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)10.167.120.0/21
network10.167.120.0/21
broadcast10.167.127.255
first host10.167.120.1
last host10.167.127.254
subnet mask255.255.248.0
wildcard0.0.7.255
addresses2,048
usable hosts2,046
classA
ipcalc 10.167.120.0/21
address00001010.10100111.01111000.00000000
subnet mask11111111.11111111.11111000.00000000
network00001010.10100111.01111000.00000000
broadcast00001010.10100111.01111111.11111111
green = network part, grey = host part
hex0x0aa77800
decimal178747392
reverse dns0.120.167.10.in-addr.arpa
ipv4-mapped::ffff:aa7:7800

/21 split into /28 · 128 subnets

close ×
#networkhost rangebroadcast
110.167.120.0/2810.167.120.1 – 10.167.120.1410.167.120.15
210.167.120.16/2810.167.120.17 – 10.167.120.3010.167.120.31
310.167.120.32/2810.167.120.33 – 10.167.120.4610.167.120.47
410.167.120.48/2810.167.120.49 – 10.167.120.6210.167.120.63
510.167.120.64/2810.167.120.65 – 10.167.120.7810.167.120.79
610.167.120.80/2810.167.120.81 – 10.167.120.9410.167.120.95
710.167.120.96/2810.167.120.97 – 10.167.120.11010.167.120.111
810.167.120.112/2810.167.120.113 – 10.167.120.12610.167.120.127
910.167.120.128/2810.167.120.129 – 10.167.120.14210.167.120.143
1010.167.120.144/2810.167.120.145 – 10.167.120.15810.167.120.159
1110.167.120.160/2810.167.120.161 – 10.167.120.17410.167.120.175
1210.167.120.176/2810.167.120.177 – 10.167.120.19010.167.120.191
1310.167.120.192/2810.167.120.193 – 10.167.120.20610.167.120.207
1410.167.120.208/2810.167.120.209 – 10.167.120.22210.167.120.223
1510.167.120.224/2810.167.120.225 – 10.167.120.23810.167.120.239
1610.167.120.240/2810.167.120.241 – 10.167.120.25410.167.120.255
1710.167.121.0/2810.167.121.1 – 10.167.121.1410.167.121.15
1810.167.121.16/2810.167.121.17 – 10.167.121.3010.167.121.31
1910.167.121.32/2810.167.121.33 – 10.167.121.4610.167.121.47
2010.167.121.48/2810.167.121.49 – 10.167.121.6210.167.121.63
2110.167.121.64/2810.167.121.65 – 10.167.121.7810.167.121.79
2210.167.121.80/2810.167.121.81 – 10.167.121.9410.167.121.95
2310.167.121.96/2810.167.121.97 – 10.167.121.11010.167.121.111
2410.167.121.112/2810.167.121.113 – 10.167.121.12610.167.121.127
2510.167.121.128/2810.167.121.129 – 10.167.121.14210.167.121.143
2610.167.121.144/2810.167.121.145 – 10.167.121.15810.167.121.159
2710.167.121.160/2810.167.121.161 – 10.167.121.17410.167.121.175
2810.167.121.176/2810.167.121.177 – 10.167.121.19010.167.121.191
2910.167.121.192/2810.167.121.193 – 10.167.121.20610.167.121.207
3010.167.121.208/2810.167.121.209 – 10.167.121.22210.167.121.223
3110.167.121.224/2810.167.121.225 – 10.167.121.23810.167.121.239
3210.167.121.240/2810.167.121.241 – 10.167.121.25410.167.121.255
3310.167.122.0/2810.167.122.1 – 10.167.122.1410.167.122.15
3410.167.122.16/2810.167.122.17 – 10.167.122.3010.167.122.31
3510.167.122.32/2810.167.122.33 – 10.167.122.4610.167.122.47
3610.167.122.48/2810.167.122.49 – 10.167.122.6210.167.122.63
3710.167.122.64/2810.167.122.65 – 10.167.122.7810.167.122.79
