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)10.2.16.128/25

network10.2.16.128/25

broadcast10.2.16.255

first host10.2.16.129

last host10.2.16.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.2.16.128/25

address00001010.00000010.00010000.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000010.00010000.10000000

broadcast00001010.00000010.00010000.11111111

green = network part, grey = host part

hex0x0a021080

decimal167907456

reverse dns128.16.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:1080

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.16.128/32	10.2.16.128 – 10.2.16.128	10.2.16.128
2	10.2.16.129/32	10.2.16.129 – 10.2.16.129	10.2.16.129
3	10.2.16.130/32	10.2.16.130 – 10.2.16.130	10.2.16.130
4	10.2.16.131/32	10.2.16.131 – 10.2.16.131	10.2.16.131
5	10.2.16.132/32	10.2.16.132 – 10.2.16.132	10.2.16.132
6	10.2.16.133/32	10.2.16.133 – 10.2.16.133	10.2.16.133
7	10.2.16.134/32	10.2.16.134 – 10.2.16.134	10.2.16.134
8	10.2.16.135/32	10.2.16.135 – 10.2.16.135	10.2.16.135
9	10.2.16.136/32	10.2.16.136 – 10.2.16.136	10.2.16.136
10	10.2.16.137/32	10.2.16.137 – 10.2.16.137	10.2.16.137
11	10.2.16.138/32	10.2.16.138 – 10.2.16.138	10.2.16.138
12	10.2.16.139/32	10.2.16.139 – 10.2.16.139	10.2.16.139
13	10.2.16.140/32	10.2.16.140 – 10.2.16.140	10.2.16.140
14	10.2.16.141/32	10.2.16.141 – 10.2.16.141	10.2.16.141
15	10.2.16.142/32	10.2.16.142 – 10.2.16.142	10.2.16.142
16	10.2.16.143/32	10.2.16.143 – 10.2.16.143	10.2.16.143
17	10.2.16.144/32	10.2.16.144 – 10.2.16.144	10.2.16.144
18	10.2.16.145/32	10.2.16.145 – 10.2.16.145	10.2.16.145
19	10.2.16.146/32	10.2.16.146 – 10.2.16.146	10.2.16.146
20	10.2.16.147/32	10.2.16.147 – 10.2.16.147	10.2.16.147
21	10.2.16.148/32	10.2.16.148 – 10.2.16.148	10.2.16.148
22	10.2.16.149/32	10.2.16.149 – 10.2.16.149	10.2.16.149
23	10.2.16.150/32	10.2.16.150 – 10.2.16.150	10.2.16.150
24	10.2.16.151/32	10.2.16.151 – 10.2.16.151	10.2.16.151
25	10.2.16.152/32	10.2.16.152 – 10.2.16.152	10.2.16.152
26	10.2.16.153/32	10.2.16.153 – 10.2.16.153	10.2.16.153
27	10.2.16.154/32	10.2.16.154 – 10.2.16.154	10.2.16.154
28	10.2.16.155/32	10.2.16.155 – 10.2.16.155	10.2.16.155
29	10.2.16.156/32	10.2.16.156 – 10.2.16.156	10.2.16.156
30	10.2.16.157/32	10.2.16.157 – 10.2.16.157	10.2.16.157
31	10.2.16.158/32	10.2.16.158 – 10.2.16.158	10.2.16.158
32	10.2.16.159/32	10.2.16.159 – 10.2.16.159	10.2.16.159
33	10.2.16.160/32	10.2.16.160 – 10.2.16.160	10.2.16.160
34	10.2.16.161/32	10.2.16.161 – 10.2.16.161	10.2.16.161
35	10.2.16.162/32	10.2.16.162 – 10.2.16.162	10.2.16.162
36	10.2.16.163/32	10.2.16.163 – 10.2.16.163	10.2.16.163
