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)10.0.17.128/25

network10.0.17.128/25

broadcast10.0.17.255

first host10.0.17.129

last host10.0.17.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.0.17.128/25

address00001010.00000000.00010001.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000000.00010001.10000000

broadcast00001010.00000000.00010001.11111111

green = network part, grey = host part

hex0x0a001180

decimal167776640

reverse dns128.17.0.10.in-addr.arpa

ipv4-mapped::ffff:a00:1180

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.0.17.128/32	10.0.17.128 – 10.0.17.128	10.0.17.128
2	10.0.17.129/32	10.0.17.129 – 10.0.17.129	10.0.17.129
3	10.0.17.130/32	10.0.17.130 – 10.0.17.130	10.0.17.130
4	10.0.17.131/32	10.0.17.131 – 10.0.17.131	10.0.17.131
5	10.0.17.132/32	10.0.17.132 – 10.0.17.132	10.0.17.132
6	10.0.17.133/32	10.0.17.133 – 10.0.17.133	10.0.17.133
7	10.0.17.134/32	10.0.17.134 – 10.0.17.134	10.0.17.134
8	10.0.17.135/32	10.0.17.135 – 10.0.17.135	10.0.17.135
9	10.0.17.136/32	10.0.17.136 – 10.0.17.136	10.0.17.136
10	10.0.17.137/32	10.0.17.137 – 10.0.17.137	10.0.17.137
11	10.0.17.138/32	10.0.17.138 – 10.0.17.138	10.0.17.138
12	10.0.17.139/32	10.0.17.139 – 10.0.17.139	10.0.17.139
13	10.0.17.140/32	10.0.17.140 – 10.0.17.140	10.0.17.140
14	10.0.17.141/32	10.0.17.141 – 10.0.17.141	10.0.17.141
15	10.0.17.142/32	10.0.17.142 – 10.0.17.142	10.0.17.142
16	10.0.17.143/32	10.0.17.143 – 10.0.17.143	10.0.17.143
17	10.0.17.144/32	10.0.17.144 – 10.0.17.144	10.0.17.144
18	10.0.17.145/32	10.0.17.145 – 10.0.17.145	10.0.17.145
19	10.0.17.146/32	10.0.17.146 – 10.0.17.146	10.0.17.146
20	10.0.17.147/32	10.0.17.147 – 10.0.17.147	10.0.17.147
21	10.0.17.148/32	10.0.17.148 – 10.0.17.148	10.0.17.148
22	10.0.17.149/32	10.0.17.149 – 10.0.17.149	10.0.17.149
23	10.0.17.150/32	10.0.17.150 – 10.0.17.150	10.0.17.150
24	10.0.17.151/32	10.0.17.151 – 10.0.17.151	10.0.17.151
25	10.0.17.152/32	10.0.17.152 – 10.0.17.152	10.0.17.152
26	10.0.17.153/32	10.0.17.153 – 10.0.17.153	10.0.17.153
27	10.0.17.154/32	10.0.17.154 – 10.0.17.154	10.0.17.154
28	10.0.17.155/32	10.0.17.155 – 10.0.17.155	10.0.17.155
29	10.0.17.156/32	10.0.17.156 – 10.0.17.156	10.0.17.156
30	10.0.17.157/32	10.0.17.157 – 10.0.17.157	10.0.17.157
31	10.0.17.158/32	10.0.17.158 – 10.0.17.158	10.0.17.158
32	10.0.17.159/32	10.0.17.159 – 10.0.17.159	10.0.17.159
33	10.0.17.160/32	10.0.17.160 – 10.0.17.160	10.0.17.160
34	10.0.17.161/32	10.0.17.161 – 10.0.17.161	10.0.17.161
35	10.0.17.162/32	10.0.17.162 – 10.0.17.162	10.0.17.162
36	10.0.17.163/32	10.0.17.163 – 10.0.17.163	10.0.17.163
37	10.0.17.164/32	10.0.17.164 – 10.0.17.164	10.0.17.164
