ip
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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)10.3.72.128/25
network10.3.72.128/25
broadcast10.3.72.255
first host10.3.72.129
last host10.3.72.254
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classA
ipcalc 10.3.72.128/25
address00001010.00000011.01001000.10000000
subnet mask11111111.11111111.11111111.10000000
network00001010.00000011.01001000.10000000
broadcast00001010.00000011.01001000.11111111
green = network part, grey = host part
hex0x0a034880
decimal167987328
reverse dns128.72.3.10.in-addr.arpa
ipv4-mapped::ffff:a03:4880

/25 split into /30 · 32 subnets

close ×
#networkhost rangebroadcast
110.3.72.128/3010.3.72.129 – 10.3.72.13010.3.72.131
210.3.72.132/3010.3.72.133 – 10.3.72.13410.3.72.135
310.3.72.136/3010.3.72.137 – 10.3.72.13810.3.72.139
410.3.72.140/3010.3.72.141 – 10.3.72.14210.3.72.143
510.3.72.144/3010.3.72.145 – 10.3.72.14610.3.72.147
610.3.72.148/3010.3.72.149 – 10.3.72.15010.3.72.151
710.3.72.152/3010.3.72.153 – 10.3.72.15410.3.72.155
810.3.72.156/3010.3.72.157 – 10.3.72.15810.3.72.159
910.3.72.160/3010.3.72.161 – 10.3.72.16210.3.72.163
1010.3.72.164/3010.3.72.165 – 10.3.72.16610.3.72.167
1110.3.72.168/3010.3.72.169 – 10.3.72.17010.3.72.171
1210.3.72.172/3010.3.72.173 – 10.3.72.17410.3.72.175
1310.3.72.176/3010.3.72.177 – 10.3.72.17810.3.72.179
1410.3.72.180/3010.3.72.181 – 10.3.72.18210.3.72.183
1510.3.72.184/3010.3.72.185 – 10.3.72.18610.3.72.187
1610.3.72.188/3010.3.72.189 – 10.3.72.19010.3.72.191
1710.3.72.192/3010.3.72.193 – 10.3.72.19410.3.72.195
1810.3.72.196/3010.3.72.197 – 10.3.72.19810.3.72.199
1910.3.72.200/3010.3.72.201 – 10.3.72.20210.3.72.203
2010.3.72.204/3010.3.72.205 – 10.3.72.20610.3.72.207
2110.3.72.208/3010.3.72.209 – 10.3.72.21010.3.72.211
2210.3.72.212/3010.3.72.213 – 10.3.72.21410.3.72.215
2310.3.72.216/3010.3.72.217 – 10.3.72.21810.3.72.219
2410.3.72.220/3010.3.72.221 – 10.3.72.22210.3.72.223
2510.3.72.224/3010.3.72.225 – 10.3.72.22610.3.72.227
2610.3.72.228/3010.3.72.229 – 10.3.72.23010.3.72.231
2710.3.72.232/3010.3.72.233 – 10.3.72.23410.3.72.235
2810.3.72.236/3010.3.72.237 – 10.3.72.23810.3.72.239
2910.3.72.240/3010.3.72.241 – 10.3.72.24210.3.72.243
3010.3.72.244/3010.3.72.245 – 10.3.72.24610.3.72.247
3110.3.72.248/3010.3.72.249 – 10.3.72.25010.3.72.251
3210.3.72.252/3010.3.72.253 – 10.3.72.25410.3.72.255
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 →