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)10.2.23.128/25

network10.2.23.128/25

broadcast10.2.23.255

first host10.2.23.129

last host10.2.23.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.2.23.128/25

address00001010.00000010.00010111.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000010.00010111.10000000

broadcast00001010.00000010.00010111.11111111

green = network part, grey = host part

hex0x0a021780

decimal167909248

reverse dns128.23.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:1780

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.23.128/32	10.2.23.128 – 10.2.23.128	10.2.23.128
2	10.2.23.129/32	10.2.23.129 – 10.2.23.129	10.2.23.129
3	10.2.23.130/32	10.2.23.130 – 10.2.23.130	10.2.23.130
4	10.2.23.131/32	10.2.23.131 – 10.2.23.131	10.2.23.131
5	10.2.23.132/32	10.2.23.132 – 10.2.23.132	10.2.23.132
6	10.2.23.133/32	10.2.23.133 – 10.2.23.133	10.2.23.133
7	10.2.23.134/32	10.2.23.134 – 10.2.23.134	10.2.23.134
8	10.2.23.135/32	10.2.23.135 – 10.2.23.135	10.2.23.135
9	10.2.23.136/32	10.2.23.136 – 10.2.23.136	10.2.23.136
10	10.2.23.137/32	10.2.23.137 – 10.2.23.137	10.2.23.137
11	10.2.23.138/32	10.2.23.138 – 10.2.23.138	10.2.23.138
12	10.2.23.139/32	10.2.23.139 – 10.2.23.139	10.2.23.139
13	10.2.23.140/32	10.2.23.140 – 10.2.23.140	10.2.23.140
14	10.2.23.141/32	10.2.23.141 – 10.2.23.141	10.2.23.141
15	10.2.23.142/32	10.2.23.142 – 10.2.23.142	10.2.23.142
16	10.2.23.143/32	10.2.23.143 – 10.2.23.143	10.2.23.143
17	10.2.23.144/32	10.2.23.144 – 10.2.23.144	10.2.23.144
18	10.2.23.145/32	10.2.23.145 – 10.2.23.145	10.2.23.145
19	10.2.23.146/32	10.2.23.146 – 10.2.23.146	10.2.23.146
20	10.2.23.147/32	10.2.23.147 – 10.2.23.147	10.2.23.147
21	10.2.23.148/32	10.2.23.148 – 10.2.23.148	10.2.23.148
22	10.2.23.149/32	10.2.23.149 – 10.2.23.149	10.2.23.149
23	10.2.23.150/32	10.2.23.150 – 10.2.23.150	10.2.23.150
24	10.2.23.151/32	10.2.23.151 – 10.2.23.151	10.2.23.151
25	10.2.23.152/32	10.2.23.152 – 10.2.23.152	10.2.23.152
26	10.2.23.153/32	10.2.23.153 – 10.2.23.153	10.2.23.153
27	10.2.23.154/32	10.2.23.154 – 10.2.23.154	10.2.23.154
28	10.2.23.155/32	10.2.23.155 – 10.2.23.155	10.2.23.155
29	10.2.23.156/32	10.2.23.156 – 10.2.23.156	10.2.23.156
30	10.2.23.157/32	10.2.23.157 – 10.2.23.157	10.2.23.157
31	10.2.23.158/32	10.2.23.158 – 10.2.23.158	10.2.23.158
32	10.2.23.159/32	10.2.23.159 – 10.2.23.159	10.2.23.159
33	10.2.23.160/32	10.2.23.160 – 10.2.23.160	10.2.23.160
34	10.2.23.161/32	10.2.23.161 – 10.2.23.161	10.2.23.161
35	10.2.23.162/32	10.2.23.162 – 10.2.23.162	10.2.23.162
36	10.2.23.163/32	10.2.23.163 – 10.2.23.163	10.2.23.163
