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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)10.12.64.0/20
network10.12.64.0/20
broadcast10.12.79.255
first host10.12.64.1
last host10.12.79.254
subnet mask255.255.240.0
wildcard0.0.15.255
addresses4,096
usable hosts4,094
classA
ipcalc 10.12.64.0/20
address00001010.00001100.01000000.00000000
subnet mask11111111.11111111.11110000.00000000
network00001010.00001100.01000000.00000000
broadcast00001010.00001100.01001111.11111111
green = network part, grey = host part
hex0x0a0c4000
decimal168574976
reverse dns0.64.12.10.in-addr.arpa
ipv4-mapped::ffff:a0c:4000

/20 split into /26 · 64 subnets

close ×
#networkhost rangebroadcast
110.12.64.0/2610.12.64.1 – 10.12.64.6210.12.64.63
210.12.64.64/2610.12.64.65 – 10.12.64.12610.12.64.127
310.12.64.128/2610.12.64.129 – 10.12.64.19010.12.64.191
410.12.64.192/2610.12.64.193 – 10.12.64.25410.12.64.255
510.12.65.0/2610.12.65.1 – 10.12.65.6210.12.65.63
610.12.65.64/2610.12.65.65 – 10.12.65.12610.12.65.127
710.12.65.128/2610.12.65.129 – 10.12.65.19010.12.65.191
810.12.65.192/2610.12.65.193 – 10.12.65.25410.12.65.255
910.12.66.0/2610.12.66.1 – 10.12.66.6210.12.66.63
1010.12.66.64/2610.12.66.65 – 10.12.66.12610.12.66.127
1110.12.66.128/2610.12.66.129 – 10.12.66.19010.12.66.191
1210.12.66.192/2610.12.66.193 – 10.12.66.25410.12.66.255
1310.12.67.0/2610.12.67.1 – 10.12.67.6210.12.67.63
1410.12.67.64/2610.12.67.65 – 10.12.67.12610.12.67.127
1510.12.67.128/2610.12.67.129 – 10.12.67.19010.12.67.191
1610.12.67.192/2610.12.67.193 – 10.12.67.25410.12.67.255
1710.12.68.0/2610.12.68.1 – 10.12.68.6210.12.68.63
1810.12.68.64/2610.12.68.65 – 10.12.68.12610.12.68.127
1910.12.68.128/2610.12.68.129 – 10.12.68.19010.12.68.191
2010.12.68.192/2610.12.68.193 – 10.12.68.25410.12.68.255
2110.12.69.0/2610.12.69.1 – 10.12.69.6210.12.69.63
2210.12.69.64/2610.12.69.65 – 10.12.69.12610.12.69.127
2310.12.69.128/2610.12.69.129 – 10.12.69.19010.12.69.191
2410.12.69.192/2610.12.69.193 – 10.12.69.25410.12.69.255
2510.12.70.0/2610.12.70.1 – 10.12.70.6210.12.70.63
2610.12.70.64/2610.12.70.65 – 10.12.70.12610.12.70.127
2710.12.70.128/2610.12.70.129 – 10.12.70.19010.12.70.191
2810.12.70.192/2610.12.70.193 – 10.12.70.25410.12.70.255
2910.12.71.0/2610.12.71.1 – 10.12.71.6210.12.71.63
3010.12.71.64/2610.12.71.65 – 10.12.71.12610.12.71.127
3110.12.71.128/2610.12.71.129 – 10.12.71.19010.12.71.191
3210.12.71.192/2610.12.71.193 – 10.12.71.25410.12.71.255
3310.12.72.0/2610.12.72.1 – 10.12.72.6210.12.72.63
3410.12.72.64/2610.12.72.65 – 10.12.72.12610.12.72.127
3510.12.72.128/2610.12.72.129 – 10.12.72.19010.12.72.191
3610.12.72.192/2610.12.72.193 – 10.12.72.25410.12.72.255
3710.12.73.0/2610.12.73.1 – 10.12.73.6210.12.73.63
3810.12.73.64/2610.12.73.65 – 10.12.73.12610.12.73.127
3910.12.73.128/2610.12.73.129 – 10.12.73.19010.12.73.191
4010.12.73.192/2610.12.73.193 – 10.12.73.25410.12.73.255
4110.12.74.0/2610.12.74.1 – 10.12.74.6210.12.74.63
4210.12.74.64/2610.12.74.65 – 10.12.74.12610.12.74.127
4310.12.74.128/2610.12.74.129 – 10.12.74.19010.12.74.191
4410.12.74.192/2610.12.74.193 – 10.12.74.25410.12.74.255
4510.12.75.0/2610.12.75.1 – 10.12.75.6210.12.75.63
4610.12.75.64/2610.12.75.65 – 10.12.75.12610.12.75.127
4710.12.75.128/2610.12.75.129 – 10.12.75.19010.12.75.191
4810.12.75.192/2610.12.75.193 – 10.12.75.25410.12.75.255
4910.12.76.0/2610.12.76.1 – 10.12.76.6210.12.76.63
5010.12.76.64/2610.12.76.65 – 10.12.76.12610.12.76.127
5110.12.76.128/2610.12.76.129 – 10.12.76.19010.12.76.191
5210.12.76.192/2610.12.76.193 – 10.12.76.25410.12.76.255
5310.12.77.0/2610.12.77.1 – 10.12.77.6210.12.77.63
5410.12.77.64/2610.12.77.65 – 10.12.77.12610.12.77.127
5510.12.77.128/2610.12.77.129 – 10.12.77.19010.12.77.191
5610.12.77.192/2610.12.77.193 – 10.12.77.25410.12.77.255
5710.12.78.0/2610.12.78.1 – 10.12.78.6210.12.78.63
5810.12.78.64/2610.12.78.65 – 10.12.78.12610.12.78.127
5910.12.78.128/2610.12.78.129 – 10.12.78.19010.12.78.191
6010.12.78.192/2610.12.78.193 – 10.12.78.25410.12.78.255
6110.12.79.0/2610.12.79.1 – 10.12.79.6210.12.79.63
6210.12.79.64/2610.12.79.65 – 10.12.79.12610.12.79.127
6310.12.79.128/2610.12.79.129 – 10.12.79.19010.12.79.191
6410.12.79.192/2610.12.79.193 – 10.12.79.25410.12.79.255
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 →