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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)10.66.0.0/15
network10.66.0.0/15
broadcast10.67.255.255
first host10.66.0.1
last host10.67.255.254
subnet mask255.254.0.0
wildcard0.1.255.255
addresses131,072
usable hosts131,070
classA
ipcalc 10.66.0.0/15
address00001010.01000010.00000000.00000000
subnet mask11111111.11111110.00000000.00000000
network00001010.01000010.00000000.00000000
broadcast00001010.01000011.11111111.11111111
green = network part, grey = host part
hex0x0a420000
decimal172097536
reverse dns0.0.66.10.in-addr.arpa
ipv4-mapped::ffff:a42:0

/15 split into /21 · 64 subnets

close ×
#networkhost rangebroadcast
110.66.0.0/2110.66.0.1 – 10.66.7.25410.66.7.255
210.66.8.0/2110.66.8.1 – 10.66.15.25410.66.15.255
310.66.16.0/2110.66.16.1 – 10.66.23.25410.66.23.255
410.66.24.0/2110.66.24.1 – 10.66.31.25410.66.31.255
510.66.32.0/2110.66.32.1 – 10.66.39.25410.66.39.255
610.66.40.0/2110.66.40.1 – 10.66.47.25410.66.47.255
710.66.48.0/2110.66.48.1 – 10.66.55.25410.66.55.255
810.66.56.0/2110.66.56.1 – 10.66.63.25410.66.63.255
910.66.64.0/2110.66.64.1 – 10.66.71.25410.66.71.255
1010.66.72.0/2110.66.72.1 – 10.66.79.25410.66.79.255
1110.66.80.0/2110.66.80.1 – 10.66.87.25410.66.87.255
1210.66.88.0/2110.66.88.1 – 10.66.95.25410.66.95.255
1310.66.96.0/2110.66.96.1 – 10.66.103.25410.66.103.255
1410.66.104.0/2110.66.104.1 – 10.66.111.25410.66.111.255
1510.66.112.0/2110.66.112.1 – 10.66.119.25410.66.119.255
1610.66.120.0/2110.66.120.1 – 10.66.127.25410.66.127.255
1710.66.128.0/2110.66.128.1 – 10.66.135.25410.66.135.255
1810.66.136.0/2110.66.136.1 – 10.66.143.25410.66.143.255
1910.66.144.0/2110.66.144.1 – 10.66.151.25410.66.151.255
2010.66.152.0/2110.66.152.1 – 10.66.159.25410.66.159.255
2110.66.160.0/2110.66.160.1 – 10.66.167.25410.66.167.255
2210.66.168.0/2110.66.168.1 – 10.66.175.25410.66.175.255
2310.66.176.0/2110.66.176.1 – 10.66.183.25410.66.183.255
2410.66.184.0/2110.66.184.1 – 10.66.191.25410.66.191.255
2510.66.192.0/2110.66.192.1 – 10.66.199.25410.66.199.255
2610.66.200.0/2110.66.200.1 – 10.66.207.25410.66.207.255
2710.66.208.0/2110.66.208.1 – 10.66.215.25410.66.215.255
2810.66.216.0/2110.66.216.1 – 10.66.223.25410.66.223.255
2910.66.224.0/2110.66.224.1 – 10.66.231.25410.66.231.255
3010.66.232.0/2110.66.232.1 – 10.66.239.25410.66.239.255
3110.66.240.0/2110.66.240.1 – 10.66.247.25410.66.247.255
3210.66.248.0/2110.66.248.1 – 10.66.255.25410.66.255.255
3310.67.0.0/2110.67.0.1 – 10.67.7.25410.67.7.255
3410.67.8.0/2110.67.8.1 – 10.67.15.25410.67.15.255
3510.67.16.0/2110.67.16.1 – 10.67.23.25410.67.23.255
3610.67.24.0/2110.67.24.1 – 10.67.31.25410.67.31.255
3710.67.32.0/2110.67.32.1 – 10.67.39.25410.67.39.255
3810.67.40.0/2110.67.40.1 – 10.67.47.25410.67.47.255
3910.67.48.0/2110.67.48.1 – 10.67.55.25410.67.55.255
4010.67.56.0/2110.67.56.1 – 10.67.63.25410.67.63.255
4110.67.64.0/2110.67.64.1 – 10.67.71.25410.67.71.255
4210.67.72.0/2110.67.72.1 – 10.67.79.25410.67.79.255
4310.67.80.0/2110.67.80.1 – 10.67.87.25410.67.87.255
4410.67.88.0/2110.67.88.1 – 10.67.95.25410.67.95.255
4510.67.96.0/2110.67.96.1 – 10.67.103.25410.67.103.255
4610.67.104.0/2110.67.104.1 – 10.67.111.25410.67.111.255
4710.67.112.0/2110.67.112.1 – 10.67.119.25410.67.119.255
4810.67.120.0/2110.67.120.1 – 10.67.127.25410.67.127.255
4910.67.128.0/2110.67.128.1 – 10.67.135.25410.67.135.255
5010.67.136.0/2110.67.136.1 – 10.67.143.25410.67.143.255
5110.67.144.0/2110.67.144.1 – 10.67.151.25410.67.151.255
5210.67.152.0/2110.67.152.1 – 10.67.159.25410.67.159.255
5310.67.160.0/2110.67.160.1 – 10.67.167.25410.67.167.255
5410.67.168.0/2110.67.168.1 – 10.67.175.25410.67.175.255
5510.67.176.0/2110.67.176.1 – 10.67.183.25410.67.183.255
5610.67.184.0/2110.67.184.1 – 10.67.191.25410.67.191.255
5710.67.192.0/2110.67.192.1 – 10.67.199.25410.67.199.255
5810.67.200.0/2110.67.200.1 – 10.67.207.25410.67.207.255
5910.67.208.0/2110.67.208.1 – 10.67.215.25410.67.215.255
6010.67.216.0/2110.67.216.1 – 10.67.223.25410.67.223.255
6110.67.224.0/2110.67.224.1 – 10.67.231.25410.67.231.255
6210.67.232.0/2110.67.232.1 – 10.67.239.25410.67.239.255
6310.67.240.0/2110.67.240.1 – 10.67.247.25410.67.247.255
6410.67.248.0/2110.67.248.1 – 10.67.255.25410.67.255.255
01 / table

IPv4 CIDR prefix table.

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

prefixsubnet maskaddresseshostsin your /15
/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-
/15255.254.0.0131,072131,0701
/16255.255.0.065,53665,5342 split →
/17255.255.128.032,76832,7664 split →
/18255.255.192.016,38416,3828 split →
/19255.255.224.08,1928,19016 split →
/20255.255.240.04,0964,09432 split →
/21255.255.248.02,0482,04664 split →
/22255.255.252.01,0241,022128 split →
/23255.255.254.0512510256 split →
/24255.255.255.0256254512 split →
/25255.255.255.1281281261,024 split →
/26255.255.255.19264622,048 split →
/27255.255.255.22432304,096 split →
/28255.255.255.24016148,192 split →
/29255.255.255.2488616,384 split →
/30255.255.255.2524232,768 split →
/31255.255.255.2542265,536 split →
/32255.255.255.25511131,072 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 →