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)172.16.0.128/25

network172.16.0.128/25

broadcast172.16.0.255

first host172.16.0.129

last host172.16.0.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classB

ipcalc 172.16.0.128/25

address10101100.00010000.00000000.10000000

subnet mask11111111.11111111.11111111.10000000

network10101100.00010000.00000000.10000000

broadcast10101100.00010000.00000000.11111111

green = network part, grey = host part

hex0xac100080

decimal2886729856

reverse dns128.0.16.172.in-addr.arpa

ipv4-mapped::ffff:ac10:80

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	172.16.0.128/32	172.16.0.128 – 172.16.0.128	172.16.0.128
2	172.16.0.129/32	172.16.0.129 – 172.16.0.129	172.16.0.129
3	172.16.0.130/32	172.16.0.130 – 172.16.0.130	172.16.0.130
4	172.16.0.131/32	172.16.0.131 – 172.16.0.131	172.16.0.131
5	172.16.0.132/32	172.16.0.132 – 172.16.0.132	172.16.0.132
6	172.16.0.133/32	172.16.0.133 – 172.16.0.133	172.16.0.133
7	172.16.0.134/32	172.16.0.134 – 172.16.0.134	172.16.0.134
8	172.16.0.135/32	172.16.0.135 – 172.16.0.135	172.16.0.135
9	172.16.0.136/32	172.16.0.136 – 172.16.0.136	172.16.0.136
10	172.16.0.137/32	172.16.0.137 – 172.16.0.137	172.16.0.137
11	172.16.0.138/32	172.16.0.138 – 172.16.0.138	172.16.0.138
12	172.16.0.139/32	172.16.0.139 – 172.16.0.139	172.16.0.139
13	172.16.0.140/32	172.16.0.140 – 172.16.0.140	172.16.0.140
14	172.16.0.141/32	172.16.0.141 – 172.16.0.141	172.16.0.141
15	172.16.0.142/32	172.16.0.142 – 172.16.0.142	172.16.0.142
16	172.16.0.143/32	172.16.0.143 – 172.16.0.143	172.16.0.143
17	172.16.0.144/32	172.16.0.144 – 172.16.0.144	172.16.0.144
18	172.16.0.145/32	172.16.0.145 – 172.16.0.145	172.16.0.145
19	172.16.0.146/32	172.16.0.146 – 172.16.0.146	172.16.0.146
20	172.16.0.147/32	172.16.0.147 – 172.16.0.147	172.16.0.147
21	172.16.0.148/32	172.16.0.148 – 172.16.0.148	172.16.0.148
22	172.16.0.149/32	172.16.0.149 – 172.16.0.149	172.16.0.149
23	172.16.0.150/32	172.16.0.150 – 172.16.0.150	172.16.0.150
24	172.16.0.151/32	172.16.0.151 – 172.16.0.151	172.16.0.151
25	172.16.0.152/32	172.16.0.152 – 172.16.0.152	172.16.0.152
26	172.16.0.153/32	172.16.0.153 – 172.16.0.153	172.16.0.153
27	172.16.0.154/32	172.16.0.154 – 172.16.0.154	172.16.0.154
28	172.16.0.155/32	172.16.0.155 – 172.16.0.155	172.16.0.155
29	172.16.0.156/32	172.16.0.156 – 172.16.0.156	172.16.0.156
30	172.16.0.157/32	172.16.0.157 – 172.16.0.157	172.16.0.157
31	172.16.0.158/32	172.16.0.158 – 172.16.0.158	172.16.0.158
32	172.16.0.159/32	172.16.0.159 – 172.16.0.159	172.16.0.159
33	172.16.0.160/32	172.16.0.160 – 172.16.0.160	172.16.0.160
34	172.16.0.161/32	172.16.0.161 – 172.16.0.161	172.16.0.161
35	172.16.0.162/32	172.16.0.162 – 172.16.0.162	172.16.0.162
36	172.16.0.163/32	172.16.0.163 – 172.16.0.163	172.16.0.163
