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)10.3.63.128/25

network10.3.63.128/25

broadcast10.3.63.255

first host10.3.63.129

last host10.3.63.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.3.63.128/25

address00001010.00000011.00111111.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000011.00111111.10000000

broadcast00001010.00000011.00111111.11111111

green = network part, grey = host part

hex0x0a033f80

decimal167985024

reverse dns128.63.3.10.in-addr.arpa

ipv4-mapped::ffff:a03:3f80

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.3.63.128/32	10.3.63.128 – 10.3.63.128	10.3.63.128
2	10.3.63.129/32	10.3.63.129 – 10.3.63.129	10.3.63.129
3	10.3.63.130/32	10.3.63.130 – 10.3.63.130	10.3.63.130
4	10.3.63.131/32	10.3.63.131 – 10.3.63.131	10.3.63.131
5	10.3.63.132/32	10.3.63.132 – 10.3.63.132	10.3.63.132
6	10.3.63.133/32	10.3.63.133 – 10.3.63.133	10.3.63.133
7	10.3.63.134/32	10.3.63.134 – 10.3.63.134	10.3.63.134
8	10.3.63.135/32	10.3.63.135 – 10.3.63.135	10.3.63.135
9	10.3.63.136/32	10.3.63.136 – 10.3.63.136	10.3.63.136
10	10.3.63.137/32	10.3.63.137 – 10.3.63.137	10.3.63.137
11	10.3.63.138/32	10.3.63.138 – 10.3.63.138	10.3.63.138
12	10.3.63.139/32	10.3.63.139 – 10.3.63.139	10.3.63.139
13	10.3.63.140/32	10.3.63.140 – 10.3.63.140	10.3.63.140
14	10.3.63.141/32	10.3.63.141 – 10.3.63.141	10.3.63.141
15	10.3.63.142/32	10.3.63.142 – 10.3.63.142	10.3.63.142
16	10.3.63.143/32	10.3.63.143 – 10.3.63.143	10.3.63.143
17	10.3.63.144/32	10.3.63.144 – 10.3.63.144	10.3.63.144
18	10.3.63.145/32	10.3.63.145 – 10.3.63.145	10.3.63.145
19	10.3.63.146/32	10.3.63.146 – 10.3.63.146	10.3.63.146
20	10.3.63.147/32	10.3.63.147 – 10.3.63.147	10.3.63.147
21	10.3.63.148/32	10.3.63.148 – 10.3.63.148	10.3.63.148
22	10.3.63.149/32	10.3.63.149 – 10.3.63.149	10.3.63.149
23	10.3.63.150/32	10.3.63.150 – 10.3.63.150	10.3.63.150
24	10.3.63.151/32	10.3.63.151 – 10.3.63.151	10.3.63.151
25	10.3.63.152/32	10.3.63.152 – 10.3.63.152	10.3.63.152
26	10.3.63.153/32	10.3.63.153 – 10.3.63.153	10.3.63.153
27	10.3.63.154/32	10.3.63.154 – 10.3.63.154	10.3.63.154
28	10.3.63.155/32	10.3.63.155 – 10.3.63.155	10.3.63.155
29	10.3.63.156/32	10.3.63.156 – 10.3.63.156	10.3.63.156
30	10.3.63.157/32	10.3.63.157 – 10.3.63.157	10.3.63.157
31	10.3.63.158/32	10.3.63.158 – 10.3.63.158	10.3.63.158
32	10.3.63.159/32	10.3.63.159 – 10.3.63.159	10.3.63.159
33	10.3.63.160/32	10.3.63.160 – 10.3.63.160	10.3.63.160
34	10.3.63.161/32	10.3.63.161 – 10.3.63.161	10.3.63.161
35	10.3.63.162/32	10.3.63.162 – 10.3.63.162	10.3.63.162
36	10.3.63.163/32	10.3.63.163 – 10.3.63.163	10.3.63.163
37	10.3.63.164/32	10.3.63.164 – 10.3.63.164	10.3.63.164
