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)10.45.3.128/25

network10.45.3.128/25

broadcast10.45.3.255

first host10.45.3.129

last host10.45.3.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.45.3.128/25

address00001010.00101101.00000011.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00101101.00000011.10000000

broadcast00001010.00101101.00000011.11111111

green = network part, grey = host part

hex0x0a2d0380

decimal170722176

reverse dns128.3.45.10.in-addr.arpa

ipv4-mapped::ffff:a2d:380

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.45.3.128/32	10.45.3.128 – 10.45.3.128	10.45.3.128
2	10.45.3.129/32	10.45.3.129 – 10.45.3.129	10.45.3.129
3	10.45.3.130/32	10.45.3.130 – 10.45.3.130	10.45.3.130
4	10.45.3.131/32	10.45.3.131 – 10.45.3.131	10.45.3.131
5	10.45.3.132/32	10.45.3.132 – 10.45.3.132	10.45.3.132
6	10.45.3.133/32	10.45.3.133 – 10.45.3.133	10.45.3.133
7	10.45.3.134/32	10.45.3.134 – 10.45.3.134	10.45.3.134
8	10.45.3.135/32	10.45.3.135 – 10.45.3.135	10.45.3.135
9	10.45.3.136/32	10.45.3.136 – 10.45.3.136	10.45.3.136
10	10.45.3.137/32	10.45.3.137 – 10.45.3.137	10.45.3.137
11	10.45.3.138/32	10.45.3.138 – 10.45.3.138	10.45.3.138
12	10.45.3.139/32	10.45.3.139 – 10.45.3.139	10.45.3.139
13	10.45.3.140/32	10.45.3.140 – 10.45.3.140	10.45.3.140
14	10.45.3.141/32	10.45.3.141 – 10.45.3.141	10.45.3.141
15	10.45.3.142/32	10.45.3.142 – 10.45.3.142	10.45.3.142
16	10.45.3.143/32	10.45.3.143 – 10.45.3.143	10.45.3.143
17	10.45.3.144/32	10.45.3.144 – 10.45.3.144	10.45.3.144
18	10.45.3.145/32	10.45.3.145 – 10.45.3.145	10.45.3.145
19	10.45.3.146/32	10.45.3.146 – 10.45.3.146	10.45.3.146
20	10.45.3.147/32	10.45.3.147 – 10.45.3.147	10.45.3.147
21	10.45.3.148/32	10.45.3.148 – 10.45.3.148	10.45.3.148
22	10.45.3.149/32	10.45.3.149 – 10.45.3.149	10.45.3.149
23	10.45.3.150/32	10.45.3.150 – 10.45.3.150	10.45.3.150
24	10.45.3.151/32	10.45.3.151 – 10.45.3.151	10.45.3.151
25	10.45.3.152/32	10.45.3.152 – 10.45.3.152	10.45.3.152
26	10.45.3.153/32	10.45.3.153 – 10.45.3.153	10.45.3.153
27	10.45.3.154/32	10.45.3.154 – 10.45.3.154	10.45.3.154
28	10.45.3.155/32	10.45.3.155 – 10.45.3.155	10.45.3.155
29	10.45.3.156/32	10.45.3.156 – 10.45.3.156	10.45.3.156
30	10.45.3.157/32	10.45.3.157 – 10.45.3.157	10.45.3.157
31	10.45.3.158/32	10.45.3.158 – 10.45.3.158	10.45.3.158
32	10.45.3.159/32	10.45.3.159 – 10.45.3.159	10.45.3.159
33	10.45.3.160/32	10.45.3.160 – 10.45.3.160	10.45.3.160
34	10.45.3.161/32	10.45.3.161 – 10.45.3.161	10.45.3.161
35	10.45.3.162/32	10.45.3.162 – 10.45.3.162	10.45.3.162
36	10.45.3.163/32	10.45.3.163 – 10.45.3.163	10.45.3.163
37	10.45.3.164/32	10.45.3.164 – 10.45.3.164	10.45.3.164