37	172.16.0.164/32	172.16.0.164 – 172.16.0.164	172.16.0.164
38	172.16.0.165/32	172.16.0.165 – 172.16.0.165	172.16.0.165
39	172.16.0.166/32	172.16.0.166 – 172.16.0.166	172.16.0.166
40	172.16.0.167/32	172.16.0.167 – 172.16.0.167	172.16.0.167
41	172.16.0.168/32	172.16.0.168 – 172.16.0.168	172.16.0.168
42	172.16.0.169/32	172.16.0.169 – 172.16.0.169	172.16.0.169
43	172.16.0.170/32	172.16.0.170 – 172.16.0.170	172.16.0.170
44	172.16.0.171/32	172.16.0.171 – 172.16.0.171	172.16.0.171
45	172.16.0.172/32	172.16.0.172 – 172.16.0.172	172.16.0.172
46	172.16.0.173/32	172.16.0.173 – 172.16.0.173	172.16.0.173
47	172.16.0.174/32	172.16.0.174 – 172.16.0.174	172.16.0.174
48	172.16.0.175/32	172.16.0.175 – 172.16.0.175	172.16.0.175
49	172.16.0.176/32	172.16.0.176 – 172.16.0.176	172.16.0.176
50	172.16.0.177/32	172.16.0.177 – 172.16.0.177	172.16.0.177
51	172.16.0.178/32	172.16.0.178 – 172.16.0.178	172.16.0.178
52	172.16.0.179/32	172.16.0.179 – 172.16.0.179	172.16.0.179
53	172.16.0.180/32	172.16.0.180 – 172.16.0.180	172.16.0.180
54	172.16.0.181/32	172.16.0.181 – 172.16.0.181	172.16.0.181
55	172.16.0.182/32	172.16.0.182 – 172.16.0.182	172.16.0.182
56	172.16.0.183/32	172.16.0.183 – 172.16.0.183	172.16.0.183
57	172.16.0.184/32	172.16.0.184 – 172.16.0.184	172.16.0.184
58	172.16.0.185/32	172.16.0.185 – 172.16.0.185	172.16.0.185
59	172.16.0.186/32	172.16.0.186 – 172.16.0.186	172.16.0.186
60	172.16.0.187/32	172.16.0.187 – 172.16.0.187	172.16.0.187
61	172.16.0.188/32	172.16.0.188 – 172.16.0.188	172.16.0.188
62	172.16.0.189/32	172.16.0.189 – 172.16.0.189	172.16.0.189
63	172.16.0.190/32	172.16.0.190 – 172.16.0.190	172.16.0.190
64	172.16.0.191/32	172.16.0.191 – 172.16.0.191	172.16.0.191
65	172.16.0.192/32	172.16.0.192 – 172.16.0.192	172.16.0.192
66	172.16.0.193/32	172.16.0.193 – 172.16.0.193	172.16.0.193
67	172.16.0.194/32	172.16.0.194 – 172.16.0.194	172.16.0.194
68	172.16.0.195/32	172.16.0.195 – 172.16.0.195	172.16.0.195
69	172.16.0.196/32	172.16.0.196 – 172.16.0.196	172.16.0.196
70	172.16.0.197/32	172.16.0.197 – 172.16.0.197	172.16.0.197
71	172.16.0.198/32	172.16.0.198 – 172.16.0.198	172.16.0.198
72	172.16.0.199/32	172.16.0.199 – 172.16.0.199	172.16.0.199
73	172.16.0.200/32	172.16.0.200 – 172.16.0.200	172.16.0.200
74	172.16.0.201/32	172.16.0.201 – 172.16.0.201	172.16.0.201
75	172.16.0.202/32	172.16.0.202 – 172.16.0.202	172.16.0.202
76	172.16.0.203/32	172.16.0.203 – 172.16.0.203	172.16.0.203
77	172.16.0.204/32	172.16.0.204 – 172.16.0.204	172.16.0.204
78	172.16.0.205/32	172.16.0.205 – 172.16.0.205	172.16.0.205
79	172.16.0.206/32	172.16.0.206 – 172.16.0.206	172.16.0.206
80	172.16.0.207/32	172.16.0.207 – 172.16.0.207	172.16.0.207
81	172.16.0.208/32	172.16.0.208 – 172.16.0.208	172.16.0.208
82	172.16.0.209/32	172.16.0.209 – 172.16.0.209	172.16.0.209
83	172.16.0.210/32	172.16.0.210 – 172.16.0.210	172.16.0.210
