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)10.2.217.128/25

network10.2.217.128/25

broadcast10.2.217.255

first host10.2.217.129

last host10.2.217.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.2.217.128/25

address00001010.00000010.11011001.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000010.11011001.10000000

broadcast00001010.00000010.11011001.11111111

green = network part, grey = host part

hex0x0a02d980

decimal167958912

reverse dns128.217.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:d980

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.217.128/32	10.2.217.128 – 10.2.217.128	10.2.217.128
2	10.2.217.129/32	10.2.217.129 – 10.2.217.129	10.2.217.129
3	10.2.217.130/32	10.2.217.130 – 10.2.217.130	10.2.217.130
4	10.2.217.131/32	10.2.217.131 – 10.2.217.131	10.2.217.131
5	10.2.217.132/32	10.2.217.132 – 10.2.217.132	10.2.217.132
6	10.2.217.133/32	10.2.217.133 – 10.2.217.133	10.2.217.133
7	10.2.217.134/32	10.2.217.134 – 10.2.217.134	10.2.217.134
8	10.2.217.135/32	10.2.217.135 – 10.2.217.135	10.2.217.135
9	10.2.217.136/32	10.2.217.136 – 10.2.217.136	10.2.217.136
10	10.2.217.137/32	10.2.217.137 – 10.2.217.137	10.2.217.137
11	10.2.217.138/32	10.2.217.138 – 10.2.217.138	10.2.217.138
12	10.2.217.139/32	10.2.217.139 – 10.2.217.139	10.2.217.139
13	10.2.217.140/32	10.2.217.140 – 10.2.217.140	10.2.217.140
14	10.2.217.141/32	10.2.217.141 – 10.2.217.141	10.2.217.141
15	10.2.217.142/32	10.2.217.142 – 10.2.217.142	10.2.217.142
16	10.2.217.143/32	10.2.217.143 – 10.2.217.143	10.2.217.143
17	10.2.217.144/32	10.2.217.144 – 10.2.217.144	10.2.217.144
18	10.2.217.145/32	10.2.217.145 – 10.2.217.145	10.2.217.145
19	10.2.217.146/32	10.2.217.146 – 10.2.217.146	10.2.217.146
20	10.2.217.147/32	10.2.217.147 – 10.2.217.147	10.2.217.147
21	10.2.217.148/32	10.2.217.148 – 10.2.217.148	10.2.217.148
22	10.2.217.149/32	10.2.217.149 – 10.2.217.149	10.2.217.149
23	10.2.217.150/32	10.2.217.150 – 10.2.217.150	10.2.217.150
24	10.2.217.151/32	10.2.217.151 – 10.2.217.151	10.2.217.151
25	10.2.217.152/32	10.2.217.152 – 10.2.217.152	10.2.217.152
26	10.2.217.153/32	10.2.217.153 – 10.2.217.153	10.2.217.153
27	10.2.217.154/32	10.2.217.154 – 10.2.217.154	10.2.217.154
28	10.2.217.155/32	10.2.217.155 – 10.2.217.155	10.2.217.155
29	10.2.217.156/32	10.2.217.156 – 10.2.217.156	10.2.217.156
30	10.2.217.157/32	10.2.217.157 – 10.2.217.157	10.2.217.157
31	10.2.217.158/32	10.2.217.158 – 10.2.217.158	10.2.217.158
32	10.2.217.159/32	10.2.217.159 – 10.2.217.159	10.2.217.159
33	10.2.217.160/32	10.2.217.160 – 10.2.217.160	10.2.217.160
34	10.2.217.161/32	10.2.217.161 – 10.2.217.161	10.2.217.161
35	10.2.217.162/32	10.2.217.162 – 10.2.217.162	10.2.217.162
36	10.2.217.163/32	10.2.217.163 – 10.2.217.163	10.2.217.163
37	10.2.217.164/32	10.2.217.164 – 10.2.217.164	10.2.217.164
