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)10.2.124.128/25

network10.2.124.128/25

broadcast10.2.124.255

first host10.2.124.129

last host10.2.124.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.2.124.128/25

address00001010.00000010.01111100.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000010.01111100.10000000

broadcast00001010.00000010.01111100.11111111

green = network part, grey = host part

hex0x0a027c80

decimal167935104

reverse dns128.124.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:7c80

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.124.128/32	10.2.124.128 – 10.2.124.128	10.2.124.128
2	10.2.124.129/32	10.2.124.129 – 10.2.124.129	10.2.124.129
3	10.2.124.130/32	10.2.124.130 – 10.2.124.130	10.2.124.130
4	10.2.124.131/32	10.2.124.131 – 10.2.124.131	10.2.124.131
5	10.2.124.132/32	10.2.124.132 – 10.2.124.132	10.2.124.132
6	10.2.124.133/32	10.2.124.133 – 10.2.124.133	10.2.124.133
7	10.2.124.134/32	10.2.124.134 – 10.2.124.134	10.2.124.134
8	10.2.124.135/32	10.2.124.135 – 10.2.124.135	10.2.124.135
9	10.2.124.136/32	10.2.124.136 – 10.2.124.136	10.2.124.136
10	10.2.124.137/32	10.2.124.137 – 10.2.124.137	10.2.124.137
11	10.2.124.138/32	10.2.124.138 – 10.2.124.138	10.2.124.138
12	10.2.124.139/32	10.2.124.139 – 10.2.124.139	10.2.124.139
13	10.2.124.140/32	10.2.124.140 – 10.2.124.140	10.2.124.140
14	10.2.124.141/32	10.2.124.141 – 10.2.124.141	10.2.124.141
15	10.2.124.142/32	10.2.124.142 – 10.2.124.142	10.2.124.142
16	10.2.124.143/32	10.2.124.143 – 10.2.124.143	10.2.124.143
17	10.2.124.144/32	10.2.124.144 – 10.2.124.144	10.2.124.144
18	10.2.124.145/32	10.2.124.145 – 10.2.124.145	10.2.124.145
19	10.2.124.146/32	10.2.124.146 – 10.2.124.146	10.2.124.146
20	10.2.124.147/32	10.2.124.147 – 10.2.124.147	10.2.124.147
21	10.2.124.148/32	10.2.124.148 – 10.2.124.148	10.2.124.148
22	10.2.124.149/32	10.2.124.149 – 10.2.124.149	10.2.124.149
23	10.2.124.150/32	10.2.124.150 – 10.2.124.150	10.2.124.150
24	10.2.124.151/32	10.2.124.151 – 10.2.124.151	10.2.124.151
25	10.2.124.152/32	10.2.124.152 – 10.2.124.152	10.2.124.152
26	10.2.124.153/32	10.2.124.153 – 10.2.124.153	10.2.124.153
27	10.2.124.154/32	10.2.124.154 – 10.2.124.154	10.2.124.154
28	10.2.124.155/32	10.2.124.155 – 10.2.124.155	10.2.124.155
29	10.2.124.156/32	10.2.124.156 – 10.2.124.156	10.2.124.156
30	10.2.124.157/32	10.2.124.157 – 10.2.124.157	10.2.124.157
31	10.2.124.158/32	10.2.124.158 – 10.2.124.158	10.2.124.158
32	10.2.124.159/32	10.2.124.159 – 10.2.124.159	10.2.124.159
33	10.2.124.160/32	10.2.124.160 – 10.2.124.160	10.2.124.160
34	10.2.124.161/32	10.2.124.161 – 10.2.124.161	10.2.124.161
35	10.2.124.162/32	10.2.124.162 – 10.2.124.162	10.2.124.162
36	10.2.124.163/32	10.2.124.163 – 10.2.124.163	10.2.124.163
37	10.2.124.164/32	10.2.124.164 – 10.2.124.164	10.2.124.164
