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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)10.7.232.0/21
network10.7.232.0/21
broadcast10.7.239.255
first host10.7.232.1
last host10.7.239.254
subnet mask255.255.248.0
wildcard0.0.7.255
addresses2,048
usable hosts2,046
classA
ipcalc 10.7.232.0/21
address00001010.00000111.11101000.00000000
subnet mask11111111.11111111.11111000.00000000
network00001010.00000111.11101000.00000000
broadcast00001010.00000111.11101111.11111111
green = network part, grey = host part
hex0x0a07e800
decimal168290304
reverse dns0.232.7.10.in-addr.arpa
ipv4-mapped::ffff:a07:e800

/21 split into /27 · 64 subnets

close ×
#networkhost rangebroadcast
110.7.232.0/2710.7.232.1 – 10.7.232.3010.7.232.31
210.7.232.32/2710.7.232.33 – 10.7.232.6210.7.232.63
310.7.232.64/2710.7.232.65 – 10.7.232.9410.7.232.95
410.7.232.96/2710.7.232.97 – 10.7.232.12610.7.232.127
510.7.232.128/2710.7.232.129 – 10.7.232.15810.7.232.159
610.7.232.160/2710.7.232.161 – 10.7.232.19010.7.232.191
710.7.232.192/2710.7.232.193 – 10.7.232.22210.7.232.223
810.7.232.224/2710.7.232.225 – 10.7.232.25410.7.232.255
910.7.233.0/2710.7.233.1 – 10.7.233.3010.7.233.31
1010.7.233.32/2710.7.233.33 – 10.7.233.6210.7.233.63
1110.7.233.64/2710.7.233.65 – 10.7.233.9410.7.233.95
1210.7.233.96/2710.7.233.97 – 10.7.233.12610.7.233.127
1310.7.233.128/2710.7.233.129 – 10.7.233.15810.7.233.159
1410.7.233.160/2710.7.233.161 – 10.7.233.19010.7.233.191
1510.7.233.192/2710.7.233.193 – 10.7.233.22210.7.233.223
1610.7.233.224/2710.7.233.225 – 10.7.233.25410.7.233.255
1710.7.234.0/2710.7.234.1 – 10.7.234.3010.7.234.31
1810.7.234.32/2710.7.234.33 – 10.7.234.6210.7.234.63
1910.7.234.64/2710.7.234.65 – 10.7.234.9410.7.234.95
2010.7.234.96/2710.7.234.97 – 10.7.234.12610.7.234.127
2110.7.234.128/2710.7.234.129 – 10.7.234.15810.7.234.159
2210.7.234.160/2710.7.234.161 – 10.7.234.19010.7.234.191
2310.7.234.192/2710.7.234.193 – 10.7.234.22210.7.234.223
2410.7.234.224/2710.7.234.225 – 10.7.234.25410.7.234.255
2510.7.235.0/2710.7.235.1 – 10.7.235.3010.7.235.31
2610.7.235.32/2710.7.235.33 – 10.7.235.6210.7.235.63
2710.7.235.64/2710.7.235.65 – 10.7.235.9410.7.235.95
2810.7.235.96/2710.7.235.97 – 10.7.235.12610.7.235.127
2910.7.235.128/2710.7.235.129 – 10.7.235.15810.7.235.159
3010.7.235.160/2710.7.235.161 – 10.7.235.19010.7.235.191
3110.7.235.192/2710.7.235.193 – 10.7.235.22210.7.235.223
3210.7.235.224/2710.7.235.225 – 10.7.235.25410.7.235.255
3310.7.236.0/2710.7.236.1 – 10.7.236.3010.7.236.31
3410.7.236.32/2710.7.236.33 – 10.7.236.6210.7.236.63
3510.7.236.64/2710.7.236.65 – 10.7.236.9410.7.236.95
3610.7.236.96/2710.7.236.97 – 10.7.236.12610.7.236.127
3710.7.236.128/2710.7.236.129 – 10.7.236.15810.7.236.159
3810.7.236.160/2710.7.236.161 – 10.7.236.19010.7.236.191
3910.7.236.192/2710.7.236.193 – 10.7.236.22210.7.236.223
4010.7.236.224/2710.7.236.225 – 10.7.236.25410.7.236.255
4110.7.237.0/2710.7.237.1 – 10.7.237.3010.7.237.31
4210.7.237.32/2710.7.237.33 – 10.7.237.6210.7.237.63
4310.7.237.64/2710.7.237.65 – 10.7.237.9410.7.237.95
4410.7.237.96/2710.7.237.97 – 10.7.237.12610.7.237.127
4510.7.237.128/2710.7.237.129 – 10.7.237.15810.7.237.159
4610.7.237.160/2710.7.237.161 – 10.7.237.19010.7.237.191
4710.7.237.192/2710.7.237.193 – 10.7.237.22210.7.237.223
4810.7.237.224/2710.7.237.225 – 10.7.237.25410.7.237.255
4910.7.238.0/2710.7.238.1 – 10.7.238.3010.7.238.31
5010.7.238.32/2710.7.238.33 – 10.7.238.6210.7.238.63
5110.7.238.64/2710.7.238.65 – 10.7.238.9410.7.238.95
5210.7.238.96/2710.7.238.97 – 10.7.238.12610.7.238.127
5310.7.238.128/2710.7.238.129 – 10.7.238.15810.7.238.159
5410.7.238.160/2710.7.238.161 – 10.7.238.19010.7.238.191
5510.7.238.192/2710.7.238.193 – 10.7.238.22210.7.238.223
5610.7.238.224/2710.7.238.225 – 10.7.238.25410.7.238.255
5710.7.239.0/2710.7.239.1 – 10.7.239.3010.7.239.31
5810.7.239.32/2710.7.239.33 – 10.7.239.6210.7.239.63
5910.7.239.64/2710.7.239.65 – 10.7.239.9410.7.239.95
6010.7.239.96/2710.7.239.97 – 10.7.239.12610.7.239.127
6110.7.239.128/2710.7.239.129 – 10.7.239.15810.7.239.159
6210.7.239.160/2710.7.239.161 – 10.7.239.19010.7.239.191
6310.7.239.192/2710.7.239.193 – 10.7.239.22210.7.239.223
6410.7.239.224/2710.7.239.225 – 10.7.239.25410.7.239.255
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 →