58
60	10.2.255.59/32	10.2.255.59 – 10.2.255.59	10.2.255.59
61	10.2.255.60/32	10.2.255.60 – 10.2.255.60	10.2.255.60
62	10.2.255.61/32	10.2.255.61 – 10.2.255.61	10.2.255.61
63	10.2.255.62/32	10.2.255.62 – 10.2.255.62	10.2.255.62
64	10.2.255.63/32	10.2.255.63 – 10.2.255.63	10.2.255.63
65	10.2.255.64/32	10.2.255.64 – 10.2.255.64	10.2.255.64
66	10.2.255.65/32	10.2.255.65 – 10.2.255.65	10.2.255.65
67	10.2.255.66/32	10.2.255.66 – 10.2.255.66	10.2.255.66
68	10.2.255.67/32	10.2.255.67 – 10.2.255.67	10.2.255.67
69	10.2.255.68/32	10.2.255.68 – 10.2.255.68	10.2.255.68
70	10.2.255.69/32	10.2.255.69 – 10.2.255.69	10.2.255.69
71	10.2.255.70/32	10.2.255.70 – 10.2.255.70	10.2.255.70
72	10.2.255.71/32	10.2.255.71 – 10.2.255.71	10.2.255.71
73	10.2.255.72/32	10.2.255.72 – 10.2.255.72	10.2.255.72
74	10.2.255.73/32	10.2.255.73 – 10.2.255.73	10.2.255.73
75	10.2.255.74/32	10.2.255.74 – 10.2.255.74	10.2.255.74
76	10.2.255.75/32	10.2.255.75 – 10.2.255.75	10.2.255.75
77	10.2.255.76/32	10.2.255.76 – 10.2.255.76	10.2.255.76
78	10.2.255.77/32	10.2.255.77 – 10.2.255.77	10.2.255.77
79	10.2.255.78/32	10.2.255.78 – 10.2.255.78	10.2.255.78
80	10.2.255.79/32	10.2.255.79 – 10.2.255.79	10.2.255.79
81	10.2.255.80/32	10.2.255.80 – 10.2.255.80	10.2.255.80
82	10.2.255.81/32	10.2.255.81 – 10.2.255.81	10.2.255.81
83	10.2.255.82/32	10.2.255.82 – 10.2.255.82	10.2.255.82
84	10.2.255.83/32	10.2.255.83 – 10.2.255.83	10.2.255.83
85	10.2.255.84/32	10.2.255.84 – 10.2.255.84	10.2.255.84
86	10.2.255.85/32	10.2.255.85 – 10.2.255.85	10.2.255.85
87	10.2.255.86/32	10.2.255.86 – 10.2.255.86	10.2.255.86
88	10.2.255.87/32	10.2.255.87 – 10.2.255.87	10.2.255.87
89	10.2.255.88/32	10.2.255.88 – 10.2.255.88	10.2.255.88
90	10.2.255.89/32	10.2.255.89 – 10.2.255.89	10.2.255.89
91	10.2.255.90/32	10.2.255.90 – 10.2.255.90	10.2.255.90
92	10.2.255.91/32	10.2.255.91 – 10.2.255.91	10.2.255.91
93	10.2.255.92/32	10.2.255.92 – 10.2.255.92	10.2.255.92
94	10.2.255.93/32	10.2.255.93 – 10.2.255.93	10.2.255.93
95	10.2.255.94/32	10.2.255.94 – 10.2.255.94	10.2.255.94
96	10.2.255.95/32	10.2.255.95 – 10.2.255.95	10.2.255.95
97	10.2.255.96/32	10.2.255.96 – 10.2.255.96	10.2.255.96
98	10.2.255.97/32	10.2.255.97 – 10.2.255.97	10.2.255.97
99	10.2.255.98/32	10.2.255.98 – 10.2.255.98	10.2.255.98
100	10.2.255.99/32	10.2.255.99 – 10.2.255.99	10.2.255.99
101	10.2.255.100/32	10.2.255.100 – 10.2.255.100	10.2.255.100
102	10.2.255.101/32	10.2.255.101 – 10.2.255.101	10.2.255.101
103	10.2.255.102/32	10.2.255.102 – 10.2.255.102	10.2.255.102
104	10.2.255.103/32	10.2.255.103 – 10.2.255.103	10.2.255.103
105	10.2.255.104/32	10.2.255.104 – 10.2.255.104	10.2.255.104
106	10.2.255.105/32	10.2.255.105 – 10.2.255.105	10.2.255.105
107	10.2.255.106/32	10.2.255.106 – 10.2.255.106	10.2.255.106
108	10.2.255.107/32	10.2.255.107 – 10.2.255.107	10.2.255.107
109	10.2.255.108/32	10.2.255.108 – 10.2.255.108	10.2.255.108
110	10.2.255.109/32	10.2.255.109 – 10.2.255.109	10.2.255.109
111	10.2.255.110/32	10.2.255.110 – 10.2.255.110	10.2.255.110
112	10.2.255.111/32	10.2.255.111 – 10.2.255.111	10.2.255.111
113	10.2.255.112/32	10.2.255.112 – 10.2.255.112	10.2.255.112
114	10.2.255.113/32	10.2.255.113 – 10.2.255.113	10.2.255.113
115	10.2.255.114/32	10.2.255.114 – 10.2.255.114	10.2.255.114
116	10.2.255.115/32	10.2.255.115 – 10.2.255.115	10.2.255.115
117	10.2.255.116/32	10.2.255.116 – 10.2.255.116	10.2.255.116
118	10.2.255.117/32	10.2.255.117 – 10.2.255.117	10.2.255.117
119	10.2.255.118/32	10.2.255.118 – 10.2.255.118	10.2.255.118
120	10.2.255.119/32	10.2.255.119 – 10.2.255.119	10.2.255.119
121	10.2.255.120/32	10.2.255.120 – 10.2.255.120	10.2.255.120
122	10.2.255.121/32	10.2.255.121 – 10.2.255.121	10.2.255.121
123	10.2.255.122/32	10.2.255.122 – 10.2.255.122	10.2.255.122
124	10.2.255.123/32	10.2.255.123 – 10.2.255.123	10.2.255.123
125	10.2.255.124/32	10.2.255.124 – 10.2.255.124	10.2.255.124
126	10.2.255.125/32	10.2.255.125 – 10.2.255.125	10.2.255.125
127	10.2.255.126/32	10.2.255.126 – 10.2.255.126	10.2.255.126
128	10.2.255.127/32	10.2.255.127 – 10.2.255.127	10.2.255.127

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 →