84	172.16.0.211/32	172.16.0.211 – 172.16.0.211	172.16.0.211
85	172.16.0.212/32	172.16.0.212 – 172.16.0.212	172.16.0.212
86	172.16.0.213/32	172.16.0.213 – 172.16.0.213	172.16.0.213
87	172.16.0.214/32	172.16.0.214 – 172.16.0.214	172.16.0.214
88	172.16.0.215/32	172.16.0.215 – 172.16.0.215	172.16.0.215
89	172.16.0.216/32	172.16.0.216 – 172.16.0.216	172.16.0.216
90	172.16.0.217/32	172.16.0.217 – 172.16.0.217	172.16.0.217
91	172.16.0.218/32	172.16.0.218 – 172.16.0.218	172.16.0.218
92	172.16.0.219/32	172.16.0.219 – 172.16.0.219	172.16.0.219
93	172.16.0.220/32	172.16.0.220 – 172.16.0.220	172.16.0.220
94	172.16.0.221/32	172.16.0.221 – 172.16.0.221	172.16.0.221
95	172.16.0.222/32	172.16.0.222 – 172.16.0.222	172.16.0.222
96	172.16.0.223/32	172.16.0.223 – 172.16.0.223	172.16.0.223
97	172.16.0.224/32	172.16.0.224 – 172.16.0.224	172.16.0.224
98	172.16.0.225/32	172.16.0.225 – 172.16.0.225	172.16.0.225
99	172.16.0.226/32	172.16.0.226 – 172.16.0.226	172.16.0.226
100	172.16.0.227/32	172.16.0.227 – 172.16.0.227	172.16.0.227
101	172.16.0.228/32	172.16.0.228 – 172.16.0.228	172.16.0.228
102	172.16.0.229/32	172.16.0.229 – 172.16.0.229	172.16.0.229
103	172.16.0.230/32	172.16.0.230 – 172.16.0.230	172.16.0.230
104	172.16.0.231/32	172.16.0.231 – 172.16.0.231	172.16.0.231
105	172.16.0.232/32	172.16.0.232 – 172.16.0.232	172.16.0.232
106	172.16.0.233/32	172.16.0.233 – 172.16.0.233	172.16.0.233
107	172.16.0.234/32	172.16.0.234 – 172.16.0.234	172.16.0.234
108	172.16.0.235/32	172.16.0.235 – 172.16.0.235	172.16.0.235
109	172.16.0.236/32	172.16.0.236 – 172.16.0.236	172.16.0.236
110	172.16.0.237/32	172.16.0.237 – 172.16.0.237	172.16.0.237
111	172.16.0.238/32	172.16.0.238 – 172.16.0.238	172.16.0.238
112	172.16.0.239/32	172.16.0.239 – 172.16.0.239	172.16.0.239
113	172.16.0.240/32	172.16.0.240 – 172.16.0.240	172.16.0.240
114	172.16.0.241/32	172.16.0.241 – 172.16.0.241	172.16.0.241
115	172.16.0.242/32	172.16.0.242 – 172.16.0.242	172.16.0.242
116	172.16.0.243/32	172.16.0.243 – 172.16.0.243	172.16.0.243
117	172.16.0.244/32	172.16.0.244 – 172.16.0.244	172.16.0.244
118	172.16.0.245/32	172.16.0.245 – 172.16.0.245	172.16.0.245
119	172.16.0.246/32	172.16.0.246 – 172.16.0.246	172.16.0.246
120	172.16.0.247/32	172.16.0.247 – 172.16.0.247	172.16.0.247
121	172.16.0.248/32	172.16.0.248 – 172.16.0.248	172.16.0.248
122	172.16.0.249/32	172.16.0.249 – 172.16.0.249	172.16.0.249
123	172.16.0.250/32	172.16.0.250 – 172.16.0.250	172.16.0.250
124	172.16.0.251/32	172.16.0.251 – 172.16.0.251	172.16.0.251
125	172.16.0.252/32	172.16.0.252 – 172.16.0.252	172.16.0.252
126	172.16.0.253/32	172.16.0.253 – 172.16.0.253	172.16.0.253
127	172.16.0.254/32	172.16.0.254 – 172.16.0.254	172.16.0.254
128	172.16.0.255/32	172.16.0.255 – 172.16.0.255	172.16.0.255

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 →