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
Try:192.168.1.10/2410.0.0.0/8172.16.5.4/20203.0.113.9/29
IPv6 calculator →
private IP (RFC 1918)10.7.136.0/21
network10.7.136.0/21
broadcast10.7.143.255
first host10.7.136.1
last host10.7.143.254
subnet mask255.255.248.0
wildcard0.0.7.255
addresses2,048
usable hosts2,046
classA
ipcalc 10.7.136.0/21
address00001010.00000111.10001000.00000000
subnet mask11111111.11111111.11111000.00000000
network00001010.00000111.10001000.00000000
broadcast00001010.00000111.10001111.11111111
green = network part, grey = host part
hex0x0a078800
decimal168265728
reverse dns0.136.7.10.in-addr.arpa
ipv4-mapped::ffff:a07:8800

/21 split into /28 · 128 subnets

close ×
#networkhost rangebroadcast
110.7.136.0/2810.7.136.1 – 10.7.136.1410.7.136.15
210.7.136.16/2810.7.136.17 – 10.7.136.3010.7.136.31
310.7.136.32/2810.7.136.33 – 10.7.136.4610.7.136.47
410.7.136.48/2810.7.136.49 – 10.7.136.6210.7.136.63
510.7.136.64/2810.7.136.65 – 10.7.136.7810.7.136.79
610.7.136.80/2810.7.136.81 – 10.7.136.9410.7.136.95
710.7.136.96/2810.7.136.97 – 10.7.136.11010.7.136.111
810.7.136.112/2810.7.136.113 – 10.7.136.12610.7.136.127
910.7.136.128/2810.7.136.129 – 10.7.136.14210.7.136.143
1010.7.136.144/2810.7.136.145 – 10.7.136.15810.7.136.159
1110.7.136.160/2810.7.136.161 – 10.7.136.17410.7.136.175
1210.7.136.176/2810.7.136.177 – 10.7.136.19010.7.136.191
1310.7.136.192/2810.7.136.193 – 10.7.136.20610.7.136.207
1410.7.136.208/2810.7.136.209 – 10.7.136.22210.7.136.223
1510.7.136.224/2810.7.136.225 – 10.7.136.23810.7.136.239
1610.7.136.240/2810.7.136.241 – 10.7.136.25410.7.136.255
1710.7.137.0/2810.7.137.1 – 10.7.137.1410.7.137.15
1810.7.137.16/2810.7.137.17 – 10.7.137.3010.7.137.31
1910.7.137.32/2810.7.137.33 – 10.7.137.4610.7.137.47
2010.7.137.48/2810.7.137.49 – 10.7.137.6210.7.137.63
2110.7.137.64/2810.7.137.65 – 10.7.137.7810.7.137.79
2210.7.137.80/2810.7.137.81 – 10.7.137.9410.7.137.95
2310.7.137.96/2810.7.137.97 – 10.7.137.11010.7.137.111
2410.7.137.112/2810.7.137.113 – 10.7.137.12610.7.137.127
2510.7.137.128/2810.7.137.129 – 10.7.137.14210.7.137.143
2610.7.137.144/2810.7.137.145 – 10.7.137.15810.7.137.159
2710.7.137.160/2810.7.137.161 – 10.7.137.17410.7.137.175
2810.7.137.176/2810.7.137.177 – 10.7.137.19010.7.137.191
2910.7.137.192/2810.7.137.193 – 10.7.137.20610.7.137.207
3010.7.137.208/2810.7.137.209 – 10.7.137.22210.7.137.223
3110.7.137.224/2810.7.137.225 – 10.7.137.23810.7.137.239
3210.7.137.240/2810.7.137.241 – 10.7.137.25410.7.137.255
3310.7.138.0/2810.7.138.1 – 10.7.138.1410.7.138.15
3410.7.138.16/2810.7.138.17 – 10.7.138.3010.7.138.31
3510.7.138.32/2810.7.138.33 – 10.7.138.4610.7.138.47
