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)10.0.33.128/25

network10.0.33.128/25

broadcast10.0.33.255

first host10.0.33.129

last host10.0.33.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.0.33.128/25

address00001010.00000000.00100001.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000000.00100001.10000000

broadcast00001010.00000000.00100001.11111111

green = network part, grey = host part

hex0x0a002180

decimal167780736

reverse dns128.33.0.10.in-addr.arpa

ipv4-mapped::ffff:a00:2180

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.0.33.128/32	10.0.33.128 – 10.0.33.128	10.0.33.128
2	10.0.33.129/32	10.0.33.129 – 10.0.33.129	10.0.33.129
3	10.0.33.130/32	10.0.33.130 – 10.0.33.130	10.0.33.130
4	10.0.33.131/32	10.0.33.131 – 10.0.33.131	10.0.33.131
5	10.0.33.132/32	10.0.33.132 – 10.0.33.132	10.0.33.132
6	10.0.33.133/32	10.0.33.133 – 10.0.33.133	10.0.33.133
7	10.0.33.134/32	10.0.33.134 – 10.0.33.134	10.0.33.134
8	10.0.33.135/32	10.0.33.135 – 10.0.33.135	10.0.33.135
9	10.0.33.136/32	10.0.33.136 – 10.0.33.136	10.0.33.136
10	10.0.33.137/32	10.0.33.137 – 10.0.33.137	10.0.33.137
11	10.0.33.138/32	10.0.33.138 – 10.0.33.138	10.0.33.138
12	10.0.33.139/32	10.0.33.139 – 10.0.33.139	10.0.33.139
13	10.0.33.140/32	10.0.33.140 – 10.0.33.140	10.0.33.140
14	10.0.33.141/32	10.0.33.141 – 10.0.33.141	10.0.33.141
15	10.0.33.142/32	10.0.33.142 – 10.0.33.142	10.0.33.142
16	10.0.33.143/32	10.0.33.143 – 10.0.33.143	10.0.33.143
17	10.0.33.144/32	10.0.33.144 – 10.0.33.144	10.0.33.144
18	10.0.33.145/32	10.0.33.145 – 10.0.33.145	10.0.33.145
19	10.0.33.146/32	10.0.33.146 – 10.0.33.146	10.0.33.146
20	10.0.33.147/32	10.0.33.147 – 10.0.33.147	10.0.33.147
21	10.0.33.148/32	10.0.33.148 – 10.0.33.148	10.0.33.148
22	10.0.33.149/32	10.0.33.149 – 10.0.33.149	10.0.33.149
23	10.0.33.150/32	10.0.33.150 – 10.0.33.150	10.0.33.150
24	10.0.33.151/32	10.0.33.151 – 10.0.33.151	10.0.33.151
25	10.0.33.152/32	10.0.33.152 – 10.0.33.152	10.0.33.152
26	10.0.33.153/32	10.0.33.153 – 10.0.33.153	10.0.33.153
27	10.0.33.154/32	10.0.33.154 – 10.0.33.154	10.0.33.154
28	10.0.33.155/32	10.0.33.155 – 10.0.33.155	10.0.33.155
29	10.0.33.156/32	10.0.33.156 – 10.0.33.156	10.0.33.156
30	10.0.33.157/32	10.0.33.157 – 10.0.33.157	10.0.33.157
31	10.0.33.158/32	10.0.33.158 – 10.0.33.158	10.0.33.158
32	10.0.33.159/32	10.0.33.159 – 10.0.33.159	10.0.33.159
33	10.0.33.160/32	10.0.33.160 – 10.0.33.160	10.0.33.160
34	10.0.33.161/32	10.0.33.161 – 10.0.33.161	10.0.33.161
35	10.0.33.162/32	10.0.33.162 – 10.0.33.162	10.0.33.162
36	10.0.33.163/32	10.0.33.163 – 10.0.33.163	10.0.33.163
37	10.0.33.164/32	10.0.33.164 – 10.0.33.164	10.0.33.164
