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)10.2.45.128/25

network10.2.45.128/25

broadcast10.2.45.255

first host10.2.45.129

last host10.2.45.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.2.45.128/25

address00001010.00000010.00101101.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000010.00101101.10000000

broadcast00001010.00000010.00101101.11111111

green = network part, grey = host part

hex0x0a022d80

decimal167914880

reverse dns128.45.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:2d80

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.45.128/32	10.2.45.128 – 10.2.45.128	10.2.45.128
2	10.2.45.129/32	10.2.45.129 – 10.2.45.129	10.2.45.129
3	10.2.45.130/32	10.2.45.130 – 10.2.45.130	10.2.45.130
4	10.2.45.131/32	10.2.45.131 – 10.2.45.131	10.2.45.131
5	10.2.45.132/32	10.2.45.132 – 10.2.45.132	10.2.45.132
6	10.2.45.133/32	10.2.45.133 – 10.2.45.133	10.2.45.133
7	10.2.45.134/32	10.2.45.134 – 10.2.45.134	10.2.45.134
8	10.2.45.135/32	10.2.45.135 – 10.2.45.135	10.2.45.135
9	10.2.45.136/32	10.2.45.136 – 10.2.45.136	10.2.45.136
10	10.2.45.137/32	10.2.45.137 – 10.2.45.137	10.2.45.137
11	10.2.45.138/32	10.2.45.138 – 10.2.45.138	10.2.45.138
12	10.2.45.139/32	10.2.45.139 – 10.2.45.139	10.2.45.139
13	10.2.45.140/32	10.2.45.140 – 10.2.45.140	10.2.45.140
14	10.2.45.141/32	10.2.45.141 – 10.2.45.141	10.2.45.141
15	10.2.45.142/32	10.2.45.142 – 10.2.45.142	10.2.45.142
16	10.2.45.143/32	10.2.45.143 – 10.2.45.143	10.2.45.143
17	10.2.45.144/32	10.2.45.144 – 10.2.45.144	10.2.45.144
18	10.2.45.145/32	10.2.45.145 – 10.2.45.145	10.2.45.145
19	10.2.45.146/32	10.2.45.146 – 10.2.45.146	10.2.45.146
20	10.2.45.147/32	10.2.45.147 – 10.2.45.147	10.2.45.147
21	10.2.45.148/32	10.2.45.148 – 10.2.45.148	10.2.45.148
22	10.2.45.149/32	10.2.45.149 – 10.2.45.149	10.2.45.149
23	10.2.45.150/32	10.2.45.150 – 10.2.45.150	10.2.45.150
24	10.2.45.151/32	10.2.45.151 – 10.2.45.151	10.2.45.151
25	10.2.45.152/32	10.2.45.152 – 10.2.45.152	10.2.45.152
26	10.2.45.153/32	10.2.45.153 – 10.2.45.153	10.2.45.153
27	10.2.45.154/32	10.2.45.154 – 10.2.45.154	10.2.45.154
28	10.2.45.155/32	10.2.45.155 – 10.2.45.155	10.2.45.155
29	10.2.45.156/32	10.2.45.156 – 10.2.45.156	10.2.45.156
30	10.2.45.157/32	10.2.45.157 – 10.2.45.157	10.2.45.157
31	10.2.45.158/32	10.2.45.158 – 10.2.45.158	10.2.45.158
32	10.2.45.159/32	10.2.45.159 – 10.2.45.159	10.2.45.159
33	10.2.45.160/32	10.2.45.160 – 10.2.45.160	10.2.45.160
34	10.2.45.161/32	10.2.45.161 – 10.2.45.161	10.2.45.161
35	10.2.45.162/32	10.2.45.162 – 10.2.45.162	10.2.45.162
36	10.2.45.163/32	10.2.45.163 – 10.2.45.163	10.2.45.163
