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)10.2.66.0/24

network10.2.66.0/24

broadcast10.2.66.255

first host10.2.66.1

last host10.2.66.254

subnet mask255.255.255.0

wildcard0.0.0.255

addresses256

usable hosts254

classA

ipcalc 10.2.66.0/24

address00001010.00000010.01000010.00000000

subnet mask11111111.11111111.11111111.00000000

network00001010.00000010.01000010.00000000

broadcast00001010.00000010.01000010.11111111

green = network part, grey = host part

hex0x0a024200

decimal167920128

reverse dns0.66.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:4200

/24 split into /31 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.66.0/31	10.2.66.0 – 10.2.66.1	10.2.66.1
2	10.2.66.2/31	10.2.66.2 – 10.2.66.3	10.2.66.3
3	10.2.66.4/31	10.2.66.4 – 10.2.66.5	10.2.66.5
4	10.2.66.6/31	10.2.66.6 – 10.2.66.7	10.2.66.7
5	10.2.66.8/31	10.2.66.8 – 10.2.66.9	10.2.66.9
6	10.2.66.10/31	10.2.66.10 – 10.2.66.11	10.2.66.11
7	10.2.66.12/31	10.2.66.12 – 10.2.66.13	10.2.66.13
8	10.2.66.14/31	10.2.66.14 – 10.2.66.15	10.2.66.15
9	10.2.66.16/31	10.2.66.16 – 10.2.66.17	10.2.66.17
10	10.2.66.18/31	10.2.66.18 – 10.2.66.19	10.2.66.19
11	10.2.66.20/31	10.2.66.20 – 10.2.66.21	10.2.66.21
12	10.2.66.22/31	10.2.66.22 – 10.2.66.23	10.2.66.23
13	10.2.66.24/31	10.2.66.24 – 10.2.66.25	10.2.66.25
14	10.2.66.26/31	10.2.66.26 – 10.2.66.27	10.2.66.27
15	10.2.66.28/31	10.2.66.28 – 10.2.66.29	10.2.66.29
16	10.2.66.30/31	10.2.66.30 – 10.2.66.31	10.2.66.31
17	10.2.66.32/31	10.2.66.32 – 10.2.66.33	10.2.66.33
18	10.2.66.34/31	10.2.66.34 – 10.2.66.35	10.2.66.35
19	10.2.66.36/31	10.2.66.36 – 10.2.66.37	10.2.66.37
20	10.2.66.38/31	10.2.66.38 – 10.2.66.39	10.2.66.39
21	10.2.66.40/31	10.2.66.40 – 10.2.66.41	10.2.66.41
22	10.2.66.42/31	10.2.66.42 – 10.2.66.43	10.2.66.43
23	10.2.66.44/31	10.2.66.44 – 10.2.66.45	10.2.66.45
24	10.2.66.46/31	10.2.66.46 – 10.2.66.47	10.2.66.47
25	10.2.66.48/31	10.2.66.48 – 10.2.66.49	10.2.66.49
26	10.2.66.50/31	10.2.66.50 – 10.2.66.51	10.2.66.51
27	10.2.66.52/31	10.2.66.52 – 10.2.66.53	10.2.66.53
28	10.2.66.54/31	10.2.66.54 – 10.2.66.55	10.2.66.55
29	10.2.66.56/31	10.2.66.56 – 10.2.66.57	10.2.66.57
30	10.2.66.58/31	10.2.66.58 – 10.2.66.59	10.2.66.59
31	10.2.66.60/31	10.2.66.60 – 10.2.66.61	10.2.66.61
32	10.2.66.62/31	10.2.66.62 – 10.2.66.63	10.2.66.63
33	10.2.66.64/31	10.2.66.64 – 10.2.66.65	10.2.66.65
34	10.2.66.66/31	10.2.66.66 – 10.2.66.67	10.2.66.67
35	10.2.66.68/31	10.2.66.68 – 10.2.66.69	10.2.66.69
36	10.2.66.70/31	10.2.66.70 – 10.2.66.71	10.2.66.71
37	10.2.66.72/31	10.2.66.72 – 10.2.66.73	10.2.66.73
38	10.2.66.74/31	10.2.66.74 – 10.2.66.75	10.2.66.75
39	10.2.66.76/31	10.2.66.76 – 10.2.66.77	10.2.66.77
40	10.2.66.78/31	10.2.66.78 – 10.2.66.79	10.2.66.79
