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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.

$ ipcalc
Try:192.168.1.10/2410.0.0.0/8172.16.5.4/20203.0.113.9/29
IPv6 calculator →
private IP (RFC 1918)10.0.12.128/25
network10.0.12.128/25
broadcast10.0.12.255
first host10.0.12.129
last host10.0.12.254
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classA
ipcalc 10.0.12.128/25
address00001010.00000000.00001100.10000000
subnet mask11111111.11111111.11111111.10000000
network00001010.00000000.00001100.10000000
broadcast00001010.00000000.00001100.11111111
green = network part, grey = host part
hex0x0a000c80
decimal167775360
reverse dns128.12.0.10.in-addr.arpa
ipv4-mapped::ffff:a00:c80

/25 split into /31 · 64 subnets

close ×
#networkhost rangebroadcast
110.0.12.128/3110.0.12.128 – 10.0.12.12910.0.12.129
210.0.12.130/3110.0.12.130 – 10.0.12.13110.0.12.131
310.0.12.132/3110.0.12.132 – 10.0.12.13310.0.12.133
410.0.12.134/3110.0.12.134 – 10.0.12.13510.0.12.135
510.0.12.136/3110.0.12.136 – 10.0.12.13710.0.12.137
610.0.12.138/3110.0.12.138 – 10.0.12.13910.0.12.139
710.0.12.140/3110.0.12.140 – 10.0.12.14110.0.12.141
810.0.12.142/3110.0.12.142 – 10.0.12.14310.0.12.143
910.0.12.144/3110.0.12.144 – 10.0.12.14510.0.12.145
1010.0.12.146/3110.0.12.146 – 10.0.12.14710.0.12.147
1110.0.12.148/3110.0.12.148 – 10.0.12.14910.0.12.149
1210.0.12.150/3110.0.12.150 – 10.0.12.15110.0.12.151
1310.0.12.152/3110.0.12.152 – 10.0.12.15310.0.12.153
1410.0.12.154/3110.0.12.154 – 10.0.12.15510.0.12.155
1510.0.12.156/3110.0.12.156 – 10.0.12.15710.0.12.157
1610.0.12.158/3110.0.12.158 – 10.0.12.15910.0.12.159
1710.0.12.160/3110.0.12.160 – 10.0.12.16110.0.12.161
1810.0.12.162/3110.0.12.162 – 10.0.12.16310.0.12.163
1910.0.12.164/3110.0.12.164 – 10.0.12.16510.0.12.165
2010.0.12.166/3110.0.12.166 – 10.0.12.16710.0.12.167
2110.0.12.168/3110.0.12.168 – 10.0.12.16910.0.12.169
2210.0.12.170/3110.0.12.170 – 10.0.12.17110.0.12.171
2310.0.12.172/3110.0.12.172 – 10.0.12.17310.0.12.173
2410.0.12.174/3110.0.12.174 – 10.0.12.17510.0.12.175
2510.0.12.176/3110.0.12.176 – 10.0.12.17710.0.12.177
2610.0.12.178/3110.0.12.178 – 10.0.12.17910.0.12.179
2710.0.12.180/3110.0.12.180 – 10.0.12.18110.0.12.181
2810.0.12.182/3110.0.12.182 – 10.0.12.18310.0.12.183
2910.0.12.184/3110.0.12.184 – 10.0.12.18510.0.12.185
3010.0.12.186/3110.0.12.186 – 10.0.12.18710.0.12.187
3110.0.12.188/3110.0.12.188 – 10.0.12.18910.0.12.189
3210.0.12.190/3110.0.12.190 – 10.0.12.19110.0.12.191
3310.0.12.192/3110.0.12.192 – 10.0.12.19310.0.12.193
3410.0.12.194/3110.0.12.194 – 10.0.12.19510.0.12.195
3510.0.12.196/3110.0.12.196 – 10.0.12.19710.0.12.197
3610.0.12.198/3110.0.12.198 – 10.0.12.19910.0.12.199
3710.0.12.200/3110.0.12.200 – 10.0.12.20110.0.12.201
3810.0.12.202/3110.0.12.202 – 10.0.12.20310.0.12.203
3910.0.12.204/3110.0.12.204 – 10.0.12.20510.0.12.205
4010.0.12.206/3110.0.12.206 – 10.0.12.20710.0.12.207
4110.0.12.208/3110.0.12.208 – 10.0.12.20910.0.12.209
4210.0.12.210/3110.0.12.210 – 10.0.12.21110.0.12.211
4310.0.12.212/3110.0.12.212 – 10.0.12.21310.0.12.213
4410.0.12.214/3110.0.12.214 – 10.0.12.21510.0.12.215
4510.0.12.216/3110.0.12.216 – 10.0.12.21710.0.12.217
4610.0.12.218/3110.0.12.218 – 10.0.12.21910.0.12.219
4710.0.12.220/3110.0.12.220 – 10.0.12.22110.0.12.221
4810.0.12.222/3110.0.12.222 – 10.0.12.22310.0.12.223
4910.0.12.224/3110.0.12.224 – 10.0.12.22510.0.12.225
5010.0.12.226/3110.0.12.226 – 10.0.12.22710.0.12.227
5110.0.12.228/3110.0.12.228 – 10.0.12.22910.0.12.229
5210.0.12.230/3110.0.12.230 – 10.0.12.23110.0.12.231
5310.0.12.232/3110.0.12.232 – 10.0.12.23310.0.12.233
5410.0.12.234/3110.0.12.234 – 10.0.12.23510.0.12.235
5510.0.12.236/3110.0.12.236 – 10.0.12.23710.0.12.237
5610.0.12.238/3110.0.12.238 – 10.0.12.23910.0.12.239
5710.0.12.240/3110.0.12.240 – 10.0.12.24110.0.12.241
5810.0.12.242/3110.0.12.242 – 10.0.12.24310.0.12.243
5910.0.12.244/3110.0.12.244 – 10.0.12.24510.0.12.245
6010.0.12.246/3110.0.12.246 – 10.0.12.24710.0.12.247
6110.0.12.248/3110.0.12.248 – 10.0.12.24910.0.12.249
6210.0.12.250/3110.0.12.250 – 10.0.12.25110.0.12.251
6310.0.12.252/3110.0.12.252 – 10.0.12.25310.0.12.253
6410.0.12.254/3110.0.12.254 – 10.0.12.25510.0.12.255
01 / table

