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)10.2.203.0/25

network10.2.203.0/25

broadcast10.2.203.127

first host10.2.203.1

last host10.2.203.126

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.2.203.0/25

address00001010.00000010.11001011.00000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000010.11001011.00000000

broadcast00001010.00000010.11001011.01111111

green = network part, grey = host part

hex0x0a02cb00

decimal167955200

reverse dns0.203.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:cb00

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.203.0/32	10.2.203.0 – 10.2.203.0	10.2.203.0
2	10.2.203.1/32	10.2.203.1 – 10.2.203.1	10.2.203.1
3	10.2.203.2/32	10.2.203.2 – 10.2.203.2	10.2.203.2
4	10.2.203.3/32	10.2.203.3 – 10.2.203.3	10.2.203.3
5	10.2.203.4/32	10.2.203.4 – 10.2.203.4	10.2.203.4
6	10.2.203.5/32	10.2.203.5 – 10.2.203.5	10.2.203.5
7	10.2.203.6/32	10.2.203.6 – 10.2.203.6	10.2.203.6
8	10.2.203.7/32	10.2.203.7 – 10.2.203.7	10.2.203.7
9	10.2.203.8/32	10.2.203.8 – 10.2.203.8	10.2.203.8
10	10.2.203.9/32	10.2.203.9 – 10.2.203.9	10.2.203.9
11	10.2.203.10/32	10.2.203.10 – 10.2.203.10	10.2.203.10
12	10.2.203.11/32	10.2.203.11 – 10.2.203.11	10.2.203.11
13	10.2.203.12/32	10.2.203.12 – 10.2.203.12	10.2.203.12
14	10.2.203.13/32	10.2.203.13 – 10.2.203.13	10.2.203.13
15	10.2.203.14/32	10.2.203.14 – 10.2.203.14	10.2.203.14
16	10.2.203.15/32	10.2.203.15 – 10.2.203.15	10.2.203.15
17	10.2.203.16/32	10.2.203.16 – 10.2.203.16	10.2.203.16
18	10.2.203.17/32	10.2.203.17 – 10.2.203.17	10.2.203.17
19	10.2.203.18/32	10.2.203.18 – 10.2.203.18	10.2.203.18
20	10.2.203.19/32	10.2.203.19 – 10.2.203.19	10.2.203.19
21	10.2.203.20/32	10.2.203.20 – 10.2.203.20	10.2.203.20
22	10.2.203.21/32	10.2.203.21 – 10.2.203.21	10.2.203.21
23	10.2.203.22/32	10.2.203.22 – 10.2.203.22	10.2.203.22
24	10.2.203.23/32	10.2.203.23 – 10.2.203.23	10.2.203.23
25	10.2.203.24/32	10.2.203.24 – 10.2.203.24	10.2.203.24
26	10.2.203.25/32	10.2.203.25 – 10.2.203.25	10.2.203.25
27	10.2.203.26/32	10.2.203.26 – 10.2.203.26	10.2.203.26
28	10.2.203.27/32	10.2.203.27 – 10.2.203.27	10.2.203.27
29	10.2.203.28/32	10.2.203.28 – 10.2.203.28	10.2.203.28
30	10.2.203.29/32	10.2.203.29 – 10.2.203.29	10.2.203.29
31	10.2.203.30/32	10.2.203.30 – 10.2.203.30	10.2.203.30
32	10.2.203.31/32	10.2.203.31 – 10.2.203.31	10.2.203.31
33	10.2.203.32/32	10.2.203.32 – 10.2.203.32	10.2.203.32
34	10.2.203.33/32	10.2.203.33 – 10.2.203.33	10.2.203.33
35	10.2.203.34/32	10.2.203.34 – 10.2.203.34	10.2.203.34
36	10.2.203.35/32	10.2.203.35 – 10.2.203.35	10.2.203.35
37	10.2.203.36/32	10.2.203.36 – 10.2.203.36	10.2.203.36
