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)10.3.99.128/25

network10.3.99.128/25

broadcast10.3.99.255

first host10.3.99.129

last host10.3.99.254

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.3.99.128/25

address00001010.00000011.01100011.10000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000011.01100011.10000000

broadcast00001010.00000011.01100011.11111111

green = network part, grey = host part

hex0x0a036380

decimal167994240

reverse dns128.99.3.10.in-addr.arpa

ipv4-mapped::ffff:a03:6380

/25 split into /32 · 128 subnets

close ×

#	network	host range	broadcast
1	10.3.99.128/32	10.3.99.128 – 10.3.99.128	10.3.99.128
2	10.3.99.129/32	10.3.99.129 – 10.3.99.129	10.3.99.129
3	10.3.99.130/32	10.3.99.130 – 10.3.99.130	10.3.99.130
4	10.3.99.131/32	10.3.99.131 – 10.3.99.131	10.3.99.131
5	10.3.99.132/32	10.3.99.132 – 10.3.99.132	10.3.99.132
6	10.3.99.133/32	10.3.99.133 – 10.3.99.133	10.3.99.133
7	10.3.99.134/32	10.3.99.134 – 10.3.99.134	10.3.99.134
8	10.3.99.135/32	10.3.99.135 – 10.3.99.135	10.3.99.135
9	10.3.99.136/32	10.3.99.136 – 10.3.99.136	10.3.99.136
10	10.3.99.137/32	10.3.99.137 – 10.3.99.137	10.3.99.137
11	10.3.99.138/32	10.3.99.138 – 10.3.99.138	10.3.99.138
12	10.3.99.139/32	10.3.99.139 – 10.3.99.139	10.3.99.139
13	10.3.99.140/32	10.3.99.140 – 10.3.99.140	10.3.99.140
14	10.3.99.141/32	10.3.99.141 – 10.3.99.141	10.3.99.141
15	10.3.99.142/32	10.3.99.142 – 10.3.99.142	10.3.99.142
16	10.3.99.143/32	10.3.99.143 – 10.3.99.143	10.3.99.143
17	10.3.99.144/32	10.3.99.144 – 10.3.99.144	10.3.99.144
18	10.3.99.145/32	10.3.99.145 – 10.3.99.145	10.3.99.145
19	10.3.99.146/32	10.3.99.146 – 10.3.99.146	10.3.99.146
20	10.3.99.147/32	10.3.99.147 – 10.3.99.147	10.3.99.147
21	10.3.99.148/32	10.3.99.148 – 10.3.99.148	10.3.99.148
22	10.3.99.149/32	10.3.99.149 – 10.3.99.149	10.3.99.149
23	10.3.99.150/32	10.3.99.150 – 10.3.99.150	10.3.99.150
24	10.3.99.151/32	10.3.99.151 – 10.3.99.151	10.3.99.151
25	10.3.99.152/32	10.3.99.152 – 10.3.99.152	10.3.99.152
26	10.3.99.153/32	10.3.99.153 – 10.3.99.153	10.3.99.153
27	10.3.99.154/32	10.3.99.154 – 10.3.99.154	10.3.99.154
28	10.3.99.155/32	10.3.99.155 – 10.3.99.155	10.3.99.155
29	10.3.99.156/32	10.3.99.156 – 10.3.99.156	10.3.99.156
30	10.3.99.157/32	10.3.99.157 – 10.3.99.157	10.3.99.157
31	10.3.99.158/32	10.3.99.158 – 10.3.99.158	10.3.99.158
32	10.3.99.159/32	10.3.99.159 – 10.3.99.159	10.3.99.159
33	10.3.99.160/32	10.3.99.160 – 10.3.99.160	10.3.99.160
34	10.3.99.161/32	10.3.99.161 – 10.3.99.161	10.3.99.161
35	10.3.99.162/32	10.3.99.162 – 10.3.99.162	10.3.99.162
36	10.3.99.163/32	10.3.99.163 – 10.3.99.163	10.3.99.163
