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)10.45.4.128/25

network10.45.4.128/25

broadcast10.45.4.255

first host10.45.4.129

last host10.45.4.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.45.4.128/25

address00001010.00101101.00000100.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00101101.00000100.10000000

broadcast00001010.00101101.00000100.11111111

green = network part, grey = host part

hex0x0a2d0480

decimal170722432

reverse dns128.4.45.10.in-addr.arpa

ipv4-mapped::ffff:a2d:480

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.45.4.128/32	10.45.4.128 – 10.45.4.128	10.45.4.128
2	10.45.4.129/32	10.45.4.129 – 10.45.4.129	10.45.4.129
3	10.45.4.130/32	10.45.4.130 – 10.45.4.130	10.45.4.130
4	10.45.4.131/32	10.45.4.131 – 10.45.4.131	10.45.4.131
5	10.45.4.132/32	10.45.4.132 – 10.45.4.132	10.45.4.132
6	10.45.4.133/32	10.45.4.133 – 10.45.4.133	10.45.4.133
7	10.45.4.134/32	10.45.4.134 – 10.45.4.134	10.45.4.134
8	10.45.4.135/32	10.45.4.135 – 10.45.4.135	10.45.4.135
9	10.45.4.136/32	10.45.4.136 – 10.45.4.136	10.45.4.136
10	10.45.4.137/32	10.45.4.137 – 10.45.4.137	10.45.4.137
11	10.45.4.138/32	10.45.4.138 – 10.45.4.138	10.45.4.138
12	10.45.4.139/32	10.45.4.139 – 10.45.4.139	10.45.4.139
13	10.45.4.140/32	10.45.4.140 – 10.45.4.140	10.45.4.140
14	10.45.4.141/32	10.45.4.141 – 10.45.4.141	10.45.4.141
15	10.45.4.142/32	10.45.4.142 – 10.45.4.142	10.45.4.142
16	10.45.4.143/32	10.45.4.143 – 10.45.4.143	10.45.4.143
17	10.45.4.144/32	10.45.4.144 – 10.45.4.144	10.45.4.144
18	10.45.4.145/32	10.45.4.145 – 10.45.4.145	10.45.4.145
19	10.45.4.146/32	10.45.4.146 – 10.45.4.146	10.45.4.146
20	10.45.4.147/32	10.45.4.147 – 10.45.4.147	10.45.4.147
21	10.45.4.148/32	10.45.4.148 – 10.45.4.148	10.45.4.148
22	10.45.4.149/32	10.45.4.149 – 10.45.4.149	10.45.4.149
23	10.45.4.150/32	10.45.4.150 – 10.45.4.150	10.45.4.150
24	10.45.4.151/32	10.45.4.151 – 10.45.4.151	10.45.4.151
25	10.45.4.152/32	10.45.4.152 – 10.45.4.152	10.45.4.152
26	10.45.4.153/32	10.45.4.153 – 10.45.4.153	10.45.4.153
27	10.45.4.154/32	10.45.4.154 – 10.45.4.154	10.45.4.154
28	10.45.4.155/32	10.45.4.155 – 10.45.4.155	10.45.4.155
29	10.45.4.156/32	10.45.4.156 – 10.45.4.156	10.45.4.156
30	10.45.4.157/32	10.45.4.157 – 10.45.4.157	10.45.4.157
31	10.45.4.158/32	10.45.4.158 – 10.45.4.158	10.45.4.158
32	10.45.4.159/32	10.45.4.159 – 10.45.4.159	10.45.4.159
33	10.45.4.160/32	10.45.4.160 – 10.45.4.160	10.45.4.160
34	10.45.4.161/32	10.45.4.161 – 10.45.4.161	10.45.4.161
35	10.45.4.162/32	10.45.4.162 – 10.45.4.162	10.45.4.162
36	10.45.4.163/32	10.45.4.163 – 10.45.4.163	10.45.4.163
37	10.45.4.164/32	10.45.4.164 – 10.45.4.164	10.45.4.164