38	10.0.33.165/32	10.0.33.165 – 10.0.33.165	10.0.33.165
39	10.0.33.166/32	10.0.33.166 – 10.0.33.166	10.0.33.166
40	10.0.33.167/32	10.0.33.167 – 10.0.33.167	10.0.33.167
41	10.0.33.168/32	10.0.33.168 – 10.0.33.168	10.0.33.168
42	10.0.33.169/32	10.0.33.169 – 10.0.33.169	10.0.33.169
43	10.0.33.170/32	10.0.33.170 – 10.0.33.170	10.0.33.170
44	10.0.33.171/32	10.0.33.171 – 10.0.33.171	10.0.33.171
45	10.0.33.172/32	10.0.33.172 – 10.0.33.172	10.0.33.172
46	10.0.33.173/32	10.0.33.173 – 10.0.33.173	10.0.33.173
47	10.0.33.174/32	10.0.33.174 – 10.0.33.174	10.0.33.174
48	10.0.33.175/32	10.0.33.175 – 10.0.33.175	10.0.33.175
49	10.0.33.176/32	10.0.33.176 – 10.0.33.176	10.0.33.176
50	10.0.33.177/32	10.0.33.177 – 10.0.33.177	10.0.33.177
51	10.0.33.178/32	10.0.33.178 – 10.0.33.178	10.0.33.178
52	10.0.33.179/32	10.0.33.179 – 10.0.33.179	10.0.33.179
53	10.0.33.180/32	10.0.33.180 – 10.0.33.180	10.0.33.180
54	10.0.33.181/32	10.0.33.181 – 10.0.33.181	10.0.33.181
55	10.0.33.182/32	10.0.33.182 – 10.0.33.182	10.0.33.182
56	10.0.33.183/32	10.0.33.183 – 10.0.33.183	10.0.33.183
57	10.0.33.184/32	10.0.33.184 – 10.0.33.184	10.0.33.184
58	10.0.33.185/32	10.0.33.185 – 10.0.33.185	10.0.33.185
59	10.0.33.186/32	10.0.33.186 – 10.0.33.186	10.0.33.186
60	10.0.33.187/32	10.0.33.187 – 10.0.33.187	10.0.33.187
61	10.0.33.188/32	10.0.33.188 – 10.0.33.188	10.0.33.188
62	10.0.33.189/32	10.0.33.189 – 10.0.33.189	10.0.33.189
63	10.0.33.190/32	10.0.33.190 – 10.0.33.190	10.0.33.190
64	10.0.33.191/32	10.0.33.191 – 10.0.33.191	10.0.33.191
65	10.0.33.192/32	10.0.33.192 – 10.0.33.192	10.0.33.192
66	10.0.33.193/32	10.0.33.193 – 10.0.33.193	10.0.33.193
67	10.0.33.194/32	10.0.33.194 – 10.0.33.194	10.0.33.194
68	10.0.33.195/32	10.0.33.195 – 10.0.33.195	10.0.33.195
69	10.0.33.196/32	10.0.33.196 – 10.0.33.196	10.0.33.196
70	10.0.33.197/32	10.0.33.197 – 10.0.33.197	10.0.33.197
71	10.0.33.198/32	10.0.33.198 – 10.0.33.198	10.0.33.198
72	10.0.33.199/32	10.0.33.199 – 10.0.33.199	10.0.33.199
73	10.0.33.200/32	10.0.33.200 – 10.0.33.200	10.0.33.200
74	10.0.33.201/32	10.0.33.201 – 10.0.33.201	10.0.33.201
75	10.0.33.202/32	10.0.33.202 – 10.0.33.202	10.0.33.202
76	10.0.33.203/32	10.0.33.203 – 10.0.33.203	10.0.33.203
77	10.0.33.204/32	10.0.33.204 – 10.0.33.204	10.0.33.204
78	10.0.33.205/32	10.0.33.205 – 10.0.33.205	10.0.33.205
79	10.0.33.206/32	10.0.33.206 – 10.0.33.206	10.0.33.206
80	10.0.33.207/32	10.0.33.207 – 10.0.33.207	10.0.33.207
81	10.0.33.208/32	10.0.33.208 – 10.0.33.208	10.0.33.208
82	10.0.33.209/32	10.0.33.209 – 10.0.33.209	10.0.33.209
83	10.0.33.210/32	10.0.33.210 – 10.0.33.210	10.0.33.210
