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)10.2.30.128/25

network10.2.30.128/25

broadcast10.2.30.255

first host10.2.30.129

last host10.2.30.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.2.30.128/25

address00001010.00000010.00011110.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000010.00011110.10000000

broadcast00001010.00000010.00011110.11111111

green = network part, grey = host part

hex0x0a021e80

decimal167911040

reverse dns128.30.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:1e80

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.30.128/32	10.2.30.128 – 10.2.30.128	10.2.30.128
2	10.2.30.129/32	10.2.30.129 – 10.2.30.129	10.2.30.129
3	10.2.30.130/32	10.2.30.130 – 10.2.30.130	10.2.30.130
4	10.2.30.131/32	10.2.30.131 – 10.2.30.131	10.2.30.131
5	10.2.30.132/32	10.2.30.132 – 10.2.30.132	10.2.30.132
6	10.2.30.133/32	10.2.30.133 – 10.2.30.133	10.2.30.133
7	10.2.30.134/32	10.2.30.134 – 10.2.30.134	10.2.30.134
8	10.2.30.135/32	10.2.30.135 – 10.2.30.135	10.2.30.135
9	10.2.30.136/32	10.2.30.136 – 10.2.30.136	10.2.30.136
10	10.2.30.137/32	10.2.30.137 – 10.2.30.137	10.2.30.137
11	10.2.30.138/32	10.2.30.138 – 10.2.30.138	10.2.30.138
12	10.2.30.139/32	10.2.30.139 – 10.2.30.139	10.2.30.139
13	10.2.30.140/32	10.2.30.140 – 10.2.30.140	10.2.30.140
14	10.2.30.141/32	10.2.30.141 – 10.2.30.141	10.2.30.141
15	10.2.30.142/32	10.2.30.142 – 10.2.30.142	10.2.30.142
16	10.2.30.143/32	10.2.30.143 – 10.2.30.143	10.2.30.143
17	10.2.30.144/32	10.2.30.144 – 10.2.30.144	10.2.30.144
18	10.2.30.145/32	10.2.30.145 – 10.2.30.145	10.2.30.145
19	10.2.30.146/32	10.2.30.146 – 10.2.30.146	10.2.30.146
20	10.2.30.147/32	10.2.30.147 – 10.2.30.147	10.2.30.147
21	10.2.30.148/32	10.2.30.148 – 10.2.30.148	10.2.30.148
22	10.2.30.149/32	10.2.30.149 – 10.2.30.149	10.2.30.149
23	10.2.30.150/32	10.2.30.150 – 10.2.30.150	10.2.30.150
24	10.2.30.151/32	10.2.30.151 – 10.2.30.151	10.2.30.151
25	10.2.30.152/32	10.2.30.152 – 10.2.30.152	10.2.30.152
26	10.2.30.153/32	10.2.30.153 – 10.2.30.153	10.2.30.153
27	10.2.30.154/32	10.2.30.154 – 10.2.30.154	10.2.30.154
28	10.2.30.155/32	10.2.30.155 – 10.2.30.155	10.2.30.155
29	10.2.30.156/32	10.2.30.156 – 10.2.30.156	10.2.30.156
30	10.2.30.157/32	10.2.30.157 – 10.2.30.157	10.2.30.157
31	10.2.30.158/32	10.2.30.158 – 10.2.30.158	10.2.30.158
32	10.2.30.159/32	10.2.30.159 – 10.2.30.159	10.2.30.159
33	10.2.30.160/32	10.2.30.160 – 10.2.30.160	10.2.30.160
34	10.2.30.161/32	10.2.30.161 – 10.2.30.161	10.2.30.161
35	10.2.30.162/32	10.2.30.162 – 10.2.30.162	10.2.30.162
36	10.2.30.163/32	10.2.30.163 – 10.2.30.163	10.2.30.163
