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)10.3.166.128/25

network10.3.166.128/25

broadcast10.3.166.255

first host10.3.166.129

last host10.3.166.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.3.166.128/25

address00001010.00000011.10100110.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000011.10100110.10000000

broadcast00001010.00000011.10100110.11111111

green = network part, grey = host part

hex0x0a03a680

decimal168011392

reverse dns128.166.3.10.in-addr.arpa

ipv4-mapped::ffff:a03:a680

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.3.166.128/32	10.3.166.128 – 10.3.166.128	10.3.166.128
2	10.3.166.129/32	10.3.166.129 – 10.3.166.129	10.3.166.129
3	10.3.166.130/32	10.3.166.130 – 10.3.166.130	10.3.166.130
4	10.3.166.131/32	10.3.166.131 – 10.3.166.131	10.3.166.131
5	10.3.166.132/32	10.3.166.132 – 10.3.166.132	10.3.166.132
6	10.3.166.133/32	10.3.166.133 – 10.3.166.133	10.3.166.133
7	10.3.166.134/32	10.3.166.134 – 10.3.166.134	10.3.166.134
8	10.3.166.135/32	10.3.166.135 – 10.3.166.135	10.3.166.135
9	10.3.166.136/32	10.3.166.136 – 10.3.166.136	10.3.166.136
10	10.3.166.137/32	10.3.166.137 – 10.3.166.137	10.3.166.137
11	10.3.166.138/32	10.3.166.138 – 10.3.166.138	10.3.166.138
12	10.3.166.139/32	10.3.166.139 – 10.3.166.139	10.3.166.139
13	10.3.166.140/32	10.3.166.140 – 10.3.166.140	10.3.166.140
14	10.3.166.141/32	10.3.166.141 – 10.3.166.141	10.3.166.141
15	10.3.166.142/32	10.3.166.142 – 10.3.166.142	10.3.166.142
16	10.3.166.143/32	10.3.166.143 – 10.3.166.143	10.3.166.143
17	10.3.166.144/32	10.3.166.144 – 10.3.166.144	10.3.166.144
18	10.3.166.145/32	10.3.166.145 – 10.3.166.145	10.3.166.145
19	10.3.166.146/32	10.3.166.146 – 10.3.166.146	10.3.166.146
20	10.3.166.147/32	10.3.166.147 – 10.3.166.147	10.3.166.147
21	10.3.166.148/32	10.3.166.148 – 10.3.166.148	10.3.166.148
22	10.3.166.149/32	10.3.166.149 – 10.3.166.149	10.3.166.149
23	10.3.166.150/32	10.3.166.150 – 10.3.166.150	10.3.166.150
24	10.3.166.151/32	10.3.166.151 – 10.3.166.151	10.3.166.151
25	10.3.166.152/32	10.3.166.152 – 10.3.166.152	10.3.166.152
26	10.3.166.153/32	10.3.166.153 – 10.3.166.153	10.3.166.153
27	10.3.166.154/32	10.3.166.154 – 10.3.166.154	10.3.166.154
28	10.3.166.155/32	10.3.166.155 – 10.3.166.155	10.3.166.155
29	10.3.166.156/32	10.3.166.156 – 10.3.166.156	10.3.166.156
30	10.3.166.157/32	10.3.166.157 – 10.3.166.157	10.3.166.157
31	10.3.166.158/32	10.3.166.158 – 10.3.166.158	10.3.166.158
32	10.3.166.159/32	10.3.166.159 – 10.3.166.159	10.3.166.159
33	10.3.166.160/32	10.3.166.160 – 10.3.166.160	10.3.166.160
34	10.3.166.161/32	10.3.166.161 – 10.3.166.161	10.3.166.161
35	10.3.166.162/32	10.3.166.162 – 10.3.166.162	10.3.166.162
36	10.3.166.163/32	10.3.166.163 – 10.3.166.163	10.3.166.163
37	10.3.166.164/32	10.3.166.164 – 10.3.166.164	10.3.166.164