84	10.0.33.211/32	10.0.33.211 – 10.0.33.211	10.0.33.211
85	10.0.33.212/32	10.0.33.212 – 10.0.33.212	10.0.33.212
86	10.0.33.213/32	10.0.33.213 – 10.0.33.213	10.0.33.213
87	10.0.33.214/32	10.0.33.214 – 10.0.33.214	10.0.33.214
88	10.0.33.215/32	10.0.33.215 – 10.0.33.215	10.0.33.215
89	10.0.33.216/32	10.0.33.216 – 10.0.33.216	10.0.33.216
90	10.0.33.217/32	10.0.33.217 – 10.0.33.217	10.0.33.217
91	10.0.33.218/32	10.0.33.218 – 10.0.33.218	10.0.33.218
92	10.0.33.219/32	10.0.33.219 – 10.0.33.219	10.0.33.219
93	10.0.33.220/32	10.0.33.220 – 10.0.33.220	10.0.33.220
94	10.0.33.221/32	10.0.33.221 – 10.0.33.221	10.0.33.221
95	10.0.33.222/32	10.0.33.222 – 10.0.33.222	10.0.33.222
96	10.0.33.223/32	10.0.33.223 – 10.0.33.223	10.0.33.223
97	10.0.33.224/32	10.0.33.224 – 10.0.33.224	10.0.33.224
98	10.0.33.225/32	10.0.33.225 – 10.0.33.225	10.0.33.225
99	10.0.33.226/32	10.0.33.226 – 10.0.33.226	10.0.33.226
100	10.0.33.227/32	10.0.33.227 – 10.0.33.227	10.0.33.227
101	10.0.33.228/32	10.0.33.228 – 10.0.33.228	10.0.33.228
102	10.0.33.229/32	10.0.33.229 – 10.0.33.229	10.0.33.229
103	10.0.33.230/32	10.0.33.230 – 10.0.33.230	10.0.33.230
104	10.0.33.231/32	10.0.33.231 – 10.0.33.231	10.0.33.231
105	10.0.33.232/32	10.0.33.232 – 10.0.33.232	10.0.33.232
106	10.0.33.233/32	10.0.33.233 – 10.0.33.233	10.0.33.233
107	10.0.33.234/32	10.0.33.234 – 10.0.33.234	10.0.33.234
108	10.0.33.235/32	10.0.33.235 – 10.0.33.235	10.0.33.235
109	10.0.33.236/32	10.0.33.236 – 10.0.33.236	10.0.33.236
110	10.0.33.237/32	10.0.33.237 – 10.0.33.237	10.0.33.237
111	10.0.33.238/32	10.0.33.238 – 10.0.33.238	10.0.33.238
112	10.0.33.239/32	10.0.33.239 – 10.0.33.239	10.0.33.239
113	10.0.33.240/32	10.0.33.240 – 10.0.33.240	10.0.33.240
114	10.0.33.241/32	10.0.33.241 – 10.0.33.241	10.0.33.241
115	10.0.33.242/32	10.0.33.242 – 10.0.33.242	10.0.33.242
116	10.0.33.243/32	10.0.33.243 – 10.0.33.243	10.0.33.243
117	10.0.33.244/32	10.0.33.244 – 10.0.33.244	10.0.33.244
118	10.0.33.245/32	10.0.33.245 – 10.0.33.245	10.0.33.245
119	10.0.33.246/32	10.0.33.246 – 10.0.33.246	10.0.33.246
120	10.0.33.247/32	10.0.33.247 – 10.0.33.247	10.0.33.247
121	10.0.33.248/32	10.0.33.248 – 10.0.33.248	10.0.33.248
122	10.0.33.249/32	10.0.33.249 – 10.0.33.249	10.0.33.249
123	10.0.33.250/32	10.0.33.250 – 10.0.33.250	10.0.33.250
124	10.0.33.251/32	10.0.33.251 – 10.0.33.251	10.0.33.251
125	10.0.33.252/32	10.0.33.252 – 10.0.33.252	10.0.33.252
126	10.0.33.253/32	10.0.33.253 – 10.0.33.253	10.0.33.253
127	10.0.33.254/32	10.0.33.254 – 10.0.33.254	10.0.33.254
128	10.0.33.255/32	10.0.33.255 – 10.0.33.255	10.0.33.255

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 →