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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)10.81.0.0/16
network10.81.0.0/16
broadcast10.81.255.255
first host10.81.0.1
last host10.81.255.254
subnet mask255.255.0.0
wildcard0.0.255.255
addresses65,536
usable hosts65,534
classA
ipcalc 10.81.0.0/16
address00001010.01010001.00000000.00000000
subnet mask11111111.11111111.00000000.00000000
network00001010.01010001.00000000.00000000
broadcast00001010.01010001.11111111.11111111
green = network part, grey = host part
hex0x0a510000
decimal173080576
reverse dns0.0.81.10.in-addr.arpa
ipv4-mapped::ffff:a51:0

/16 split into /22 · 64 subnets

close ×
#networkhost rangebroadcast
110.81.0.0/2210.81.0.1 – 10.81.3.25410.81.3.255
210.81.4.0/2210.81.4.1 – 10.81.7.25410.81.7.255
310.81.8.0/2210.81.8.1 – 10.81.11.25410.81.11.255
410.81.12.0/2210.81.12.1 – 10.81.15.25410.81.15.255
510.81.16.0/2210.81.16.1 – 10.81.19.25410.81.19.255
610.81.20.0/2210.81.20.1 – 10.81.23.25410.81.23.255
710.81.24.0/2210.81.24.1 – 10.81.27.25410.81.27.255
810.81.28.0/2210.81.28.1 – 10.81.31.25410.81.31.255
910.81.32.0/2210.81.32.1 – 10.81.35.25410.81.35.255
1010.81.36.0/2210.81.36.1 – 10.81.39.25410.81.39.255
1110.81.40.0/2210.81.40.1 – 10.81.43.25410.81.43.255
1210.81.44.0/2210.81.44.1 – 10.81.47.25410.81.47.255
1310.81.48.0/2210.81.48.1 – 10.81.51.25410.81.51.255
1410.81.52.0/2210.81.52.1 – 10.81.55.25410.81.55.255
1510.81.56.0/2210.81.56.1 – 10.81.59.25410.81.59.255
1610.81.60.0/2210.81.60.1 – 10.81.63.25410.81.63.255
1710.81.64.0/2210.81.64.1 – 10.81.67.25410.81.67.255
1810.81.68.0/2210.81.68.1 – 10.81.71.25410.81.71.255
1910.81.72.0/2210.81.72.1 – 10.81.75.25410.81.75.255
2010.81.76.0/2210.81.76.1 – 10.81.79.25410.81.79.255
2110.81.80.0/2210.81.80.1 – 10.81.83.25410.81.83.255
2210.81.84.0/2210.81.84.1 – 10.81.87.25410.81.87.255
2310.81.88.0/2210.81.88.1 – 10.81.91.25410.81.91.255
2410.81.92.0/2210.81.92.1 – 10.81.95.25410.81.95.255
2510.81.96.0/2210.81.96.1 – 10.81.99.25410.81.99.255
2610.81.100.0/2210.81.100.1 – 10.81.103.25410.81.103.255
2710.81.104.0/2210.81.104.1 – 10.81.107.25410.81.107.255
2810.81.108.0/2210.81.108.1 – 10.81.111.25410.81.111.255
2910.81.112.0/2210.81.112.1 – 10.81.115.25410.81.115.255
3010.81.116.0/2210.81.116.1 – 10.81.119.25410.81.119.255
3110.81.120.0/2210.81.120.1 – 10.81.123.25410.81.123.255
3210.81.124.0/2210.81.124.1 – 10.81.127.25410.81.127.255
3310.81.128.0/2210.81.128.1 – 10.81.131.25410.81.131.255
3410.81.132.0/2210.81.132.1 – 10.81.135.25410.81.135.255
3510.81.136.0/2210.81.136.1 – 10.81.139.25410.81.139.255
3610.81.140.0/2210.81.140.1 – 10.81.143.25410.81.143.255
3710.81.144.0/2210.81.144.1 – 10.81.147.25410.81.147.255
3810.81.148.0/2210.81.148.1 – 10.81.151.25410.81.151.255
3910.81.152.0/2210.81.152.1 – 10.81.155.25410.81.155.255
4010.81.156.0/2210.81.156.1 – 10.81.159.25410.81.159.255
4110.81.160.0/2210.81.160.1 – 10.81.163.25410.81.163.255
4210.81.164.0/2210.81.164.1 – 10.81.167.25410.81.167.255
4310.81.168.0/2210.81.168.1 – 10.81.171.25410.81.171.255
4410.81.172.0/2210.81.172.1 – 10.81.175.25410.81.175.255
4510.81.176.0/2210.81.176.1 – 10.81.179.25410.81.179.255
4610.81.180.0/2210.81.180.1 – 10.81.183.25410.81.183.255
4710.81.184.0/2210.81.184.1 – 10.81.187.25410.81.187.255
4810.81.188.0/2210.81.188.1 – 10.81.191.25410.81.191.255
4910.81.192.0/2210.81.192.1 – 10.81.195.25410.81.195.255
5010.81.196.0/2210.81.196.1 – 10.81.199.25410.81.199.255
5110.81.200.0/2210.81.200.1 – 10.81.203.25410.81.203.255
5210.81.204.0/2210.81.204.1 – 10.81.207.25410.81.207.255
5310.81.208.0/2210.81.208.1 – 10.81.211.25410.81.211.255
5410.81.212.0/2210.81.212.1 – 10.81.215.25410.81.215.255
5510.81.216.0/2210.81.216.1 – 10.81.219.25410.81.219.255
5610.81.220.0/2210.81.220.1 – 10.81.223.25410.81.223.255
5710.81.224.0/2210.81.224.1 – 10.81.227.25410.81.227.255
5810.81.228.0/2210.81.228.1 – 10.81.231.25410.81.231.255
5910.81.232.0/2210.81.232.1 – 10.81.235.25410.81.235.255
6010.81.236.0/2210.81.236.1 – 10.81.239.25410.81.239.255
6110.81.240.0/2210.81.240.1 – 10.81.243.25410.81.243.255
6210.81.244.0/2210.81.244.1 – 10.81.247.25410.81.247.255
6310.81.248.0/2210.81.248.1 – 10.81.251.25410.81.251.255
6410.81.252.0/2210.81.252.1 – 10.81.255.25410.81.255.255
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 →