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)172.16.2.128/25

network172.16.2.128/25

broadcast172.16.2.255

first host172.16.2.129

last host172.16.2.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classB

ipcalc 172.16.2.128/25

address10101100.00010000.00000010.10000000

subnet mask11111111.11111111.11111111.10000000

network10101100.00010000.00000010.10000000

broadcast10101100.00010000.00000010.11111111

green = network part, grey = host part

hex0xac100280

decimal2886730368

reverse dns128.2.16.172.in-addr.arpa

ipv4-mapped::ffff:ac10:280

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	172.16.2.128/32	172.16.2.128 – 172.16.2.128	172.16.2.128
2	172.16.2.129/32	172.16.2.129 – 172.16.2.129	172.16.2.129
3	172.16.2.130/32	172.16.2.130 – 172.16.2.130	172.16.2.130
4	172.16.2.131/32	172.16.2.131 – 172.16.2.131	172.16.2.131
5	172.16.2.132/32	172.16.2.132 – 172.16.2.132	172.16.2.132
6	172.16.2.133/32	172.16.2.133 – 172.16.2.133	172.16.2.133
7	172.16.2.134/32	172.16.2.134 – 172.16.2.134	172.16.2.134
8	172.16.2.135/32	172.16.2.135 – 172.16.2.135	172.16.2.135
9	172.16.2.136/32	172.16.2.136 – 172.16.2.136	172.16.2.136
10	172.16.2.137/32	172.16.2.137 – 172.16.2.137	172.16.2.137
11	172.16.2.138/32	172.16.2.138 – 172.16.2.138	172.16.2.138
12	172.16.2.139/32	172.16.2.139 – 172.16.2.139	172.16.2.139
13	172.16.2.140/32	172.16.2.140 – 172.16.2.140	172.16.2.140
14	172.16.2.141/32	172.16.2.141 – 172.16.2.141	172.16.2.141
15	172.16.2.142/32	172.16.2.142 – 172.16.2.142	172.16.2.142
16	172.16.2.143/32	172.16.2.143 – 172.16.2.143	172.16.2.143
17	172.16.2.144/32	172.16.2.144 – 172.16.2.144	172.16.2.144
18	172.16.2.145/32	172.16.2.145 – 172.16.2.145	172.16.2.145
19	172.16.2.146/32	172.16.2.146 – 172.16.2.146	172.16.2.146
20	172.16.2.147/32	172.16.2.147 – 172.16.2.147	172.16.2.147
21	172.16.2.148/32	172.16.2.148 – 172.16.2.148	172.16.2.148
22	172.16.2.149/32	172.16.2.149 – 172.16.2.149	172.16.2.149
23	172.16.2.150/32	172.16.2.150 – 172.16.2.150	172.16.2.150
24	172.16.2.151/32	172.16.2.151 – 172.16.2.151	172.16.2.151
25	172.16.2.152/32	172.16.2.152 – 172.16.2.152	172.16.2.152
26	172.16.2.153/32	172.16.2.153 – 172.16.2.153	172.16.2.153
27	172.16.2.154/32	172.16.2.154 – 172.16.2.154	172.16.2.154
28	172.16.2.155/32	172.16.2.155 – 172.16.2.155	172.16.2.155
29	172.16.2.156/32	172.16.2.156 – 172.16.2.156	172.16.2.156
30	172.16.2.157/32	172.16.2.157 – 172.16.2.157	172.16.2.157
31	172.16.2.158/32	172.16.2.158 – 172.16.2.158	172.16.2.158
32	172.16.2.159/32	172.16.2.159 – 172.16.2.159	172.16.2.159
33	172.16.2.160/32	172.16.2.160 – 172.16.2.160	172.16.2.160
34	172.16.2.161/32	172.16.2.161 – 172.16.2.161	172.16.2.161
35	172.16.2.162/32	172.16.2.162 – 172.16.2.162	172.16.2.162
36	172.16.2.163/32	172.16.2.163 – 172.16.2.163	172.16.2.163