IPv4 CIDR prefix table.

Click a prefix longer than your network to split it into subnets.

prefixsubnet maskaddresseshostsin your /25
/00.0.0.04,294,967,2964,294,967,294-
/1128.0.0.02,147,483,6482,147,483,646-
/2192.0.0.01,073,741,8241,073,741,822-
/3224.0.0.0536,870,912536,870,910-
/4240.0.0.0268,435,456268,435,454-
/5248.0.0.0134,217,728134,217,726-
/6252.0.0.067,108,86467,108,862-
/7254.0.0.033,554,43233,554,430-
/8255.0.0.016,777,21616,777,214-
/9255.128.0.08,388,6088,388,606-
/10255.192.0.04,194,3044,194,302-
/11255.224.0.02,097,1522,097,150-
/12255.240.0.01,048,5761,048,574-
/13255.248.0.0524,288524,286-
/14255.252.0.0262,144262,142-
/15255.254.0.0131,072131,070-
/16255.255.0.065,53665,534-
/17255.255.128.032,76832,766-
/18255.255.192.016,38416,382-
/19255.255.224.08,1928,190-
/20255.255.240.04,0964,094-
/21255.255.248.02,0482,046-
/22255.255.252.01,0241,022-
/23255.255.254.0512510-
/24255.255.255.0256254-
/25255.255.255.1281281261
/26255.255.255.19264622 split →
/27255.255.255.22432304 split →
/28255.255.255.24016148 split →
/29255.255.255.2488616 split →
/30255.255.255.2524232 split →
/31255.255.255.2542264 split →
/32255.255.255.25511128 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 →