ip
ipku.in

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
private IP (RFC 1918)10.5.200.0/21
network10.5.200.0/21
broadcast10.5.207.255
first host10.5.200.1
last host10.5.207.254
subnet mask255.255.248.0
wildcard0.0.7.255
addresses2,048
usable hosts2,046
classA
ipcalc 10.5.200.0/21
address00001010.00000101.11001000.00000000
subnet mask11111111.11111111.11111000.00000000
network00001010.00000101.11001000.00000000
broadcast00001010.00000101.11001111.11111111
green = network part, grey = host part
hex0x0a05c800
decimal168151040
reverse dns0.200.5.10.in-addr.arpa
ipv4-mapped::ffff:a05:c800

/21 split into /28 · 128 subnets

close ×
#networkhost rangebroadcast
110.5.200.0/2810.5.200.1 – 10.5.200.1410.5.200.15
210.5.200.16/2810.5.200.17 – 10.5.200.3010.5.200.31
310.5.200.32/2810.5.200.33 – 10.5.200.4610.5.200.47
410.5.200.48/2810.5.200.49 – 10.5.200.6210.5.200.63
510.5.200.64/2810.5.200.65 – 10.5.200.7810.5.200.79
610.5.200.80/2810.5.200.81 – 10.5.200.9410.5.200.95
710.5.200.96/2810.5.200.97 – 10.5.200.11010.5.200.111
810.5.200.112/2810.5.200.113 – 10.5.200.12610.5.200.127
910.5.200.128/2810.5.200.129 – 10.5.200.14210.5.200.143
1010.5.200.144/2810.5.200.145 – 10.5.200.15810.5.200.159
1110.5.200.160/2810.5.200.161 – 10.5.200.17410.5.200.175
1210.5.200.176/2810.5.200.177 – 10.5.200.19010.5.200.191
1310.5.200.192/2810.5.200.193 – 10.5.200.20610.5.200.207
1410.5.200.208/2810.5.200.209 – 10.5.200.22210.5.200.223
1510.5.200.224/2810.5.200.225 – 10.5.200.23810.5.200.239
1610.5.200.240/2810.5.200.241 – 10.5.200.25410.5.200.255
1710.5.201.0/2810.5.201.1 – 10.5.201.1410.5.201.15
1810.5.201.16/2810.5.201.17 – 10.5.201.3010.5.201.31
1910.5.201.32/2810.5.201.33 – 10.5.201.4610.5.201.47
2010.5.201.48/2810.5.201.49 – 10.5.201.6210.5.201.63
2110.5.201.64/2810.5.201.65 – 10.5.201.7810.5.201.79
2210.5.201.80/2810.5.201.81 – 10.5.201.9410.5.201.95
2310.5.201.96/2810.5.201.97 – 10.5.201.11010.5.201.111
2410.5.201.112/2810.5.201.113 – 10.5.201.12610.5.201.127
2510.5.201.128/2810.5.201.129 – 10.5.201.14210.5.201.143
2610.5.201.144/2810.5.201.145 – 10.5.201.15810.5.201.159
2710.5.201.160/2810.5.201.161 – 10.5.201.17410.5.201.175
2810.5.201.176/2810.5.201.177 – 10.5.201.19010.5.201.191
2910.5.201.192/2810.5.201.193 – 10.5.201.20610.5.201.207
3010.5.201.208/2810.5.201.209 – 10.5.201.22210.5.201.223
3110.5.201.224/2810.5.201.225 – 10.5.201.23810.5.201.239
3210.5.201.240/2810.5.201.241 – 10.5.201.25410.5.201.255
3310.5.202.0/2810.5.202.1 – 10.5.202.1410.5.202.15
3410.5.202.16/2810.5.202.17 – 10.5.202.3010.5.202.31
3510.5.202.32/2810.5.202.33 – 10.5.202.4610.5.202.47
