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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)10.0.65.128/25
network10.0.65.128/25
broadcast10.0.65.255
first host10.0.65.129
last host10.0.65.254
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classA
ipcalc 10.0.65.128/25
address00001010.00000000.01000001.10000000
subnet mask11111111.11111111.11111111.10000000
network00001010.00000000.01000001.10000000
broadcast00001010.00000000.01000001.11111111
green = network part, grey = host part
hex0x0a004180
decimal167788928
reverse dns128.65.0.10.in-addr.arpa
ipv4-mapped::ffff:a00:4180

/25 split into /31 · 64 subnets

close ×
#networkhost rangebroadcast
110.0.65.128/3110.0.65.128 – 10.0.65.12910.0.65.129
210.0.65.130/3110.0.65.130 – 10.0.65.13110.0.65.131
310.0.65.132/3110.0.65.132 – 10.0.65.13310.0.65.133
410.0.65.134/3110.0.65.134 – 10.0.65.13510.0.65.135
510.0.65.136/3110.0.65.136 – 10.0.65.13710.0.65.137
610.0.65.138/3110.0.65.138 – 10.0.65.13910.0.65.139
710.0.65.140/3110.0.65.140 – 10.0.65.14110.0.65.141
810.0.65.142/3110.0.65.142 – 10.0.65.14310.0.65.143
910.0.65.144/3110.0.65.144 – 10.0.65.14510.0.65.145
1010.0.65.146/3110.0.65.146 – 10.0.65.14710.0.65.147
1110.0.65.148/3110.0.65.148 – 10.0.65.14910.0.65.149
1210.0.65.150/3110.0.65.150 – 10.0.65.15110.0.65.151
1310.0.65.152/3110.0.65.152 – 10.0.65.15310.0.65.153
1410.0.65.154/3110.0.65.154 – 10.0.65.15510.0.65.155
1510.0.65.156/3110.0.65.156 – 10.0.65.15710.0.65.157
1610.0.65.158/3110.0.65.158 – 10.0.65.15910.0.65.159
1710.0.65.160/3110.0.65.160 – 10.0.65.16110.0.65.161
1810.0.65.162/3110.0.65.162 – 10.0.65.16310.0.65.163
1910.0.65.164/3110.0.65.164 – 10.0.65.16510.0.65.165
2010.0.65.166/3110.0.65.166 – 10.0.65.16710.0.65.167
2110.0.65.168/3110.0.65.168 – 10.0.65.16910.0.65.169
2210.0.65.170/3110.0.65.170 – 10.0.65.17110.0.65.171
2310.0.65.172/3110.0.65.172 – 10.0.65.17310.0.65.173
2410.0.65.174/3110.0.65.174 – 10.0.65.17510.0.65.175
2510.0.65.176/3110.0.65.176 – 10.0.65.17710.0.65.177
2610.0.65.178/3110.0.65.178 – 10.0.65.17910.0.65.179
2710.0.65.180/3110.0.65.180 – 10.0.65.18110.0.65.181
2810.0.65.182/3110.0.65.182 – 10.0.65.18310.0.65.183
2910.0.65.184/3110.0.65.184 – 10.0.65.18510.0.65.185
3010.0.65.186/3110.0.65.186 – 10.0.65.18710.0.65.187
3110.0.65.188/3110.0.65.188 – 10.0.65.18910.0.65.189
3210.0.65.190/3110.0.65.190 – 10.0.65.19110.0.65.191
3310.0.65.192/3110.0.65.192 – 10.0.65.19310.0.65.193
3410.0.65.194/3110.0.65.194 – 10.0.65.19510.0.65.195
3510.0.65.196/3110.0.65.196 – 10.0.65.19710.0.65.197
3610.0.65.198/3110.0.65.198 – 10.0.65.19910.0.65.199
3710.0.65.200/3110.0.65.200 – 10.0.65.20110.0.65.201
3810.0.65.202/3110.0.65.202 – 10.0.65.20310.0.65.203
3910.0.65.204/3110.0.65.204 – 10.0.65.20510.0.65.205
4010.0.65.206/3110.0.65.206 – 10.0.65.20710.0.65.207
4110.0.65.208/3110.0.65.208 – 10.0.65.20910.0.65.209
4210.0.65.210/3110.0.65.210 – 10.0.65.21110.0.65.211
4310.0.65.212/3110.0.65.212 – 10.0.65.21310.0.65.213
4410.0.65.214/3110.0.65.214 – 10.0.65.21510.0.65.215
4510.0.65.216/3110.0.65.216 – 10.0.65.21710.0.65.217
4610.0.65.218/3110.0.65.218 – 10.0.65.21910.0.65.219
4710.0.65.220/3110.0.65.220 – 10.0.65.22110.0.65.221
4810.0.65.222/3110.0.65.222 – 10.0.65.22310.0.65.223
4910.0.65.224/3110.0.65.224 – 10.0.65.22510.0.65.225
5010.0.65.226/3110.0.65.226 – 10.0.65.22710.0.65.227
5110.0.65.228/3110.0.65.228 – 10.0.65.22910.0.65.229
5210.0.65.230/3110.0.65.230 – 10.0.65.23110.0.65.231
5310.0.65.232/3110.0.65.232 – 10.0.65.23310.0.65.233
5410.0.65.234/3110.0.65.234 – 10.0.65.23510.0.65.235
5510.0.65.236/3110.0.65.236 – 10.0.65.23710.0.65.237
5610.0.65.238/3110.0.65.238 – 10.0.65.23910.0.65.239
5710.0.65.240/3110.0.65.240 – 10.0.65.24110.0.65.241
5810.0.65.242/3110.0.65.242 – 10.0.65.24310.0.65.243
5910.0.65.244/3110.0.65.244 – 10.0.65.24510.0.65.245
6010.0.65.246/3110.0.65.246 – 10.0.65.24710.0.65.247
6110.0.65.248/3110.0.65.248 – 10.0.65.24910.0.65.249
6210.0.65.250/3110.0.65.250 – 10.0.65.25110.0.65.251
6310.0.65.252/3110.0.65.252 – 10.0.65.25310.0.65.253
6410.0.65.254/3110.0.65.254 – 10.0.65.25510.0.65.255
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 →