38	10.45.4.165/32	10.45.4.165 – 10.45.4.165	10.45.4.165
39	10.45.4.166/32	10.45.4.166 – 10.45.4.166	10.45.4.166
40	10.45.4.167/32	10.45.4.167 – 10.45.4.167	10.45.4.167
41	10.45.4.168/32	10.45.4.168 – 10.45.4.168	10.45.4.168
42	10.45.4.169/32	10.45.4.169 – 10.45.4.169	10.45.4.169
43	10.45.4.170/32	10.45.4.170 – 10.45.4.170	10.45.4.170
44	10.45.4.171/32	10.45.4.171 – 10.45.4.171	10.45.4.171
45	10.45.4.172/32	10.45.4.172 – 10.45.4.172	10.45.4.172
46	10.45.4.173/32	10.45.4.173 – 10.45.4.173	10.45.4.173
47	10.45.4.174/32	10.45.4.174 – 10.45.4.174	10.45.4.174
48	10.45.4.175/32	10.45.4.175 – 10.45.4.175	10.45.4.175
49	10.45.4.176/32	10.45.4.176 – 10.45.4.176	10.45.4.176
50	10.45.4.177/32	10.45.4.177 – 10.45.4.177	10.45.4.177
51	10.45.4.178/32	10.45.4.178 – 10.45.4.178	10.45.4.178
52	10.45.4.179/32	10.45.4.179 – 10.45.4.179	10.45.4.179
53	10.45.4.180/32	10.45.4.180 – 10.45.4.180	10.45.4.180
54	10.45.4.181/32	10.45.4.181 – 10.45.4.181	10.45.4.181
55	10.45.4.182/32	10.45.4.182 – 10.45.4.182	10.45.4.182
56	10.45.4.183/32	10.45.4.183 – 10.45.4.183	10.45.4.183
57	10.45.4.184/32	10.45.4.184 – 10.45.4.184	10.45.4.184
58	10.45.4.185/32	10.45.4.185 – 10.45.4.185	10.45.4.185
59	10.45.4.186/32	10.45.4.186 – 10.45.4.186	10.45.4.186
60	10.45.4.187/32	10.45.4.187 – 10.45.4.187	10.45.4.187
61	10.45.4.188/32	10.45.4.188 – 10.45.4.188	10.45.4.188
62	10.45.4.189/32	10.45.4.189 – 10.45.4.189	10.45.4.189
63	10.45.4.190/32	10.45.4.190 – 10.45.4.190	10.45.4.190
64	10.45.4.191/32	10.45.4.191 – 10.45.4.191	10.45.4.191
65	10.45.4.192/32	10.45.4.192 – 10.45.4.192	10.45.4.192
66	10.45.4.193/32	10.45.4.193 – 10.45.4.193	10.45.4.193
67	10.45.4.194/32	10.45.4.194 – 10.45.4.194	10.45.4.194
68	10.45.4.195/32	10.45.4.195 – 10.45.4.195	10.45.4.195
69	10.45.4.196/32	10.45.4.196 – 10.45.4.196	10.45.4.196
70	10.45.4.197/32	10.45.4.197 – 10.45.4.197	10.45.4.197
71	10.45.4.198/32	10.45.4.198 – 10.45.4.198	10.45.4.198
72	10.45.4.199/32	10.45.4.199 – 10.45.4.199	10.45.4.199
73	10.45.4.200/32	10.45.4.200 – 10.45.4.200	10.45.4.200
74	10.45.4.201/32	10.45.4.201 – 10.45.4.201	10.45.4.201
75	10.45.4.202/32	10.45.4.202 – 10.45.4.202	10.45.4.202
76	10.45.4.203/32	10.45.4.203 – 10.45.4.203	10.45.4.203
77	10.45.4.204/32	10.45.4.204 – 10.45.4.204	10.45.4.204
78	10.45.4.205/32	10.45.4.205 – 10.45.4.205	10.45.4.205
79	10.45.4.206/32	10.45.4.206 – 10.45.4.206	10.45.4.206
80	10.45.4.207/32	10.45.4.207 – 10.45.4.207	10.45.4.207
81	10.45.4.208/32	10.45.4.208 – 10.45.4.208	10.45.4.208
82	10.45.4.209/32	10.45.4.209 – 10.45.4.209	10.45.4.209
83	10.45.4.210/32	10.45.4.210 – 10.45.4.210	10.45.4.210