38	10.0.17.165/32	10.0.17.165 – 10.0.17.165	10.0.17.165
39	10.0.17.166/32	10.0.17.166 – 10.0.17.166	10.0.17.166
40	10.0.17.167/32	10.0.17.167 – 10.0.17.167	10.0.17.167
41	10.0.17.168/32	10.0.17.168 – 10.0.17.168	10.0.17.168
42	10.0.17.169/32	10.0.17.169 – 10.0.17.169	10.0.17.169
43	10.0.17.170/32	10.0.17.170 – 10.0.17.170	10.0.17.170
44	10.0.17.171/32	10.0.17.171 – 10.0.17.171	10.0.17.171
45	10.0.17.172/32	10.0.17.172 – 10.0.17.172	10.0.17.172
46	10.0.17.173/32	10.0.17.173 – 10.0.17.173	10.0.17.173
47	10.0.17.174/32	10.0.17.174 – 10.0.17.174	10.0.17.174
48	10.0.17.175/32	10.0.17.175 – 10.0.17.175	10.0.17.175
49	10.0.17.176/32	10.0.17.176 – 10.0.17.176	10.0.17.176
50	10.0.17.177/32	10.0.17.177 – 10.0.17.177	10.0.17.177
51	10.0.17.178/32	10.0.17.178 – 10.0.17.178	10.0.17.178
52	10.0.17.179/32	10.0.17.179 – 10.0.17.179	10.0.17.179
53	10.0.17.180/32	10.0.17.180 – 10.0.17.180	10.0.17.180
54	10.0.17.181/32	10.0.17.181 – 10.0.17.181	10.0.17.181
55	10.0.17.182/32	10.0.17.182 – 10.0.17.182	10.0.17.182
56	10.0.17.183/32	10.0.17.183 – 10.0.17.183	10.0.17.183
57	10.0.17.184/32	10.0.17.184 – 10.0.17.184	10.0.17.184
58	10.0.17.185/32	10.0.17.185 – 10.0.17.185	10.0.17.185
59	10.0.17.186/32	10.0.17.186 – 10.0.17.186	10.0.17.186
60	10.0.17.187/32	10.0.17.187 – 10.0.17.187	10.0.17.187
61	10.0.17.188/32	10.0.17.188 – 10.0.17.188	10.0.17.188
62	10.0.17.189/32	10.0.17.189 – 10.0.17.189	10.0.17.189
63	10.0.17.190/32	10.0.17.190 – 10.0.17.190	10.0.17.190
64	10.0.17.191/32	10.0.17.191 – 10.0.17.191	10.0.17.191
65	10.0.17.192/32	10.0.17.192 – 10.0.17.192	10.0.17.192
66	10.0.17.193/32	10.0.17.193 – 10.0.17.193	10.0.17.193
67	10.0.17.194/32	10.0.17.194 – 10.0.17.194	10.0.17.194
68	10.0.17.195/32	10.0.17.195 – 10.0.17.195	10.0.17.195
69	10.0.17.196/32	10.0.17.196 – 10.0.17.196	10.0.17.196
70	10.0.17.197/32	10.0.17.197 – 10.0.17.197	10.0.17.197
71	10.0.17.198/32	10.0.17.198 – 10.0.17.198	10.0.17.198
72	10.0.17.199/32	10.0.17.199 – 10.0.17.199	10.0.17.199
73	10.0.17.200/32	10.0.17.200 – 10.0.17.200	10.0.17.200
74	10.0.17.201/32	10.0.17.201 – 10.0.17.201	10.0.17.201
75	10.0.17.202/32	10.0.17.202 – 10.0.17.202	10.0.17.202
76	10.0.17.203/32	10.0.17.203 – 10.0.17.203	10.0.17.203
77	10.0.17.204/32	10.0.17.204 – 10.0.17.204	10.0.17.204
78	10.0.17.205/32	10.0.17.205 – 10.0.17.205	10.0.17.205
79	10.0.17.206/32	10.0.17.206 – 10.0.17.206	10.0.17.206
80	10.0.17.207/32	10.0.17.207 – 10.0.17.207	10.0.17.207
81	10.0.17.208/32	10.0.17.208 – 10.0.17.208	10.0.17.208
82	10.0.17.209/32	10.0.17.209 – 10.0.17.209	10.0.17.209
83	10.0.17.210/32	10.0.17.210 – 10.0.17.210	10.0.17.210