3610.7.138.48/2810.7.138.49 – 10.7.138.6210.7.138.63
3710.7.138.64/2810.7.138.65 – 10.7.138.7810.7.138.79
3810.7.138.80/2810.7.138.81 – 10.7.138.9410.7.138.95
3910.7.138.96/2810.7.138.97 – 10.7.138.11010.7.138.111
4010.7.138.112/2810.7.138.113 – 10.7.138.12610.7.138.127
4110.7.138.128/2810.7.138.129 – 10.7.138.14210.7.138.143
4210.7.138.144/2810.7.138.145 – 10.7.138.15810.7.138.159
4310.7.138.160/2810.7.138.161 – 10.7.138.17410.7.138.175
4410.7.138.176/2810.7.138.177 – 10.7.138.19010.7.138.191
4510.7.138.192/2810.7.138.193 – 10.7.138.20610.7.138.207
4610.7.138.208/2810.7.138.209 – 10.7.138.22210.7.138.223
4710.7.138.224/2810.7.138.225 – 10.7.138.23810.7.138.239
4810.7.138.240/2810.7.138.241 – 10.7.138.25410.7.138.255
4910.7.139.0/2810.7.139.1 – 10.7.139.1410.7.139.15
5010.7.139.16/2810.7.139.17 – 10.7.139.3010.7.139.31
5110.7.139.32/2810.7.139.33 – 10.7.139.4610.7.139.47
5210.7.139.48/2810.7.139.49 – 10.7.139.6210.7.139.63
5310.7.139.64/2810.7.139.65 – 10.7.139.7810.7.139.79
5410.7.139.80/2810.7.139.81 – 10.7.139.9410.7.139.95
5510.7.139.96/2810.7.139.97 – 10.7.139.11010.7.139.111
5610.7.139.112/2810.7.139.113 – 10.7.139.12610.7.139.127
5710.7.139.128/2810.7.139.129 – 10.7.139.14210.7.139.143
5810.7.139.144/2810.7.139.145 – 10.7.139.15810.7.139.159
5910.7.139.160/2810.7.139.161 – 10.7.139.17410.7.139.175
6010.7.139.176/2810.7.139.177 – 10.7.139.19010.7.139.191
6110.7.139.192/2810.7.139.193 – 10.7.139.20610.7.139.207
6210.7.139.208/2810.7.139.209 – 10.7.139.22210.7.139.223
6310.7.139.224/2810.7.139.225 – 10.7.139.23810.7.139.239
6410.7.139.240/2810.7.139.241 – 10.7.139.25410.7.139.255
6510.7.140.0/2810.7.140.1 – 10.7.140.1410.7.140.15
6610.7.140.16/2810.7.140.17 – 10.7.140.3010.7.140.31
6710.7.140.32/2810.7.140.33 – 10.7.140.4610.7.140.47
6810.7.140.48/2810.7.140.49 – 10.7.140.6210.7.140.63
6910.7.140.64/2810.7.140.65 – 10.7.140.7810.7.140.79
7010.7.140.80/2810.7.140.81 – 10.7.140.9410.7.140.95
7110.7.140.96/2810.7.140.97 – 10.7.140.11010.7.140.111
7210.7.140.112/2810.7.140.113 – 10.7.140.12610.7.140.127
7310.7.140.128/2810.7.140.129 – 10.7.140.14210.7.140.143
7410.7.140.144/2810.7.140.145 – 10.7.140.15810.7.140.159
7510.7.140.160/2810.7.140.161 – 10.7.140.17410.7.140.175
7610.7.140.176/2810.7.140.177 – 10.7.140.19010.7.140.191
7710.7.140.192/2810.7.140.193 – 10.7.140.20610.7.140.207
7810.7.140.208/2810.7.140.209 – 10.7.140.22210.7.140.223
7910.7.140.224/2810.7.140.225 – 10.7.140.23810.7.140.239
8010.7.140.240/2810.7.140.241 – 10.7.140.25410.7.140.255
8110.7.141.0/2810.7.141.1 – 10.7.141.1410.7.141.15
8210.7.141.16/2810.7.141.17 – 10.7.141.3010.7.141.31