37	10.2.16.164/32	10.2.16.164 – 10.2.16.164	10.2.16.164
38	10.2.16.165/32	10.2.16.165 – 10.2.16.165	10.2.16.165
39	10.2.16.166/32	10.2.16.166 – 10.2.16.166	10.2.16.166
40	10.2.16.167/32	10.2.16.167 – 10.2.16.167	10.2.16.167
41	10.2.16.168/32	10.2.16.168 – 10.2.16.168	10.2.16.168
42	10.2.16.169/32	10.2.16.169 – 10.2.16.169	10.2.16.169
43	10.2.16.170/32	10.2.16.170 – 10.2.16.170	10.2.16.170
44	10.2.16.171/32	10.2.16.171 – 10.2.16.171	10.2.16.171
45	10.2.16.172/32	10.2.16.172 – 10.2.16.172	10.2.16.172
46	10.2.16.173/32	10.2.16.173 – 10.2.16.173	10.2.16.173
47	10.2.16.174/32	10.2.16.174 – 10.2.16.174	10.2.16.174
48	10.2.16.175/32	10.2.16.175 – 10.2.16.175	10.2.16.175
49	10.2.16.176/32	10.2.16.176 – 10.2.16.176	10.2.16.176
50	10.2.16.177/32	10.2.16.177 – 10.2.16.177	10.2.16.177
51	10.2.16.178/32	10.2.16.178 – 10.2.16.178	10.2.16.178
52	10.2.16.179/32	10.2.16.179 – 10.2.16.179	10.2.16.179
53	10.2.16.180/32	10.2.16.180 – 10.2.16.180	10.2.16.180
54	10.2.16.181/32	10.2.16.181 – 10.2.16.181	10.2.16.181
55	10.2.16.182/32	10.2.16.182 – 10.2.16.182	10.2.16.182
56	10.2.16.183/32	10.2.16.183 – 10.2.16.183	10.2.16.183
57	10.2.16.184/32	10.2.16.184 – 10.2.16.184	10.2.16.184
58	10.2.16.185/32	10.2.16.185 – 10.2.16.185	10.2.16.185
59	10.2.16.186/32	10.2.16.186 – 10.2.16.186	10.2.16.186
60	10.2.16.187/32	10.2.16.187 – 10.2.16.187	10.2.16.187
61	10.2.16.188/32	10.2.16.188 – 10.2.16.188	10.2.16.188
62	10.2.16.189/32	10.2.16.189 – 10.2.16.189	10.2.16.189
63	10.2.16.190/32	10.2.16.190 – 10.2.16.190	10.2.16.190
64	10.2.16.191/32	10.2.16.191 – 10.2.16.191	10.2.16.191
65	10.2.16.192/32	10.2.16.192 – 10.2.16.192	10.2.16.192
66	10.2.16.193/32	10.2.16.193 – 10.2.16.193	10.2.16.193
67	10.2.16.194/32	10.2.16.194 – 10.2.16.194	10.2.16.194
68	10.2.16.195/32	10.2.16.195 – 10.2.16.195	10.2.16.195
69	10.2.16.196/32	10.2.16.196 – 10.2.16.196	10.2.16.196
70	10.2.16.197/32	10.2.16.197 – 10.2.16.197	10.2.16.197
71	10.2.16.198/32	10.2.16.198 – 10.2.16.198	10.2.16.198
72	10.2.16.199/32	10.2.16.199 – 10.2.16.199	10.2.16.199
73	10.2.16.200/32	10.2.16.200 – 10.2.16.200	10.2.16.200
74	10.2.16.201/32	10.2.16.201 – 10.2.16.201	10.2.16.201
75	10.2.16.202/32	10.2.16.202 – 10.2.16.202	10.2.16.202
76	10.2.16.203/32	10.2.16.203 – 10.2.16.203	10.2.16.203
77	10.2.16.204/32	10.2.16.204 – 10.2.16.204	10.2.16.204
78	10.2.16.205/32	10.2.16.205 – 10.2.16.205	10.2.16.205
79	10.2.16.206/32	10.2.16.206 – 10.2.16.206	10.2.16.206
80	10.2.16.207/32	10.2.16.207 – 10.2.16.207	10.2.16.207
81	10.2.16.208/32	10.2.16.208 – 10.2.16.208	10.2.16.208
82	10.2.16.209/32	10.2.16.209 – 10.2.16.209	10.2.16.209
83	10.2.16.210/32	10.2.16.210 – 10.2.16.210	10.2.16.210
