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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)10.0.19.128/25
network10.0.19.128/25
broadcast10.0.19.255
first host10.0.19.129
last host10.0.19.254
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classA
ipcalc 10.0.19.128/25
address00001010.00000000.00010011.10000000
subnet mask11111111.11111111.11111111.10000000
network00001010.00000000.00010011.10000000
broadcast00001010.00000000.00010011.11111111
green = network part, grey = host part
hex0x0a001380
decimal167777152
reverse dns128.19.0.10.in-addr.arpa
ipv4-mapped::ffff:a00:1380

/25 split into /31 · 64 subnets

close ×
#networkhost rangebroadcast
110.0.19.128/3110.0.19.128 – 10.0.19.12910.0.19.129
210.0.19.130/3110.0.19.130 – 10.0.19.13110.0.19.131
310.0.19.132/3110.0.19.132 – 10.0.19.13310.0.19.133
410.0.19.134/3110.0.19.134 – 10.0.19.13510.0.19.135
510.0.19.136/3110.0.19.136 – 10.0.19.13710.0.19.137
610.0.19.138/3110.0.19.138 – 10.0.19.13910.0.19.139
710.0.19.140/3110.0.19.140 – 10.0.19.14110.0.19.141
810.0.19.142/3110.0.19.142 – 10.0.19.14310.0.19.143
910.0.19.144/3110.0.19.144 – 10.0.19.14510.0.19.145
1010.0.19.146/3110.0.19.146 – 10.0.19.14710.0.19.147
1110.0.19.148/3110.0.19.148 – 10.0.19.14910.0.19.149
1210.0.19.150/3110.0.19.150 – 10.0.19.15110.0.19.151
1310.0.19.152/3110.0.19.152 – 10.0.19.15310.0.19.153
1410.0.19.154/3110.0.19.154 – 10.0.19.15510.0.19.155
1510.0.19.156/3110.0.19.156 – 10.0.19.15710.0.19.157
1610.0.19.158/3110.0.19.158 – 10.0.19.15910.0.19.159
1710.0.19.160/3110.0.19.160 – 10.0.19.16110.0.19.161
1810.0.19.162/3110.0.19.162 – 10.0.19.16310.0.19.163
1910.0.19.164/3110.0.19.164 – 10.0.19.16510.0.19.165
2010.0.19.166/3110.0.19.166 – 10.0.19.16710.0.19.167
2110.0.19.168/3110.0.19.168 – 10.0.19.16910.0.19.169
2210.0.19.170/3110.0.19.170 – 10.0.19.17110.0.19.171
2310.0.19.172/3110.0.19.172 – 10.0.19.17310.0.19.173
2410.0.19.174/3110.0.19.174 – 10.0.19.17510.0.19.175
2510.0.19.176/3110.0.19.176 – 10.0.19.17710.0.19.177
2610.0.19.178/3110.0.19.178 – 10.0.19.17910.0.19.179
2710.0.19.180/3110.0.19.180 – 10.0.19.18110.0.19.181
2810.0.19.182/3110.0.19.182 – 10.0.19.18310.0.19.183
2910.0.19.184/3110.0.19.184 – 10.0.19.18510.0.19.185
3010.0.19.186/3110.0.19.186 – 10.0.19.18710.0.19.187
3110.0.19.188/3110.0.19.188 – 10.0.19.18910.0.19.189
3210.0.19.190/3110.0.19.190 – 10.0.19.19110.0.19.191
3310.0.19.192/3110.0.19.192 – 10.0.19.19310.0.19.193
3410.0.19.194/3110.0.19.194 – 10.0.19.19510.0.19.195
3510.0.19.196/3110.0.19.196 – 10.0.19.19710.0.19.197
3610.0.19.198/3110.0.19.198 – 10.0.19.19910.0.19.199
3710.0.19.200/3110.0.19.200 – 10.0.19.20110.0.19.201
3810.0.19.202/3110.0.19.202 – 10.0.19.20310.0.19.203
3910.0.19.204/3110.0.19.204 – 10.0.19.20510.0.19.205
4010.0.19.206/3110.0.19.206 – 10.0.19.20710.0.19.207
4110.0.19.208/3110.0.19.208 – 10.0.19.20910.0.19.209
4210.0.19.210/3110.0.19.210 – 10.0.19.21110.0.19.211
4310.0.19.212/3110.0.19.212 – 10.0.19.21310.0.19.213
4410.0.19.214/3110.0.19.214 – 10.0.19.21510.0.19.215
4510.0.19.216/3110.0.19.216 – 10.0.19.21710.0.19.217
4610.0.19.218/3110.0.19.218 – 10.0.19.21910.0.19.219
4710.0.19.220/3110.0.19.220 – 10.0.19.22110.0.19.221
4810.0.19.222/3110.0.19.222 – 10.0.19.22310.0.19.223
4910.0.19.224/3110.0.19.224 – 10.0.19.22510.0.19.225
5010.0.19.226/3110.0.19.226 – 10.0.19.22710.0.19.227
5110.0.19.228/3110.0.19.228 – 10.0.19.22910.0.19.229
5210.0.19.230/3110.0.19.230 – 10.0.19.23110.0.19.231
5310.0.19.232/3110.0.19.232 – 10.0.19.23310.0.19.233
5410.0.19.234/3110.0.19.234 – 10.0.19.23510.0.19.235
5510.0.19.236/3110.0.19.236 – 10.0.19.23710.0.19.237
5610.0.19.238/3110.0.19.238 – 10.0.19.23910.0.19.239
5710.0.19.240/3110.0.19.240 – 10.0.19.24110.0.19.241
5810.0.19.242/3110.0.19.242 – 10.0.19.24310.0.19.243
5910.0.19.244/3110.0.19.244 – 10.0.19.24510.0.19.245
6010.0.19.246/3110.0.19.246 – 10.0.19.24710.0.19.247
6110.0.19.248/3110.0.19.248 – 10.0.19.24910.0.19.249
6210.0.19.250/3110.0.19.250 – 10.0.19.25110.0.19.251
6310.0.19.252/3110.0.19.252 – 10.0.19.25310.0.19.253
6410.0.19.254/3110.0.19.254 – 10.0.19.25510.0.19.255
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 →