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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)10.240.0.0/16
network10.240.0.0/16
broadcast10.240.255.255
first host10.240.0.1
last host10.240.255.254
subnet mask255.255.0.0
wildcard0.0.255.255
addresses65,536
usable hosts65,534
classA
ipcalc 10.240.0.0/16
address00001010.11110000.00000000.00000000
subnet mask11111111.11111111.00000000.00000000
network00001010.11110000.00000000.00000000
broadcast00001010.11110000.11111111.11111111
green = network part, grey = host part
hex0x0af00000
decimal183500800
reverse dns0.0.240.10.in-addr.arpa
ipv4-mapped::ffff:af0:0

/16 split into /21 · 32 subnets

close ×
#networkhost rangebroadcast
110.240.0.0/2110.240.0.1 – 10.240.7.25410.240.7.255
210.240.8.0/2110.240.8.1 – 10.240.15.25410.240.15.255
310.240.16.0/2110.240.16.1 – 10.240.23.25410.240.23.255
410.240.24.0/2110.240.24.1 – 10.240.31.25410.240.31.255
510.240.32.0/2110.240.32.1 – 10.240.39.25410.240.39.255
610.240.40.0/2110.240.40.1 – 10.240.47.25410.240.47.255
710.240.48.0/2110.240.48.1 – 10.240.55.25410.240.55.255
810.240.56.0/2110.240.56.1 – 10.240.63.25410.240.63.255
910.240.64.0/2110.240.64.1 – 10.240.71.25410.240.71.255
1010.240.72.0/2110.240.72.1 – 10.240.79.25410.240.79.255
1110.240.80.0/2110.240.80.1 – 10.240.87.25410.240.87.255
1210.240.88.0/2110.240.88.1 – 10.240.95.25410.240.95.255
1310.240.96.0/2110.240.96.1 – 10.240.103.25410.240.103.255
1410.240.104.0/2110.240.104.1 – 10.240.111.25410.240.111.255
1510.240.112.0/2110.240.112.1 – 10.240.119.25410.240.119.255
1610.240.120.0/2110.240.120.1 – 10.240.127.25410.240.127.255
1710.240.128.0/2110.240.128.1 – 10.240.135.25410.240.135.255
1810.240.136.0/2110.240.136.1 – 10.240.143.25410.240.143.255
1910.240.144.0/2110.240.144.1 – 10.240.151.25410.240.151.255
2010.240.152.0/2110.240.152.1 – 10.240.159.25410.240.159.255
2110.240.160.0/2110.240.160.1 – 10.240.167.25410.240.167.255
2210.240.168.0/2110.240.168.1 – 10.240.175.25410.240.175.255
2310.240.176.0/2110.240.176.1 – 10.240.183.25410.240.183.255
2410.240.184.0/2110.240.184.1 – 10.240.191.25410.240.191.255
2510.240.192.0/2110.240.192.1 – 10.240.199.25410.240.199.255
2610.240.200.0/2110.240.200.1 – 10.240.207.25410.240.207.255
2710.240.208.0/2110.240.208.1 – 10.240.215.25410.240.215.255
2810.240.216.0/2110.240.216.1 – 10.240.223.25410.240.223.255
2910.240.224.0/2110.240.224.1 – 10.240.231.25410.240.231.255
3010.240.232.0/2110.240.232.1 – 10.240.239.25410.240.239.255
3110.240.240.0/2110.240.240.1 – 10.240.247.25410.240.247.255
3210.240.248.0/2110.240.248.1 – 10.240.255.25410.240.255.255
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 →