38	10.3.166.165/32	10.3.166.165 – 10.3.166.165	10.3.166.165
39	10.3.166.166/32	10.3.166.166 – 10.3.166.166	10.3.166.166
40	10.3.166.167/32	10.3.166.167 – 10.3.166.167	10.3.166.167
41	10.3.166.168/32	10.3.166.168 – 10.3.166.168	10.3.166.168
42	10.3.166.169/32	10.3.166.169 – 10.3.166.169	10.3.166.169
43	10.3.166.170/32	10.3.166.170 – 10.3.166.170	10.3.166.170
44	10.3.166.171/32	10.3.166.171 – 10.3.166.171	10.3.166.171
45	10.3.166.172/32	10.3.166.172 – 10.3.166.172	10.3.166.172
46	10.3.166.173/32	10.3.166.173 – 10.3.166.173	10.3.166.173
47	10.3.166.174/32	10.3.166.174 – 10.3.166.174	10.3.166.174
48	10.3.166.175/32	10.3.166.175 – 10.3.166.175	10.3.166.175
49	10.3.166.176/32	10.3.166.176 – 10.3.166.176	10.3.166.176
50	10.3.166.177/32	10.3.166.177 – 10.3.166.177	10.3.166.177
51	10.3.166.178/32	10.3.166.178 – 10.3.166.178	10.3.166.178
52	10.3.166.179/32	10.3.166.179 – 10.3.166.179	10.3.166.179
53	10.3.166.180/32	10.3.166.180 – 10.3.166.180	10.3.166.180
54	10.3.166.181/32	10.3.166.181 – 10.3.166.181	10.3.166.181
55	10.3.166.182/32	10.3.166.182 – 10.3.166.182	10.3.166.182
56	10.3.166.183/32	10.3.166.183 – 10.3.166.183	10.3.166.183
57	10.3.166.184/32	10.3.166.184 – 10.3.166.184	10.3.166.184
58	10.3.166.185/32	10.3.166.185 – 10.3.166.185	10.3.166.185
59	10.3.166.186/32	10.3.166.186 – 10.3.166.186	10.3.166.186
60	10.3.166.187/32	10.3.166.187 – 10.3.166.187	10.3.166.187
61	10.3.166.188/32	10.3.166.188 – 10.3.166.188	10.3.166.188
62	10.3.166.189/32	10.3.166.189 – 10.3.166.189	10.3.166.189
63	10.3.166.190/32	10.3.166.190 – 10.3.166.190	10.3.166.190
64	10.3.166.191/32	10.3.166.191 – 10.3.166.191	10.3.166.191
65	10.3.166.192/32	10.3.166.192 – 10.3.166.192	10.3.166.192
66	10.3.166.193/32	10.3.166.193 – 10.3.166.193	10.3.166.193
67	10.3.166.194/32	10.3.166.194 – 10.3.166.194	10.3.166.194
68	10.3.166.195/32	10.3.166.195 – 10.3.166.195	10.3.166.195
69	10.3.166.196/32	10.3.166.196 – 10.3.166.196	10.3.166.196
70	10.3.166.197/32	10.3.166.197 – 10.3.166.197	10.3.166.197
71	10.3.166.198/32	10.3.166.198 – 10.3.166.198	10.3.166.198
72	10.3.166.199/32	10.3.166.199 – 10.3.166.199	10.3.166.199
73	10.3.166.200/32	10.3.166.200 – 10.3.166.200	10.3.166.200
74	10.3.166.201/32	10.3.166.201 – 10.3.166.201	10.3.166.201
75	10.3.166.202/32	10.3.166.202 – 10.3.166.202	10.3.166.202
76	10.3.166.203/32	10.3.166.203 – 10.3.166.203	10.3.166.203
77	10.3.166.204/32	10.3.166.204 – 10.3.166.204	10.3.166.204
78	10.3.166.205/32	10.3.166.205 – 10.3.166.205	10.3.166.205
79	10.3.166.206/32	10.3.166.206 – 10.3.166.206	10.3.166.206
80	10.3.166.207/32	10.3.166.207 – 10.3.166.207	10.3.166.207
81	10.3.166.208/32	10.3.166.208 – 10.3.166.208	10.3.166.208
82	10.3.166.209/32	10.3.166.209 – 10.3.166.209	10.3.166.209
83	10.3.166.210/32	10.3.166.210 – 10.3.166.210	10.3.166.210
