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)172.16.6.128/25
network172.16.6.128/25
broadcast172.16.6.255
first host172.16.6.129
last host172.16.6.254
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classB
ipcalc 172.16.6.128/25
address10101100.00010000.00000110.10000000
subnet mask11111111.11111111.11111111.10000000
network10101100.00010000.00000110.10000000
broadcast10101100.00010000.00000110.11111111
green = network part, grey = host part
hex0xac100680
decimal2886731392
reverse dns128.6.16.172.in-addr.arpa
ipv4-mapped::ffff:ac10:680

/25 split into /29 · 16 subnets

close ×
#networkhost rangebroadcast
1172.16.6.128/29172.16.6.129 – 172.16.6.134172.16.6.135
2172.16.6.136/29172.16.6.137 – 172.16.6.142172.16.6.143
3172.16.6.144/29172.16.6.145 – 172.16.6.150172.16.6.151
4172.16.6.152/29172.16.6.153 – 172.16.6.158172.16.6.159
5172.16.6.160/29172.16.6.161 – 172.16.6.166172.16.6.167
6172.16.6.168/29172.16.6.169 – 172.16.6.174172.16.6.175
7172.16.6.176/29172.16.6.177 – 172.16.6.182172.16.6.183
8172.16.6.184/29172.16.6.185 – 172.16.6.190172.16.6.191
9172.16.6.192/29172.16.6.193 – 172.16.6.198172.16.6.199
10172.16.6.200/29172.16.6.201 – 172.16.6.206172.16.6.207
11172.16.6.208/29172.16.6.209 – 172.16.6.214172.16.6.215
12172.16.6.216/29172.16.6.217 – 172.16.6.222172.16.6.223
13172.16.6.224/29172.16.6.225 – 172.16.6.230172.16.6.231
14172.16.6.232/29172.16.6.233 – 172.16.6.238172.16.6.239
15172.16.6.240/29172.16.6.241 – 172.16.6.246172.16.6.247
16172.16.6.248/29172.16.6.249 – 172.16.6.254172.16.6.255
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 →