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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)10.0.42.128/25
network10.0.42.128/25
broadcast10.0.42.255
first host10.0.42.129
last host10.0.42.254
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classA
ipcalc 10.0.42.128/25
address00001010.00000000.00101010.10000000
subnet mask11111111.11111111.11111111.10000000
network00001010.00000000.00101010.10000000
broadcast00001010.00000000.00101010.11111111
green = network part, grey = host part
hex0x0a002a80
decimal167783040
reverse dns128.42.0.10.in-addr.arpa
ipv4-mapped::ffff:a00:2a80

/25 split into /31 · 64 subnets

close ×
#networkhost rangebroadcast
110.0.42.128/3110.0.42.128 – 10.0.42.12910.0.42.129
210.0.42.130/3110.0.42.130 – 10.0.42.13110.0.42.131
310.0.42.132/3110.0.42.132 – 10.0.42.13310.0.42.133
410.0.42.134/3110.0.42.134 – 10.0.42.13510.0.42.135
510.0.42.136/3110.0.42.136 – 10.0.42.13710.0.42.137
610.0.42.138/3110.0.42.138 – 10.0.42.13910.0.42.139
710.0.42.140/3110.0.42.140 – 10.0.42.14110.0.42.141
810.0.42.142/3110.0.42.142 – 10.0.42.14310.0.42.143
910.0.42.144/3110.0.42.144 – 10.0.42.14510.0.42.145
1010.0.42.146/3110.0.42.146 – 10.0.42.14710.0.42.147
1110.0.42.148/3110.0.42.148 – 10.0.42.14910.0.42.149
1210.0.42.150/3110.0.42.150 – 10.0.42.15110.0.42.151
1310.0.42.152/3110.0.42.152 – 10.0.42.15310.0.42.153
1410.0.42.154/3110.0.42.154 – 10.0.42.15510.0.42.155
1510.0.42.156/3110.0.42.156 – 10.0.42.15710.0.42.157
1610.0.42.158/3110.0.42.158 – 10.0.42.15910.0.42.159
1710.0.42.160/3110.0.42.160 – 10.0.42.16110.0.42.161
1810.0.42.162/3110.0.42.162 – 10.0.42.16310.0.42.163
1910.0.42.164/3110.0.42.164 – 10.0.42.16510.0.42.165
2010.0.42.166/3110.0.42.166 – 10.0.42.16710.0.42.167
2110.0.42.168/3110.0.42.168 – 10.0.42.16910.0.42.169
2210.0.42.170/3110.0.42.170 – 10.0.42.17110.0.42.171
2310.0.42.172/3110.0.42.172 – 10.0.42.17310.0.42.173
2410.0.42.174/3110.0.42.174 – 10.0.42.17510.0.42.175
2510.0.42.176/3110.0.42.176 – 10.0.42.17710.0.42.177
2610.0.42.178/3110.0.42.178 – 10.0.42.17910.0.42.179
2710.0.42.180/3110.0.42.180 – 10.0.42.18110.0.42.181
2810.0.42.182/3110.0.42.182 – 10.0.42.18310.0.42.183
2910.0.42.184/3110.0.42.184 – 10.0.42.18510.0.42.185
3010.0.42.186/3110.0.42.186 – 10.0.42.18710.0.42.187
3110.0.42.188/3110.0.42.188 – 10.0.42.18910.0.42.189
3210.0.42.190/3110.0.42.190 – 10.0.42.19110.0.42.191
3310.0.42.192/3110.0.42.192 – 10.0.42.19310.0.42.193
3410.0.42.194/3110.0.42.194 – 10.0.42.19510.0.42.195
3510.0.42.196/3110.0.42.196 – 10.0.42.19710.0.42.197
3610.0.42.198/3110.0.42.198 – 10.0.42.19910.0.42.199
3710.0.42.200/3110.0.42.200 – 10.0.42.20110.0.42.201
3810.0.42.202/3110.0.42.202 – 10.0.42.20310.0.42.203
3910.0.42.204/3110.0.42.204 – 10.0.42.20510.0.42.205
4010.0.42.206/3110.0.42.206 – 10.0.42.20710.0.42.207
4110.0.42.208/3110.0.42.208 – 10.0.42.20910.0.42.209
4210.0.42.210/3110.0.42.210 – 10.0.42.21110.0.42.211
4310.0.42.212/3110.0.42.212 – 10.0.42.21310.0.42.213
4410.0.42.214/3110.0.42.214 – 10.0.42.21510.0.42.215
4510.0.42.216/3110.0.42.216 – 10.0.42.21710.0.42.217
4610.0.42.218/3110.0.42.218 – 10.0.42.21910.0.42.219
4710.0.42.220/3110.0.42.220 – 10.0.42.22110.0.42.221
4810.0.42.222/3110.0.42.222 – 10.0.42.22310.0.42.223
4910.0.42.224/3110.0.42.224 – 10.0.42.22510.0.42.225
5010.0.42.226/3110.0.42.226 – 10.0.42.22710.0.42.227
5110.0.42.228/3110.0.42.228 – 10.0.42.22910.0.42.229
5210.0.42.230/3110.0.42.230 – 10.0.42.23110.0.42.231
5310.0.42.232/3110.0.42.232 – 10.0.42.23310.0.42.233
5410.0.42.234/3110.0.42.234 – 10.0.42.23510.0.42.235
5510.0.42.236/3110.0.42.236 – 10.0.42.23710.0.42.237
5610.0.42.238/3110.0.42.238 – 10.0.42.23910.0.42.239
5710.0.42.240/3110.0.42.240 – 10.0.42.24110.0.42.241
5810.0.42.242/3110.0.42.242 – 10.0.42.24310.0.42.243
5910.0.42.244/3110.0.42.244 – 10.0.42.24510.0.42.245
6010.0.42.246/3110.0.42.246 – 10.0.42.24710.0.42.247
6110.0.42.248/3110.0.42.248 – 10.0.42.24910.0.42.249
6210.0.42.250/3110.0.42.250 – 10.0.42.25110.0.42.251
6310.0.42.252/3110.0.42.252 – 10.0.42.25310.0.42.253
6410.0.42.254/3110.0.42.254 – 10.0.42.25510.0.42.255
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 →