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)10.7.72.0/21
network10.7.72.0/21
broadcast10.7.79.255
first host10.7.72.1
last host10.7.79.254
subnet mask255.255.248.0
wildcard0.0.7.255
addresses2,048
usable hosts2,046
classA
ipcalc 10.7.72.0/21
address00001010.00000111.01001000.00000000
subnet mask11111111.11111111.11111000.00000000
network00001010.00000111.01001000.00000000
broadcast00001010.00000111.01001111.11111111
green = network part, grey = host part
hex0x0a074800
decimal168249344
reverse dns0.72.7.10.in-addr.arpa
ipv4-mapped::ffff:a07:4800

/21 split into /28 · 128 subnets

close ×
#networkhost rangebroadcast
110.7.72.0/2810.7.72.1 – 10.7.72.1410.7.72.15
210.7.72.16/2810.7.72.17 – 10.7.72.3010.7.72.31
310.7.72.32/2810.7.72.33 – 10.7.72.4610.7.72.47
410.7.72.48/2810.7.72.49 – 10.7.72.6210.7.72.63
510.7.72.64/2810.7.72.65 – 10.7.72.7810.7.72.79
610.7.72.80/2810.7.72.81 – 10.7.72.9410.7.72.95
710.7.72.96/2810.7.72.97 – 10.7.72.11010.7.72.111
810.7.72.112/2810.7.72.113 – 10.7.72.12610.7.72.127
910.7.72.128/2810.7.72.129 – 10.7.72.14210.7.72.143
1010.7.72.144/2810.7.72.145 – 10.7.72.15810.7.72.159
1110.7.72.160/2810.7.72.161 – 10.7.72.17410.7.72.175
1210.7.72.176/2810.7.72.177 – 10.7.72.19010.7.72.191
1310.7.72.192/2810.7.72.193 – 10.7.72.20610.7.72.207
1410.7.72.208/2810.7.72.209 – 10.7.72.22210.7.72.223
1510.7.72.224/2810.7.72.225 – 10.7.72.23810.7.72.239
1610.7.72.240/2810.7.72.241 – 10.7.72.25410.7.72.255
1710.7.73.0/2810.7.73.1 – 10.7.73.1410.7.73.15
1810.7.73.16/2810.7.73.17 – 10.7.73.3010.7.73.31
1910.7.73.32/2810.7.73.33 – 10.7.73.4610.7.73.47
2010.7.73.48/2810.7.73.49 – 10.7.73.6210.7.73.63
2110.7.73.64/2810.7.73.65 – 10.7.73.7810.7.73.79
2210.7.73.80/2810.7.73.81 – 10.7.73.9410.7.73.95
2310.7.73.96/2810.7.73.97 – 10.7.73.11010.7.73.111
2410.7.73.112/2810.7.73.113 – 10.7.73.12610.7.73.127
2510.7.73.128/2810.7.73.129 – 10.7.73.14210.7.73.143
2610.7.73.144/2810.7.73.145 – 10.7.73.15810.7.73.159
2710.7.73.160/2810.7.73.161 – 10.7.73.17410.7.73.175
2810.7.73.176/2810.7.73.177 – 10.7.73.19010.7.73.191
2910.7.73.192/2810.7.73.193 – 10.7.73.20610.7.73.207
3010.7.73.208/2810.7.73.209 – 10.7.73.22210.7.73.223
3110.7.73.224/2810.7.73.225 – 10.7.73.23810.7.73.239
3210.7.73.240/2810.7.73.241 – 10.7.73.25410.7.73.255
3310.7.74.0/2810.7.74.1 – 10.7.74.1410.7.74.15
3410.7.74.16/2810.7.74.17 – 10.7.74.3010.7.74.31
3510.7.74.32/2810.7.74.33 – 10.7.74.4610.7.74.47
3610.7.74.48/2810.7.74.49 – 10.7.74.6210.7.74.63
3710.7.74.64/2810.7.74.65 – 10.7.74.7810.7.74.79