37	172.16.2.164/32	172.16.2.164 – 172.16.2.164	172.16.2.164
38	172.16.2.165/32	172.16.2.165 – 172.16.2.165	172.16.2.165
39	172.16.2.166/32	172.16.2.166 – 172.16.2.166	172.16.2.166
40	172.16.2.167/32	172.16.2.167 – 172.16.2.167	172.16.2.167
41	172.16.2.168/32	172.16.2.168 – 172.16.2.168	172.16.2.168
42	172.16.2.169/32	172.16.2.169 – 172.16.2.169	172.16.2.169
43	172.16.2.170/32	172.16.2.170 – 172.16.2.170	172.16.2.170
44	172.16.2.171/32	172.16.2.171 – 172.16.2.171	172.16.2.171
45	172.16.2.172/32	172.16.2.172 – 172.16.2.172	172.16.2.172
46	172.16.2.173/32	172.16.2.173 – 172.16.2.173	172.16.2.173
47	172.16.2.174/32	172.16.2.174 – 172.16.2.174	172.16.2.174
48	172.16.2.175/32	172.16.2.175 – 172.16.2.175	172.16.2.175
49	172.16.2.176/32	172.16.2.176 – 172.16.2.176	172.16.2.176
50	172.16.2.177/32	172.16.2.177 – 172.16.2.177	172.16.2.177
51	172.16.2.178/32	172.16.2.178 – 172.16.2.178	172.16.2.178
52	172.16.2.179/32	172.16.2.179 – 172.16.2.179	172.16.2.179
53	172.16.2.180/32	172.16.2.180 – 172.16.2.180	172.16.2.180
54	172.16.2.181/32	172.16.2.181 – 172.16.2.181	172.16.2.181
55	172.16.2.182/32	172.16.2.182 – 172.16.2.182	172.16.2.182
56	172.16.2.183/32	172.16.2.183 – 172.16.2.183	172.16.2.183
57	172.16.2.184/32	172.16.2.184 – 172.16.2.184	172.16.2.184
58	172.16.2.185/32	172.16.2.185 – 172.16.2.185	172.16.2.185
59	172.16.2.186/32	172.16.2.186 – 172.16.2.186	172.16.2.186
60	172.16.2.187/32	172.16.2.187 – 172.16.2.187	172.16.2.187
61	172.16.2.188/32	172.16.2.188 – 172.16.2.188	172.16.2.188
62	172.16.2.189/32	172.16.2.189 – 172.16.2.189	172.16.2.189
63	172.16.2.190/32	172.16.2.190 – 172.16.2.190	172.16.2.190
64	172.16.2.191/32	172.16.2.191 – 172.16.2.191	172.16.2.191
65	172.16.2.192/32	172.16.2.192 – 172.16.2.192	172.16.2.192
66	172.16.2.193/32	172.16.2.193 – 172.16.2.193	172.16.2.193
67	172.16.2.194/32	172.16.2.194 – 172.16.2.194	172.16.2.194
68	172.16.2.195/32	172.16.2.195 – 172.16.2.195	172.16.2.195
69	172.16.2.196/32	172.16.2.196 – 172.16.2.196	172.16.2.196
70	172.16.2.197/32	172.16.2.197 – 172.16.2.197	172.16.2.197
71	172.16.2.198/32	172.16.2.198 – 172.16.2.198	172.16.2.198
72	172.16.2.199/32	172.16.2.199 – 172.16.2.199	172.16.2.199
73	172.16.2.200/32	172.16.2.200 – 172.16.2.200	172.16.2.200
74	172.16.2.201/32	172.16.2.201 – 172.16.2.201	172.16.2.201
75	172.16.2.202/32	172.16.2.202 – 172.16.2.202	172.16.2.202
76	172.16.2.203/32	172.16.2.203 – 172.16.2.203	172.16.2.203
77	172.16.2.204/32	172.16.2.204 – 172.16.2.204	172.16.2.204
78	172.16.2.205/32	172.16.2.205 – 172.16.2.205	172.16.2.205
79	172.16.2.206/32	172.16.2.206 – 172.16.2.206	172.16.2.206
80	172.16.2.207/32	172.16.2.207 – 172.16.2.207	172.16.2.207
81	172.16.2.208/32	172.16.2.208 – 172.16.2.208	172.16.2.208
82	172.16.2.209/32	172.16.2.209 – 172.16.2.209	172.16.2.209
83	172.16.2.210/32	172.16.2.210 – 172.16.2.210	172.16.2.210