84	10.0.17.211/32	10.0.17.211 – 10.0.17.211	10.0.17.211
85	10.0.17.212/32	10.0.17.212 – 10.0.17.212	10.0.17.212
86	10.0.17.213/32	10.0.17.213 – 10.0.17.213	10.0.17.213
87	10.0.17.214/32	10.0.17.214 – 10.0.17.214	10.0.17.214
88	10.0.17.215/32	10.0.17.215 – 10.0.17.215	10.0.17.215
89	10.0.17.216/32	10.0.17.216 – 10.0.17.216	10.0.17.216
90	10.0.17.217/32	10.0.17.217 – 10.0.17.217	10.0.17.217
91	10.0.17.218/32	10.0.17.218 – 10.0.17.218	10.0.17.218
92	10.0.17.219/32	10.0.17.219 – 10.0.17.219	10.0.17.219
93	10.0.17.220/32	10.0.17.220 – 10.0.17.220	10.0.17.220
94	10.0.17.221/32	10.0.17.221 – 10.0.17.221	10.0.17.221
95	10.0.17.222/32	10.0.17.222 – 10.0.17.222	10.0.17.222
96	10.0.17.223/32	10.0.17.223 – 10.0.17.223	10.0.17.223
97	10.0.17.224/32	10.0.17.224 – 10.0.17.224	10.0.17.224
98	10.0.17.225/32	10.0.17.225 – 10.0.17.225	10.0.17.225
99	10.0.17.226/32	10.0.17.226 – 10.0.17.226	10.0.17.226
100	10.0.17.227/32	10.0.17.227 – 10.0.17.227	10.0.17.227
101	10.0.17.228/32	10.0.17.228 – 10.0.17.228	10.0.17.228
102	10.0.17.229/32	10.0.17.229 – 10.0.17.229	10.0.17.229
103	10.0.17.230/32	10.0.17.230 – 10.0.17.230	10.0.17.230
104	10.0.17.231/32	10.0.17.231 – 10.0.17.231	10.0.17.231
105	10.0.17.232/32	10.0.17.232 – 10.0.17.232	10.0.17.232
106	10.0.17.233/32	10.0.17.233 – 10.0.17.233	10.0.17.233
107	10.0.17.234/32	10.0.17.234 – 10.0.17.234	10.0.17.234
108	10.0.17.235/32	10.0.17.235 – 10.0.17.235	10.0.17.235
109	10.0.17.236/32	10.0.17.236 – 10.0.17.236	10.0.17.236
110	10.0.17.237/32	10.0.17.237 – 10.0.17.237	10.0.17.237
111	10.0.17.238/32	10.0.17.238 – 10.0.17.238	10.0.17.238
112	10.0.17.239/32	10.0.17.239 – 10.0.17.239	10.0.17.239
113	10.0.17.240/32	10.0.17.240 – 10.0.17.240	10.0.17.240
114	10.0.17.241/32	10.0.17.241 – 10.0.17.241	10.0.17.241
115	10.0.17.242/32	10.0.17.242 – 10.0.17.242	10.0.17.242
116	10.0.17.243/32	10.0.17.243 – 10.0.17.243	10.0.17.243
117	10.0.17.244/32	10.0.17.244 – 10.0.17.244	10.0.17.244
118	10.0.17.245/32	10.0.17.245 – 10.0.17.245	10.0.17.245
119	10.0.17.246/32	10.0.17.246 – 10.0.17.246	10.0.17.246
120	10.0.17.247/32	10.0.17.247 – 10.0.17.247	10.0.17.247
121	10.0.17.248/32	10.0.17.248 – 10.0.17.248	10.0.17.248
122	10.0.17.249/32	10.0.17.249 – 10.0.17.249	10.0.17.249
123	10.0.17.250/32	10.0.17.250 – 10.0.17.250	10.0.17.250
124	10.0.17.251/32	10.0.17.251 – 10.0.17.251	10.0.17.251
125	10.0.17.252/32	10.0.17.252 – 10.0.17.252	10.0.17.252
126	10.0.17.253/32	10.0.17.253 – 10.0.17.253	10.0.17.253
127	10.0.17.254/32	10.0.17.254 – 10.0.17.254	10.0.17.254
128	10.0.17.255/32	10.0.17.255 – 10.0.17.255	10.0.17.255

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 →