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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)10.4.160.0/21
network10.4.160.0/21
broadcast10.4.167.255
first host10.4.160.1
last host10.4.167.254
subnet mask255.255.248.0
wildcard0.0.7.255
addresses2,048
usable hosts2,046
classA
ipcalc 10.4.160.0/21
address00001010.00000100.10100000.00000000
subnet mask11111111.11111111.11111000.00000000
network00001010.00000100.10100000.00000000
broadcast00001010.00000100.10100111.11111111
green = network part, grey = host part
hex0x0a04a000
decimal168075264
reverse dns0.160.4.10.in-addr.arpa
ipv4-mapped::ffff:a04:a000

/21 split into /27 · 64 subnets

close ×
#networkhost rangebroadcast
110.4.160.0/2710.4.160.1 – 10.4.160.3010.4.160.31
210.4.160.32/2710.4.160.33 – 10.4.160.6210.4.160.63
310.4.160.64/2710.4.160.65 – 10.4.160.9410.4.160.95
410.4.160.96/2710.4.160.97 – 10.4.160.12610.4.160.127
510.4.160.128/2710.4.160.129 – 10.4.160.15810.4.160.159
610.4.160.160/2710.4.160.161 – 10.4.160.19010.4.160.191
710.4.160.192/2710.4.160.193 – 10.4.160.22210.4.160.223
810.4.160.224/2710.4.160.225 – 10.4.160.25410.4.160.255
910.4.161.0/2710.4.161.1 – 10.4.161.3010.4.161.31
1010.4.161.32/2710.4.161.33 – 10.4.161.6210.4.161.63
1110.4.161.64/2710.4.161.65 – 10.4.161.9410.4.161.95
1210.4.161.96/2710.4.161.97 – 10.4.161.12610.4.161.127
1310.4.161.128/2710.4.161.129 – 10.4.161.15810.4.161.159
1410.4.161.160/2710.4.161.161 – 10.4.161.19010.4.161.191
1510.4.161.192/2710.4.161.193 – 10.4.161.22210.4.161.223
1610.4.161.224/2710.4.161.225 – 10.4.161.25410.4.161.255
1710.4.162.0/2710.4.162.1 – 10.4.162.3010.4.162.31
1810.4.162.32/2710.4.162.33 – 10.4.162.6210.4.162.63
1910.4.162.64/2710.4.162.65 – 10.4.162.9410.4.162.95
2010.4.162.96/2710.4.162.97 – 10.4.162.12610.4.162.127
2110.4.162.128/2710.4.162.129 – 10.4.162.15810.4.162.159
2210.4.162.160/2710.4.162.161 – 10.4.162.19010.4.162.191
2310.4.162.192/2710.4.162.193 – 10.4.162.22210.4.162.223
2410.4.162.224/2710.4.162.225 – 10.4.162.25410.4.162.255
2510.4.163.0/2710.4.163.1 – 10.4.163.3010.4.163.31
2610.4.163.32/2710.4.163.33 – 10.4.163.6210.4.163.63
2710.4.163.64/2710.4.163.65 – 10.4.163.9410.4.163.95
2810.4.163.96/2710.4.163.97 – 10.4.163.12610.4.163.127
2910.4.163.128/2710.4.163.129 – 10.4.163.15810.4.163.159
3010.4.163.160/2710.4.163.161 – 10.4.163.19010.4.163.191
3110.4.163.192/2710.4.163.193 – 10.4.163.22210.4.163.223
3210.4.163.224/2710.4.163.225 – 10.4.163.25410.4.163.255
3310.4.164.0/2710.4.164.1 – 10.4.164.3010.4.164.31
3410.4.164.32/2710.4.164.33 – 10.4.164.6210.4.164.63
3510.4.164.64/2710.4.164.65 – 10.4.164.9410.4.164.95
3610.4.164.96/2710.4.164.97 – 10.4.164.12610.4.164.127
3710.4.164.128/2710.4.164.129 – 10.4.164.15810.4.164.159
3810.4.164.160/2710.4.164.161 – 10.4.164.19010.4.164.191
3910.4.164.192/2710.4.164.193 – 10.4.164.22210.4.164.223
4010.4.164.224/2710.4.164.225 – 10.4.164.25410.4.164.255
4110.4.165.0/2710.4.165.1 – 10.4.165.3010.4.165.31
4210.4.165.32/2710.4.165.33 – 10.4.165.6210.4.165.63
4310.4.165.64/2710.4.165.65 – 10.4.165.9410.4.165.95
4410.4.165.96/2710.4.165.97 – 10.4.165.12610.4.165.127
4510.4.165.128/2710.4.165.129 – 10.4.165.15810.4.165.159
4610.4.165.160/2710.4.165.161 – 10.4.165.19010.4.165.191
4710.4.165.192/2710.4.165.193 – 10.4.165.22210.4.165.223
4810.4.165.224/2710.4.165.225 – 10.4.165.25410.4.165.255
4910.4.166.0/2710.4.166.1 – 10.4.166.3010.4.166.31
5010.4.166.32/2710.4.166.33 – 10.4.166.6210.4.166.63
5110.4.166.64/2710.4.166.65 – 10.4.166.9410.4.166.95
5210.4.166.96/2710.4.166.97 – 10.4.166.12610.4.166.127
5310.4.166.128/2710.4.166.129 – 10.4.166.15810.4.166.159
5410.4.166.160/2710.4.166.161 – 10.4.166.19010.4.166.191
5510.4.166.192/2710.4.166.193 – 10.4.166.22210.4.166.223
5610.4.166.224/2710.4.166.225 – 10.4.166.25410.4.166.255
5710.4.167.0/2710.4.167.1 – 10.4.167.3010.4.167.31
5810.4.167.32/2710.4.167.33 – 10.4.167.6210.4.167.63
5910.4.167.64/2710.4.167.65 – 10.4.167.9410.4.167.95
6010.4.167.96/2710.4.167.97 – 10.4.167.12610.4.167.127
6110.4.167.128/2710.4.167.129 – 10.4.167.15810.4.167.159
6210.4.167.160/2710.4.167.161 – 10.4.167.19010.4.167.191
6310.4.167.192/2710.4.167.193 – 10.4.167.22210.4.167.223
6410.4.167.224/2710.4.167.225 – 10.4.167.25410.4.167.255
01 / table

IPv4 CIDR prefix table.

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

prefixsubnet maskaddresseshostsin your /21
/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-
/20255.255.240.04,0964,094-
/21255.255.248.02,0482,0461
/22255.255.252.01,0241,0222 split →
/23255.255.254.05125104 split →
/24255.255.255.02562548 split →
/25255.255.255.12812812616 split →
/26255.255.255.192646232 split →
/27255.255.255.224323064 split →
/28255.255.255.2401614128 split →
/29255.255.255.24886256 split →
/30255.255.255.25242512 split →
/31255.255.255.254221,024 split →
/32255.255.255.255112,048 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 →