37	10.2.30.164/32	10.2.30.164 – 10.2.30.164	10.2.30.164
38	10.2.30.165/32	10.2.30.165 – 10.2.30.165	10.2.30.165
39	10.2.30.166/32	10.2.30.166 – 10.2.30.166	10.2.30.166
40	10.2.30.167/32	10.2.30.167 – 10.2.30.167	10.2.30.167
41	10.2.30.168/32	10.2.30.168 – 10.2.30.168	10.2.30.168
42	10.2.30.169/32	10.2.30.169 – 10.2.30.169	10.2.30.169
43	10.2.30.170/32	10.2.30.170 – 10.2.30.170	10.2.30.170
44	10.2.30.171/32	10.2.30.171 – 10.2.30.171	10.2.30.171
45	10.2.30.172/32	10.2.30.172 – 10.2.30.172	10.2.30.172
46	10.2.30.173/32	10.2.30.173 – 10.2.30.173	10.2.30.173
47	10.2.30.174/32	10.2.30.174 – 10.2.30.174	10.2.30.174
48	10.2.30.175/32	10.2.30.175 – 10.2.30.175	10.2.30.175
49	10.2.30.176/32	10.2.30.176 – 10.2.30.176	10.2.30.176
50	10.2.30.177/32	10.2.30.177 – 10.2.30.177	10.2.30.177
51	10.2.30.178/32	10.2.30.178 – 10.2.30.178	10.2.30.178
52	10.2.30.179/32	10.2.30.179 – 10.2.30.179	10.2.30.179
53	10.2.30.180/32	10.2.30.180 – 10.2.30.180	10.2.30.180
54	10.2.30.181/32	10.2.30.181 – 10.2.30.181	10.2.30.181
55	10.2.30.182/32	10.2.30.182 – 10.2.30.182	10.2.30.182
56	10.2.30.183/32	10.2.30.183 – 10.2.30.183	10.2.30.183
57	10.2.30.184/32	10.2.30.184 – 10.2.30.184	10.2.30.184
58	10.2.30.185/32	10.2.30.185 – 10.2.30.185	10.2.30.185
59	10.2.30.186/32	10.2.30.186 – 10.2.30.186	10.2.30.186
60	10.2.30.187/32	10.2.30.187 – 10.2.30.187	10.2.30.187
61	10.2.30.188/32	10.2.30.188 – 10.2.30.188	10.2.30.188
62	10.2.30.189/32	10.2.30.189 – 10.2.30.189	10.2.30.189
63	10.2.30.190/32	10.2.30.190 – 10.2.30.190	10.2.30.190
64	10.2.30.191/32	10.2.30.191 – 10.2.30.191	10.2.30.191
65	10.2.30.192/32	10.2.30.192 – 10.2.30.192	10.2.30.192
66	10.2.30.193/32	10.2.30.193 – 10.2.30.193	10.2.30.193
67	10.2.30.194/32	10.2.30.194 – 10.2.30.194	10.2.30.194
68	10.2.30.195/32	10.2.30.195 – 10.2.30.195	10.2.30.195
69	10.2.30.196/32	10.2.30.196 – 10.2.30.196	10.2.30.196
70	10.2.30.197/32	10.2.30.197 – 10.2.30.197	10.2.30.197
71	10.2.30.198/32	10.2.30.198 – 10.2.30.198	10.2.30.198
72	10.2.30.199/32	10.2.30.199 – 10.2.30.199	10.2.30.199
73	10.2.30.200/32	10.2.30.200 – 10.2.30.200	10.2.30.200
74	10.2.30.201/32	10.2.30.201 – 10.2.30.201	10.2.30.201
75	10.2.30.202/32	10.2.30.202 – 10.2.30.202	10.2.30.202
76	10.2.30.203/32	10.2.30.203 – 10.2.30.203	10.2.30.203
77	10.2.30.204/32	10.2.30.204 – 10.2.30.204	10.2.30.204
78	10.2.30.205/32	10.2.30.205 – 10.2.30.205	10.2.30.205
79	10.2.30.206/32	10.2.30.206 – 10.2.30.206	10.2.30.206
80	10.2.30.207/32	10.2.30.207 – 10.2.30.207	10.2.30.207
81	10.2.30.208/32	10.2.30.208 – 10.2.30.208	10.2.30.208
82	10.2.30.209/32	10.2.30.209 – 10.2.30.209	10.2.30.209
83	10.2.30.210/32	10.2.30.210 – 10.2.30.210	10.2.30.210