3810.167.122.80/2810.167.122.81 – 10.167.122.9410.167.122.95
3910.167.122.96/2810.167.122.97 – 10.167.122.11010.167.122.111
4010.167.122.112/2810.167.122.113 – 10.167.122.12610.167.122.127
4110.167.122.128/2810.167.122.129 – 10.167.122.14210.167.122.143
4210.167.122.144/2810.167.122.145 – 10.167.122.15810.167.122.159
4310.167.122.160/2810.167.122.161 – 10.167.122.17410.167.122.175
4410.167.122.176/2810.167.122.177 – 10.167.122.19010.167.122.191
4510.167.122.192/2810.167.122.193 – 10.167.122.20610.167.122.207
4610.167.122.208/2810.167.122.209 – 10.167.122.22210.167.122.223
4710.167.122.224/2810.167.122.225 – 10.167.122.23810.167.122.239
4810.167.122.240/2810.167.122.241 – 10.167.122.25410.167.122.255
4910.167.123.0/2810.167.123.1 – 10.167.123.1410.167.123.15
5010.167.123.16/2810.167.123.17 – 10.167.123.3010.167.123.31
5110.167.123.32/2810.167.123.33 – 10.167.123.4610.167.123.47
5210.167.123.48/2810.167.123.49 – 10.167.123.6210.167.123.63
5310.167.123.64/2810.167.123.65 – 10.167.123.7810.167.123.79
5410.167.123.80/2810.167.123.81 – 10.167.123.9410.167.123.95
5510.167.123.96/2810.167.123.97 – 10.167.123.11010.167.123.111
5610.167.123.112/2810.167.123.113 – 10.167.123.12610.167.123.127
5710.167.123.128/2810.167.123.129 – 10.167.123.14210.167.123.143
5810.167.123.144/2810.167.123.145 – 10.167.123.15810.167.123.159
5910.167.123.160/2810.167.123.161 – 10.167.123.17410.167.123.175
6010.167.123.176/2810.167.123.177 – 10.167.123.19010.167.123.191
6110.167.123.192/2810.167.123.193 – 10.167.123.20610.167.123.207
6210.167.123.208/2810.167.123.209 – 10.167.123.22210.167.123.223
6310.167.123.224/2810.167.123.225 – 10.167.123.23810.167.123.239
6410.167.123.240/2810.167.123.241 – 10.167.123.25410.167.123.255
6510.167.124.0/2810.167.124.1 – 10.167.124.1410.167.124.15
6610.167.124.16/2810.167.124.17 – 10.167.124.3010.167.124.31
6710.167.124.32/2810.167.124.33 – 10.167.124.4610.167.124.47
6810.167.124.48/2810.167.124.49 – 10.167.124.6210.167.124.63
6910.167.124.64/2810.167.124.65 – 10.167.124.7810.167.124.79
7010.167.124.80/2810.167.124.81 – 10.167.124.9410.167.124.95
7110.167.124.96/2810.167.124.97 – 10.167.124.11010.167.124.111
7210.167.124.112/2810.167.124.113 – 10.167.124.12610.167.124.127
7310.167.124.128/2810.167.124.129 – 10.167.124.14210.167.124.143
7410.167.124.144/2810.167.124.145 – 10.167.124.15810.167.124.159
7510.167.124.160/2810.167.124.161 – 10.167.124.17410.167.124.175
7610.167.124.176/2810.167.124.177 – 10.167.124.19010.167.124.191
7710.167.124.192/2810.167.124.193 – 10.167.124.20610.167.124.207
7810.167.124.208/2810.167.124.209 – 10.167.124.22210.167.124.223
7910.167.124.224/2810.167.124.225 – 10.167.124.23810.167.124.239
8010.167.124.240/2810.167.124.241 – 10.167.124.25410.167.124.255
8110.167.125.0/2810.167.125.1 – 10.167.125.1410.167.125.15
8210.167.125.16/2810.167.125.17 – 10.167.125.3010.167.125.31
8310.167.125.32/2810.167.125.33 – 10.167.125.4610.167.125.47
