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)10.2.243.128/25

network10.2.243.128/25

broadcast10.2.243.255

first host10.2.243.129

last host10.2.243.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.2.243.128/25

address00001010.00000010.11110011.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000010.11110011.10000000

broadcast00001010.00000010.11110011.11111111

green = network part, grey = host part

hex0x0a02f380

decimal167965568

reverse dns128.243.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:f380

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.243.128/32	10.2.243.128 – 10.2.243.128	10.2.243.128
2	10.2.243.129/32	10.2.243.129 – 10.2.243.129	10.2.243.129
3	10.2.243.130/32	10.2.243.130 – 10.2.243.130	10.2.243.130
4	10.2.243.131/32	10.2.243.131 – 10.2.243.131	10.2.243.131
5	10.2.243.132/32	10.2.243.132 – 10.2.243.132	10.2.243.132
6	10.2.243.133/32	10.2.243.133 – 10.2.243.133	10.2.243.133
7	10.2.243.134/32	10.2.243.134 – 10.2.243.134	10.2.243.134
8	10.2.243.135/32	10.2.243.135 – 10.2.243.135	10.2.243.135
9	10.2.243.136/32	10.2.243.136 – 10.2.243.136	10.2.243.136
10	10.2.243.137/32	10.2.243.137 – 10.2.243.137	10.2.243.137
11	10.2.243.138/32	10.2.243.138 – 10.2.243.138	10.2.243.138
12	10.2.243.139/32	10.2.243.139 – 10.2.243.139	10.2.243.139
13	10.2.243.140/32	10.2.243.140 – 10.2.243.140	10.2.243.140
14	10.2.243.141/32	10.2.243.141 – 10.2.243.141	10.2.243.141
15	10.2.243.142/32	10.2.243.142 – 10.2.243.142	10.2.243.142
16	10.2.243.143/32	10.2.243.143 – 10.2.243.143	10.2.243.143
17	10.2.243.144/32	10.2.243.144 – 10.2.243.144	10.2.243.144
18	10.2.243.145/32	10.2.243.145 – 10.2.243.145	10.2.243.145
19	10.2.243.146/32	10.2.243.146 – 10.2.243.146	10.2.243.146
20	10.2.243.147/32	10.2.243.147 – 10.2.243.147	10.2.243.147
21	10.2.243.148/32	10.2.243.148 – 10.2.243.148	10.2.243.148
22	10.2.243.149/32	10.2.243.149 – 10.2.243.149	10.2.243.149
23	10.2.243.150/32	10.2.243.150 – 10.2.243.150	10.2.243.150
24	10.2.243.151/32	10.2.243.151 – 10.2.243.151	10.2.243.151
25	10.2.243.152/32	10.2.243.152 – 10.2.243.152	10.2.243.152
26	10.2.243.153/32	10.2.243.153 – 10.2.243.153	10.2.243.153
27	10.2.243.154/32	10.2.243.154 – 10.2.243.154	10.2.243.154
28	10.2.243.155/32	10.2.243.155 – 10.2.243.155	10.2.243.155
29	10.2.243.156/32	10.2.243.156 – 10.2.243.156	10.2.243.156
30	10.2.243.157/32	10.2.243.157 – 10.2.243.157	10.2.243.157
31	10.2.243.158/32	10.2.243.158 – 10.2.243.158	10.2.243.158
32	10.2.243.159/32	10.2.243.159 – 10.2.243.159	10.2.243.159
33	10.2.243.160/32	10.2.243.160 – 10.2.243.160	10.2.243.160
34	10.2.243.161/32	10.2.243.161 – 10.2.243.161	10.2.243.161
35	10.2.243.162/32	10.2.243.162 – 10.2.243.162	10.2.243.162
36	10.2.243.163/32	10.2.243.163 – 10.2.243.163	10.2.243.163
37	10.2.243.164/32	10.2.243.164 – 10.2.243.164	10.2.243.164