84	172.16.2.211/32	172.16.2.211 – 172.16.2.211	172.16.2.211
85	172.16.2.212/32	172.16.2.212 – 172.16.2.212	172.16.2.212
86	172.16.2.213/32	172.16.2.213 – 172.16.2.213	172.16.2.213
87	172.16.2.214/32	172.16.2.214 – 172.16.2.214	172.16.2.214
88	172.16.2.215/32	172.16.2.215 – 172.16.2.215	172.16.2.215
89	172.16.2.216/32	172.16.2.216 – 172.16.2.216	172.16.2.216
90	172.16.2.217/32	172.16.2.217 – 172.16.2.217	172.16.2.217
91	172.16.2.218/32	172.16.2.218 – 172.16.2.218	172.16.2.218
92	172.16.2.219/32	172.16.2.219 – 172.16.2.219	172.16.2.219
93	172.16.2.220/32	172.16.2.220 – 172.16.2.220	172.16.2.220
94	172.16.2.221/32	172.16.2.221 – 172.16.2.221	172.16.2.221
95	172.16.2.222/32	172.16.2.222 – 172.16.2.222	172.16.2.222
96	172.16.2.223/32	172.16.2.223 – 172.16.2.223	172.16.2.223
97	172.16.2.224/32	172.16.2.224 – 172.16.2.224	172.16.2.224
98	172.16.2.225/32	172.16.2.225 – 172.16.2.225	172.16.2.225
99	172.16.2.226/32	172.16.2.226 – 172.16.2.226	172.16.2.226
100	172.16.2.227/32	172.16.2.227 – 172.16.2.227	172.16.2.227
101	172.16.2.228/32	172.16.2.228 – 172.16.2.228	172.16.2.228
102	172.16.2.229/32	172.16.2.229 – 172.16.2.229	172.16.2.229
103	172.16.2.230/32	172.16.2.230 – 172.16.2.230	172.16.2.230
104	172.16.2.231/32	172.16.2.231 – 172.16.2.231	172.16.2.231
105	172.16.2.232/32	172.16.2.232 – 172.16.2.232	172.16.2.232
106	172.16.2.233/32	172.16.2.233 – 172.16.2.233	172.16.2.233
107	172.16.2.234/32	172.16.2.234 – 172.16.2.234	172.16.2.234
108	172.16.2.235/32	172.16.2.235 – 172.16.2.235	172.16.2.235
109	172.16.2.236/32	172.16.2.236 – 172.16.2.236	172.16.2.236
110	172.16.2.237/32	172.16.2.237 – 172.16.2.237	172.16.2.237
111	172.16.2.238/32	172.16.2.238 – 172.16.2.238	172.16.2.238
112	172.16.2.239/32	172.16.2.239 – 172.16.2.239	172.16.2.239
113	172.16.2.240/32	172.16.2.240 – 172.16.2.240	172.16.2.240
114	172.16.2.241/32	172.16.2.241 – 172.16.2.241	172.16.2.241
115	172.16.2.242/32	172.16.2.242 – 172.16.2.242	172.16.2.242
116	172.16.2.243/32	172.16.2.243 – 172.16.2.243	172.16.2.243
117	172.16.2.244/32	172.16.2.244 – 172.16.2.244	172.16.2.244
118	172.16.2.245/32	172.16.2.245 – 172.16.2.245	172.16.2.245
119	172.16.2.246/32	172.16.2.246 – 172.16.2.246	172.16.2.246
120	172.16.2.247/32	172.16.2.247 – 172.16.2.247	172.16.2.247
121	172.16.2.248/32	172.16.2.248 – 172.16.2.248	172.16.2.248
122	172.16.2.249/32	172.16.2.249 – 172.16.2.249	172.16.2.249
123	172.16.2.250/32	172.16.2.250 – 172.16.2.250	172.16.2.250
124	172.16.2.251/32	172.16.2.251 – 172.16.2.251	172.16.2.251
125	172.16.2.252/32	172.16.2.252 – 172.16.2.252	172.16.2.252
126	172.16.2.253/32	172.16.2.253 – 172.16.2.253	172.16.2.253
127	172.16.2.254/32	172.16.2.254 – 172.16.2.254	172.16.2.254
128	172.16.2.255/32	172.16.2.255 – 172.16.2.255	172.16.2.255

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 →