8310.7.141.32/2810.7.141.33 – 10.7.141.4610.7.141.47
8410.7.141.48/2810.7.141.49 – 10.7.141.6210.7.141.63
8510.7.141.64/2810.7.141.65 – 10.7.141.7810.7.141.79
8610.7.141.80/2810.7.141.81 – 10.7.141.9410.7.141.95
8710.7.141.96/2810.7.141.97 – 10.7.141.11010.7.141.111
8810.7.141.112/2810.7.141.113 – 10.7.141.12610.7.141.127
8910.7.141.128/2810.7.141.129 – 10.7.141.14210.7.141.143
9010.7.141.144/2810.7.141.145 – 10.7.141.15810.7.141.159
9110.7.141.160/2810.7.141.161 – 10.7.141.17410.7.141.175
9210.7.141.176/2810.7.141.177 – 10.7.141.19010.7.141.191
9310.7.141.192/2810.7.141.193 – 10.7.141.20610.7.141.207
9410.7.141.208/2810.7.141.209 – 10.7.141.22210.7.141.223
9510.7.141.224/2810.7.141.225 – 10.7.141.23810.7.141.239
9610.7.141.240/2810.7.141.241 – 10.7.141.25410.7.141.255
9710.7.142.0/2810.7.142.1 – 10.7.142.1410.7.142.15
9810.7.142.16/2810.7.142.17 – 10.7.142.3010.7.142.31
9910.7.142.32/2810.7.142.33 – 10.7.142.4610.7.142.47
10010.7.142.48/2810.7.142.49 – 10.7.142.6210.7.142.63
10110.7.142.64/2810.7.142.65 – 10.7.142.7810.7.142.79
10210.7.142.80/2810.7.142.81 – 10.7.142.9410.7.142.95
10310.7.142.96/2810.7.142.97 – 10.7.142.11010.7.142.111
10410.7.142.112/2810.7.142.113 – 10.7.142.12610.7.142.127
10510.7.142.128/2810.7.142.129 – 10.7.142.14210.7.142.143
10610.7.142.144/2810.7.142.145 – 10.7.142.15810.7.142.159
10710.7.142.160/2810.7.142.161 – 10.7.142.17410.7.142.175
10810.7.142.176/2810.7.142.177 – 10.7.142.19010.7.142.191
10910.7.142.192/2810.7.142.193 – 10.7.142.20610.7.142.207
11010.7.142.208/2810.7.142.209 – 10.7.142.22210.7.142.223
11110.7.142.224/2810.7.142.225 – 10.7.142.23810.7.142.239
11210.7.142.240/2810.7.142.241 – 10.7.142.25410.7.142.255
11310.7.143.0/2810.7.143.1 – 10.7.143.1410.7.143.15
11410.7.143.16/2810.7.143.17 – 10.7.143.3010.7.143.31
11510.7.143.32/2810.7.143.33 – 10.7.143.4610.7.143.47
11610.7.143.48/2810.7.143.49 – 10.7.143.6210.7.143.63
11710.7.143.64/2810.7.143.65 – 10.7.143.7810.7.143.79
11810.7.143.80/2810.7.143.81 – 10.7.143.9410.7.143.95
11910.7.143.96/2810.7.143.97 – 10.7.143.11010.7.143.111
12010.7.143.112/2810.7.143.113 – 10.7.143.12610.7.143.127
12110.7.143.128/2810.7.143.129 – 10.7.143.14210.7.143.143
12210.7.143.144/2810.7.143.145 – 10.7.143.15810.7.143.159
12310.7.143.160/2810.7.143.161 – 10.7.143.17410.7.143.175
12410.7.143.176/2810.7.143.177 – 10.7.143.19010.7.143.191
12510.7.143.192/2810.7.143.193 – 10.7.143.20610.7.143.207
12610.7.143.208/2810.7.143.209 – 10.7.143.22210.7.143.223
12710.7.143.224/2810.7.143.225 – 10.7.143.23810.7.143.239
12810.7.143.240/2810.7.143.241 – 10.7.143.25410.7.143.255
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 →