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)10.2.40.128/25

network10.2.40.128/25

broadcast10.2.40.255

first host10.2.40.129

last host10.2.40.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.2.40.128/25

address00001010.00000010.00101000.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000010.00101000.10000000

broadcast00001010.00000010.00101000.11111111

green = network part, grey = host part

hex0x0a022880

decimal167913600

reverse dns128.40.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:2880

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.40.128/32	10.2.40.128 – 10.2.40.128	10.2.40.128
2	10.2.40.129/32	10.2.40.129 – 10.2.40.129	10.2.40.129
3	10.2.40.130/32	10.2.40.130 – 10.2.40.130	10.2.40.130
4	10.2.40.131/32	10.2.40.131 – 10.2.40.131	10.2.40.131
5	10.2.40.132/32	10.2.40.132 – 10.2.40.132	10.2.40.132
6	10.2.40.133/32	10.2.40.133 – 10.2.40.133	10.2.40.133
7	10.2.40.134/32	10.2.40.134 – 10.2.40.134	10.2.40.134
8	10.2.40.135/32	10.2.40.135 – 10.2.40.135	10.2.40.135
9	10.2.40.136/32	10.2.40.136 – 10.2.40.136	10.2.40.136
10	10.2.40.137/32	10.2.40.137 – 10.2.40.137	10.2.40.137
11	10.2.40.138/32	10.2.40.138 – 10.2.40.138	10.2.40.138
12	10.2.40.139/32	10.2.40.139 – 10.2.40.139	10.2.40.139
13	10.2.40.140/32	10.2.40.140 – 10.2.40.140	10.2.40.140
14	10.2.40.141/32	10.2.40.141 – 10.2.40.141	10.2.40.141
15	10.2.40.142/32	10.2.40.142 – 10.2.40.142	10.2.40.142
16	10.2.40.143/32	10.2.40.143 – 10.2.40.143	10.2.40.143
17	10.2.40.144/32	10.2.40.144 – 10.2.40.144	10.2.40.144
18	10.2.40.145/32	10.2.40.145 – 10.2.40.145	10.2.40.145
19	10.2.40.146/32	10.2.40.146 – 10.2.40.146	10.2.40.146
20	10.2.40.147/32	10.2.40.147 – 10.2.40.147	10.2.40.147
21	10.2.40.148/32	10.2.40.148 – 10.2.40.148	10.2.40.148
22	10.2.40.149/32	10.2.40.149 – 10.2.40.149	10.2.40.149
23	10.2.40.150/32	10.2.40.150 – 10.2.40.150	10.2.40.150
24	10.2.40.151/32	10.2.40.151 – 10.2.40.151	10.2.40.151
25	10.2.40.152/32	10.2.40.152 – 10.2.40.152	10.2.40.152
26	10.2.40.153/32	10.2.40.153 – 10.2.40.153	10.2.40.153
27	10.2.40.154/32	10.2.40.154 – 10.2.40.154	10.2.40.154
28	10.2.40.155/32	10.2.40.155 – 10.2.40.155	10.2.40.155
29	10.2.40.156/32	10.2.40.156 – 10.2.40.156	10.2.40.156
30	10.2.40.157/32	10.2.40.157 – 10.2.40.157	10.2.40.157
31	10.2.40.158/32	10.2.40.158 – 10.2.40.158	10.2.40.158
32	10.2.40.159/32	10.2.40.159 – 10.2.40.159	10.2.40.159
33	10.2.40.160/32	10.2.40.160 – 10.2.40.160	10.2.40.160
34	10.2.40.161/32	10.2.40.161 – 10.2.40.161	10.2.40.161
35	10.2.40.162/32	10.2.40.162 – 10.2.40.162	10.2.40.162
36	10.2.40.163/32	10.2.40.163 – 10.2.40.163	10.2.40.163