38	10.3.63.165/32	10.3.63.165 – 10.3.63.165	10.3.63.165
39	10.3.63.166/32	10.3.63.166 – 10.3.63.166	10.3.63.166
40	10.3.63.167/32	10.3.63.167 – 10.3.63.167	10.3.63.167
41	10.3.63.168/32	10.3.63.168 – 10.3.63.168	10.3.63.168
42	10.3.63.169/32	10.3.63.169 – 10.3.63.169	10.3.63.169
43	10.3.63.170/32	10.3.63.170 – 10.3.63.170	10.3.63.170
44	10.3.63.171/32	10.3.63.171 – 10.3.63.171	10.3.63.171
45	10.3.63.172/32	10.3.63.172 – 10.3.63.172	10.3.63.172
46	10.3.63.173/32	10.3.63.173 – 10.3.63.173	10.3.63.173
47	10.3.63.174/32	10.3.63.174 – 10.3.63.174	10.3.63.174
48	10.3.63.175/32	10.3.63.175 – 10.3.63.175	10.3.63.175
49	10.3.63.176/32	10.3.63.176 – 10.3.63.176	10.3.63.176
50	10.3.63.177/32	10.3.63.177 – 10.3.63.177	10.3.63.177
51	10.3.63.178/32	10.3.63.178 – 10.3.63.178	10.3.63.178
52	10.3.63.179/32	10.3.63.179 – 10.3.63.179	10.3.63.179
53	10.3.63.180/32	10.3.63.180 – 10.3.63.180	10.3.63.180
54	10.3.63.181/32	10.3.63.181 – 10.3.63.181	10.3.63.181
55	10.3.63.182/32	10.3.63.182 – 10.3.63.182	10.3.63.182
56	10.3.63.183/32	10.3.63.183 – 10.3.63.183	10.3.63.183
57	10.3.63.184/32	10.3.63.184 – 10.3.63.184	10.3.63.184
58	10.3.63.185/32	10.3.63.185 – 10.3.63.185	10.3.63.185
59	10.3.63.186/32	10.3.63.186 – 10.3.63.186	10.3.63.186
60	10.3.63.187/32	10.3.63.187 – 10.3.63.187	10.3.63.187
61	10.3.63.188/32	10.3.63.188 – 10.3.63.188	10.3.63.188
62	10.3.63.189/32	10.3.63.189 – 10.3.63.189	10.3.63.189
63	10.3.63.190/32	10.3.63.190 – 10.3.63.190	10.3.63.190
64	10.3.63.191/32	10.3.63.191 – 10.3.63.191	10.3.63.191
65	10.3.63.192/32	10.3.63.192 – 10.3.63.192	10.3.63.192
66	10.3.63.193/32	10.3.63.193 – 10.3.63.193	10.3.63.193
67	10.3.63.194/32	10.3.63.194 – 10.3.63.194	10.3.63.194
68	10.3.63.195/32	10.3.63.195 – 10.3.63.195	10.3.63.195
69	10.3.63.196/32	10.3.63.196 – 10.3.63.196	10.3.63.196
70	10.3.63.197/32	10.3.63.197 – 10.3.63.197	10.3.63.197
71	10.3.63.198/32	10.3.63.198 – 10.3.63.198	10.3.63.198
72	10.3.63.199/32	10.3.63.199 – 10.3.63.199	10.3.63.199
73	10.3.63.200/32	10.3.63.200 – 10.3.63.200	10.3.63.200
74	10.3.63.201/32	10.3.63.201 – 10.3.63.201	10.3.63.201
75	10.3.63.202/32	10.3.63.202 – 10.3.63.202	10.3.63.202
76	10.3.63.203/32	10.3.63.203 – 10.3.63.203	10.3.63.203
77	10.3.63.204/32	10.3.63.204 – 10.3.63.204	10.3.63.204
78	10.3.63.205/32	10.3.63.205 – 10.3.63.205	10.3.63.205
79	10.3.63.206/32	10.3.63.206 – 10.3.63.206	10.3.63.206
80	10.3.63.207/32	10.3.63.207 – 10.3.63.207	10.3.63.207
81	10.3.63.208/32	10.3.63.208 – 10.3.63.208	10.3.63.208
82	10.3.63.209/32	10.3.63.209 – 10.3.63.209	10.3.63.209
83	10.3.63.210/32	10.3.63.210 – 10.3.63.210	10.3.63.210