38	10.2.217.165/32	10.2.217.165 – 10.2.217.165	10.2.217.165
39	10.2.217.166/32	10.2.217.166 – 10.2.217.166	10.2.217.166
40	10.2.217.167/32	10.2.217.167 – 10.2.217.167	10.2.217.167
41	10.2.217.168/32	10.2.217.168 – 10.2.217.168	10.2.217.168
42	10.2.217.169/32	10.2.217.169 – 10.2.217.169	10.2.217.169
43	10.2.217.170/32	10.2.217.170 – 10.2.217.170	10.2.217.170
44	10.2.217.171/32	10.2.217.171 – 10.2.217.171	10.2.217.171
45	10.2.217.172/32	10.2.217.172 – 10.2.217.172	10.2.217.172
46	10.2.217.173/32	10.2.217.173 – 10.2.217.173	10.2.217.173
47	10.2.217.174/32	10.2.217.174 – 10.2.217.174	10.2.217.174
48	10.2.217.175/32	10.2.217.175 – 10.2.217.175	10.2.217.175
49	10.2.217.176/32	10.2.217.176 – 10.2.217.176	10.2.217.176
50	10.2.217.177/32	10.2.217.177 – 10.2.217.177	10.2.217.177
51	10.2.217.178/32	10.2.217.178 – 10.2.217.178	10.2.217.178
52	10.2.217.179/32	10.2.217.179 – 10.2.217.179	10.2.217.179
53	10.2.217.180/32	10.2.217.180 – 10.2.217.180	10.2.217.180
54	10.2.217.181/32	10.2.217.181 – 10.2.217.181	10.2.217.181
55	10.2.217.182/32	10.2.217.182 – 10.2.217.182	10.2.217.182
56	10.2.217.183/32	10.2.217.183 – 10.2.217.183	10.2.217.183
57	10.2.217.184/32	10.2.217.184 – 10.2.217.184	10.2.217.184
58	10.2.217.185/32	10.2.217.185 – 10.2.217.185	10.2.217.185
59	10.2.217.186/32	10.2.217.186 – 10.2.217.186	10.2.217.186
60	10.2.217.187/32	10.2.217.187 – 10.2.217.187	10.2.217.187
61	10.2.217.188/32	10.2.217.188 – 10.2.217.188	10.2.217.188
62	10.2.217.189/32	10.2.217.189 – 10.2.217.189	10.2.217.189
63	10.2.217.190/32	10.2.217.190 – 10.2.217.190	10.2.217.190
64	10.2.217.191/32	10.2.217.191 – 10.2.217.191	10.2.217.191
65	10.2.217.192/32	10.2.217.192 – 10.2.217.192	10.2.217.192
66	10.2.217.193/32	10.2.217.193 – 10.2.217.193	10.2.217.193
67	10.2.217.194/32	10.2.217.194 – 10.2.217.194	10.2.217.194
68	10.2.217.195/32	10.2.217.195 – 10.2.217.195	10.2.217.195
69	10.2.217.196/32	10.2.217.196 – 10.2.217.196	10.2.217.196
70	10.2.217.197/32	10.2.217.197 – 10.2.217.197	10.2.217.197
71	10.2.217.198/32	10.2.217.198 – 10.2.217.198	10.2.217.198
72	10.2.217.199/32	10.2.217.199 – 10.2.217.199	10.2.217.199
73	10.2.217.200/32	10.2.217.200 – 10.2.217.200	10.2.217.200
74	10.2.217.201/32	10.2.217.201 – 10.2.217.201	10.2.217.201
75	10.2.217.202/32	10.2.217.202 – 10.2.217.202	10.2.217.202
76	10.2.217.203/32	10.2.217.203 – 10.2.217.203	10.2.217.203
77	10.2.217.204/32	10.2.217.204 – 10.2.217.204	10.2.217.204
78	10.2.217.205/32	10.2.217.205 – 10.2.217.205	10.2.217.205
79	10.2.217.206/32	10.2.217.206 – 10.2.217.206	10.2.217.206
80	10.2.217.207/32	10.2.217.207 – 10.2.217.207	10.2.217.207
81	10.2.217.208/32	10.2.217.208 – 10.2.217.208	10.2.217.208
82	10.2.217.209/32	10.2.217.209 – 10.2.217.209	10.2.217.209
83	10.2.217.210/32	10.2.217.210 – 10.2.217.210	10.2.217.210