84	10.3.166.211/32	10.3.166.211 – 10.3.166.211	10.3.166.211
85	10.3.166.212/32	10.3.166.212 – 10.3.166.212	10.3.166.212
86	10.3.166.213/32	10.3.166.213 – 10.3.166.213	10.3.166.213
87	10.3.166.214/32	10.3.166.214 – 10.3.166.214	10.3.166.214
88	10.3.166.215/32	10.3.166.215 – 10.3.166.215	10.3.166.215
89	10.3.166.216/32	10.3.166.216 – 10.3.166.216	10.3.166.216
90	10.3.166.217/32	10.3.166.217 – 10.3.166.217	10.3.166.217
91	10.3.166.218/32	10.3.166.218 – 10.3.166.218	10.3.166.218
92	10.3.166.219/32	10.3.166.219 – 10.3.166.219	10.3.166.219
93	10.3.166.220/32	10.3.166.220 – 10.3.166.220	10.3.166.220
94	10.3.166.221/32	10.3.166.221 – 10.3.166.221	10.3.166.221
95	10.3.166.222/32	10.3.166.222 – 10.3.166.222	10.3.166.222
96	10.3.166.223/32	10.3.166.223 – 10.3.166.223	10.3.166.223
97	10.3.166.224/32	10.3.166.224 – 10.3.166.224	10.3.166.224
98	10.3.166.225/32	10.3.166.225 – 10.3.166.225	10.3.166.225
99	10.3.166.226/32	10.3.166.226 – 10.3.166.226	10.3.166.226
100	10.3.166.227/32	10.3.166.227 – 10.3.166.227	10.3.166.227
101	10.3.166.228/32	10.3.166.228 – 10.3.166.228	10.3.166.228
102	10.3.166.229/32	10.3.166.229 – 10.3.166.229	10.3.166.229
103	10.3.166.230/32	10.3.166.230 – 10.3.166.230	10.3.166.230
104	10.3.166.231/32	10.3.166.231 – 10.3.166.231	10.3.166.231
105	10.3.166.232/32	10.3.166.232 – 10.3.166.232	10.3.166.232
106	10.3.166.233/32	10.3.166.233 – 10.3.166.233	10.3.166.233
107	10.3.166.234/32	10.3.166.234 – 10.3.166.234	10.3.166.234
108	10.3.166.235/32	10.3.166.235 – 10.3.166.235	10.3.166.235
109	10.3.166.236/32	10.3.166.236 – 10.3.166.236	10.3.166.236
110	10.3.166.237/32	10.3.166.237 – 10.3.166.237	10.3.166.237
111	10.3.166.238/32	10.3.166.238 – 10.3.166.238	10.3.166.238
112	10.3.166.239/32	10.3.166.239 – 10.3.166.239	10.3.166.239
113	10.3.166.240/32	10.3.166.240 – 10.3.166.240	10.3.166.240
114	10.3.166.241/32	10.3.166.241 – 10.3.166.241	10.3.166.241
115	10.3.166.242/32	10.3.166.242 – 10.3.166.242	10.3.166.242
116	10.3.166.243/32	10.3.166.243 – 10.3.166.243	10.3.166.243
117	10.3.166.244/32	10.3.166.244 – 10.3.166.244	10.3.166.244
118	10.3.166.245/32	10.3.166.245 – 10.3.166.245	10.3.166.245
119	10.3.166.246/32	10.3.166.246 – 10.3.166.246	10.3.166.246
120	10.3.166.247/32	10.3.166.247 – 10.3.166.247	10.3.166.247
121	10.3.166.248/32	10.3.166.248 – 10.3.166.248	10.3.166.248
122	10.3.166.249/32	10.3.166.249 – 10.3.166.249	10.3.166.249
123	10.3.166.250/32	10.3.166.250 – 10.3.166.250	10.3.166.250
124	10.3.166.251/32	10.3.166.251 – 10.3.166.251	10.3.166.251
125	10.3.166.252/32	10.3.166.252 – 10.3.166.252	10.3.166.252
126	10.3.166.253/32	10.3.166.253 – 10.3.166.253	10.3.166.253
127	10.3.166.254/32	10.3.166.254 – 10.3.166.254	10.3.166.254
128	10.3.166.255/32	10.3.166.255 – 10.3.166.255	10.3.166.255

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 →