84	10.2.16.211/32	10.2.16.211 – 10.2.16.211	10.2.16.211
85	10.2.16.212/32	10.2.16.212 – 10.2.16.212	10.2.16.212
86	10.2.16.213/32	10.2.16.213 – 10.2.16.213	10.2.16.213
87	10.2.16.214/32	10.2.16.214 – 10.2.16.214	10.2.16.214
88	10.2.16.215/32	10.2.16.215 – 10.2.16.215	10.2.16.215
89	10.2.16.216/32	10.2.16.216 – 10.2.16.216	10.2.16.216
90	10.2.16.217/32	10.2.16.217 – 10.2.16.217	10.2.16.217
91	10.2.16.218/32	10.2.16.218 – 10.2.16.218	10.2.16.218
92	10.2.16.219/32	10.2.16.219 – 10.2.16.219	10.2.16.219
93	10.2.16.220/32	10.2.16.220 – 10.2.16.220	10.2.16.220
94	10.2.16.221/32	10.2.16.221 – 10.2.16.221	10.2.16.221
95	10.2.16.222/32	10.2.16.222 – 10.2.16.222	10.2.16.222
96	10.2.16.223/32	10.2.16.223 – 10.2.16.223	10.2.16.223
97	10.2.16.224/32	10.2.16.224 – 10.2.16.224	10.2.16.224
98	10.2.16.225/32	10.2.16.225 – 10.2.16.225	10.2.16.225
99	10.2.16.226/32	10.2.16.226 – 10.2.16.226	10.2.16.226
100	10.2.16.227/32	10.2.16.227 – 10.2.16.227	10.2.16.227
101	10.2.16.228/32	10.2.16.228 – 10.2.16.228	10.2.16.228
102	10.2.16.229/32	10.2.16.229 – 10.2.16.229	10.2.16.229
103	10.2.16.230/32	10.2.16.230 – 10.2.16.230	10.2.16.230
104	10.2.16.231/32	10.2.16.231 – 10.2.16.231	10.2.16.231
105	10.2.16.232/32	10.2.16.232 – 10.2.16.232	10.2.16.232
106	10.2.16.233/32	10.2.16.233 – 10.2.16.233	10.2.16.233
107	10.2.16.234/32	10.2.16.234 – 10.2.16.234	10.2.16.234
108	10.2.16.235/32	10.2.16.235 – 10.2.16.235	10.2.16.235
109	10.2.16.236/32	10.2.16.236 – 10.2.16.236	10.2.16.236
110	10.2.16.237/32	10.2.16.237 – 10.2.16.237	10.2.16.237
111	10.2.16.238/32	10.2.16.238 – 10.2.16.238	10.2.16.238
112	10.2.16.239/32	10.2.16.239 – 10.2.16.239	10.2.16.239
113	10.2.16.240/32	10.2.16.240 – 10.2.16.240	10.2.16.240
114	10.2.16.241/32	10.2.16.241 – 10.2.16.241	10.2.16.241
115	10.2.16.242/32	10.2.16.242 – 10.2.16.242	10.2.16.242
116	10.2.16.243/32	10.2.16.243 – 10.2.16.243	10.2.16.243
117	10.2.16.244/32	10.2.16.244 – 10.2.16.244	10.2.16.244
118	10.2.16.245/32	10.2.16.245 – 10.2.16.245	10.2.16.245
119	10.2.16.246/32	10.2.16.246 – 10.2.16.246	10.2.16.246
120	10.2.16.247/32	10.2.16.247 – 10.2.16.247	10.2.16.247
121	10.2.16.248/32	10.2.16.248 – 10.2.16.248	10.2.16.248
122	10.2.16.249/32	10.2.16.249 – 10.2.16.249	10.2.16.249
123	10.2.16.250/32	10.2.16.250 – 10.2.16.250	10.2.16.250
124	10.2.16.251/32	10.2.16.251 – 10.2.16.251	10.2.16.251
125	10.2.16.252/32	10.2.16.252 – 10.2.16.252	10.2.16.252
126	10.2.16.253/32	10.2.16.253 – 10.2.16.253	10.2.16.253
127	10.2.16.254/32	10.2.16.254 – 10.2.16.254	10.2.16.254
128	10.2.16.255/32	10.2.16.255 – 10.2.16.255	10.2.16.255

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 →