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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)10.78.128.0/20
network10.78.128.0/20
broadcast10.78.143.255
first host10.78.128.1
last host10.78.143.254
subnet mask255.255.240.0
wildcard0.0.15.255
addresses4,096
usable hosts4,094
classA
ipcalc 10.78.128.0/20
address00001010.01001110.10000000.00000000
subnet mask11111111.11111111.11110000.00000000
network00001010.01001110.10000000.00000000
broadcast00001010.01001110.10001111.11111111
green = network part, grey = host part
hex0x0a4e8000
decimal172916736
reverse dns0.128.78.10.in-addr.arpa
ipv4-mapped::ffff:a4e:8000

/20 split into /26 · 64 subnets

close ×
#networkhost rangebroadcast
110.78.128.0/2610.78.128.1 – 10.78.128.6210.78.128.63
210.78.128.64/2610.78.128.65 – 10.78.128.12610.78.128.127
310.78.128.128/2610.78.128.129 – 10.78.128.19010.78.128.191
410.78.128.192/2610.78.128.193 – 10.78.128.25410.78.128.255
510.78.129.0/2610.78.129.1 – 10.78.129.6210.78.129.63
610.78.129.64/2610.78.129.65 – 10.78.129.12610.78.129.127
710.78.129.128/2610.78.129.129 – 10.78.129.19010.78.129.191
810.78.129.192/2610.78.129.193 – 10.78.129.25410.78.129.255
910.78.130.0/2610.78.130.1 – 10.78.130.6210.78.130.63
1010.78.130.64/2610.78.130.65 – 10.78.130.12610.78.130.127
1110.78.130.128/2610.78.130.129 – 10.78.130.19010.78.130.191
1210.78.130.192/2610.78.130.193 – 10.78.130.25410.78.130.255
1310.78.131.0/2610.78.131.1 – 10.78.131.6210.78.131.63
1410.78.131.64/2610.78.131.65 – 10.78.131.12610.78.131.127
1510.78.131.128/2610.78.131.129 – 10.78.131.19010.78.131.191
1610.78.131.192/2610.78.131.193 – 10.78.131.25410.78.131.255
1710.78.132.0/2610.78.132.1 – 10.78.132.6210.78.132.63
1810.78.132.64/2610.78.132.65 – 10.78.132.12610.78.132.127
1910.78.132.128/2610.78.132.129 – 10.78.132.19010.78.132.191
2010.78.132.192/2610.78.132.193 – 10.78.132.25410.78.132.255
2110.78.133.0/2610.78.133.1 – 10.78.133.6210.78.133.63
2210.78.133.64/2610.78.133.65 – 10.78.133.12610.78.133.127
2310.78.133.128/2610.78.133.129 – 10.78.133.19010.78.133.191
2410.78.133.192/2610.78.133.193 – 10.78.133.25410.78.133.255
2510.78.134.0/2610.78.134.1 – 10.78.134.6210.78.134.63
2610.78.134.64/2610.78.134.65 – 10.78.134.12610.78.134.127
2710.78.134.128/2610.78.134.129 – 10.78.134.19010.78.134.191
2810.78.134.192/2610.78.134.193 – 10.78.134.25410.78.134.255
2910.78.135.0/2610.78.135.1 – 10.78.135.6210.78.135.63
3010.78.135.64/2610.78.135.65 – 10.78.135.12610.78.135.127
3110.78.135.128/2610.78.135.129 – 10.78.135.19010.78.135.191
3210.78.135.192/2610.78.135.193 – 10.78.135.25410.78.135.255
3310.78.136.0/2610.78.136.1 – 10.78.136.6210.78.136.63
3410.78.136.64/2610.78.136.65 – 10.78.136.12610.78.136.127
3510.78.136.128/2610.78.136.129 – 10.78.136.19010.78.136.191
3610.78.136.192/2610.78.136.193 – 10.78.136.25410.78.136.255
3710.78.137.0/2610.78.137.1 – 10.78.137.6210.78.137.63
3810.78.137.64/2610.78.137.65 – 10.78.137.12610.78.137.127
3910.78.137.128/2610.78.137.129 – 10.78.137.19010.78.137.191
4010.78.137.192/2610.78.137.193 – 10.78.137.25410.78.137.255
4110.78.138.0/2610.78.138.1 – 10.78.138.6210.78.138.63
4210.78.138.64/2610.78.138.65 – 10.78.138.12610.78.138.127
4310.78.138.128/2610.78.138.129 – 10.78.138.19010.78.138.191
4410.78.138.192/2610.78.138.193 – 10.78.138.25410.78.138.255
4510.78.139.0/2610.78.139.1 – 10.78.139.6210.78.139.63
4610.78.139.64/2610.78.139.65 – 10.78.139.12610.78.139.127
4710.78.139.128/2610.78.139.129 – 10.78.139.19010.78.139.191
4810.78.139.192/2610.78.139.193 – 10.78.139.25410.78.139.255
4910.78.140.0/2610.78.140.1 – 10.78.140.6210.78.140.63
5010.78.140.64/2610.78.140.65 – 10.78.140.12610.78.140.127
5110.78.140.128/2610.78.140.129 – 10.78.140.19010.78.140.191
5210.78.140.192/2610.78.140.193 – 10.78.140.25410.78.140.255
5310.78.141.0/2610.78.141.1 – 10.78.141.6210.78.141.63
5410.78.141.64/2610.78.141.65 – 10.78.141.12610.78.141.127
5510.78.141.128/2610.78.141.129 – 10.78.141.19010.78.141.191
5610.78.141.192/2610.78.141.193 – 10.78.141.25410.78.141.255
5710.78.142.0/2610.78.142.1 – 10.78.142.6210.78.142.63
5810.78.142.64/2610.78.142.65 – 10.78.142.12610.78.142.127
5910.78.142.128/2610.78.142.129 – 10.78.142.19010.78.142.191
6010.78.142.192/2610.78.142.193 – 10.78.142.25410.78.142.255
6110.78.143.0/2610.78.143.1 – 10.78.143.6210.78.143.63
6210.78.143.64/2610.78.143.65 – 10.78.143.12610.78.143.127
6310.78.143.128/2610.78.143.129 – 10.78.143.19010.78.143.191
6410.78.143.192/2610.78.143.193 – 10.78.143.25410.78.143.255
01 / table

IPv4 CIDR prefix table.

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

prefixsubnet maskaddresseshostsin your /20
/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-
/16255.255.0.065,53665,534-
/17255.255.128.032,76832,766-
/18255.255.192.016,38416,382-
/19255.255.224.08,1928,190-
/20255.255.240.04,0964,0941
/21255.255.248.02,0482,0462 split →
/22255.255.252.01,0241,0224 split →
/23255.255.254.05125108 split →
/24255.255.255.025625416 split →
/25255.255.255.12812812632 split →
/26255.255.255.192646264 split →
/27255.255.255.2243230128 split →
/28255.255.255.2401614256 split →
/29255.255.255.24886512 split →
/30255.255.255.252421,024 split →
/31255.255.255.254222,048 split →
/32255.255.255.255114,096 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 →