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)10.2.19.128/25

network10.2.19.128/25

broadcast10.2.19.255

first host10.2.19.129

last host10.2.19.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.2.19.128/25

address00001010.00000010.00010011.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000010.00010011.10000000

broadcast00001010.00000010.00010011.11111111

green = network part, grey = host part

hex0x0a021380

decimal167908224

reverse dns128.19.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:1380

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.19.128/32	10.2.19.128 – 10.2.19.128	10.2.19.128
2	10.2.19.129/32	10.2.19.129 – 10.2.19.129	10.2.19.129
3	10.2.19.130/32	10.2.19.130 – 10.2.19.130	10.2.19.130
4	10.2.19.131/32	10.2.19.131 – 10.2.19.131	10.2.19.131
5	10.2.19.132/32	10.2.19.132 – 10.2.19.132	10.2.19.132
6	10.2.19.133/32	10.2.19.133 – 10.2.19.133	10.2.19.133
7	10.2.19.134/32	10.2.19.134 – 10.2.19.134	10.2.19.134
8	10.2.19.135/32	10.2.19.135 – 10.2.19.135	10.2.19.135
9	10.2.19.136/32	10.2.19.136 – 10.2.19.136	10.2.19.136
10	10.2.19.137/32	10.2.19.137 – 10.2.19.137	10.2.19.137
11	10.2.19.138/32	10.2.19.138 – 10.2.19.138	10.2.19.138
12	10.2.19.139/32	10.2.19.139 – 10.2.19.139	10.2.19.139
13	10.2.19.140/32	10.2.19.140 – 10.2.19.140	10.2.19.140
14	10.2.19.141/32	10.2.19.141 – 10.2.19.141	10.2.19.141
15	10.2.19.142/32	10.2.19.142 – 10.2.19.142	10.2.19.142
16	10.2.19.143/32	10.2.19.143 – 10.2.19.143	10.2.19.143
17	10.2.19.144/32	10.2.19.144 – 10.2.19.144	10.2.19.144
18	10.2.19.145/32	10.2.19.145 – 10.2.19.145	10.2.19.145
19	10.2.19.146/32	10.2.19.146 – 10.2.19.146	10.2.19.146
20	10.2.19.147/32	10.2.19.147 – 10.2.19.147	10.2.19.147
21	10.2.19.148/32	10.2.19.148 – 10.2.19.148	10.2.19.148
22	10.2.19.149/32	10.2.19.149 – 10.2.19.149	10.2.19.149
23	10.2.19.150/32	10.2.19.150 – 10.2.19.150	10.2.19.150
24	10.2.19.151/32	10.2.19.151 – 10.2.19.151	10.2.19.151
25	10.2.19.152/32	10.2.19.152 – 10.2.19.152	10.2.19.152
26	10.2.19.153/32	10.2.19.153 – 10.2.19.153	10.2.19.153
27	10.2.19.154/32	10.2.19.154 – 10.2.19.154	10.2.19.154
28	10.2.19.155/32	10.2.19.155 – 10.2.19.155	10.2.19.155
29	10.2.19.156/32	10.2.19.156 – 10.2.19.156	10.2.19.156
30	10.2.19.157/32	10.2.19.157 – 10.2.19.157	10.2.19.157
31	10.2.19.158/32	10.2.19.158 – 10.2.19.158	10.2.19.158
32	10.2.19.159/32	10.2.19.159 – 10.2.19.159	10.2.19.159
33	10.2.19.160/32	10.2.19.160 – 10.2.19.160	10.2.19.160
34	10.2.19.161/32	10.2.19.161 – 10.2.19.161	10.2.19.161
35	10.2.19.162/32	10.2.19.162 – 10.2.19.162	10.2.19.162
36	10.2.19.163/32	10.2.19.163 – 10.2.19.163	10.2.19.163
37	10.2.19.164/32	10.2.19.164 – 10.2.19.164	10.2.19.164