37	10.2.40.164/32	10.2.40.164 – 10.2.40.164	10.2.40.164
38	10.2.40.165/32	10.2.40.165 – 10.2.40.165	10.2.40.165
39	10.2.40.166/32	10.2.40.166 – 10.2.40.166	10.2.40.166
40	10.2.40.167/32	10.2.40.167 – 10.2.40.167	10.2.40.167
41	10.2.40.168/32	10.2.40.168 – 10.2.40.168	10.2.40.168
42	10.2.40.169/32	10.2.40.169 – 10.2.40.169	10.2.40.169
43	10.2.40.170/32	10.2.40.170 – 10.2.40.170	10.2.40.170
44	10.2.40.171/32	10.2.40.171 – 10.2.40.171	10.2.40.171
45	10.2.40.172/32	10.2.40.172 – 10.2.40.172	10.2.40.172
46	10.2.40.173/32	10.2.40.173 – 10.2.40.173	10.2.40.173
47	10.2.40.174/32	10.2.40.174 – 10.2.40.174	10.2.40.174
48	10.2.40.175/32	10.2.40.175 – 10.2.40.175	10.2.40.175
49	10.2.40.176/32	10.2.40.176 – 10.2.40.176	10.2.40.176
50	10.2.40.177/32	10.2.40.177 – 10.2.40.177	10.2.40.177
51	10.2.40.178/32	10.2.40.178 – 10.2.40.178	10.2.40.178
52	10.2.40.179/32	10.2.40.179 – 10.2.40.179	10.2.40.179
53	10.2.40.180/32	10.2.40.180 – 10.2.40.180	10.2.40.180
54	10.2.40.181/32	10.2.40.181 – 10.2.40.181	10.2.40.181
55	10.2.40.182/32	10.2.40.182 – 10.2.40.182	10.2.40.182
56	10.2.40.183/32	10.2.40.183 – 10.2.40.183	10.2.40.183
57	10.2.40.184/32	10.2.40.184 – 10.2.40.184	10.2.40.184
58	10.2.40.185/32	10.2.40.185 – 10.2.40.185	10.2.40.185
59	10.2.40.186/32	10.2.40.186 – 10.2.40.186	10.2.40.186
60	10.2.40.187/32	10.2.40.187 – 10.2.40.187	10.2.40.187
61	10.2.40.188/32	10.2.40.188 – 10.2.40.188	10.2.40.188
62	10.2.40.189/32	10.2.40.189 – 10.2.40.189	10.2.40.189
63	10.2.40.190/32	10.2.40.190 – 10.2.40.190	10.2.40.190
64	10.2.40.191/32	10.2.40.191 – 10.2.40.191	10.2.40.191
65	10.2.40.192/32	10.2.40.192 – 10.2.40.192	10.2.40.192
66	10.2.40.193/32	10.2.40.193 – 10.2.40.193	10.2.40.193
67	10.2.40.194/32	10.2.40.194 – 10.2.40.194	10.2.40.194
68	10.2.40.195/32	10.2.40.195 – 10.2.40.195	10.2.40.195
69	10.2.40.196/32	10.2.40.196 – 10.2.40.196	10.2.40.196
70	10.2.40.197/32	10.2.40.197 – 10.2.40.197	10.2.40.197
71	10.2.40.198/32	10.2.40.198 – 10.2.40.198	10.2.40.198
72	10.2.40.199/32	10.2.40.199 – 10.2.40.199	10.2.40.199
73	10.2.40.200/32	10.2.40.200 – 10.2.40.200	10.2.40.200
74	10.2.40.201/32	10.2.40.201 – 10.2.40.201	10.2.40.201
75	10.2.40.202/32	10.2.40.202 – 10.2.40.202	10.2.40.202
76	10.2.40.203/32	10.2.40.203 – 10.2.40.203	10.2.40.203
77	10.2.40.204/32	10.2.40.204 – 10.2.40.204	10.2.40.204
78	10.2.40.205/32	10.2.40.205 – 10.2.40.205	10.2.40.205
79	10.2.40.206/32	10.2.40.206 – 10.2.40.206	10.2.40.206
80	10.2.40.207/32	10.2.40.207 – 10.2.40.207	10.2.40.207
81	10.2.40.208/32	10.2.40.208 – 10.2.40.208	10.2.40.208
82	10.2.40.209/32	10.2.40.209 – 10.2.40.209	10.2.40.209
83	10.2.40.210/32	10.2.40.210 – 10.2.40.210	10.2.40.210