38	10.45.3.165/32	10.45.3.165 – 10.45.3.165	10.45.3.165
39	10.45.3.166/32	10.45.3.166 – 10.45.3.166	10.45.3.166
40	10.45.3.167/32	10.45.3.167 – 10.45.3.167	10.45.3.167
41	10.45.3.168/32	10.45.3.168 – 10.45.3.168	10.45.3.168
42	10.45.3.169/32	10.45.3.169 – 10.45.3.169	10.45.3.169
43	10.45.3.170/32	10.45.3.170 – 10.45.3.170	10.45.3.170
44	10.45.3.171/32	10.45.3.171 – 10.45.3.171	10.45.3.171
45	10.45.3.172/32	10.45.3.172 – 10.45.3.172	10.45.3.172
46	10.45.3.173/32	10.45.3.173 – 10.45.3.173	10.45.3.173
47	10.45.3.174/32	10.45.3.174 – 10.45.3.174	10.45.3.174
48	10.45.3.175/32	10.45.3.175 – 10.45.3.175	10.45.3.175
49	10.45.3.176/32	10.45.3.176 – 10.45.3.176	10.45.3.176
50	10.45.3.177/32	10.45.3.177 – 10.45.3.177	10.45.3.177
51	10.45.3.178/32	10.45.3.178 – 10.45.3.178	10.45.3.178
52	10.45.3.179/32	10.45.3.179 – 10.45.3.179	10.45.3.179
53	10.45.3.180/32	10.45.3.180 – 10.45.3.180	10.45.3.180
54	10.45.3.181/32	10.45.3.181 – 10.45.3.181	10.45.3.181
55	10.45.3.182/32	10.45.3.182 – 10.45.3.182	10.45.3.182
56	10.45.3.183/32	10.45.3.183 – 10.45.3.183	10.45.3.183
57	10.45.3.184/32	10.45.3.184 – 10.45.3.184	10.45.3.184
58	10.45.3.185/32	10.45.3.185 – 10.45.3.185	10.45.3.185
59	10.45.3.186/32	10.45.3.186 – 10.45.3.186	10.45.3.186
60	10.45.3.187/32	10.45.3.187 – 10.45.3.187	10.45.3.187
61	10.45.3.188/32	10.45.3.188 – 10.45.3.188	10.45.3.188
62	10.45.3.189/32	10.45.3.189 – 10.45.3.189	10.45.3.189
63	10.45.3.190/32	10.45.3.190 – 10.45.3.190	10.45.3.190
64	10.45.3.191/32	10.45.3.191 – 10.45.3.191	10.45.3.191
65	10.45.3.192/32	10.45.3.192 – 10.45.3.192	10.45.3.192
66	10.45.3.193/32	10.45.3.193 – 10.45.3.193	10.45.3.193
67	10.45.3.194/32	10.45.3.194 – 10.45.3.194	10.45.3.194
68	10.45.3.195/32	10.45.3.195 – 10.45.3.195	10.45.3.195
69	10.45.3.196/32	10.45.3.196 – 10.45.3.196	10.45.3.196
70	10.45.3.197/32	10.45.3.197 – 10.45.3.197	10.45.3.197
71	10.45.3.198/32	10.45.3.198 – 10.45.3.198	10.45.3.198
72	10.45.3.199/32	10.45.3.199 – 10.45.3.199	10.45.3.199
73	10.45.3.200/32	10.45.3.200 – 10.45.3.200	10.45.3.200
74	10.45.3.201/32	10.45.3.201 – 10.45.3.201	10.45.3.201
75	10.45.3.202/32	10.45.3.202 – 10.45.3.202	10.45.3.202
76	10.45.3.203/32	10.45.3.203 – 10.45.3.203	10.45.3.203
77	10.45.3.204/32	10.45.3.204 – 10.45.3.204	10.45.3.204
78	10.45.3.205/32	10.45.3.205 – 10.45.3.205	10.45.3.205
79	10.45.3.206/32	10.45.3.206 – 10.45.3.206	10.45.3.206
80	10.45.3.207/32	10.45.3.207 – 10.45.3.207	10.45.3.207
81	10.45.3.208/32	10.45.3.208 – 10.45.3.208	10.45.3.208
82	10.45.3.209/32	10.45.3.209 – 10.45.3.209	10.45.3.209
83	10.45.3.210/32	10.45.3.210 – 10.45.3.210	10.45.3.210