38	10.2.203.37/32	10.2.203.37 – 10.2.203.37	10.2.203.37
39	10.2.203.38/32	10.2.203.38 – 10.2.203.38	10.2.203.38
40	10.2.203.39/32	10.2.203.39 – 10.2.203.39	10.2.203.39
41	10.2.203.40/32	10.2.203.40 – 10.2.203.40	10.2.203.40
42	10.2.203.41/32	10.2.203.41 – 10.2.203.41	10.2.203.41
43	10.2.203.42/32	10.2.203.42 – 10.2.203.42	10.2.203.42
44	10.2.203.43/32	10.2.203.43 – 10.2.203.43	10.2.203.43
45	10.2.203.44/32	10.2.203.44 – 10.2.203.44	10.2.203.44
46	10.2.203.45/32	10.2.203.45 – 10.2.203.45	10.2.203.45
47	10.2.203.46/32	10.2.203.46 – 10.2.203.46	10.2.203.46
48	10.2.203.47/32	10.2.203.47 – 10.2.203.47	10.2.203.47
49	10.2.203.48/32	10.2.203.48 – 10.2.203.48	10.2.203.48
50	10.2.203.49/32	10.2.203.49 – 10.2.203.49	10.2.203.49
51	10.2.203.50/32	10.2.203.50 – 10.2.203.50	10.2.203.50
52	10.2.203.51/32	10.2.203.51 – 10.2.203.51	10.2.203.51
53	10.2.203.52/32	10.2.203.52 – 10.2.203.52	10.2.203.52
54	10.2.203.53/32	10.2.203.53 – 10.2.203.53	10.2.203.53
55	10.2.203.54/32	10.2.203.54 – 10.2.203.54	10.2.203.54
56	10.2.203.55/32	10.2.203.55 – 10.2.203.55	10.2.203.55
57	10.2.203.56/32	10.2.203.56 – 10.2.203.56	10.2.203.56
58	10.2.203.57/32	10.2.203.57 – 10.2.203.57	10.2.203.57
59	10.2.203.58/32	10.2.203.58 – 10.2.203.58	10.2.203.58
60	10.2.203.59/32	10.2.203.59 – 10.2.203.59	10.2.203.59
61	10.2.203.60/32	10.2.203.60 – 10.2.203.60	10.2.203.60
62	10.2.203.61/32	10.2.203.61 – 10.2.203.61	10.2.203.61
63	10.2.203.62/32	10.2.203.62 – 10.2.203.62	10.2.203.62
64	10.2.203.63/32	10.2.203.63 – 10.2.203.63	10.2.203.63
65	10.2.203.64/32	10.2.203.64 – 10.2.203.64	10.2.203.64
66	10.2.203.65/32	10.2.203.65 – 10.2.203.65	10.2.203.65
67	10.2.203.66/32	10.2.203.66 – 10.2.203.66	10.2.203.66
68	10.2.203.67/32	10.2.203.67 – 10.2.203.67	10.2.203.67
69	10.2.203.68/32	10.2.203.68 – 10.2.203.68	10.2.203.68
70	10.2.203.69/32	10.2.203.69 – 10.2.203.69	10.2.203.69
71	10.2.203.70/32	10.2.203.70 – 10.2.203.70	10.2.203.70
72	10.2.203.71/32	10.2.203.71 – 10.2.203.71	10.2.203.71
73	10.2.203.72/32	10.2.203.72 – 10.2.203.72	10.2.203.72
74	10.2.203.73/32	10.2.203.73 – 10.2.203.73	10.2.203.73
75	10.2.203.74/32	10.2.203.74 – 10.2.203.74	10.2.203.74
76	10.2.203.75/32	10.2.203.75 – 10.2.203.75	10.2.203.75
77	10.2.203.76/32	10.2.203.76 – 10.2.203.76	10.2.203.76
78	10.2.203.77/32	10.2.203.77 – 10.2.203.77	10.2.203.77
79	10.2.203.78/32	10.2.203.78 – 10.2.203.78	10.2.203.78
80	10.2.203.79/32	10.2.203.79 – 10.2.203.79	10.2.203.79
81	10.2.203.80/32	10.2.203.80 – 10.2.203.80	10.2.203.80
82	10.2.203.81/32	10.2.203.81 – 10.2.203.81	10.2.203.81
83	10.2.203.82/32	10.2.203.82 – 10.2.203.82	10.2.203.82
84	10.2.203.83/32	10.2.203.83 – 10.2.203.83	10.2.203.83
