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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)10.0.31.128/25
network10.0.31.128/25
broadcast10.0.31.255
first host10.0.31.129
last host10.0.31.254
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classA
ipcalc 10.0.31.128/25
address00001010.00000000.00011111.10000000
subnet mask11111111.11111111.11111111.10000000
network00001010.00000000.00011111.10000000
broadcast00001010.00000000.00011111.11111111
green = network part, grey = host part
hex0x0a001f80
decimal167780224
reverse dns128.31.0.10.in-addr.arpa
ipv4-mapped::ffff:a00:1f80

/25 split into /31 · 64 subnets

close ×
#networkhost rangebroadcast
110.0.31.128/3110.0.31.128 – 10.0.31.12910.0.31.129
210.0.31.130/3110.0.31.130 – 10.0.31.13110.0.31.131
310.0.31.132/3110.0.31.132 – 10.0.31.13310.0.31.133
410.0.31.134/3110.0.31.134 – 10.0.31.13510.0.31.135
510.0.31.136/3110.0.31.136 – 10.0.31.13710.0.31.137
610.0.31.138/3110.0.31.138 – 10.0.31.13910.0.31.139
710.0.31.140/3110.0.31.140 – 10.0.31.14110.0.31.141
810.0.31.142/3110.0.31.142 – 10.0.31.14310.0.31.143
910.0.31.144/3110.0.31.144 – 10.0.31.14510.0.31.145
1010.0.31.146/3110.0.31.146 – 10.0.31.14710.0.31.147
1110.0.31.148/3110.0.31.148 – 10.0.31.14910.0.31.149
1210.0.31.150/3110.0.31.150 – 10.0.31.15110.0.31.151
1310.0.31.152/3110.0.31.152 – 10.0.31.15310.0.31.153
1410.0.31.154/3110.0.31.154 – 10.0.31.15510.0.31.155
1510.0.31.156/3110.0.31.156 – 10.0.31.15710.0.31.157
1610.0.31.158/3110.0.31.158 – 10.0.31.15910.0.31.159
1710.0.31.160/3110.0.31.160 – 10.0.31.16110.0.31.161
1810.0.31.162/3110.0.31.162 – 10.0.31.16310.0.31.163
1910.0.31.164/3110.0.31.164 – 10.0.31.16510.0.31.165
2010.0.31.166/3110.0.31.166 – 10.0.31.16710.0.31.167
2110.0.31.168/3110.0.31.168 – 10.0.31.16910.0.31.169
2210.0.31.170/3110.0.31.170 – 10.0.31.17110.0.31.171
2310.0.31.172/3110.0.31.172 – 10.0.31.17310.0.31.173
2410.0.31.174/3110.0.31.174 – 10.0.31.17510.0.31.175
2510.0.31.176/3110.0.31.176 – 10.0.31.17710.0.31.177
2610.0.31.178/3110.0.31.178 – 10.0.31.17910.0.31.179
2710.0.31.180/3110.0.31.180 – 10.0.31.18110.0.31.181
2810.0.31.182/3110.0.31.182 – 10.0.31.18310.0.31.183
2910.0.31.184/3110.0.31.184 – 10.0.31.18510.0.31.185
3010.0.31.186/3110.0.31.186 – 10.0.31.18710.0.31.187
3110.0.31.188/3110.0.31.188 – 10.0.31.18910.0.31.189
3210.0.31.190/3110.0.31.190 – 10.0.31.19110.0.31.191
3310.0.31.192/3110.0.31.192 – 10.0.31.19310.0.31.193
3410.0.31.194/3110.0.31.194 – 10.0.31.19510.0.31.195
3510.0.31.196/3110.0.31.196 – 10.0.31.19710.0.31.197
3610.0.31.198/3110.0.31.198 – 10.0.31.19910.0.31.199
3710.0.31.200/3110.0.31.200 – 10.0.31.20110.0.31.201
3810.0.31.202/3110.0.31.202 – 10.0.31.20310.0.31.203
3910.0.31.204/3110.0.31.204 – 10.0.31.20510.0.31.205
4010.0.31.206/3110.0.31.206 – 10.0.31.20710.0.31.207
4110.0.31.208/3110.0.31.208 – 10.0.31.20910.0.31.209
4210.0.31.210/3110.0.31.210 – 10.0.31.21110.0.31.211
4310.0.31.212/3110.0.31.212 – 10.0.31.21310.0.31.213
4410.0.31.214/3110.0.31.214 – 10.0.31.21510.0.31.215
4510.0.31.216/3110.0.31.216 – 10.0.31.21710.0.31.217
4610.0.31.218/3110.0.31.218 – 10.0.31.21910.0.31.219
4710.0.31.220/3110.0.31.220 – 10.0.31.22110.0.31.221
4810.0.31.222/3110.0.31.222 – 10.0.31.22310.0.31.223
4910.0.31.224/3110.0.31.224 – 10.0.31.22510.0.31.225
5010.0.31.226/3110.0.31.226 – 10.0.31.22710.0.31.227
5110.0.31.228/3110.0.31.228 – 10.0.31.22910.0.31.229
5210.0.31.230/3110.0.31.230 – 10.0.31.23110.0.31.231
5310.0.31.232/3110.0.31.232 – 10.0.31.23310.0.31.233
5410.0.31.234/3110.0.31.234 – 10.0.31.23510.0.31.235
5510.0.31.236/3110.0.31.236 – 10.0.31.23710.0.31.237
5610.0.31.238/3110.0.31.238 – 10.0.31.23910.0.31.239
5710.0.31.240/3110.0.31.240 – 10.0.31.24110.0.31.241
5810.0.31.242/3110.0.31.242 – 10.0.31.24310.0.31.243
5910.0.31.244/3110.0.31.244 – 10.0.31.24510.0.31.245
6010.0.31.246/3110.0.31.246 – 10.0.31.24710.0.31.247
6110.0.31.248/3110.0.31.248 – 10.0.31.24910.0.31.249
6210.0.31.250/3110.0.31.250 – 10.0.31.25110.0.31.251
6310.0.31.252/3110.0.31.252 – 10.0.31.25310.0.31.253
6410.0.31.254/3110.0.31.254 – 10.0.31.25510.0.31.255
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 →