38	10.2.243.165/32	10.2.243.165 – 10.2.243.165	10.2.243.165
39	10.2.243.166/32	10.2.243.166 – 10.2.243.166	10.2.243.166
40	10.2.243.167/32	10.2.243.167 – 10.2.243.167	10.2.243.167
41	10.2.243.168/32	10.2.243.168 – 10.2.243.168	10.2.243.168
42	10.2.243.169/32	10.2.243.169 – 10.2.243.169	10.2.243.169
43	10.2.243.170/32	10.2.243.170 – 10.2.243.170	10.2.243.170
44	10.2.243.171/32	10.2.243.171 – 10.2.243.171	10.2.243.171
45	10.2.243.172/32	10.2.243.172 – 10.2.243.172	10.2.243.172
46	10.2.243.173/32	10.2.243.173 – 10.2.243.173	10.2.243.173
47	10.2.243.174/32	10.2.243.174 – 10.2.243.174	10.2.243.174
48	10.2.243.175/32	10.2.243.175 – 10.2.243.175	10.2.243.175
49	10.2.243.176/32	10.2.243.176 – 10.2.243.176	10.2.243.176
50	10.2.243.177/32	10.2.243.177 – 10.2.243.177	10.2.243.177
51	10.2.243.178/32	10.2.243.178 – 10.2.243.178	10.2.243.178
52	10.2.243.179/32	10.2.243.179 – 10.2.243.179	10.2.243.179
53	10.2.243.180/32	10.2.243.180 – 10.2.243.180	10.2.243.180
54	10.2.243.181/32	10.2.243.181 – 10.2.243.181	10.2.243.181
55	10.2.243.182/32	10.2.243.182 – 10.2.243.182	10.2.243.182
56	10.2.243.183/32	10.2.243.183 – 10.2.243.183	10.2.243.183
57	10.2.243.184/32	10.2.243.184 – 10.2.243.184	10.2.243.184
58	10.2.243.185/32	10.2.243.185 – 10.2.243.185	10.2.243.185
59	10.2.243.186/32	10.2.243.186 – 10.2.243.186	10.2.243.186
60	10.2.243.187/32	10.2.243.187 – 10.2.243.187	10.2.243.187
61	10.2.243.188/32	10.2.243.188 – 10.2.243.188	10.2.243.188
62	10.2.243.189/32	10.2.243.189 – 10.2.243.189	10.2.243.189
63	10.2.243.190/32	10.2.243.190 – 10.2.243.190	10.2.243.190
64	10.2.243.191/32	10.2.243.191 – 10.2.243.191	10.2.243.191
65	10.2.243.192/32	10.2.243.192 – 10.2.243.192	10.2.243.192
66	10.2.243.193/32	10.2.243.193 – 10.2.243.193	10.2.243.193
67	10.2.243.194/32	10.2.243.194 – 10.2.243.194	10.2.243.194
68	10.2.243.195/32	10.2.243.195 – 10.2.243.195	10.2.243.195
69	10.2.243.196/32	10.2.243.196 – 10.2.243.196	10.2.243.196
70	10.2.243.197/32	10.2.243.197 – 10.2.243.197	10.2.243.197
71	10.2.243.198/32	10.2.243.198 – 10.2.243.198	10.2.243.198
72	10.2.243.199/32	10.2.243.199 – 10.2.243.199	10.2.243.199
73	10.2.243.200/32	10.2.243.200 – 10.2.243.200	10.2.243.200
74	10.2.243.201/32	10.2.243.201 – 10.2.243.201	10.2.243.201
75	10.2.243.202/32	10.2.243.202 – 10.2.243.202	10.2.243.202
76	10.2.243.203/32	10.2.243.203 – 10.2.243.203	10.2.243.203
77	10.2.243.204/32	10.2.243.204 – 10.2.243.204	10.2.243.204
78	10.2.243.205/32	10.2.243.205 – 10.2.243.205	10.2.243.205
79	10.2.243.206/32	10.2.243.206 – 10.2.243.206	10.2.243.206
80	10.2.243.207/32	10.2.243.207 – 10.2.243.207	10.2.243.207
81	10.2.243.208/32	10.2.243.208 – 10.2.243.208	10.2.243.208
82	10.2.243.209/32	10.2.243.209 – 10.2.243.209	10.2.243.209
83	10.2.243.210/32	10.2.243.210 – 10.2.243.210	10.2.243.210