37	10.2.23.164/32	10.2.23.164 – 10.2.23.164	10.2.23.164
38	10.2.23.165/32	10.2.23.165 – 10.2.23.165	10.2.23.165
39	10.2.23.166/32	10.2.23.166 – 10.2.23.166	10.2.23.166
40	10.2.23.167/32	10.2.23.167 – 10.2.23.167	10.2.23.167
41	10.2.23.168/32	10.2.23.168 – 10.2.23.168	10.2.23.168
42	10.2.23.169/32	10.2.23.169 – 10.2.23.169	10.2.23.169
43	10.2.23.170/32	10.2.23.170 – 10.2.23.170	10.2.23.170
44	10.2.23.171/32	10.2.23.171 – 10.2.23.171	10.2.23.171
45	10.2.23.172/32	10.2.23.172 – 10.2.23.172	10.2.23.172
46	10.2.23.173/32	10.2.23.173 – 10.2.23.173	10.2.23.173
47	10.2.23.174/32	10.2.23.174 – 10.2.23.174	10.2.23.174
48	10.2.23.175/32	10.2.23.175 – 10.2.23.175	10.2.23.175
49	10.2.23.176/32	10.2.23.176 – 10.2.23.176	10.2.23.176
50	10.2.23.177/32	10.2.23.177 – 10.2.23.177	10.2.23.177
51	10.2.23.178/32	10.2.23.178 – 10.2.23.178	10.2.23.178
52	10.2.23.179/32	10.2.23.179 – 10.2.23.179	10.2.23.179
53	10.2.23.180/32	10.2.23.180 – 10.2.23.180	10.2.23.180
54	10.2.23.181/32	10.2.23.181 – 10.2.23.181	10.2.23.181
55	10.2.23.182/32	10.2.23.182 – 10.2.23.182	10.2.23.182
56	10.2.23.183/32	10.2.23.183 – 10.2.23.183	10.2.23.183
57	10.2.23.184/32	10.2.23.184 – 10.2.23.184	10.2.23.184
58	10.2.23.185/32	10.2.23.185 – 10.2.23.185	10.2.23.185
59	10.2.23.186/32	10.2.23.186 – 10.2.23.186	10.2.23.186
60	10.2.23.187/32	10.2.23.187 – 10.2.23.187	10.2.23.187
61	10.2.23.188/32	10.2.23.188 – 10.2.23.188	10.2.23.188
62	10.2.23.189/32	10.2.23.189 – 10.2.23.189	10.2.23.189
63	10.2.23.190/32	10.2.23.190 – 10.2.23.190	10.2.23.190
64	10.2.23.191/32	10.2.23.191 – 10.2.23.191	10.2.23.191
65	10.2.23.192/32	10.2.23.192 – 10.2.23.192	10.2.23.192
66	10.2.23.193/32	10.2.23.193 – 10.2.23.193	10.2.23.193
67	10.2.23.194/32	10.2.23.194 – 10.2.23.194	10.2.23.194
68	10.2.23.195/32	10.2.23.195 – 10.2.23.195	10.2.23.195
69	10.2.23.196/32	10.2.23.196 – 10.2.23.196	10.2.23.196
70	10.2.23.197/32	10.2.23.197 – 10.2.23.197	10.2.23.197
71	10.2.23.198/32	10.2.23.198 – 10.2.23.198	10.2.23.198
72	10.2.23.199/32	10.2.23.199 – 10.2.23.199	10.2.23.199
73	10.2.23.200/32	10.2.23.200 – 10.2.23.200	10.2.23.200
74	10.2.23.201/32	10.2.23.201 – 10.2.23.201	10.2.23.201
75	10.2.23.202/32	10.2.23.202 – 10.2.23.202	10.2.23.202
76	10.2.23.203/32	10.2.23.203 – 10.2.23.203	10.2.23.203
77	10.2.23.204/32	10.2.23.204 – 10.2.23.204	10.2.23.204
78	10.2.23.205/32	10.2.23.205 – 10.2.23.205	10.2.23.205
79	10.2.23.206/32	10.2.23.206 – 10.2.23.206	10.2.23.206
80	10.2.23.207/32	10.2.23.207 – 10.2.23.207	10.2.23.207
81	10.2.23.208/32	10.2.23.208 – 10.2.23.208	10.2.23.208
82	10.2.23.209/32	10.2.23.209 – 10.2.23.209	10.2.23.209
83	10.2.23.210/32	10.2.23.210 – 10.2.23.210	10.2.23.210