37	10.2.45.164/32	10.2.45.164 – 10.2.45.164	10.2.45.164
38	10.2.45.165/32	10.2.45.165 – 10.2.45.165	10.2.45.165
39	10.2.45.166/32	10.2.45.166 – 10.2.45.166	10.2.45.166
40	10.2.45.167/32	10.2.45.167 – 10.2.45.167	10.2.45.167
41	10.2.45.168/32	10.2.45.168 – 10.2.45.168	10.2.45.168
42	10.2.45.169/32	10.2.45.169 – 10.2.45.169	10.2.45.169
43	10.2.45.170/32	10.2.45.170 – 10.2.45.170	10.2.45.170
44	10.2.45.171/32	10.2.45.171 – 10.2.45.171	10.2.45.171
45	10.2.45.172/32	10.2.45.172 – 10.2.45.172	10.2.45.172
46	10.2.45.173/32	10.2.45.173 – 10.2.45.173	10.2.45.173
47	10.2.45.174/32	10.2.45.174 – 10.2.45.174	10.2.45.174
48	10.2.45.175/32	10.2.45.175 – 10.2.45.175	10.2.45.175
49	10.2.45.176/32	10.2.45.176 – 10.2.45.176	10.2.45.176
50	10.2.45.177/32	10.2.45.177 – 10.2.45.177	10.2.45.177
51	10.2.45.178/32	10.2.45.178 – 10.2.45.178	10.2.45.178
52	10.2.45.179/32	10.2.45.179 – 10.2.45.179	10.2.45.179
53	10.2.45.180/32	10.2.45.180 – 10.2.45.180	10.2.45.180
54	10.2.45.181/32	10.2.45.181 – 10.2.45.181	10.2.45.181
55	10.2.45.182/32	10.2.45.182 – 10.2.45.182	10.2.45.182
56	10.2.45.183/32	10.2.45.183 – 10.2.45.183	10.2.45.183
57	10.2.45.184/32	10.2.45.184 – 10.2.45.184	10.2.45.184
58	10.2.45.185/32	10.2.45.185 – 10.2.45.185	10.2.45.185
59	10.2.45.186/32	10.2.45.186 – 10.2.45.186	10.2.45.186
60	10.2.45.187/32	10.2.45.187 – 10.2.45.187	10.2.45.187
61	10.2.45.188/32	10.2.45.188 – 10.2.45.188	10.2.45.188
62	10.2.45.189/32	10.2.45.189 – 10.2.45.189	10.2.45.189
63	10.2.45.190/32	10.2.45.190 – 10.2.45.190	10.2.45.190
64	10.2.45.191/32	10.2.45.191 – 10.2.45.191	10.2.45.191
65	10.2.45.192/32	10.2.45.192 – 10.2.45.192	10.2.45.192
66	10.2.45.193/32	10.2.45.193 – 10.2.45.193	10.2.45.193
67	10.2.45.194/32	10.2.45.194 – 10.2.45.194	10.2.45.194
68	10.2.45.195/32	10.2.45.195 – 10.2.45.195	10.2.45.195
69	10.2.45.196/32	10.2.45.196 – 10.2.45.196	10.2.45.196
70	10.2.45.197/32	10.2.45.197 – 10.2.45.197	10.2.45.197
71	10.2.45.198/32	10.2.45.198 – 10.2.45.198	10.2.45.198
72	10.2.45.199/32	10.2.45.199 – 10.2.45.199	10.2.45.199
73	10.2.45.200/32	10.2.45.200 – 10.2.45.200	10.2.45.200
74	10.2.45.201/32	10.2.45.201 – 10.2.45.201	10.2.45.201
75	10.2.45.202/32	10.2.45.202 – 10.2.45.202	10.2.45.202
76	10.2.45.203/32	10.2.45.203 – 10.2.45.203	10.2.45.203
77	10.2.45.204/32	10.2.45.204 – 10.2.45.204	10.2.45.204
78	10.2.45.205/32	10.2.45.205 – 10.2.45.205	10.2.45.205
79	10.2.45.206/32	10.2.45.206 – 10.2.45.206	10.2.45.206
80	10.2.45.207/32	10.2.45.207 – 10.2.45.207	10.2.45.207
81	10.2.45.208/32	10.2.45.208 – 10.2.45.208	10.2.45.208
82	10.2.45.209/32	10.2.45.209 – 10.2.45.209	10.2.45.209
83	10.2.45.210/32	10.2.45.210 – 10.2.45.210	10.2.45.210