84	10.45.4.211/32	10.45.4.211 – 10.45.4.211	10.45.4.211
85	10.45.4.212/32	10.45.4.212 – 10.45.4.212	10.45.4.212
86	10.45.4.213/32	10.45.4.213 – 10.45.4.213	10.45.4.213
87	10.45.4.214/32	10.45.4.214 – 10.45.4.214	10.45.4.214
88	10.45.4.215/32	10.45.4.215 – 10.45.4.215	10.45.4.215
89	10.45.4.216/32	10.45.4.216 – 10.45.4.216	10.45.4.216
90	10.45.4.217/32	10.45.4.217 – 10.45.4.217	10.45.4.217
91	10.45.4.218/32	10.45.4.218 – 10.45.4.218	10.45.4.218
92	10.45.4.219/32	10.45.4.219 – 10.45.4.219	10.45.4.219
93	10.45.4.220/32	10.45.4.220 – 10.45.4.220	10.45.4.220
94	10.45.4.221/32	10.45.4.221 – 10.45.4.221	10.45.4.221
95	10.45.4.222/32	10.45.4.222 – 10.45.4.222	10.45.4.222
96	10.45.4.223/32	10.45.4.223 – 10.45.4.223	10.45.4.223
97	10.45.4.224/32	10.45.4.224 – 10.45.4.224	10.45.4.224
98	10.45.4.225/32	10.45.4.225 – 10.45.4.225	10.45.4.225
99	10.45.4.226/32	10.45.4.226 – 10.45.4.226	10.45.4.226
100	10.45.4.227/32	10.45.4.227 – 10.45.4.227	10.45.4.227
101	10.45.4.228/32	10.45.4.228 – 10.45.4.228	10.45.4.228
102	10.45.4.229/32	10.45.4.229 – 10.45.4.229	10.45.4.229
103	10.45.4.230/32	10.45.4.230 – 10.45.4.230	10.45.4.230
104	10.45.4.231/32	10.45.4.231 – 10.45.4.231	10.45.4.231
105	10.45.4.232/32	10.45.4.232 – 10.45.4.232	10.45.4.232
106	10.45.4.233/32	10.45.4.233 – 10.45.4.233	10.45.4.233
107	10.45.4.234/32	10.45.4.234 – 10.45.4.234	10.45.4.234
108	10.45.4.235/32	10.45.4.235 – 10.45.4.235	10.45.4.235
109	10.45.4.236/32	10.45.4.236 – 10.45.4.236	10.45.4.236
110	10.45.4.237/32	10.45.4.237 – 10.45.4.237	10.45.4.237
111	10.45.4.238/32	10.45.4.238 – 10.45.4.238	10.45.4.238
112	10.45.4.239/32	10.45.4.239 – 10.45.4.239	10.45.4.239
113	10.45.4.240/32	10.45.4.240 – 10.45.4.240	10.45.4.240
114	10.45.4.241/32	10.45.4.241 – 10.45.4.241	10.45.4.241
115	10.45.4.242/32	10.45.4.242 – 10.45.4.242	10.45.4.242
116	10.45.4.243/32	10.45.4.243 – 10.45.4.243	10.45.4.243
117	10.45.4.244/32	10.45.4.244 – 10.45.4.244	10.45.4.244
118	10.45.4.245/32	10.45.4.245 – 10.45.4.245	10.45.4.245
119	10.45.4.246/32	10.45.4.246 – 10.45.4.246	10.45.4.246
120	10.45.4.247/32	10.45.4.247 – 10.45.4.247	10.45.4.247
121	10.45.4.248/32	10.45.4.248 – 10.45.4.248	10.45.4.248
122	10.45.4.249/32	10.45.4.249 – 10.45.4.249	10.45.4.249
123	10.45.4.250/32	10.45.4.250 – 10.45.4.250	10.45.4.250
124	10.45.4.251/32	10.45.4.251 – 10.45.4.251	10.45.4.251
125	10.45.4.252/32	10.45.4.252 – 10.45.4.252	10.45.4.252
126	10.45.4.253/32	10.45.4.253 – 10.45.4.253	10.45.4.253
127	10.45.4.254/32	10.45.4.254 – 10.45.4.254	10.45.4.254
128	10.45.4.255/32	10.45.4.255 – 10.45.4.255	10.45.4.255

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 →