38	10.2.19.165/32	10.2.19.165 – 10.2.19.165	10.2.19.165
39	10.2.19.166/32	10.2.19.166 – 10.2.19.166	10.2.19.166
40	10.2.19.167/32	10.2.19.167 – 10.2.19.167	10.2.19.167
41	10.2.19.168/32	10.2.19.168 – 10.2.19.168	10.2.19.168
42	10.2.19.169/32	10.2.19.169 – 10.2.19.169	10.2.19.169
43	10.2.19.170/32	10.2.19.170 – 10.2.19.170	10.2.19.170
44	10.2.19.171/32	10.2.19.171 – 10.2.19.171	10.2.19.171
45	10.2.19.172/32	10.2.19.172 – 10.2.19.172	10.2.19.172
46	10.2.19.173/32	10.2.19.173 – 10.2.19.173	10.2.19.173
47	10.2.19.174/32	10.2.19.174 – 10.2.19.174	10.2.19.174
48	10.2.19.175/32	10.2.19.175 – 10.2.19.175	10.2.19.175
49	10.2.19.176/32	10.2.19.176 – 10.2.19.176	10.2.19.176
50	10.2.19.177/32	10.2.19.177 – 10.2.19.177	10.2.19.177
51	10.2.19.178/32	10.2.19.178 – 10.2.19.178	10.2.19.178
52	10.2.19.179/32	10.2.19.179 – 10.2.19.179	10.2.19.179
53	10.2.19.180/32	10.2.19.180 – 10.2.19.180	10.2.19.180
54	10.2.19.181/32	10.2.19.181 – 10.2.19.181	10.2.19.181
55	10.2.19.182/32	10.2.19.182 – 10.2.19.182	10.2.19.182
56	10.2.19.183/32	10.2.19.183 – 10.2.19.183	10.2.19.183
57	10.2.19.184/32	10.2.19.184 – 10.2.19.184	10.2.19.184
58	10.2.19.185/32	10.2.19.185 – 10.2.19.185	10.2.19.185
59	10.2.19.186/32	10.2.19.186 – 10.2.19.186	10.2.19.186
60	10.2.19.187/32	10.2.19.187 – 10.2.19.187	10.2.19.187
61	10.2.19.188/32	10.2.19.188 – 10.2.19.188	10.2.19.188
62	10.2.19.189/32	10.2.19.189 – 10.2.19.189	10.2.19.189
63	10.2.19.190/32	10.2.19.190 – 10.2.19.190	10.2.19.190
64	10.2.19.191/32	10.2.19.191 – 10.2.19.191	10.2.19.191
65	10.2.19.192/32	10.2.19.192 – 10.2.19.192	10.2.19.192
66	10.2.19.193/32	10.2.19.193 – 10.2.19.193	10.2.19.193
67	10.2.19.194/32	10.2.19.194 – 10.2.19.194	10.2.19.194
68	10.2.19.195/32	10.2.19.195 – 10.2.19.195	10.2.19.195
69	10.2.19.196/32	10.2.19.196 – 10.2.19.196	10.2.19.196
70	10.2.19.197/32	10.2.19.197 – 10.2.19.197	10.2.19.197
71	10.2.19.198/32	10.2.19.198 – 10.2.19.198	10.2.19.198
72	10.2.19.199/32	10.2.19.199 – 10.2.19.199	10.2.19.199
73	10.2.19.200/32	10.2.19.200 – 10.2.19.200	10.2.19.200
74	10.2.19.201/32	10.2.19.201 – 10.2.19.201	10.2.19.201
75	10.2.19.202/32	10.2.19.202 – 10.2.19.202	10.2.19.202
76	10.2.19.203/32	10.2.19.203 – 10.2.19.203	10.2.19.203
77	10.2.19.204/32	10.2.19.204 – 10.2.19.204	10.2.19.204
78	10.2.19.205/32	10.2.19.205 – 10.2.19.205	10.2.19.205
79	10.2.19.206/32	10.2.19.206 – 10.2.19.206	10.2.19.206
80	10.2.19.207/32	10.2.19.207 – 10.2.19.207	10.2.19.207
81	10.2.19.208/32	10.2.19.208 – 10.2.19.208	10.2.19.208
82	10.2.19.209/32	10.2.19.209 – 10.2.19.209	10.2.19.209
83	10.2.19.210/32	10.2.19.210 – 10.2.19.210	10.2.19.210
84	10.2.19.211/32	10.2.19.211 – 10.2.19.211	10.2.19.211