41	10.2.66.80/31	10.2.66.80 – 10.2.66.81	10.2.66.81
42	10.2.66.82/31	10.2.66.82 – 10.2.66.83	10.2.66.83
43	10.2.66.84/31	10.2.66.84 – 10.2.66.85	10.2.66.85
44	10.2.66.86/31	10.2.66.86 – 10.2.66.87	10.2.66.87
45	10.2.66.88/31	10.2.66.88 – 10.2.66.89	10.2.66.89
46	10.2.66.90/31	10.2.66.90 – 10.2.66.91	10.2.66.91
47	10.2.66.92/31	10.2.66.92 – 10.2.66.93	10.2.66.93
48	10.2.66.94/31	10.2.66.94 – 10.2.66.95	10.2.66.95
49	10.2.66.96/31	10.2.66.96 – 10.2.66.97	10.2.66.97
50	10.2.66.98/31	10.2.66.98 – 10.2.66.99	10.2.66.99
51	10.2.66.100/31	10.2.66.100 – 10.2.66.101	10.2.66.101
52	10.2.66.102/31	10.2.66.102 – 10.2.66.103	10.2.66.103
53	10.2.66.104/31	10.2.66.104 – 10.2.66.105	10.2.66.105
54	10.2.66.106/31	10.2.66.106 – 10.2.66.107	10.2.66.107
55	10.2.66.108/31	10.2.66.108 – 10.2.66.109	10.2.66.109
56	10.2.66.110/31	10.2.66.110 – 10.2.66.111	10.2.66.111
57	10.2.66.112/31	10.2.66.112 – 10.2.66.113	10.2.66.113
58	10.2.66.114/31	10.2.66.114 – 10.2.66.115	10.2.66.115
59	10.2.66.116/31	10.2.66.116 – 10.2.66.117	10.2.66.117
60	10.2.66.118/31	10.2.66.118 – 10.2.66.119	10.2.66.119
61	10.2.66.120/31	10.2.66.120 – 10.2.66.121	10.2.66.121
62	10.2.66.122/31	10.2.66.122 – 10.2.66.123	10.2.66.123
63	10.2.66.124/31	10.2.66.124 – 10.2.66.125	10.2.66.125
64	10.2.66.126/31	10.2.66.126 – 10.2.66.127	10.2.66.127
65	10.2.66.128/31	10.2.66.128 – 10.2.66.129	10.2.66.129
66	10.2.66.130/31	10.2.66.130 – 10.2.66.131	10.2.66.131
67	10.2.66.132/31	10.2.66.132 – 10.2.66.133	10.2.66.133
68	10.2.66.134/31	10.2.66.134 – 10.2.66.135	10.2.66.135
69	10.2.66.136/31	10.2.66.136 – 10.2.66.137	10.2.66.137
70	10.2.66.138/31	10.2.66.138 – 10.2.66.139	10.2.66.139
71	10.2.66.140/31	10.2.66.140 – 10.2.66.141	10.2.66.141
72	10.2.66.142/31	10.2.66.142 – 10.2.66.143	10.2.66.143
73	10.2.66.144/31	10.2.66.144 – 10.2.66.145	10.2.66.145
74	10.2.66.146/31	10.2.66.146 – 10.2.66.147	10.2.66.147
75	10.2.66.148/31	10.2.66.148 – 10.2.66.149	10.2.66.149
76	10.2.66.150/31	10.2.66.150 – 10.2.66.151	10.2.66.151
77	10.2.66.152/31	10.2.66.152 – 10.2.66.153	10.2.66.153
78	10.2.66.154/31	10.2.66.154 – 10.2.66.155	10.2.66.155
79	10.2.66.156/31	10.2.66.156 – 10.2.66.157	10.2.66.157
80	10.2.66.158/31	10.2.66.158 – 10.2.66.159	10.2.66.159
81	10.2.66.160/31	10.2.66.160 – 10.2.66.161	10.2.66.161
82	10.2.66.162/31	10.2.66.162 – 10.2.66.163	10.2.66.163
83	10.2.66.164/31	10.2.66.164 – 10.2.66.165	10.2.66.165
84	10.2.66.166/31	10.2.66.166 – 10.2.66.167	10.2.66.167
85	10.2.66.168/31	10.2.66.168 – 10.2.66.169	10.2.66.169
86	10.2.66.170/31	10.2.66.170 – 10.2.66.171	10.2.66.171
87	10.2.66.172/31	10.2.66.172 – 10.2.66.173	10.2.66.173
88	10.2.66.174/31	10.2.66.174 – 10.2.66.175	10.2.66.175
89	10.2.66.176/31	10.2.66.176 – 10.2.66.177	10.2.66.177