84	10.2.243.211/32	10.2.243.211 – 10.2.243.211	10.2.243.211
85	10.2.243.212/32	10.2.243.212 – 10.2.243.212	10.2.243.212
86	10.2.243.213/32	10.2.243.213 – 10.2.243.213	10.2.243.213
87	10.2.243.214/32	10.2.243.214 – 10.2.243.214	10.2.243.214
88	10.2.243.215/32	10.2.243.215 – 10.2.243.215	10.2.243.215
89	10.2.243.216/32	10.2.243.216 – 10.2.243.216	10.2.243.216
90	10.2.243.217/32	10.2.243.217 – 10.2.243.217	10.2.243.217
91	10.2.243.218/32	10.2.243.218 – 10.2.243.218	10.2.243.218
92	10.2.243.219/32	10.2.243.219 – 10.2.243.219	10.2.243.219
93	10.2.243.220/32	10.2.243.220 – 10.2.243.220	10.2.243.220
94	10.2.243.221/32	10.2.243.221 – 10.2.243.221	10.2.243.221
95	10.2.243.222/32	10.2.243.222 – 10.2.243.222	10.2.243.222
96	10.2.243.223/32	10.2.243.223 – 10.2.243.223	10.2.243.223
97	10.2.243.224/32	10.2.243.224 – 10.2.243.224	10.2.243.224
98	10.2.243.225/32	10.2.243.225 – 10.2.243.225	10.2.243.225
99	10.2.243.226/32	10.2.243.226 – 10.2.243.226	10.2.243.226
100	10.2.243.227/32	10.2.243.227 – 10.2.243.227	10.2.243.227
101	10.2.243.228/32	10.2.243.228 – 10.2.243.228	10.2.243.228
102	10.2.243.229/32	10.2.243.229 – 10.2.243.229	10.2.243.229
103	10.2.243.230/32	10.2.243.230 – 10.2.243.230	10.2.243.230
104	10.2.243.231/32	10.2.243.231 – 10.2.243.231	10.2.243.231
105	10.2.243.232/32	10.2.243.232 – 10.2.243.232	10.2.243.232
106	10.2.243.233/32	10.2.243.233 – 10.2.243.233	10.2.243.233
107	10.2.243.234/32	10.2.243.234 – 10.2.243.234	10.2.243.234
108	10.2.243.235/32	10.2.243.235 – 10.2.243.235	10.2.243.235
109	10.2.243.236/32	10.2.243.236 – 10.2.243.236	10.2.243.236
110	10.2.243.237/32	10.2.243.237 – 10.2.243.237	10.2.243.237
111	10.2.243.238/32	10.2.243.238 – 10.2.243.238	10.2.243.238
112	10.2.243.239/32	10.2.243.239 – 10.2.243.239	10.2.243.239
113	10.2.243.240/32	10.2.243.240 – 10.2.243.240	10.2.243.240
114	10.2.243.241/32	10.2.243.241 – 10.2.243.241	10.2.243.241
115	10.2.243.242/32	10.2.243.242 – 10.2.243.242	10.2.243.242
116	10.2.243.243/32	10.2.243.243 – 10.2.243.243	10.2.243.243
117	10.2.243.244/32	10.2.243.244 – 10.2.243.244	10.2.243.244
118	10.2.243.245/32	10.2.243.245 – 10.2.243.245	10.2.243.245
119	10.2.243.246/32	10.2.243.246 – 10.2.243.246	10.2.243.246
120	10.2.243.247/32	10.2.243.247 – 10.2.243.247	10.2.243.247
121	10.2.243.248/32	10.2.243.248 – 10.2.243.248	10.2.243.248
122	10.2.243.249/32	10.2.243.249 – 10.2.243.249	10.2.243.249
123	10.2.243.250/32	10.2.243.250 – 10.2.243.250	10.2.243.250
124	10.2.243.251/32	10.2.243.251 – 10.2.243.251	10.2.243.251
125	10.2.243.252/32	10.2.243.252 – 10.2.243.252	10.2.243.252
126	10.2.243.253/32	10.2.243.253 – 10.2.243.253	10.2.243.253
127	10.2.243.254/32	10.2.243.254 – 10.2.243.254	10.2.243.254
128	10.2.243.255/32	10.2.243.255 – 10.2.243.255	10.2.243.255

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 →