84	10.2.40.211/32	10.2.40.211 – 10.2.40.211	10.2.40.211
85	10.2.40.212/32	10.2.40.212 – 10.2.40.212	10.2.40.212
86	10.2.40.213/32	10.2.40.213 – 10.2.40.213	10.2.40.213
87	10.2.40.214/32	10.2.40.214 – 10.2.40.214	10.2.40.214
88	10.2.40.215/32	10.2.40.215 – 10.2.40.215	10.2.40.215
89	10.2.40.216/32	10.2.40.216 – 10.2.40.216	10.2.40.216
90	10.2.40.217/32	10.2.40.217 – 10.2.40.217	10.2.40.217
91	10.2.40.218/32	10.2.40.218 – 10.2.40.218	10.2.40.218
92	10.2.40.219/32	10.2.40.219 – 10.2.40.219	10.2.40.219
93	10.2.40.220/32	10.2.40.220 – 10.2.40.220	10.2.40.220
94	10.2.40.221/32	10.2.40.221 – 10.2.40.221	10.2.40.221
95	10.2.40.222/32	10.2.40.222 – 10.2.40.222	10.2.40.222
96	10.2.40.223/32	10.2.40.223 – 10.2.40.223	10.2.40.223
97	10.2.40.224/32	10.2.40.224 – 10.2.40.224	10.2.40.224
98	10.2.40.225/32	10.2.40.225 – 10.2.40.225	10.2.40.225
99	10.2.40.226/32	10.2.40.226 – 10.2.40.226	10.2.40.226
100	10.2.40.227/32	10.2.40.227 – 10.2.40.227	10.2.40.227
101	10.2.40.228/32	10.2.40.228 – 10.2.40.228	10.2.40.228
102	10.2.40.229/32	10.2.40.229 – 10.2.40.229	10.2.40.229
103	10.2.40.230/32	10.2.40.230 – 10.2.40.230	10.2.40.230
104	10.2.40.231/32	10.2.40.231 – 10.2.40.231	10.2.40.231
105	10.2.40.232/32	10.2.40.232 – 10.2.40.232	10.2.40.232
106	10.2.40.233/32	10.2.40.233 – 10.2.40.233	10.2.40.233
107	10.2.40.234/32	10.2.40.234 – 10.2.40.234	10.2.40.234
108	10.2.40.235/32	10.2.40.235 – 10.2.40.235	10.2.40.235
109	10.2.40.236/32	10.2.40.236 – 10.2.40.236	10.2.40.236
110	10.2.40.237/32	10.2.40.237 – 10.2.40.237	10.2.40.237
111	10.2.40.238/32	10.2.40.238 – 10.2.40.238	10.2.40.238
112	10.2.40.239/32	10.2.40.239 – 10.2.40.239	10.2.40.239
113	10.2.40.240/32	10.2.40.240 – 10.2.40.240	10.2.40.240
114	10.2.40.241/32	10.2.40.241 – 10.2.40.241	10.2.40.241
115	10.2.40.242/32	10.2.40.242 – 10.2.40.242	10.2.40.242
116	10.2.40.243/32	10.2.40.243 – 10.2.40.243	10.2.40.243
117	10.2.40.244/32	10.2.40.244 – 10.2.40.244	10.2.40.244
118	10.2.40.245/32	10.2.40.245 – 10.2.40.245	10.2.40.245
119	10.2.40.246/32	10.2.40.246 – 10.2.40.246	10.2.40.246
120	10.2.40.247/32	10.2.40.247 – 10.2.40.247	10.2.40.247
121	10.2.40.248/32	10.2.40.248 – 10.2.40.248	10.2.40.248
122	10.2.40.249/32	10.2.40.249 – 10.2.40.249	10.2.40.249
123	10.2.40.250/32	10.2.40.250 – 10.2.40.250	10.2.40.250
124	10.2.40.251/32	10.2.40.251 – 10.2.40.251	10.2.40.251
125	10.2.40.252/32	10.2.40.252 – 10.2.40.252	10.2.40.252
126	10.2.40.253/32	10.2.40.253 – 10.2.40.253	10.2.40.253
127	10.2.40.254/32	10.2.40.254 – 10.2.40.254	10.2.40.254
128	10.2.40.255/32	10.2.40.255 – 10.2.40.255	10.2.40.255

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 →