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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)10.4.224.0/21
network10.4.224.0/21
broadcast10.4.231.255
first host10.4.224.1
last host10.4.231.254
subnet mask255.255.248.0
wildcard0.0.7.255
addresses2,048
usable hosts2,046
classA
ipcalc 10.4.224.0/21
address00001010.00000100.11100000.00000000
subnet mask11111111.11111111.11111000.00000000
network00001010.00000100.11100000.00000000
broadcast00001010.00000100.11100111.11111111
green = network part, grey = host part
hex0x0a04e000
decimal168091648
reverse dns0.224.4.10.in-addr.arpa
ipv4-mapped::ffff:a04:e000

/21 split into /27 · 64 subnets

close ×
#networkhost rangebroadcast
110.4.224.0/2710.4.224.1 – 10.4.224.3010.4.224.31
210.4.224.32/2710.4.224.33 – 10.4.224.6210.4.224.63
310.4.224.64/2710.4.224.65 – 10.4.224.9410.4.224.95
410.4.224.96/2710.4.224.97 – 10.4.224.12610.4.224.127
510.4.224.128/2710.4.224.129 – 10.4.224.15810.4.224.159
610.4.224.160/2710.4.224.161 – 10.4.224.19010.4.224.191
710.4.224.192/2710.4.224.193 – 10.4.224.22210.4.224.223
810.4.224.224/2710.4.224.225 – 10.4.224.25410.4.224.255
910.4.225.0/2710.4.225.1 – 10.4.225.3010.4.225.31
1010.4.225.32/2710.4.225.33 – 10.4.225.6210.4.225.63
1110.4.225.64/2710.4.225.65 – 10.4.225.9410.4.225.95
1210.4.225.96/2710.4.225.97 – 10.4.225.12610.4.225.127
1310.4.225.128/2710.4.225.129 – 10.4.225.15810.4.225.159
1410.4.225.160/2710.4.225.161 – 10.4.225.19010.4.225.191
1510.4.225.192/2710.4.225.193 – 10.4.225.22210.4.225.223
1610.4.225.224/2710.4.225.225 – 10.4.225.25410.4.225.255
1710.4.226.0/2710.4.226.1 – 10.4.226.3010.4.226.31
1810.4.226.32/2710.4.226.33 – 10.4.226.6210.4.226.63
1910.4.226.64/2710.4.226.65 – 10.4.226.9410.4.226.95
2010.4.226.96/2710.4.226.97 – 10.4.226.12610.4.226.127
2110.4.226.128/2710.4.226.129 – 10.4.226.15810.4.226.159
2210.4.226.160/2710.4.226.161 – 10.4.226.19010.4.226.191
2310.4.226.192/2710.4.226.193 – 10.4.226.22210.4.226.223
2410.4.226.224/2710.4.226.225 – 10.4.226.25410.4.226.255
2510.4.227.0/2710.4.227.1 – 10.4.227.3010.4.227.31
2610.4.227.32/2710.4.227.33 – 10.4.227.6210.4.227.63
2710.4.227.64/2710.4.227.65 – 10.4.227.9410.4.227.95
2810.4.227.96/2710.4.227.97 – 10.4.227.12610.4.227.127
2910.4.227.128/2710.4.227.129 – 10.4.227.15810.4.227.159
3010.4.227.160/2710.4.227.161 – 10.4.227.19010.4.227.191
3110.4.227.192/2710.4.227.193 – 10.4.227.22210.4.227.223
3210.4.227.224/2710.4.227.225 – 10.4.227.25410.4.227.255
3310.4.228.0/2710.4.228.1 – 10.4.228.3010.4.228.31
3410.4.228.32/2710.4.228.33 – 10.4.228.6210.4.228.63
3510.4.228.64/2710.4.228.65 – 10.4.228.9410.4.228.95
3610.4.228.96/2710.4.228.97 – 10.4.228.12610.4.228.127
3710.4.228.128/2710.4.228.129 – 10.4.228.15810.4.228.159
3810.4.228.160/2710.4.228.161 – 10.4.228.19010.4.228.191
3910.4.228.192/2710.4.228.193 – 10.4.228.22210.4.228.223
4010.4.228.224/2710.4.228.225 – 10.4.228.25410.4.228.255
4110.4.229.0/2710.4.229.1 – 10.4.229.3010.4.229.31
4210.4.229.32/2710.4.229.33 – 10.4.229.6210.4.229.63
4310.4.229.64/2710.4.229.65 – 10.4.229.9410.4.229.95
4410.4.229.96/2710.4.229.97 – 10.4.229.12610.4.229.127
4510.4.229.128/2710.4.229.129 – 10.4.229.15810.4.229.159
4610.4.229.160/2710.4.229.161 – 10.4.229.19010.4.229.191
4710.4.229.192/2710.4.229.193 – 10.4.229.22210.4.229.223
4810.4.229.224/2710.4.229.225 – 10.4.229.25410.4.229.255
4910.4.230.0/2710.4.230.1 – 10.4.230.3010.4.230.31
5010.4.230.32/2710.4.230.33 – 10.4.230.6210.4.230.63
5110.4.230.64/2710.4.230.65 – 10.4.230.9410.4.230.95
5210.4.230.96/2710.4.230.97 – 10.4.230.12610.4.230.127
5310.4.230.128/2710.4.230.129 – 10.4.230.15810.4.230.159
5410.4.230.160/2710.4.230.161 – 10.4.230.19010.4.230.191
5510.4.230.192/2710.4.230.193 – 10.4.230.22210.4.230.223
5610.4.230.224/2710.4.230.225 – 10.4.230.25410.4.230.255
5710.4.231.0/2710.4.231.1 – 10.4.231.3010.4.231.31
5810.4.231.32/2710.4.231.33 – 10.4.231.6210.4.231.63
5910.4.231.64/2710.4.231.65 – 10.4.231.9410.4.231.95
6010.4.231.96/2710.4.231.97 – 10.4.231.12610.4.231.127
6110.4.231.128/2710.4.231.129 – 10.4.231.15810.4.231.159
6210.4.231.160/2710.4.231.161 – 10.4.231.19010.4.231.191
6310.4.231.192/2710.4.231.193 – 10.4.231.22210.4.231.223
6410.4.231.224/2710.4.231.225 – 10.4.231.25410.4.231.255
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 →