84	10.2.30.211/32	10.2.30.211 – 10.2.30.211	10.2.30.211
85	10.2.30.212/32	10.2.30.212 – 10.2.30.212	10.2.30.212
86	10.2.30.213/32	10.2.30.213 – 10.2.30.213	10.2.30.213
87	10.2.30.214/32	10.2.30.214 – 10.2.30.214	10.2.30.214
88	10.2.30.215/32	10.2.30.215 – 10.2.30.215	10.2.30.215
89	10.2.30.216/32	10.2.30.216 – 10.2.30.216	10.2.30.216
90	10.2.30.217/32	10.2.30.217 – 10.2.30.217	10.2.30.217
91	10.2.30.218/32	10.2.30.218 – 10.2.30.218	10.2.30.218
92	10.2.30.219/32	10.2.30.219 – 10.2.30.219	10.2.30.219
93	10.2.30.220/32	10.2.30.220 – 10.2.30.220	10.2.30.220
94	10.2.30.221/32	10.2.30.221 – 10.2.30.221	10.2.30.221
95	10.2.30.222/32	10.2.30.222 – 10.2.30.222	10.2.30.222
96	10.2.30.223/32	10.2.30.223 – 10.2.30.223	10.2.30.223
97	10.2.30.224/32	10.2.30.224 – 10.2.30.224	10.2.30.224
98	10.2.30.225/32	10.2.30.225 – 10.2.30.225	10.2.30.225
99	10.2.30.226/32	10.2.30.226 – 10.2.30.226	10.2.30.226
100	10.2.30.227/32	10.2.30.227 – 10.2.30.227	10.2.30.227
101	10.2.30.228/32	10.2.30.228 – 10.2.30.228	10.2.30.228
102	10.2.30.229/32	10.2.30.229 – 10.2.30.229	10.2.30.229
103	10.2.30.230/32	10.2.30.230 – 10.2.30.230	10.2.30.230
104	10.2.30.231/32	10.2.30.231 – 10.2.30.231	10.2.30.231
105	10.2.30.232/32	10.2.30.232 – 10.2.30.232	10.2.30.232
106	10.2.30.233/32	10.2.30.233 – 10.2.30.233	10.2.30.233
107	10.2.30.234/32	10.2.30.234 – 10.2.30.234	10.2.30.234
108	10.2.30.235/32	10.2.30.235 – 10.2.30.235	10.2.30.235
109	10.2.30.236/32	10.2.30.236 – 10.2.30.236	10.2.30.236
110	10.2.30.237/32	10.2.30.237 – 10.2.30.237	10.2.30.237
111	10.2.30.238/32	10.2.30.238 – 10.2.30.238	10.2.30.238
112	10.2.30.239/32	10.2.30.239 – 10.2.30.239	10.2.30.239
113	10.2.30.240/32	10.2.30.240 – 10.2.30.240	10.2.30.240
114	10.2.30.241/32	10.2.30.241 – 10.2.30.241	10.2.30.241
115	10.2.30.242/32	10.2.30.242 – 10.2.30.242	10.2.30.242
116	10.2.30.243/32	10.2.30.243 – 10.2.30.243	10.2.30.243
117	10.2.30.244/32	10.2.30.244 – 10.2.30.244	10.2.30.244
118	10.2.30.245/32	10.2.30.245 – 10.2.30.245	10.2.30.245
119	10.2.30.246/32	10.2.30.246 – 10.2.30.246	10.2.30.246
120	10.2.30.247/32	10.2.30.247 – 10.2.30.247	10.2.30.247
121	10.2.30.248/32	10.2.30.248 – 10.2.30.248	10.2.30.248
122	10.2.30.249/32	10.2.30.249 – 10.2.30.249	10.2.30.249
123	10.2.30.250/32	10.2.30.250 – 10.2.30.250	10.2.30.250
124	10.2.30.251/32	10.2.30.251 – 10.2.30.251	10.2.30.251
125	10.2.30.252/32	10.2.30.252 – 10.2.30.252	10.2.30.252
126	10.2.30.253/32	10.2.30.253 – 10.2.30.253	10.2.30.253
127	10.2.30.254/32	10.2.30.254 – 10.2.30.254	10.2.30.254
128	10.2.30.255/32	10.2.30.255 – 10.2.30.255	10.2.30.255

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 →