84	10.3.63.211/32	10.3.63.211 – 10.3.63.211	10.3.63.211
85	10.3.63.212/32	10.3.63.212 – 10.3.63.212	10.3.63.212
86	10.3.63.213/32	10.3.63.213 – 10.3.63.213	10.3.63.213
87	10.3.63.214/32	10.3.63.214 – 10.3.63.214	10.3.63.214
88	10.3.63.215/32	10.3.63.215 – 10.3.63.215	10.3.63.215
89	10.3.63.216/32	10.3.63.216 – 10.3.63.216	10.3.63.216
90	10.3.63.217/32	10.3.63.217 – 10.3.63.217	10.3.63.217
91	10.3.63.218/32	10.3.63.218 – 10.3.63.218	10.3.63.218
92	10.3.63.219/32	10.3.63.219 – 10.3.63.219	10.3.63.219
93	10.3.63.220/32	10.3.63.220 – 10.3.63.220	10.3.63.220
94	10.3.63.221/32	10.3.63.221 – 10.3.63.221	10.3.63.221
95	10.3.63.222/32	10.3.63.222 – 10.3.63.222	10.3.63.222
96	10.3.63.223/32	10.3.63.223 – 10.3.63.223	10.3.63.223
97	10.3.63.224/32	10.3.63.224 – 10.3.63.224	10.3.63.224
98	10.3.63.225/32	10.3.63.225 – 10.3.63.225	10.3.63.225
99	10.3.63.226/32	10.3.63.226 – 10.3.63.226	10.3.63.226
100	10.3.63.227/32	10.3.63.227 – 10.3.63.227	10.3.63.227
101	10.3.63.228/32	10.3.63.228 – 10.3.63.228	10.3.63.228
102	10.3.63.229/32	10.3.63.229 – 10.3.63.229	10.3.63.229
103	10.3.63.230/32	10.3.63.230 – 10.3.63.230	10.3.63.230
104	10.3.63.231/32	10.3.63.231 – 10.3.63.231	10.3.63.231
105	10.3.63.232/32	10.3.63.232 – 10.3.63.232	10.3.63.232
106	10.3.63.233/32	10.3.63.233 – 10.3.63.233	10.3.63.233
107	10.3.63.234/32	10.3.63.234 – 10.3.63.234	10.3.63.234
108	10.3.63.235/32	10.3.63.235 – 10.3.63.235	10.3.63.235
109	10.3.63.236/32	10.3.63.236 – 10.3.63.236	10.3.63.236
110	10.3.63.237/32	10.3.63.237 – 10.3.63.237	10.3.63.237
111	10.3.63.238/32	10.3.63.238 – 10.3.63.238	10.3.63.238
112	10.3.63.239/32	10.3.63.239 – 10.3.63.239	10.3.63.239
113	10.3.63.240/32	10.3.63.240 – 10.3.63.240	10.3.63.240
114	10.3.63.241/32	10.3.63.241 – 10.3.63.241	10.3.63.241
115	10.3.63.242/32	10.3.63.242 – 10.3.63.242	10.3.63.242
116	10.3.63.243/32	10.3.63.243 – 10.3.63.243	10.3.63.243
117	10.3.63.244/32	10.3.63.244 – 10.3.63.244	10.3.63.244
118	10.3.63.245/32	10.3.63.245 – 10.3.63.245	10.3.63.245
119	10.3.63.246/32	10.3.63.246 – 10.3.63.246	10.3.63.246
120	10.3.63.247/32	10.3.63.247 – 10.3.63.247	10.3.63.247
121	10.3.63.248/32	10.3.63.248 – 10.3.63.248	10.3.63.248
122	10.3.63.249/32	10.3.63.249 – 10.3.63.249	10.3.63.249
123	10.3.63.250/32	10.3.63.250 – 10.3.63.250	10.3.63.250
124	10.3.63.251/32	10.3.63.251 – 10.3.63.251	10.3.63.251
125	10.3.63.252/32	10.3.63.252 – 10.3.63.252	10.3.63.252
126	10.3.63.253/32	10.3.63.253 – 10.3.63.253	10.3.63.253
127	10.3.63.254/32	10.3.63.254 – 10.3.63.254	10.3.63.254
128	10.3.63.255/32	10.3.63.255 – 10.3.63.255	10.3.63.255

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 →