85	10.2.19.212/32	10.2.19.212 – 10.2.19.212	10.2.19.212
86	10.2.19.213/32	10.2.19.213 – 10.2.19.213	10.2.19.213
87	10.2.19.214/32	10.2.19.214 – 10.2.19.214	10.2.19.214
88	10.2.19.215/32	10.2.19.215 – 10.2.19.215	10.2.19.215
89	10.2.19.216/32	10.2.19.216 – 10.2.19.216	10.2.19.216
90	10.2.19.217/32	10.2.19.217 – 10.2.19.217	10.2.19.217
91	10.2.19.218/32	10.2.19.218 – 10.2.19.218	10.2.19.218
92	10.2.19.219/32	10.2.19.219 – 10.2.19.219	10.2.19.219
93	10.2.19.220/32	10.2.19.220 – 10.2.19.220	10.2.19.220
94	10.2.19.221/32	10.2.19.221 – 10.2.19.221	10.2.19.221
95	10.2.19.222/32	10.2.19.222 – 10.2.19.222	10.2.19.222
96	10.2.19.223/32	10.2.19.223 – 10.2.19.223	10.2.19.223
97	10.2.19.224/32	10.2.19.224 – 10.2.19.224	10.2.19.224
98	10.2.19.225/32	10.2.19.225 – 10.2.19.225	10.2.19.225
99	10.2.19.226/32	10.2.19.226 – 10.2.19.226	10.2.19.226
100	10.2.19.227/32	10.2.19.227 – 10.2.19.227	10.2.19.227
101	10.2.19.228/32	10.2.19.228 – 10.2.19.228	10.2.19.228
102	10.2.19.229/32	10.2.19.229 – 10.2.19.229	10.2.19.229
103	10.2.19.230/32	10.2.19.230 – 10.2.19.230	10.2.19.230
104	10.2.19.231/32	10.2.19.231 – 10.2.19.231	10.2.19.231
105	10.2.19.232/32	10.2.19.232 – 10.2.19.232	10.2.19.232
106	10.2.19.233/32	10.2.19.233 – 10.2.19.233	10.2.19.233
107	10.2.19.234/32	10.2.19.234 – 10.2.19.234	10.2.19.234
108	10.2.19.235/32	10.2.19.235 – 10.2.19.235	10.2.19.235
109	10.2.19.236/32	10.2.19.236 – 10.2.19.236	10.2.19.236
110	10.2.19.237/32	10.2.19.237 – 10.2.19.237	10.2.19.237
111	10.2.19.238/32	10.2.19.238 – 10.2.19.238	10.2.19.238
112	10.2.19.239/32	10.2.19.239 – 10.2.19.239	10.2.19.239
113	10.2.19.240/32	10.2.19.240 – 10.2.19.240	10.2.19.240
114	10.2.19.241/32	10.2.19.241 – 10.2.19.241	10.2.19.241
115	10.2.19.242/32	10.2.19.242 – 10.2.19.242	10.2.19.242
116	10.2.19.243/32	10.2.19.243 – 10.2.19.243	10.2.19.243
117	10.2.19.244/32	10.2.19.244 – 10.2.19.244	10.2.19.244
118	10.2.19.245/32	10.2.19.245 – 10.2.19.245	10.2.19.245
119	10.2.19.246/32	10.2.19.246 – 10.2.19.246	10.2.19.246
120	10.2.19.247/32	10.2.19.247 – 10.2.19.247	10.2.19.247
121	10.2.19.248/32	10.2.19.248 – 10.2.19.248	10.2.19.248
122	10.2.19.249/32	10.2.19.249 – 10.2.19.249	10.2.19.249
123	10.2.19.250/32	10.2.19.250 – 10.2.19.250	10.2.19.250
124	10.2.19.251/32	10.2.19.251 – 10.2.19.251	10.2.19.251
125	10.2.19.252/32	10.2.19.252 – 10.2.19.252	10.2.19.252
126	10.2.19.253/32	10.2.19.253 – 10.2.19.253	10.2.19.253
127	10.2.19.254/32	10.2.19.254 – 10.2.19.254	10.2.19.254
128	10.2.19.255/32	10.2.19.255 – 10.2.19.255	10.2.19.255

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 /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 →