8410.167.125.48/2810.167.125.49 – 10.167.125.6210.167.125.63
8510.167.125.64/2810.167.125.65 – 10.167.125.7810.167.125.79
8610.167.125.80/2810.167.125.81 – 10.167.125.9410.167.125.95
8710.167.125.96/2810.167.125.97 – 10.167.125.11010.167.125.111
8810.167.125.112/2810.167.125.113 – 10.167.125.12610.167.125.127
8910.167.125.128/2810.167.125.129 – 10.167.125.14210.167.125.143
9010.167.125.144/2810.167.125.145 – 10.167.125.15810.167.125.159
9110.167.125.160/2810.167.125.161 – 10.167.125.17410.167.125.175
9210.167.125.176/2810.167.125.177 – 10.167.125.19010.167.125.191
9310.167.125.192/2810.167.125.193 – 10.167.125.20610.167.125.207
9410.167.125.208/2810.167.125.209 – 10.167.125.22210.167.125.223
9510.167.125.224/2810.167.125.225 – 10.167.125.23810.167.125.239
9610.167.125.240/2810.167.125.241 – 10.167.125.25410.167.125.255
9710.167.126.0/2810.167.126.1 – 10.167.126.1410.167.126.15
9810.167.126.16/2810.167.126.17 – 10.167.126.3010.167.126.31
9910.167.126.32/2810.167.126.33 – 10.167.126.4610.167.126.47
10010.167.126.48/2810.167.126.49 – 10.167.126.6210.167.126.63
10110.167.126.64/2810.167.126.65 – 10.167.126.7810.167.126.79
10210.167.126.80/2810.167.126.81 – 10.167.126.9410.167.126.95
10310.167.126.96/2810.167.126.97 – 10.167.126.11010.167.126.111
10410.167.126.112/2810.167.126.113 – 10.167.126.12610.167.126.127
10510.167.126.128/2810.167.126.129 – 10.167.126.14210.167.126.143
10610.167.126.144/2810.167.126.145 – 10.167.126.15810.167.126.159
10710.167.126.160/2810.167.126.161 – 10.167.126.17410.167.126.175
10810.167.126.176/2810.167.126.177 – 10.167.126.19010.167.126.191
10910.167.126.192/2810.167.126.193 – 10.167.126.20610.167.126.207
11010.167.126.208/2810.167.126.209 – 10.167.126.22210.167.126.223
11110.167.126.224/2810.167.126.225 – 10.167.126.23810.167.126.239
11210.167.126.240/2810.167.126.241 – 10.167.126.25410.167.126.255
11310.167.127.0/2810.167.127.1 – 10.167.127.1410.167.127.15
11410.167.127.16/2810.167.127.17 – 10.167.127.3010.167.127.31
11510.167.127.32/2810.167.127.33 – 10.167.127.4610.167.127.47
11610.167.127.48/2810.167.127.49 – 10.167.127.6210.167.127.63
11710.167.127.64/2810.167.127.65 – 10.167.127.7810.167.127.79
11810.167.127.80/2810.167.127.81 – 10.167.127.9410.167.127.95
11910.167.127.96/2810.167.127.97 – 10.167.127.11010.167.127.111
12010.167.127.112/2810.167.127.113 – 10.167.127.12610.167.127.127
12110.167.127.128/2810.167.127.129 – 10.167.127.14210.167.127.143
12210.167.127.144/2810.167.127.145 – 10.167.127.15810.167.127.159
12310.167.127.160/2810.167.127.161 – 10.167.127.17410.167.127.175
12410.167.127.176/2810.167.127.177 – 10.167.127.19010.167.127.191
12510.167.127.192/2810.167.127.193 – 10.167.127.20610.167.127.207
12610.167.127.208/2810.167.127.209 – 10.167.127.22210.167.127.223
12710.167.127.224/2810.167.127.225 – 10.167.127.23810.167.127.239
12810.167.127.240/2810.167.127.241 – 10.167.127.25410.167.127.255
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 →