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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)10.66.0.0/16
network10.66.0.0/16
broadcast10.66.255.255
first host10.66.0.1
last host10.66.255.254
subnet mask255.255.0.0
wildcard0.0.255.255
addresses65,536
usable hosts65,534
classA
ipcalc 10.66.0.0/16
address00001010.01000010.00000000.00000000
subnet mask11111111.11111111.00000000.00000000
network00001010.01000010.00000000.00000000
broadcast00001010.01000010.11111111.11111111
green = network part, grey = host part
hex0x0a420000
decimal172097536
reverse dns0.0.66.10.in-addr.arpa
ipv4-mapped::ffff:a42:0

/16 split into /22 · 64 subnets

close ×
#networkhost rangebroadcast
110.66.0.0/2210.66.0.1 – 10.66.3.25410.66.3.255
210.66.4.0/2210.66.4.1 – 10.66.7.25410.66.7.255
310.66.8.0/2210.66.8.1 – 10.66.11.25410.66.11.255
410.66.12.0/2210.66.12.1 – 10.66.15.25410.66.15.255
510.66.16.0/2210.66.16.1 – 10.66.19.25410.66.19.255
610.66.20.0/2210.66.20.1 – 10.66.23.25410.66.23.255
710.66.24.0/2210.66.24.1 – 10.66.27.25410.66.27.255
810.66.28.0/2210.66.28.1 – 10.66.31.25410.66.31.255
910.66.32.0/2210.66.32.1 – 10.66.35.25410.66.35.255
1010.66.36.0/2210.66.36.1 – 10.66.39.25410.66.39.255
1110.66.40.0/2210.66.40.1 – 10.66.43.25410.66.43.255
1210.66.44.0/2210.66.44.1 – 10.66.47.25410.66.47.255
1310.66.48.0/2210.66.48.1 – 10.66.51.25410.66.51.255
1410.66.52.0/2210.66.52.1 – 10.66.55.25410.66.55.255
1510.66.56.0/2210.66.56.1 – 10.66.59.25410.66.59.255
1610.66.60.0/2210.66.60.1 – 10.66.63.25410.66.63.255
1710.66.64.0/2210.66.64.1 – 10.66.67.25410.66.67.255
1810.66.68.0/2210.66.68.1 – 10.66.71.25410.66.71.255
1910.66.72.0/2210.66.72.1 – 10.66.75.25410.66.75.255
2010.66.76.0/2210.66.76.1 – 10.66.79.25410.66.79.255
2110.66.80.0/2210.66.80.1 – 10.66.83.25410.66.83.255
2210.66.84.0/2210.66.84.1 – 10.66.87.25410.66.87.255
2310.66.88.0/2210.66.88.1 – 10.66.91.25410.66.91.255
2410.66.92.0/2210.66.92.1 – 10.66.95.25410.66.95.255
2510.66.96.0/2210.66.96.1 – 10.66.99.25410.66.99.255
2610.66.100.0/2210.66.100.1 – 10.66.103.25410.66.103.255
2710.66.104.0/2210.66.104.1 – 10.66.107.25410.66.107.255
2810.66.108.0/2210.66.108.1 – 10.66.111.25410.66.111.255
2910.66.112.0/2210.66.112.1 – 10.66.115.25410.66.115.255
3010.66.116.0/2210.66.116.1 – 10.66.119.25410.66.119.255
3110.66.120.0/2210.66.120.1 – 10.66.123.25410.66.123.255
3210.66.124.0/2210.66.124.1 – 10.66.127.25410.66.127.255
3310.66.128.0/2210.66.128.1 – 10.66.131.25410.66.131.255
3410.66.132.0/2210.66.132.1 – 10.66.135.25410.66.135.255
3510.66.136.0/2210.66.136.1 – 10.66.139.25410.66.139.255
3610.66.140.0/2210.66.140.1 – 10.66.143.25410.66.143.255
3710.66.144.0/2210.66.144.1 – 10.66.147.25410.66.147.255
3810.66.148.0/2210.66.148.1 – 10.66.151.25410.66.151.255
3910.66.152.0/2210.66.152.1 – 10.66.155.25410.66.155.255
4010.66.156.0/2210.66.156.1 – 10.66.159.25410.66.159.255
4110.66.160.0/2210.66.160.1 – 10.66.163.25410.66.163.255
4210.66.164.0/2210.66.164.1 – 10.66.167.25410.66.167.255
4310.66.168.0/2210.66.168.1 – 10.66.171.25410.66.171.255
4410.66.172.0/2210.66.172.1 – 10.66.175.25410.66.175.255
4510.66.176.0/2210.66.176.1 – 10.66.179.25410.66.179.255
4610.66.180.0/2210.66.180.1 – 10.66.183.25410.66.183.255
4710.66.184.0/2210.66.184.1 – 10.66.187.25410.66.187.255
4810.66.188.0/2210.66.188.1 – 10.66.191.25410.66.191.255
4910.66.192.0/2210.66.192.1 – 10.66.195.25410.66.195.255
5010.66.196.0/2210.66.196.1 – 10.66.199.25410.66.199.255
5110.66.200.0/2210.66.200.1 – 10.66.203.25410.66.203.255
5210.66.204.0/2210.66.204.1 – 10.66.207.25410.66.207.255
5310.66.208.0/2210.66.208.1 – 10.66.211.25410.66.211.255
5410.66.212.0/2210.66.212.1 – 10.66.215.25410.66.215.255
5510.66.216.0/2210.66.216.1 – 10.66.219.25410.66.219.255
5610.66.220.0/2210.66.220.1 – 10.66.223.25410.66.223.255
5710.66.224.0/2210.66.224.1 – 10.66.227.25410.66.227.255
5810.66.228.0/2210.66.228.1 – 10.66.231.25410.66.231.255
5910.66.232.0/2210.66.232.1 – 10.66.235.25410.66.235.255
6010.66.236.0/2210.66.236.1 – 10.66.239.25410.66.239.255
6110.66.240.0/2210.66.240.1 – 10.66.243.25410.66.243.255
6210.66.244.0/2210.66.244.1 – 10.66.247.25410.66.247.255
6310.66.248.0/2210.66.248.1 – 10.66.251.25410.66.251.255
6410.66.252.0/2210.66.252.1 – 10.66.255.25410.66.255.255
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 →