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)10.0.19.0/24

network10.0.19.0/24

broadcast10.0.19.255

first host10.0.19.1

last host10.0.19.254

subnet mask255.255.255.0

wildcard0.0.0.255

addresses256

usable hosts254

classA

ipcalc 10.0.19.0/24

address00001010.00000000.00010011.00000000

subnet mask11111111.11111111.11111111.00000000

network00001010.00000000.00010011.00000000

broadcast00001010.00000000.00010011.11111111

green = network part, grey = host part

hex0x0a001300

decimal167777024

reverse dns0.19.0.10.in-addr.arpa

ipv4-mapped::ffff:a00:1300

/24 split into /31 · 128 subnets

close ×

#	network	host range	broadcast
1	10.0.19.0/31	10.0.19.0 – 10.0.19.1	10.0.19.1
2	10.0.19.2/31	10.0.19.2 – 10.0.19.3	10.0.19.3
3	10.0.19.4/31	10.0.19.4 – 10.0.19.5	10.0.19.5
4	10.0.19.6/31	10.0.19.6 – 10.0.19.7	10.0.19.7
5	10.0.19.8/31	10.0.19.8 – 10.0.19.9	10.0.19.9
6	10.0.19.10/31	10.0.19.10 – 10.0.19.11	10.0.19.11
7	10.0.19.12/31	10.0.19.12 – 10.0.19.13	10.0.19.13
8	10.0.19.14/31	10.0.19.14 – 10.0.19.15	10.0.19.15
9	10.0.19.16/31	10.0.19.16 – 10.0.19.17	10.0.19.17
10	10.0.19.18/31	10.0.19.18 – 10.0.19.19	10.0.19.19
11	10.0.19.20/31	10.0.19.20 – 10.0.19.21	10.0.19.21
12	10.0.19.22/31	10.0.19.22 – 10.0.19.23	10.0.19.23
13	10.0.19.24/31	10.0.19.24 – 10.0.19.25	10.0.19.25
14	10.0.19.26/31	10.0.19.26 – 10.0.19.27	10.0.19.27
15	10.0.19.28/31	10.0.19.28 – 10.0.19.29	10.0.19.29
16	10.0.19.30/31	10.0.19.30 – 10.0.19.31	10.0.19.31
17	10.0.19.32/31	10.0.19.32 – 10.0.19.33	10.0.19.33
18	10.0.19.34/31	10.0.19.34 – 10.0.19.35	10.0.19.35
19	10.0.19.36/31	10.0.19.36 – 10.0.19.37	10.0.19.37
20	10.0.19.38/31	10.0.19.38 – 10.0.19.39	10.0.19.39
21	10.0.19.40/31	10.0.19.40 – 10.0.19.41	10.0.19.41
22	10.0.19.42/31	10.0.19.42 – 10.0.19.43	10.0.19.43
23	10.0.19.44/31	10.0.19.44 – 10.0.19.45	10.0.19.45
24	10.0.19.46/31	10.0.19.46 – 10.0.19.47	10.0.19.47
25	10.0.19.48/31	10.0.19.48 – 10.0.19.49	10.0.19.49
26	10.0.19.50/31	10.0.19.50 – 10.0.19.51	10.0.19.51
27	10.0.19.52/31	10.0.19.52 – 10.0.19.53	10.0.19.53
28	10.0.19.54/31	10.0.19.54 – 10.0.19.55	10.0.19.55
29	10.0.19.56/31	10.0.19.56 – 10.0.19.57	10.0.19.57
30	10.0.19.58/31	10.0.19.58 – 10.0.19.59	10.0.19.59
31	10.0.19.60/31	10.0.19.60 – 10.0.19.61	10.0.19.61
32	10.0.19.62/31	10.0.19.62 – 10.0.19.63	10.0.19.63
33	10.0.19.64/31	10.0.19.64 – 10.0.19.65	10.0.19.65
34	10.0.19.66/31	10.0.19.66 – 10.0.19.67	10.0.19.67
35	10.0.19.68/31	10.0.19.68 – 10.0.19.69	10.0.19.69
36	10.0.19.70/31	10.0.19.70 – 10.0.19.71	10.0.19.71
37	10.0.19.72/31	10.0.19.72 – 10.0.19.73	10.0.19.73