3610.5.202.48/2810.5.202.49 – 10.5.202.6210.5.202.63
3710.5.202.64/2810.5.202.65 – 10.5.202.7810.5.202.79
3810.5.202.80/2810.5.202.81 – 10.5.202.9410.5.202.95
3910.5.202.96/2810.5.202.97 – 10.5.202.11010.5.202.111
4010.5.202.112/2810.5.202.113 – 10.5.202.12610.5.202.127
4110.5.202.128/2810.5.202.129 – 10.5.202.14210.5.202.143
4210.5.202.144/2810.5.202.145 – 10.5.202.15810.5.202.159
4310.5.202.160/2810.5.202.161 – 10.5.202.17410.5.202.175
4410.5.202.176/2810.5.202.177 – 10.5.202.19010.5.202.191
4510.5.202.192/2810.5.202.193 – 10.5.202.20610.5.202.207
4610.5.202.208/2810.5.202.209 – 10.5.202.22210.5.202.223
4710.5.202.224/2810.5.202.225 – 10.5.202.23810.5.202.239
4810.5.202.240/2810.5.202.241 – 10.5.202.25410.5.202.255
4910.5.203.0/2810.5.203.1 – 10.5.203.1410.5.203.15
5010.5.203.16/2810.5.203.17 – 10.5.203.3010.5.203.31
5110.5.203.32/2810.5.203.33 – 10.5.203.4610.5.203.47
5210.5.203.48/2810.5.203.49 – 10.5.203.6210.5.203.63
5310.5.203.64/2810.5.203.65 – 10.5.203.7810.5.203.79
5410.5.203.80/2810.5.203.81 – 10.5.203.9410.5.203.95
5510.5.203.96/2810.5.203.97 – 10.5.203.11010.5.203.111
5610.5.203.112/2810.5.203.113 – 10.5.203.12610.5.203.127
5710.5.203.128/2810.5.203.129 – 10.5.203.14210.5.203.143
5810.5.203.144/2810.5.203.145 – 10.5.203.15810.5.203.159
5910.5.203.160/2810.5.203.161 – 10.5.203.17410.5.203.175
6010.5.203.176/2810.5.203.177 – 10.5.203.19010.5.203.191
6110.5.203.192/2810.5.203.193 – 10.5.203.20610.5.203.207
6210.5.203.208/2810.5.203.209 – 10.5.203.22210.5.203.223
6310.5.203.224/2810.5.203.225 – 10.5.203.23810.5.203.239
6410.5.203.240/2810.5.203.241 – 10.5.203.25410.5.203.255
6510.5.204.0/2810.5.204.1 – 10.5.204.1410.5.204.15
6610.5.204.16/2810.5.204.17 – 10.5.204.3010.5.204.31
6710.5.204.32/2810.5.204.33 – 10.5.204.4610.5.204.47
6810.5.204.48/2810.5.204.49 – 10.5.204.6210.5.204.63
6910.5.204.64/2810.5.204.65 – 10.5.204.7810.5.204.79
7010.5.204.80/2810.5.204.81 – 10.5.204.9410.5.204.95
7110.5.204.96/2810.5.204.97 – 10.5.204.11010.5.204.111
7210.5.204.112/2810.5.204.113 – 10.5.204.12610.5.204.127
7310.5.204.128/2810.5.204.129 – 10.5.204.14210.5.204.143
7410.5.204.144/2810.5.204.145 – 10.5.204.15810.5.204.159
7510.5.204.160/2810.5.204.161 – 10.5.204.17410.5.204.175
7610.5.204.176/2810.5.204.177 – 10.5.204.19010.5.204.191
7710.5.204.192/2810.5.204.193 – 10.5.204.20610.5.204.207
7810.5.204.208/2810.5.204.209 – 10.5.204.22210.5.204.223
7910.5.204.224/2810.5.204.225 – 10.5.204.23810.5.204.239
8010.5.204.240/2810.5.204.241 – 10.5.204.25410.5.204.255
8110.5.205.0/2810.5.205.1 – 10.5.205.1410.5.205.15
8210.5.205.16/2810.5.205.17 – 10.5.205.3010.5.205.31