84	10.2.217.211/32	10.2.217.211 – 10.2.217.211	10.2.217.211
85	10.2.217.212/32	10.2.217.212 – 10.2.217.212	10.2.217.212
86	10.2.217.213/32	10.2.217.213 – 10.2.217.213	10.2.217.213
87	10.2.217.214/32	10.2.217.214 – 10.2.217.214	10.2.217.214
88	10.2.217.215/32	10.2.217.215 – 10.2.217.215	10.2.217.215
89	10.2.217.216/32	10.2.217.216 – 10.2.217.216	10.2.217.216
90	10.2.217.217/32	10.2.217.217 – 10.2.217.217	10.2.217.217
91	10.2.217.218/32	10.2.217.218 – 10.2.217.218	10.2.217.218
92	10.2.217.219/32	10.2.217.219 – 10.2.217.219	10.2.217.219
93	10.2.217.220/32	10.2.217.220 – 10.2.217.220	10.2.217.220
94	10.2.217.221/32	10.2.217.221 – 10.2.217.221	10.2.217.221
95	10.2.217.222/32	10.2.217.222 – 10.2.217.222	10.2.217.222
96	10.2.217.223/32	10.2.217.223 – 10.2.217.223	10.2.217.223
97	10.2.217.224/32	10.2.217.224 – 10.2.217.224	10.2.217.224
98	10.2.217.225/32	10.2.217.225 – 10.2.217.225	10.2.217.225
99	10.2.217.226/32	10.2.217.226 – 10.2.217.226	10.2.217.226
100	10.2.217.227/32	10.2.217.227 – 10.2.217.227	10.2.217.227
101	10.2.217.228/32	10.2.217.228 – 10.2.217.228	10.2.217.228
102	10.2.217.229/32	10.2.217.229 – 10.2.217.229	10.2.217.229
103	10.2.217.230/32	10.2.217.230 – 10.2.217.230	10.2.217.230
104	10.2.217.231/32	10.2.217.231 – 10.2.217.231	10.2.217.231
105	10.2.217.232/32	10.2.217.232 – 10.2.217.232	10.2.217.232
106	10.2.217.233/32	10.2.217.233 – 10.2.217.233	10.2.217.233
107	10.2.217.234/32	10.2.217.234 – 10.2.217.234	10.2.217.234
108	10.2.217.235/32	10.2.217.235 – 10.2.217.235	10.2.217.235
109	10.2.217.236/32	10.2.217.236 – 10.2.217.236	10.2.217.236
110	10.2.217.237/32	10.2.217.237 – 10.2.217.237	10.2.217.237
111	10.2.217.238/32	10.2.217.238 – 10.2.217.238	10.2.217.238
112	10.2.217.239/32	10.2.217.239 – 10.2.217.239	10.2.217.239
113	10.2.217.240/32	10.2.217.240 – 10.2.217.240	10.2.217.240
114	10.2.217.241/32	10.2.217.241 – 10.2.217.241	10.2.217.241
115	10.2.217.242/32	10.2.217.242 – 10.2.217.242	10.2.217.242
116	10.2.217.243/32	10.2.217.243 – 10.2.217.243	10.2.217.243
117	10.2.217.244/32	10.2.217.244 – 10.2.217.244	10.2.217.244
118	10.2.217.245/32	10.2.217.245 – 10.2.217.245	10.2.217.245
119	10.2.217.246/32	10.2.217.246 – 10.2.217.246	10.2.217.246
120	10.2.217.247/32	10.2.217.247 – 10.2.217.247	10.2.217.247
121	10.2.217.248/32	10.2.217.248 – 10.2.217.248	10.2.217.248
122	10.2.217.249/32	10.2.217.249 – 10.2.217.249	10.2.217.249
123	10.2.217.250/32	10.2.217.250 – 10.2.217.250	10.2.217.250
124	10.2.217.251/32	10.2.217.251 – 10.2.217.251	10.2.217.251
125	10.2.217.252/32	10.2.217.252 – 10.2.217.252	10.2.217.252
126	10.2.217.253/32	10.2.217.253 – 10.2.217.253	10.2.217.253
127	10.2.217.254/32	10.2.217.254 – 10.2.217.254	10.2.217.254
128	10.2.217.255/32	10.2.217.255 – 10.2.217.255	10.2.217.255

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 →