85	10.2.203.84/32	10.2.203.84 – 10.2.203.84	10.2.203.84
86	10.2.203.85/32	10.2.203.85 – 10.2.203.85	10.2.203.85
87	10.2.203.86/32	10.2.203.86 – 10.2.203.86	10.2.203.86
88	10.2.203.87/32	10.2.203.87 – 10.2.203.87	10.2.203.87
89	10.2.203.88/32	10.2.203.88 – 10.2.203.88	10.2.203.88
90	10.2.203.89/32	10.2.203.89 – 10.2.203.89	10.2.203.89
91	10.2.203.90/32	10.2.203.90 – 10.2.203.90	10.2.203.90
92	10.2.203.91/32	10.2.203.91 – 10.2.203.91	10.2.203.91
93	10.2.203.92/32	10.2.203.92 – 10.2.203.92	10.2.203.92
94	10.2.203.93/32	10.2.203.93 – 10.2.203.93	10.2.203.93
95	10.2.203.94/32	10.2.203.94 – 10.2.203.94	10.2.203.94
96	10.2.203.95/32	10.2.203.95 – 10.2.203.95	10.2.203.95
97	10.2.203.96/32	10.2.203.96 – 10.2.203.96	10.2.203.96
98	10.2.203.97/32	10.2.203.97 – 10.2.203.97	10.2.203.97
99	10.2.203.98/32	10.2.203.98 – 10.2.203.98	10.2.203.98
100	10.2.203.99/32	10.2.203.99 – 10.2.203.99	10.2.203.99
101	10.2.203.100/32	10.2.203.100 – 10.2.203.100	10.2.203.100
102	10.2.203.101/32	10.2.203.101 – 10.2.203.101	10.2.203.101
103	10.2.203.102/32	10.2.203.102 – 10.2.203.102	10.2.203.102
104	10.2.203.103/32	10.2.203.103 – 10.2.203.103	10.2.203.103
105	10.2.203.104/32	10.2.203.104 – 10.2.203.104	10.2.203.104
106	10.2.203.105/32	10.2.203.105 – 10.2.203.105	10.2.203.105
107	10.2.203.106/32	10.2.203.106 – 10.2.203.106	10.2.203.106
108	10.2.203.107/32	10.2.203.107 – 10.2.203.107	10.2.203.107
109	10.2.203.108/32	10.2.203.108 – 10.2.203.108	10.2.203.108
110	10.2.203.109/32	10.2.203.109 – 10.2.203.109	10.2.203.109
111	10.2.203.110/32	10.2.203.110 – 10.2.203.110	10.2.203.110
112	10.2.203.111/32	10.2.203.111 – 10.2.203.111	10.2.203.111
113	10.2.203.112/32	10.2.203.112 – 10.2.203.112	10.2.203.112
114	10.2.203.113/32	10.2.203.113 – 10.2.203.113	10.2.203.113
115	10.2.203.114/32	10.2.203.114 – 10.2.203.114	10.2.203.114
116	10.2.203.115/32	10.2.203.115 – 10.2.203.115	10.2.203.115
117	10.2.203.116/32	10.2.203.116 – 10.2.203.116	10.2.203.116
118	10.2.203.117/32	10.2.203.117 – 10.2.203.117	10.2.203.117
119	10.2.203.118/32	10.2.203.118 – 10.2.203.118	10.2.203.118
120	10.2.203.119/32	10.2.203.119 – 10.2.203.119	10.2.203.119
121	10.2.203.120/32	10.2.203.120 – 10.2.203.120	10.2.203.120
122	10.2.203.121/32	10.2.203.121 – 10.2.203.121	10.2.203.121
123	10.2.203.122/32	10.2.203.122 – 10.2.203.122	10.2.203.122
124	10.2.203.123/32	10.2.203.123 – 10.2.203.123	10.2.203.123
125	10.2.203.124/32	10.2.203.124 – 10.2.203.124	10.2.203.124
126	10.2.203.125/32	10.2.203.125 – 10.2.203.125	10.2.203.125
127	10.2.203.126/32	10.2.203.126 – 10.2.203.126	10.2.203.126
128	10.2.203.127/32	10.2.203.127 – 10.2.203.127	10.2.203.127

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 →