38	10.2.124.165/32	10.2.124.165 – 10.2.124.165	10.2.124.165
39	10.2.124.166/32	10.2.124.166 – 10.2.124.166	10.2.124.166
40	10.2.124.167/32	10.2.124.167 – 10.2.124.167	10.2.124.167
41	10.2.124.168/32	10.2.124.168 – 10.2.124.168	10.2.124.168
42	10.2.124.169/32	10.2.124.169 – 10.2.124.169	10.2.124.169
43	10.2.124.170/32	10.2.124.170 – 10.2.124.170	10.2.124.170
44	10.2.124.171/32	10.2.124.171 – 10.2.124.171	10.2.124.171
45	10.2.124.172/32	10.2.124.172 – 10.2.124.172	10.2.124.172
46	10.2.124.173/32	10.2.124.173 – 10.2.124.173	10.2.124.173
47	10.2.124.174/32	10.2.124.174 – 10.2.124.174	10.2.124.174
48	10.2.124.175/32	10.2.124.175 – 10.2.124.175	10.2.124.175
49	10.2.124.176/32	10.2.124.176 – 10.2.124.176	10.2.124.176
50	10.2.124.177/32	10.2.124.177 – 10.2.124.177	10.2.124.177
51	10.2.124.178/32	10.2.124.178 – 10.2.124.178	10.2.124.178
52	10.2.124.179/32	10.2.124.179 – 10.2.124.179	10.2.124.179
53	10.2.124.180/32	10.2.124.180 – 10.2.124.180	10.2.124.180
54	10.2.124.181/32	10.2.124.181 – 10.2.124.181	10.2.124.181
55	10.2.124.182/32	10.2.124.182 – 10.2.124.182	10.2.124.182
56	10.2.124.183/32	10.2.124.183 – 10.2.124.183	10.2.124.183
57	10.2.124.184/32	10.2.124.184 – 10.2.124.184	10.2.124.184
58	10.2.124.185/32	10.2.124.185 – 10.2.124.185	10.2.124.185
59	10.2.124.186/32	10.2.124.186 – 10.2.124.186	10.2.124.186
60	10.2.124.187/32	10.2.124.187 – 10.2.124.187	10.2.124.187
61	10.2.124.188/32	10.2.124.188 – 10.2.124.188	10.2.124.188
62	10.2.124.189/32	10.2.124.189 – 10.2.124.189	10.2.124.189
63	10.2.124.190/32	10.2.124.190 – 10.2.124.190	10.2.124.190
64	10.2.124.191/32	10.2.124.191 – 10.2.124.191	10.2.124.191
65	10.2.124.192/32	10.2.124.192 – 10.2.124.192	10.2.124.192
66	10.2.124.193/32	10.2.124.193 – 10.2.124.193	10.2.124.193
67	10.2.124.194/32	10.2.124.194 – 10.2.124.194	10.2.124.194
68	10.2.124.195/32	10.2.124.195 – 10.2.124.195	10.2.124.195
69	10.2.124.196/32	10.2.124.196 – 10.2.124.196	10.2.124.196
70	10.2.124.197/32	10.2.124.197 – 10.2.124.197	10.2.124.197
71	10.2.124.198/32	10.2.124.198 – 10.2.124.198	10.2.124.198
72	10.2.124.199/32	10.2.124.199 – 10.2.124.199	10.2.124.199
73	10.2.124.200/32	10.2.124.200 – 10.2.124.200	10.2.124.200
74	10.2.124.201/32	10.2.124.201 – 10.2.124.201	10.2.124.201
75	10.2.124.202/32	10.2.124.202 – 10.2.124.202	10.2.124.202
76	10.2.124.203/32	10.2.124.203 – 10.2.124.203	10.2.124.203
77	10.2.124.204/32	10.2.124.204 – 10.2.124.204	10.2.124.204
78	10.2.124.205/32	10.2.124.205 – 10.2.124.205	10.2.124.205
79	10.2.124.206/32	10.2.124.206 – 10.2.124.206	10.2.124.206
80	10.2.124.207/32	10.2.124.207 – 10.2.124.207	10.2.124.207
81	10.2.124.208/32	10.2.124.208 – 10.2.124.208	10.2.124.208
82	10.2.124.209/32	10.2.124.209 – 10.2.124.209	10.2.124.209
83	10.2.124.210/32	10.2.124.210 – 10.2.124.210	10.2.124.210