37	10.3.99.164/32	10.3.99.164 – 10.3.99.164	10.3.99.164
38	10.3.99.165/32	10.3.99.165 – 10.3.99.165	10.3.99.165
39	10.3.99.166/32	10.3.99.166 – 10.3.99.166	10.3.99.166
40	10.3.99.167/32	10.3.99.167 – 10.3.99.167	10.3.99.167
41	10.3.99.168/32	10.3.99.168 – 10.3.99.168	10.3.99.168
42	10.3.99.169/32	10.3.99.169 – 10.3.99.169	10.3.99.169
43	10.3.99.170/32	10.3.99.170 – 10.3.99.170	10.3.99.170
44	10.3.99.171/32	10.3.99.171 – 10.3.99.171	10.3.99.171
45	10.3.99.172/32	10.3.99.172 – 10.3.99.172	10.3.99.172
46	10.3.99.173/32	10.3.99.173 – 10.3.99.173	10.3.99.173
47	10.3.99.174/32	10.3.99.174 – 10.3.99.174	10.3.99.174
48	10.3.99.175/32	10.3.99.175 – 10.3.99.175	10.3.99.175
49	10.3.99.176/32	10.3.99.176 – 10.3.99.176	10.3.99.176
50	10.3.99.177/32	10.3.99.177 – 10.3.99.177	10.3.99.177
51	10.3.99.178/32	10.3.99.178 – 10.3.99.178	10.3.99.178
52	10.3.99.179/32	10.3.99.179 – 10.3.99.179	10.3.99.179
53	10.3.99.180/32	10.3.99.180 – 10.3.99.180	10.3.99.180
54	10.3.99.181/32	10.3.99.181 – 10.3.99.181	10.3.99.181
55	10.3.99.182/32	10.3.99.182 – 10.3.99.182	10.3.99.182
56	10.3.99.183/32	10.3.99.183 – 10.3.99.183	10.3.99.183
57	10.3.99.184/32	10.3.99.184 – 10.3.99.184	10.3.99.184
58	10.3.99.185/32	10.3.99.185 – 10.3.99.185	10.3.99.185
59	10.3.99.186/32	10.3.99.186 – 10.3.99.186	10.3.99.186
60	10.3.99.187/32	10.3.99.187 – 10.3.99.187	10.3.99.187
61	10.3.99.188/32	10.3.99.188 – 10.3.99.188	10.3.99.188
62	10.3.99.189/32	10.3.99.189 – 10.3.99.189	10.3.99.189
63	10.3.99.190/32	10.3.99.190 – 10.3.99.190	10.3.99.190
64	10.3.99.191/32	10.3.99.191 – 10.3.99.191	10.3.99.191
65	10.3.99.192/32	10.3.99.192 – 10.3.99.192	10.3.99.192
66	10.3.99.193/32	10.3.99.193 – 10.3.99.193	10.3.99.193
67	10.3.99.194/32	10.3.99.194 – 10.3.99.194	10.3.99.194
68	10.3.99.195/32	10.3.99.195 – 10.3.99.195	10.3.99.195
69	10.3.99.196/32	10.3.99.196 – 10.3.99.196	10.3.99.196
70	10.3.99.197/32	10.3.99.197 – 10.3.99.197	10.3.99.197
71	10.3.99.198/32	10.3.99.198 – 10.3.99.198	10.3.99.198
72	10.3.99.199/32	10.3.99.199 – 10.3.99.199	10.3.99.199
73	10.3.99.200/32	10.3.99.200 – 10.3.99.200	10.3.99.200
74	10.3.99.201/32	10.3.99.201 – 10.3.99.201	10.3.99.201
75	10.3.99.202/32	10.3.99.202 – 10.3.99.202	10.3.99.202
76	10.3.99.203/32	10.3.99.203 – 10.3.99.203	10.3.99.203
77	10.3.99.204/32	10.3.99.204 – 10.3.99.204	10.3.99.204
78	10.3.99.205/32	10.3.99.205 – 10.3.99.205	10.3.99.205
79	10.3.99.206/32	10.3.99.206 – 10.3.99.206	10.3.99.206
80	10.3.99.207/32	10.3.99.207 – 10.3.99.207	10.3.99.207
81	10.3.99.208/32	10.3.99.208 – 10.3.99.208	10.3.99.208
82	10.3.99.209/32	10.3.99.209 – 10.3.99.209	10.3.99.209
83	10.3.99.210/32	10.3.99.210 – 10.3.99.210	10.3.99.210
