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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)10.2.45.128/25
network10.2.45.128/25
broadcast10.2.45.255
first host10.2.45.129
last host10.2.45.254
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classA
ipcalc 10.2.45.128/25
address00001010.00000010.00101101.10000000
subnet mask11111111.11111111.11111111.10000000
network00001010.00000010.00101101.10000000
broadcast00001010.00000010.00101101.11111111
green = network part, grey = host part
hex0x0a022d80
decimal167914880
reverse dns128.45.2.10.in-addr.arpa
ipv4-mapped::ffff:a02:2d80

/25 split into /31 · 64 subnets

close ×
#networkhost rangebroadcast
110.2.45.128/3110.2.45.128 – 10.2.45.12910.2.45.129
210.2.45.130/3110.2.45.130 – 10.2.45.13110.2.45.131
310.2.45.132/3110.2.45.132 – 10.2.45.13310.2.45.133
410.2.45.134/3110.2.45.134 – 10.2.45.13510.2.45.135
510.2.45.136/3110.2.45.136 – 10.2.45.13710.2.45.137
610.2.45.138/3110.2.45.138 – 10.2.45.13910.2.45.139
710.2.45.140/3110.2.45.140 – 10.2.45.14110.2.45.141
810.2.45.142/3110.2.45.142 – 10.2.45.14310.2.45.143
910.2.45.144/3110.2.45.144 – 10.2.45.14510.2.45.145
1010.2.45.146/3110.2.45.146 – 10.2.45.14710.2.45.147
1110.2.45.148/3110.2.45.148 – 10.2.45.14910.2.45.149
1210.2.45.150/3110.2.45.150 – 10.2.45.15110.2.45.151
1310.2.45.152/3110.2.45.152 – 10.2.45.15310.2.45.153
1410.2.45.154/3110.2.45.154 – 10.2.45.15510.2.45.155
1510.2.45.156/3110.2.45.156 – 10.2.45.15710.2.45.157
1610.2.45.158/3110.2.45.158 – 10.2.45.15910.2.45.159
1710.2.45.160/3110.2.45.160 – 10.2.45.16110.2.45.161
1810.2.45.162/3110.2.45.162 – 10.2.45.16310.2.45.163
1910.2.45.164/3110.2.45.164 – 10.2.45.16510.2.45.165
2010.2.45.166/3110.2.45.166 – 10.2.45.16710.2.45.167
2110.2.45.168/3110.2.45.168 – 10.2.45.16910.2.45.169
2210.2.45.170/3110.2.45.170 – 10.2.45.17110.2.45.171
2310.2.45.172/3110.2.45.172 – 10.2.45.17310.2.45.173
2410.2.45.174/3110.2.45.174 – 10.2.45.17510.2.45.175
2510.2.45.176/3110.2.45.176 – 10.2.45.17710.2.45.177
2610.2.45.178/3110.2.45.178 – 10.2.45.17910.2.45.179
2710.2.45.180/3110.2.45.180 – 10.2.45.18110.2.45.181
2810.2.45.182/3110.2.45.182 – 10.2.45.18310.2.45.183
2910.2.45.184/3110.2.45.184 – 10.2.45.18510.2.45.185
3010.2.45.186/3110.2.45.186 – 10.2.45.18710.2.45.187
3110.2.45.188/3110.2.45.188 – 10.2.45.18910.2.45.189
3210.2.45.190/3110.2.45.190 – 10.2.45.19110.2.45.191
3310.2.45.192/3110.2.45.192 – 10.2.45.19310.2.45.193
3410.2.45.194/3110.2.45.194 – 10.2.45.19510.2.45.195
3510.2.45.196/3110.2.45.196 – 10.2.45.19710.2.45.197
3610.2.45.198/3110.2.45.198 – 10.2.45.19910.2.45.199
3710.2.45.200/3110.2.45.200 – 10.2.45.20110.2.45.201
3810.2.45.202/3110.2.45.202 – 10.2.45.20310.2.45.203
3910.2.45.204/3110.2.45.204 – 10.2.45.20510.2.45.205
4010.2.45.206/3110.2.45.206 – 10.2.45.20710.2.45.207
4110.2.45.208/3110.2.45.208 – 10.2.45.20910.2.45.209
4210.2.45.210/3110.2.45.210 – 10.2.45.21110.2.45.211
4310.2.45.212/3110.2.45.212 – 10.2.45.21310.2.45.213
4410.2.45.214/3110.2.45.214 – 10.2.45.21510.2.45.215
4510.2.45.216/3110.2.45.216 – 10.2.45.21710.2.45.217
4610.2.45.218/3110.2.45.218 – 10.2.45.21910.2.45.219
4710.2.45.220/3110.2.45.220 – 10.2.45.22110.2.45.221
4810.2.45.222/3110.2.45.222 – 10.2.45.22310.2.45.223
4910.2.45.224/3110.2.45.224 – 10.2.45.22510.2.45.225
5010.2.45.226/3110.2.45.226 – 10.2.45.22710.2.45.227
5110.2.45.228/3110.2.45.228 – 10.2.45.22910.2.45.229
5210.2.45.230/3110.2.45.230 – 10.2.45.23110.2.45.231
5310.2.45.232/3110.2.45.232 – 10.2.45.23310.2.45.233
5410.2.45.234/3110.2.45.234 – 10.2.45.23510.2.45.235
5510.2.45.236/3110.2.45.236 – 10.2.45.23710.2.45.237
5610.2.45.238/3110.2.45.238 – 10.2.45.23910.2.45.239
5710.2.45.240/3110.2.45.240 – 10.2.45.24110.2.45.241
5810.2.45.242/3110.2.45.242 – 10.2.45.24310.2.45.243
5910.2.45.244/3110.2.45.244 – 10.2.45.24510.2.45.245
6010.2.45.246/3110.2.45.246 – 10.2.45.24710.2.45.247
6110.2.45.248/3110.2.45.248 – 10.2.45.24910.2.45.249
6210.2.45.250/3110.2.45.250 – 10.2.45.25110.2.45.251
6310.2.45.252/3110.2.45.252 – 10.2.45.25310.2.45.253
6410.2.45.254/3110.2.45.254 – 10.2.45.25510.2.45.255
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 →