8310.5.205.32/2810.5.205.33 – 10.5.205.4610.5.205.47
8410.5.205.48/2810.5.205.49 – 10.5.205.6210.5.205.63
8510.5.205.64/2810.5.205.65 – 10.5.205.7810.5.205.79
8610.5.205.80/2810.5.205.81 – 10.5.205.9410.5.205.95
8710.5.205.96/2810.5.205.97 – 10.5.205.11010.5.205.111
8810.5.205.112/2810.5.205.113 – 10.5.205.12610.5.205.127
8910.5.205.128/2810.5.205.129 – 10.5.205.14210.5.205.143
9010.5.205.144/2810.5.205.145 – 10.5.205.15810.5.205.159
9110.5.205.160/2810.5.205.161 – 10.5.205.17410.5.205.175
9210.5.205.176/2810.5.205.177 – 10.5.205.19010.5.205.191
9310.5.205.192/2810.5.205.193 – 10.5.205.20610.5.205.207
9410.5.205.208/2810.5.205.209 – 10.5.205.22210.5.205.223
9510.5.205.224/2810.5.205.225 – 10.5.205.23810.5.205.239
9610.5.205.240/2810.5.205.241 – 10.5.205.25410.5.205.255
9710.5.206.0/2810.5.206.1 – 10.5.206.1410.5.206.15
9810.5.206.16/2810.5.206.17 – 10.5.206.3010.5.206.31
9910.5.206.32/2810.5.206.33 – 10.5.206.4610.5.206.47
10010.5.206.48/2810.5.206.49 – 10.5.206.6210.5.206.63
10110.5.206.64/2810.5.206.65 – 10.5.206.7810.5.206.79
10210.5.206.80/2810.5.206.81 – 10.5.206.9410.5.206.95
10310.5.206.96/2810.5.206.97 – 10.5.206.11010.5.206.111
10410.5.206.112/2810.5.206.113 – 10.5.206.12610.5.206.127
10510.5.206.128/2810.5.206.129 – 10.5.206.14210.5.206.143
10610.5.206.144/2810.5.206.145 – 10.5.206.15810.5.206.159
10710.5.206.160/2810.5.206.161 – 10.5.206.17410.5.206.175
10810.5.206.176/2810.5.206.177 – 10.5.206.19010.5.206.191
10910.5.206.192/2810.5.206.193 – 10.5.206.20610.5.206.207
11010.5.206.208/2810.5.206.209 – 10.5.206.22210.5.206.223
11110.5.206.224/2810.5.206.225 – 10.5.206.23810.5.206.239
11210.5.206.240/2810.5.206.241 – 10.5.206.25410.5.206.255
11310.5.207.0/2810.5.207.1 – 10.5.207.1410.5.207.15
11410.5.207.16/2810.5.207.17 – 10.5.207.3010.5.207.31
11510.5.207.32/2810.5.207.33 – 10.5.207.4610.5.207.47
11610.5.207.48/2810.5.207.49 – 10.5.207.6210.5.207.63
11710.5.207.64/2810.5.207.65 – 10.5.207.7810.5.207.79
11810.5.207.80/2810.5.207.81 – 10.5.207.9410.5.207.95
11910.5.207.96/2810.5.207.97 – 10.5.207.11010.5.207.111
12010.5.207.112/2810.5.207.113 – 10.5.207.12610.5.207.127
12110.5.207.128/2810.5.207.129 – 10.5.207.14210.5.207.143
12210.5.207.144/2810.5.207.145 – 10.5.207.15810.5.207.159
12310.5.207.160/2810.5.207.161 – 10.5.207.17410.5.207.175
12410.5.207.176/2810.5.207.177 – 10.5.207.19010.5.207.191
12510.5.207.192/2810.5.207.193 – 10.5.207.20610.5.207.207
12610.5.207.208/2810.5.207.209 – 10.5.207.22210.5.207.223
12710.5.207.224/2810.5.207.225 – 10.5.207.23810.5.207.239
12810.5.207.240/2810.5.207.241 – 10.5.207.25410.5.207.255
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 →