84	10.3.99.211/32	10.3.99.211 – 10.3.99.211	10.3.99.211
85	10.3.99.212/32	10.3.99.212 – 10.3.99.212	10.3.99.212
86	10.3.99.213/32	10.3.99.213 – 10.3.99.213	10.3.99.213
87	10.3.99.214/32	10.3.99.214 – 10.3.99.214	10.3.99.214
88	10.3.99.215/32	10.3.99.215 – 10.3.99.215	10.3.99.215
89	10.3.99.216/32	10.3.99.216 – 10.3.99.216	10.3.99.216
90	10.3.99.217/32	10.3.99.217 – 10.3.99.217	10.3.99.217
91	10.3.99.218/32	10.3.99.218 – 10.3.99.218	10.3.99.218
92	10.3.99.219/32	10.3.99.219 – 10.3.99.219	10.3.99.219
93	10.3.99.220/32	10.3.99.220 – 10.3.99.220	10.3.99.220
94	10.3.99.221/32	10.3.99.221 – 10.3.99.221	10.3.99.221
95	10.3.99.222/32	10.3.99.222 – 10.3.99.222	10.3.99.222
96	10.3.99.223/32	10.3.99.223 – 10.3.99.223	10.3.99.223
97	10.3.99.224/32	10.3.99.224 – 10.3.99.224	10.3.99.224
98	10.3.99.225/32	10.3.99.225 – 10.3.99.225	10.3.99.225
99	10.3.99.226/32	10.3.99.226 – 10.3.99.226	10.3.99.226
100	10.3.99.227/32	10.3.99.227 – 10.3.99.227	10.3.99.227
101	10.3.99.228/32	10.3.99.228 – 10.3.99.228	10.3.99.228
102	10.3.99.229/32	10.3.99.229 – 10.3.99.229	10.3.99.229
103	10.3.99.230/32	10.3.99.230 – 10.3.99.230	10.3.99.230
104	10.3.99.231/32	10.3.99.231 – 10.3.99.231	10.3.99.231
105	10.3.99.232/32	10.3.99.232 – 10.3.99.232	10.3.99.232
106	10.3.99.233/32	10.3.99.233 – 10.3.99.233	10.3.99.233
107	10.3.99.234/32	10.3.99.234 – 10.3.99.234	10.3.99.234
108	10.3.99.235/32	10.3.99.235 – 10.3.99.235	10.3.99.235
109	10.3.99.236/32	10.3.99.236 – 10.3.99.236	10.3.99.236
110	10.3.99.237/32	10.3.99.237 – 10.3.99.237	10.3.99.237
111	10.3.99.238/32	10.3.99.238 – 10.3.99.238	10.3.99.238
112	10.3.99.239/32	10.3.99.239 – 10.3.99.239	10.3.99.239
113	10.3.99.240/32	10.3.99.240 – 10.3.99.240	10.3.99.240
114	10.3.99.241/32	10.3.99.241 – 10.3.99.241	10.3.99.241
115	10.3.99.242/32	10.3.99.242 – 10.3.99.242	10.3.99.242
116	10.3.99.243/32	10.3.99.243 – 10.3.99.243	10.3.99.243
117	10.3.99.244/32	10.3.99.244 – 10.3.99.244	10.3.99.244
118	10.3.99.245/32	10.3.99.245 – 10.3.99.245	10.3.99.245
119	10.3.99.246/32	10.3.99.246 – 10.3.99.246	10.3.99.246
120	10.3.99.247/32	10.3.99.247 – 10.3.99.247	10.3.99.247
121	10.3.99.248/32	10.3.99.248 – 10.3.99.248	10.3.99.248
122	10.3.99.249/32	10.3.99.249 – 10.3.99.249	10.3.99.249
123	10.3.99.250/32	10.3.99.250 – 10.3.99.250	10.3.99.250
124	10.3.99.251/32	10.3.99.251 – 10.3.99.251	10.3.99.251
125	10.3.99.252/32	10.3.99.252 – 10.3.99.252	10.3.99.252
126	10.3.99.253/32	10.3.99.253 – 10.3.99.253	10.3.99.253
127	10.3.99.254/32	10.3.99.254 – 10.3.99.254	10.3.99.254
128	10.3.99.255/32	10.3.99.255 – 10.3.99.255	10.3.99.255

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 →