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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)10.125.0.0/16
network10.125.0.0/16
broadcast10.125.255.255
first host10.125.0.1
last host10.125.255.254
subnet mask255.255.0.0
wildcard0.0.255.255
addresses65,536
usable hosts65,534
classA
ipcalc 10.125.0.0/16
address00001010.01111101.00000000.00000000
subnet mask11111111.11111111.00000000.00000000
network00001010.01111101.00000000.00000000
broadcast00001010.01111101.11111111.11111111
green = network part, grey = host part
hex0x0a7d0000
decimal175964160
reverse dns0.0.125.10.in-addr.arpa
ipv4-mapped::ffff:a7d:0

/16 split into /21 · 32 subnets

close ×
#networkhost rangebroadcast
110.125.0.0/2110.125.0.1 – 10.125.7.25410.125.7.255
210.125.8.0/2110.125.8.1 – 10.125.15.25410.125.15.255
310.125.16.0/2110.125.16.1 – 10.125.23.25410.125.23.255
410.125.24.0/2110.125.24.1 – 10.125.31.25410.125.31.255
510.125.32.0/2110.125.32.1 – 10.125.39.25410.125.39.255
610.125.40.0/2110.125.40.1 – 10.125.47.25410.125.47.255
710.125.48.0/2110.125.48.1 – 10.125.55.25410.125.55.255
810.125.56.0/2110.125.56.1 – 10.125.63.25410.125.63.255
910.125.64.0/2110.125.64.1 – 10.125.71.25410.125.71.255
1010.125.72.0/2110.125.72.1 – 10.125.79.25410.125.79.255
1110.125.80.0/2110.125.80.1 – 10.125.87.25410.125.87.255
1210.125.88.0/2110.125.88.1 – 10.125.95.25410.125.95.255
1310.125.96.0/2110.125.96.1 – 10.125.103.25410.125.103.255
1410.125.104.0/2110.125.104.1 – 10.125.111.25410.125.111.255
1510.125.112.0/2110.125.112.1 – 10.125.119.25410.125.119.255
1610.125.120.0/2110.125.120.1 – 10.125.127.25410.125.127.255
1710.125.128.0/2110.125.128.1 – 10.125.135.25410.125.135.255
1810.125.136.0/2110.125.136.1 – 10.125.143.25410.125.143.255
1910.125.144.0/2110.125.144.1 – 10.125.151.25410.125.151.255
2010.125.152.0/2110.125.152.1 – 10.125.159.25410.125.159.255
2110.125.160.0/2110.125.160.1 – 10.125.167.25410.125.167.255
2210.125.168.0/2110.125.168.1 – 10.125.175.25410.125.175.255
2310.125.176.0/2110.125.176.1 – 10.125.183.25410.125.183.255
2410.125.184.0/2110.125.184.1 – 10.125.191.25410.125.191.255
2510.125.192.0/2110.125.192.1 – 10.125.199.25410.125.199.255
2610.125.200.0/2110.125.200.1 – 10.125.207.25410.125.207.255
2710.125.208.0/2110.125.208.1 – 10.125.215.25410.125.215.255
2810.125.216.0/2110.125.216.1 – 10.125.223.25410.125.223.255
2910.125.224.0/2110.125.224.1 – 10.125.231.25410.125.231.255
3010.125.232.0/2110.125.232.1 – 10.125.239.25410.125.239.255
3110.125.240.0/2110.125.240.1 – 10.125.247.25410.125.247.255
3210.125.248.0/2110.125.248.1 – 10.125.255.25410.125.255.255
01 / table

IPv4 CIDR prefix table.

Click a prefix longer than your network to split it into subnets.

prefixsubnet maskaddresseshostsin your /16
/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-
/16255.255.0.065,53665,5341
/17255.255.128.032,76832,7662 split →
/18255.255.192.016,38416,3824 split →
/19255.255.224.08,1928,1908 split →
/20255.255.240.04,0964,09416 split →
/21255.255.248.02,0482,04632 split →
/22255.255.252.01,0241,02264 split →
/23255.255.254.0512510128 split →
/24255.255.255.0256254256 split →
/25255.255.255.128128126512 split →
/26255.255.255.19264621,024 split →
/27255.255.255.22432302,048 split →
/28255.255.255.24016144,096 split →
/29255.255.255.248868,192 split →
/30255.255.255.2524216,384 split →
/31255.255.255.2542232,768 split →
/32255.255.255.2551165,536 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 →