84	10.45.3.211/32	10.45.3.211 – 10.45.3.211	10.45.3.211
85	10.45.3.212/32	10.45.3.212 – 10.45.3.212	10.45.3.212
86	10.45.3.213/32	10.45.3.213 – 10.45.3.213	10.45.3.213
87	10.45.3.214/32	10.45.3.214 – 10.45.3.214	10.45.3.214
88	10.45.3.215/32	10.45.3.215 – 10.45.3.215	10.45.3.215
89	10.45.3.216/32	10.45.3.216 – 10.45.3.216	10.45.3.216
90	10.45.3.217/32	10.45.3.217 – 10.45.3.217	10.45.3.217
91	10.45.3.218/32	10.45.3.218 – 10.45.3.218	10.45.3.218
92	10.45.3.219/32	10.45.3.219 – 10.45.3.219	10.45.3.219
93	10.45.3.220/32	10.45.3.220 – 10.45.3.220	10.45.3.220
94	10.45.3.221/32	10.45.3.221 – 10.45.3.221	10.45.3.221
95	10.45.3.222/32	10.45.3.222 – 10.45.3.222	10.45.3.222
96	10.45.3.223/32	10.45.3.223 – 10.45.3.223	10.45.3.223
97	10.45.3.224/32	10.45.3.224 – 10.45.3.224	10.45.3.224
98	10.45.3.225/32	10.45.3.225 – 10.45.3.225	10.45.3.225
99	10.45.3.226/32	10.45.3.226 – 10.45.3.226	10.45.3.226
100	10.45.3.227/32	10.45.3.227 – 10.45.3.227	10.45.3.227
101	10.45.3.228/32	10.45.3.228 – 10.45.3.228	10.45.3.228
102	10.45.3.229/32	10.45.3.229 – 10.45.3.229	10.45.3.229
103	10.45.3.230/32	10.45.3.230 – 10.45.3.230	10.45.3.230
104	10.45.3.231/32	10.45.3.231 – 10.45.3.231	10.45.3.231
105	10.45.3.232/32	10.45.3.232 – 10.45.3.232	10.45.3.232
106	10.45.3.233/32	10.45.3.233 – 10.45.3.233	10.45.3.233
107	10.45.3.234/32	10.45.3.234 – 10.45.3.234	10.45.3.234
108	10.45.3.235/32	10.45.3.235 – 10.45.3.235	10.45.3.235
109	10.45.3.236/32	10.45.3.236 – 10.45.3.236	10.45.3.236
110	10.45.3.237/32	10.45.3.237 – 10.45.3.237	10.45.3.237
111	10.45.3.238/32	10.45.3.238 – 10.45.3.238	10.45.3.238
112	10.45.3.239/32	10.45.3.239 – 10.45.3.239	10.45.3.239
113	10.45.3.240/32	10.45.3.240 – 10.45.3.240	10.45.3.240
114	10.45.3.241/32	10.45.3.241 – 10.45.3.241	10.45.3.241
115	10.45.3.242/32	10.45.3.242 – 10.45.3.242	10.45.3.242
116	10.45.3.243/32	10.45.3.243 – 10.45.3.243	10.45.3.243
117	10.45.3.244/32	10.45.3.244 – 10.45.3.244	10.45.3.244
118	10.45.3.245/32	10.45.3.245 – 10.45.3.245	10.45.3.245
119	10.45.3.246/32	10.45.3.246 – 10.45.3.246	10.45.3.246
120	10.45.3.247/32	10.45.3.247 – 10.45.3.247	10.45.3.247
121	10.45.3.248/32	10.45.3.248 – 10.45.3.248	10.45.3.248
122	10.45.3.249/32	10.45.3.249 – 10.45.3.249	10.45.3.249
123	10.45.3.250/32	10.45.3.250 – 10.45.3.250	10.45.3.250
124	10.45.3.251/32	10.45.3.251 – 10.45.3.251	10.45.3.251
125	10.45.3.252/32	10.45.3.252 – 10.45.3.252	10.45.3.252
126	10.45.3.253/32	10.45.3.253 – 10.45.3.253	10.45.3.253
127	10.45.3.254/32	10.45.3.254 – 10.45.3.254	10.45.3.254
128	10.45.3.255/32	10.45.3.255 – 10.45.3.255	10.45.3.255

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 →