38	10.0.19.74/31	10.0.19.74 – 10.0.19.75	10.0.19.75
39	10.0.19.76/31	10.0.19.76 – 10.0.19.77	10.0.19.77
40	10.0.19.78/31	10.0.19.78 – 10.0.19.79	10.0.19.79
41	10.0.19.80/31	10.0.19.80 – 10.0.19.81	10.0.19.81
42	10.0.19.82/31	10.0.19.82 – 10.0.19.83	10.0.19.83
43	10.0.19.84/31	10.0.19.84 – 10.0.19.85	10.0.19.85
44	10.0.19.86/31	10.0.19.86 – 10.0.19.87	10.0.19.87
45	10.0.19.88/31	10.0.19.88 – 10.0.19.89	10.0.19.89
46	10.0.19.90/31	10.0.19.90 – 10.0.19.91	10.0.19.91
47	10.0.19.92/31	10.0.19.92 – 10.0.19.93	10.0.19.93
48	10.0.19.94/31	10.0.19.94 – 10.0.19.95	10.0.19.95
49	10.0.19.96/31	10.0.19.96 – 10.0.19.97	10.0.19.97
50	10.0.19.98/31	10.0.19.98 – 10.0.19.99	10.0.19.99
51	10.0.19.100/31	10.0.19.100 – 10.0.19.101	10.0.19.101
52	10.0.19.102/31	10.0.19.102 – 10.0.19.103	10.0.19.103
53	10.0.19.104/31	10.0.19.104 – 10.0.19.105	10.0.19.105
54	10.0.19.106/31	10.0.19.106 – 10.0.19.107	10.0.19.107
55	10.0.19.108/31	10.0.19.108 – 10.0.19.109	10.0.19.109
56	10.0.19.110/31	10.0.19.110 – 10.0.19.111	10.0.19.111
57	10.0.19.112/31	10.0.19.112 – 10.0.19.113	10.0.19.113
58	10.0.19.114/31	10.0.19.114 – 10.0.19.115	10.0.19.115
59	10.0.19.116/31	10.0.19.116 – 10.0.19.117	10.0.19.117
60	10.0.19.118/31	10.0.19.118 – 10.0.19.119	10.0.19.119
61	10.0.19.120/31	10.0.19.120 – 10.0.19.121	10.0.19.121
62	10.0.19.122/31	10.0.19.122 – 10.0.19.123	10.0.19.123
63	10.0.19.124/31	10.0.19.124 – 10.0.19.125	10.0.19.125
64	10.0.19.126/31	10.0.19.126 – 10.0.19.127	10.0.19.127
65	10.0.19.128/31	10.0.19.128 – 10.0.19.129	10.0.19.129
66	10.0.19.130/31	10.0.19.130 – 10.0.19.131	10.0.19.131
67	10.0.19.132/31	10.0.19.132 – 10.0.19.133	10.0.19.133
68	10.0.19.134/31	10.0.19.134 – 10.0.19.135	10.0.19.135
69	10.0.19.136/31	10.0.19.136 – 10.0.19.137	10.0.19.137
70	10.0.19.138/31	10.0.19.138 – 10.0.19.139	10.0.19.139
71	10.0.19.140/31	10.0.19.140 – 10.0.19.141	10.0.19.141
72	10.0.19.142/31	10.0.19.142 – 10.0.19.143	10.0.19.143
73	10.0.19.144/31	10.0.19.144 – 10.0.19.145	10.0.19.145
74	10.0.19.146/31	10.0.19.146 – 10.0.19.147	10.0.19.147
75	10.0.19.148/31	10.0.19.148 – 10.0.19.149	10.0.19.149
76	10.0.19.150/31	10.0.19.150 – 10.0.19.151	10.0.19.151
77	10.0.19.152/31	10.0.19.152 – 10.0.19.153	10.0.19.153
78	10.0.19.154/31	10.0.19.154 – 10.0.19.155	10.0.19.155
79	10.0.19.156/31	10.0.19.156 – 10.0.19.157	10.0.19.157
80	10.0.19.158/31	10.0.19.158 – 10.0.19.159	10.0.19.159
81	10.0.19.160/31	10.0.19.160 – 10.0.19.161	10.0.19.161
82	10.0.19.162/31	10.0.19.162 – 10.0.19.163	10.0.19.163
83	10.0.19.164/31	10.0.19.164 – 10.0.19.165	10.0.19.165
84	10.0.19.166/31	10.0.19.166 – 10.0.19.167	10.0.19.167