84	10.2.23.211/32	10.2.23.211 – 10.2.23.211	10.2.23.211
85	10.2.23.212/32	10.2.23.212 – 10.2.23.212	10.2.23.212
86	10.2.23.213/32	10.2.23.213 – 10.2.23.213	10.2.23.213
87	10.2.23.214/32	10.2.23.214 – 10.2.23.214	10.2.23.214
88	10.2.23.215/32	10.2.23.215 – 10.2.23.215	10.2.23.215
89	10.2.23.216/32	10.2.23.216 – 10.2.23.216	10.2.23.216
90	10.2.23.217/32	10.2.23.217 – 10.2.23.217	10.2.23.217
91	10.2.23.218/32	10.2.23.218 – 10.2.23.218	10.2.23.218
92	10.2.23.219/32	10.2.23.219 – 10.2.23.219	10.2.23.219
93	10.2.23.220/32	10.2.23.220 – 10.2.23.220	10.2.23.220
94	10.2.23.221/32	10.2.23.221 – 10.2.23.221	10.2.23.221
95	10.2.23.222/32	10.2.23.222 – 10.2.23.222	10.2.23.222
96	10.2.23.223/32	10.2.23.223 – 10.2.23.223	10.2.23.223
97	10.2.23.224/32	10.2.23.224 – 10.2.23.224	10.2.23.224
98	10.2.23.225/32	10.2.23.225 – 10.2.23.225	10.2.23.225
99	10.2.23.226/32	10.2.23.226 – 10.2.23.226	10.2.23.226
100	10.2.23.227/32	10.2.23.227 – 10.2.23.227	10.2.23.227
101	10.2.23.228/32	10.2.23.228 – 10.2.23.228	10.2.23.228
102	10.2.23.229/32	10.2.23.229 – 10.2.23.229	10.2.23.229
103	10.2.23.230/32	10.2.23.230 – 10.2.23.230	10.2.23.230
104	10.2.23.231/32	10.2.23.231 – 10.2.23.231	10.2.23.231
105	10.2.23.232/32	10.2.23.232 – 10.2.23.232	10.2.23.232
106	10.2.23.233/32	10.2.23.233 – 10.2.23.233	10.2.23.233
107	10.2.23.234/32	10.2.23.234 – 10.2.23.234	10.2.23.234
108	10.2.23.235/32	10.2.23.235 – 10.2.23.235	10.2.23.235
109	10.2.23.236/32	10.2.23.236 – 10.2.23.236	10.2.23.236
110	10.2.23.237/32	10.2.23.237 – 10.2.23.237	10.2.23.237
111	10.2.23.238/32	10.2.23.238 – 10.2.23.238	10.2.23.238
112	10.2.23.239/32	10.2.23.239 – 10.2.23.239	10.2.23.239
113	10.2.23.240/32	10.2.23.240 – 10.2.23.240	10.2.23.240
114	10.2.23.241/32	10.2.23.241 – 10.2.23.241	10.2.23.241
115	10.2.23.242/32	10.2.23.242 – 10.2.23.242	10.2.23.242
116	10.2.23.243/32	10.2.23.243 – 10.2.23.243	10.2.23.243
117	10.2.23.244/32	10.2.23.244 – 10.2.23.244	10.2.23.244
118	10.2.23.245/32	10.2.23.245 – 10.2.23.245	10.2.23.245
119	10.2.23.246/32	10.2.23.246 – 10.2.23.246	10.2.23.246
120	10.2.23.247/32	10.2.23.247 – 10.2.23.247	10.2.23.247
121	10.2.23.248/32	10.2.23.248 – 10.2.23.248	10.2.23.248
122	10.2.23.249/32	10.2.23.249 – 10.2.23.249	10.2.23.249
123	10.2.23.250/32	10.2.23.250 – 10.2.23.250	10.2.23.250
124	10.2.23.251/32	10.2.23.251 – 10.2.23.251	10.2.23.251
125	10.2.23.252/32	10.2.23.252 – 10.2.23.252	10.2.23.252
126	10.2.23.253/32	10.2.23.253 – 10.2.23.253	10.2.23.253
127	10.2.23.254/32	10.2.23.254 – 10.2.23.254	10.2.23.254
128	10.2.23.255/32	10.2.23.255 – 10.2.23.255	10.2.23.255

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 →