84	10.2.45.211/32	10.2.45.211 – 10.2.45.211	10.2.45.211
85	10.2.45.212/32	10.2.45.212 – 10.2.45.212	10.2.45.212
86	10.2.45.213/32	10.2.45.213 – 10.2.45.213	10.2.45.213
87	10.2.45.214/32	10.2.45.214 – 10.2.45.214	10.2.45.214
88	10.2.45.215/32	10.2.45.215 – 10.2.45.215	10.2.45.215
89	10.2.45.216/32	10.2.45.216 – 10.2.45.216	10.2.45.216
90	10.2.45.217/32	10.2.45.217 – 10.2.45.217	10.2.45.217
91	10.2.45.218/32	10.2.45.218 – 10.2.45.218	10.2.45.218
92	10.2.45.219/32	10.2.45.219 – 10.2.45.219	10.2.45.219
93	10.2.45.220/32	10.2.45.220 – 10.2.45.220	10.2.45.220
94	10.2.45.221/32	10.2.45.221 – 10.2.45.221	10.2.45.221
95	10.2.45.222/32	10.2.45.222 – 10.2.45.222	10.2.45.222
96	10.2.45.223/32	10.2.45.223 – 10.2.45.223	10.2.45.223
97	10.2.45.224/32	10.2.45.224 – 10.2.45.224	10.2.45.224
98	10.2.45.225/32	10.2.45.225 – 10.2.45.225	10.2.45.225
99	10.2.45.226/32	10.2.45.226 – 10.2.45.226	10.2.45.226
100	10.2.45.227/32	10.2.45.227 – 10.2.45.227	10.2.45.227
101	10.2.45.228/32	10.2.45.228 – 10.2.45.228	10.2.45.228
102	10.2.45.229/32	10.2.45.229 – 10.2.45.229	10.2.45.229
103	10.2.45.230/32	10.2.45.230 – 10.2.45.230	10.2.45.230
104	10.2.45.231/32	10.2.45.231 – 10.2.45.231	10.2.45.231
105	10.2.45.232/32	10.2.45.232 – 10.2.45.232	10.2.45.232
106	10.2.45.233/32	10.2.45.233 – 10.2.45.233	10.2.45.233
107	10.2.45.234/32	10.2.45.234 – 10.2.45.234	10.2.45.234
108	10.2.45.235/32	10.2.45.235 – 10.2.45.235	10.2.45.235
109	10.2.45.236/32	10.2.45.236 – 10.2.45.236	10.2.45.236
110	10.2.45.237/32	10.2.45.237 – 10.2.45.237	10.2.45.237
111	10.2.45.238/32	10.2.45.238 – 10.2.45.238	10.2.45.238
112	10.2.45.239/32	10.2.45.239 – 10.2.45.239	10.2.45.239
113	10.2.45.240/32	10.2.45.240 – 10.2.45.240	10.2.45.240
114	10.2.45.241/32	10.2.45.241 – 10.2.45.241	10.2.45.241
115	10.2.45.242/32	10.2.45.242 – 10.2.45.242	10.2.45.242
116	10.2.45.243/32	10.2.45.243 – 10.2.45.243	10.2.45.243
117	10.2.45.244/32	10.2.45.244 – 10.2.45.244	10.2.45.244
118	10.2.45.245/32	10.2.45.245 – 10.2.45.245	10.2.45.245
119	10.2.45.246/32	10.2.45.246 – 10.2.45.246	10.2.45.246
120	10.2.45.247/32	10.2.45.247 – 10.2.45.247	10.2.45.247
121	10.2.45.248/32	10.2.45.248 – 10.2.45.248	10.2.45.248
122	10.2.45.249/32	10.2.45.249 – 10.2.45.249	10.2.45.249
123	10.2.45.250/32	10.2.45.250 – 10.2.45.250	10.2.45.250
124	10.2.45.251/32	10.2.45.251 – 10.2.45.251	10.2.45.251
125	10.2.45.252/32	10.2.45.252 – 10.2.45.252	10.2.45.252
126	10.2.45.253/32	10.2.45.253 – 10.2.45.253	10.2.45.253
127	10.2.45.254/32	10.2.45.254 – 10.2.45.254	10.2.45.254
128	10.2.45.255/32	10.2.45.255 – 10.2.45.255	10.2.45.255

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 →