84	10.2.124.211/32	10.2.124.211 – 10.2.124.211	10.2.124.211
85	10.2.124.212/32	10.2.124.212 – 10.2.124.212	10.2.124.212
86	10.2.124.213/32	10.2.124.213 – 10.2.124.213	10.2.124.213
87	10.2.124.214/32	10.2.124.214 – 10.2.124.214	10.2.124.214
88	10.2.124.215/32	10.2.124.215 – 10.2.124.215	10.2.124.215
89	10.2.124.216/32	10.2.124.216 – 10.2.124.216	10.2.124.216
90	10.2.124.217/32	10.2.124.217 – 10.2.124.217	10.2.124.217
91	10.2.124.218/32	10.2.124.218 – 10.2.124.218	10.2.124.218
92	10.2.124.219/32	10.2.124.219 – 10.2.124.219	10.2.124.219
93	10.2.124.220/32	10.2.124.220 – 10.2.124.220	10.2.124.220
94	10.2.124.221/32	10.2.124.221 – 10.2.124.221	10.2.124.221
95	10.2.124.222/32	10.2.124.222 – 10.2.124.222	10.2.124.222
96	10.2.124.223/32	10.2.124.223 – 10.2.124.223	10.2.124.223
97	10.2.124.224/32	10.2.124.224 – 10.2.124.224	10.2.124.224
98	10.2.124.225/32	10.2.124.225 – 10.2.124.225	10.2.124.225
99	10.2.124.226/32	10.2.124.226 – 10.2.124.226	10.2.124.226
100	10.2.124.227/32	10.2.124.227 – 10.2.124.227	10.2.124.227
101	10.2.124.228/32	10.2.124.228 – 10.2.124.228	10.2.124.228
102	10.2.124.229/32	10.2.124.229 – 10.2.124.229	10.2.124.229
103	10.2.124.230/32	10.2.124.230 – 10.2.124.230	10.2.124.230
104	10.2.124.231/32	10.2.124.231 – 10.2.124.231	10.2.124.231
105	10.2.124.232/32	10.2.124.232 – 10.2.124.232	10.2.124.232
106	10.2.124.233/32	10.2.124.233 – 10.2.124.233	10.2.124.233
107	10.2.124.234/32	10.2.124.234 – 10.2.124.234	10.2.124.234
108	10.2.124.235/32	10.2.124.235 – 10.2.124.235	10.2.124.235
109	10.2.124.236/32	10.2.124.236 – 10.2.124.236	10.2.124.236
110	10.2.124.237/32	10.2.124.237 – 10.2.124.237	10.2.124.237
111	10.2.124.238/32	10.2.124.238 – 10.2.124.238	10.2.124.238
112	10.2.124.239/32	10.2.124.239 – 10.2.124.239	10.2.124.239
113	10.2.124.240/32	10.2.124.240 – 10.2.124.240	10.2.124.240
114	10.2.124.241/32	10.2.124.241 – 10.2.124.241	10.2.124.241
115	10.2.124.242/32	10.2.124.242 – 10.2.124.242	10.2.124.242
116	10.2.124.243/32	10.2.124.243 – 10.2.124.243	10.2.124.243
117	10.2.124.244/32	10.2.124.244 – 10.2.124.244	10.2.124.244
118	10.2.124.245/32	10.2.124.245 – 10.2.124.245	10.2.124.245
119	10.2.124.246/32	10.2.124.246 – 10.2.124.246	10.2.124.246
120	10.2.124.247/32	10.2.124.247 – 10.2.124.247	10.2.124.247
121	10.2.124.248/32	10.2.124.248 – 10.2.124.248	10.2.124.248
122	10.2.124.249/32	10.2.124.249 – 10.2.124.249	10.2.124.249
123	10.2.124.250/32	10.2.124.250 – 10.2.124.250	10.2.124.250
124	10.2.124.251/32	10.2.124.251 – 10.2.124.251	10.2.124.251
125	10.2.124.252/32	10.2.124.252 – 10.2.124.252	10.2.124.252
126	10.2.124.253/32	10.2.124.253 – 10.2.124.253	10.2.124.253
127	10.2.124.254/32	10.2.124.254 – 10.2.124.254	10.2.124.254
128	10.2.124.255/32	10.2.124.255 – 10.2.124.255	10.2.124.255

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 →