90	10.2.66.178/31	10.2.66.178 – 10.2.66.179	10.2.66.179
91	10.2.66.180/31	10.2.66.180 – 10.2.66.181	10.2.66.181
92	10.2.66.182/31	10.2.66.182 – 10.2.66.183	10.2.66.183
93	10.2.66.184/31	10.2.66.184 – 10.2.66.185	10.2.66.185
94	10.2.66.186/31	10.2.66.186 – 10.2.66.187	10.2.66.187
95	10.2.66.188/31	10.2.66.188 – 10.2.66.189	10.2.66.189
96	10.2.66.190/31	10.2.66.190 – 10.2.66.191	10.2.66.191
97	10.2.66.192/31	10.2.66.192 – 10.2.66.193	10.2.66.193
98	10.2.66.194/31	10.2.66.194 – 10.2.66.195	10.2.66.195
99	10.2.66.196/31	10.2.66.196 – 10.2.66.197	10.2.66.197
100	10.2.66.198/31	10.2.66.198 – 10.2.66.199	10.2.66.199
101	10.2.66.200/31	10.2.66.200 – 10.2.66.201	10.2.66.201
102	10.2.66.202/31	10.2.66.202 – 10.2.66.203	10.2.66.203
103	10.2.66.204/31	10.2.66.204 – 10.2.66.205	10.2.66.205
104	10.2.66.206/31	10.2.66.206 – 10.2.66.207	10.2.66.207
105	10.2.66.208/31	10.2.66.208 – 10.2.66.209	10.2.66.209
106	10.2.66.210/31	10.2.66.210 – 10.2.66.211	10.2.66.211
107	10.2.66.212/31	10.2.66.212 – 10.2.66.213	10.2.66.213
108	10.2.66.214/31	10.2.66.214 – 10.2.66.215	10.2.66.215
109	10.2.66.216/31	10.2.66.216 – 10.2.66.217	10.2.66.217
110	10.2.66.218/31	10.2.66.218 – 10.2.66.219	10.2.66.219
111	10.2.66.220/31	10.2.66.220 – 10.2.66.221	10.2.66.221
112	10.2.66.222/31	10.2.66.222 – 10.2.66.223	10.2.66.223
113	10.2.66.224/31	10.2.66.224 – 10.2.66.225	10.2.66.225
114	10.2.66.226/31	10.2.66.226 – 10.2.66.227	10.2.66.227
115	10.2.66.228/31	10.2.66.228 – 10.2.66.229	10.2.66.229
116	10.2.66.230/31	10.2.66.230 – 10.2.66.231	10.2.66.231
117	10.2.66.232/31	10.2.66.232 – 10.2.66.233	10.2.66.233
118	10.2.66.234/31	10.2.66.234 – 10.2.66.235	10.2.66.235
119	10.2.66.236/31	10.2.66.236 – 10.2.66.237	10.2.66.237
120	10.2.66.238/31	10.2.66.238 – 10.2.66.239	10.2.66.239
121	10.2.66.240/31	10.2.66.240 – 10.2.66.241	10.2.66.241
122	10.2.66.242/31	10.2.66.242 – 10.2.66.243	10.2.66.243
123	10.2.66.244/31	10.2.66.244 – 10.2.66.245	10.2.66.245
124	10.2.66.246/31	10.2.66.246 – 10.2.66.247	10.2.66.247
125	10.2.66.248/31	10.2.66.248 – 10.2.66.249	10.2.66.249
126	10.2.66.250/31	10.2.66.250 – 10.2.66.251	10.2.66.251
127	10.2.66.252/31	10.2.66.252 – 10.2.66.253	10.2.66.253
128	10.2.66.254/31	10.2.66.254 – 10.2.66.255	10.2.66.255

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 /24
/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	1
/25	255.255.255.128	128	126	2 split →
/26	255.255.255.192	64	62	4 split →
/27	255.255.255.224	32	30	8 split →
/28	255.255.255.240	16	14	16 split →
/29	255.255.255.248	8	6	32 split →
/30	255.255.255.252	4	2	64 split →
/31	255.255.255.254	2	2	128 split →
/32	255.255.255.255	1	1	256 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 →