85	10.0.19.168/31	10.0.19.168 – 10.0.19.169	10.0.19.169
86	10.0.19.170/31	10.0.19.170 – 10.0.19.171	10.0.19.171
87	10.0.19.172/31	10.0.19.172 – 10.0.19.173	10.0.19.173
88	10.0.19.174/31	10.0.19.174 – 10.0.19.175	10.0.19.175
89	10.0.19.176/31	10.0.19.176 – 10.0.19.177	10.0.19.177
90	10.0.19.178/31	10.0.19.178 – 10.0.19.179	10.0.19.179
91	10.0.19.180/31	10.0.19.180 – 10.0.19.181	10.0.19.181
92	10.0.19.182/31	10.0.19.182 – 10.0.19.183	10.0.19.183
93	10.0.19.184/31	10.0.19.184 – 10.0.19.185	10.0.19.185
94	10.0.19.186/31	10.0.19.186 – 10.0.19.187	10.0.19.187
95	10.0.19.188/31	10.0.19.188 – 10.0.19.189	10.0.19.189
96	10.0.19.190/31	10.0.19.190 – 10.0.19.191	10.0.19.191
97	10.0.19.192/31	10.0.19.192 – 10.0.19.193	10.0.19.193
98	10.0.19.194/31	10.0.19.194 – 10.0.19.195	10.0.19.195
99	10.0.19.196/31	10.0.19.196 – 10.0.19.197	10.0.19.197
100	10.0.19.198/31	10.0.19.198 – 10.0.19.199	10.0.19.199
101	10.0.19.200/31	10.0.19.200 – 10.0.19.201	10.0.19.201
102	10.0.19.202/31	10.0.19.202 – 10.0.19.203	10.0.19.203
103	10.0.19.204/31	10.0.19.204 – 10.0.19.205	10.0.19.205
104	10.0.19.206/31	10.0.19.206 – 10.0.19.207	10.0.19.207
105	10.0.19.208/31	10.0.19.208 – 10.0.19.209	10.0.19.209
106	10.0.19.210/31	10.0.19.210 – 10.0.19.211	10.0.19.211
107	10.0.19.212/31	10.0.19.212 – 10.0.19.213	10.0.19.213
108	10.0.19.214/31	10.0.19.214 – 10.0.19.215	10.0.19.215
109	10.0.19.216/31	10.0.19.216 – 10.0.19.217	10.0.19.217
110	10.0.19.218/31	10.0.19.218 – 10.0.19.219	10.0.19.219
111	10.0.19.220/31	10.0.19.220 – 10.0.19.221	10.0.19.221
112	10.0.19.222/31	10.0.19.222 – 10.0.19.223	10.0.19.223
113	10.0.19.224/31	10.0.19.224 – 10.0.19.225	10.0.19.225
114	10.0.19.226/31	10.0.19.226 – 10.0.19.227	10.0.19.227
115	10.0.19.228/31	10.0.19.228 – 10.0.19.229	10.0.19.229
116	10.0.19.230/31	10.0.19.230 – 10.0.19.231	10.0.19.231
117	10.0.19.232/31	10.0.19.232 – 10.0.19.233	10.0.19.233
118	10.0.19.234/31	10.0.19.234 – 10.0.19.235	10.0.19.235
119	10.0.19.236/31	10.0.19.236 – 10.0.19.237	10.0.19.237
120	10.0.19.238/31	10.0.19.238 – 10.0.19.239	10.0.19.239
121	10.0.19.240/31	10.0.19.240 – 10.0.19.241	10.0.19.241
122	10.0.19.242/31	10.0.19.242 – 10.0.19.243	10.0.19.243
123	10.0.19.244/31	10.0.19.244 – 10.0.19.245	10.0.19.245
124	10.0.19.246/31	10.0.19.246 – 10.0.19.247	10.0.19.247
125	10.0.19.248/31	10.0.19.248 – 10.0.19.249	10.0.19.249
126	10.0.19.250/31	10.0.19.250 – 10.0.19.251	10.0.19.251
127	10.0.19.252/31	10.0.19.252 – 10.0.19.253	10.0.19.253
128	10.0.19.254/31	10.0.19.254 – 10.0.19.255	10.0.19.255

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 →