3810.7.74.80/2810.7.74.81 – 10.7.74.9410.7.74.95
3910.7.74.96/2810.7.74.97 – 10.7.74.11010.7.74.111
4010.7.74.112/2810.7.74.113 – 10.7.74.12610.7.74.127
4110.7.74.128/2810.7.74.129 – 10.7.74.14210.7.74.143
4210.7.74.144/2810.7.74.145 – 10.7.74.15810.7.74.159
4310.7.74.160/2810.7.74.161 – 10.7.74.17410.7.74.175
4410.7.74.176/2810.7.74.177 – 10.7.74.19010.7.74.191
4510.7.74.192/2810.7.74.193 – 10.7.74.20610.7.74.207
4610.7.74.208/2810.7.74.209 – 10.7.74.22210.7.74.223
4710.7.74.224/2810.7.74.225 – 10.7.74.23810.7.74.239
4810.7.74.240/2810.7.74.241 – 10.7.74.25410.7.74.255
4910.7.75.0/2810.7.75.1 – 10.7.75.1410.7.75.15
5010.7.75.16/2810.7.75.17 – 10.7.75.3010.7.75.31
5110.7.75.32/2810.7.75.33 – 10.7.75.4610.7.75.47
5210.7.75.48/2810.7.75.49 – 10.7.75.6210.7.75.63
5310.7.75.64/2810.7.75.65 – 10.7.75.7810.7.75.79
5410.7.75.80/2810.7.75.81 – 10.7.75.9410.7.75.95
5510.7.75.96/2810.7.75.97 – 10.7.75.11010.7.75.111
5610.7.75.112/2810.7.75.113 – 10.7.75.12610.7.75.127
5710.7.75.128/2810.7.75.129 – 10.7.75.14210.7.75.143
5810.7.75.144/2810.7.75.145 – 10.7.75.15810.7.75.159
5910.7.75.160/2810.7.75.161 – 10.7.75.17410.7.75.175
6010.7.75.176/2810.7.75.177 – 10.7.75.19010.7.75.191
6110.7.75.192/2810.7.75.193 – 10.7.75.20610.7.75.207
6210.7.75.208/2810.7.75.209 – 10.7.75.22210.7.75.223
6310.7.75.224/2810.7.75.225 – 10.7.75.23810.7.75.239
6410.7.75.240/2810.7.75.241 – 10.7.75.25410.7.75.255
6510.7.76.0/2810.7.76.1 – 10.7.76.1410.7.76.15
6610.7.76.16/2810.7.76.17 – 10.7.76.3010.7.76.31
6710.7.76.32/2810.7.76.33 – 10.7.76.4610.7.76.47
6810.7.76.48/2810.7.76.49 – 10.7.76.6210.7.76.63
6910.7.76.64/2810.7.76.65 – 10.7.76.7810.7.76.79
7010.7.76.80/2810.7.76.81 – 10.7.76.9410.7.76.95
7110.7.76.96/2810.7.76.97 – 10.7.76.11010.7.76.111
7210.7.76.112/2810.7.76.113 – 10.7.76.12610.7.76.127
7310.7.76.128/2810.7.76.129 – 10.7.76.14210.7.76.143
7410.7.76.144/2810.7.76.145 – 10.7.76.15810.7.76.159
7510.7.76.160/2810.7.76.161 – 10.7.76.17410.7.76.175
7610.7.76.176/2810.7.76.177 – 10.7.76.19010.7.76.191
7710.7.76.192/2810.7.76.193 – 10.7.76.20610.7.76.207
7810.7.76.208/2810.7.76.209 – 10.7.76.22210.7.76.223
7910.7.76.224/2810.7.76.225 – 10.7.76.23810.7.76.239
8010.7.76.240/2810.7.76.241 – 10.7.76.25410.7.76.255
8110.7.77.0/2810.7.77.1 – 10.7.77.1410.7.77.15
8210.7.77.16/2810.7.77.17 – 10.7.77.3010.7.77.31
8310.7.77.32/2810.7.77.33 – 10.7.77.4610.7.77.47
8410.7.77.48/2810.7.77.49 – 10.7.77.6210.7.77.63
8510.7.77.64/2810.7.77.65 – 10.7.77.7810.7.77.79
8610.7.77.80/2810.7.77.81 – 10.7.77.9410.7.77.95
8710.7.77.96/2810.7.77.97 – 10.7.77.11010.7.77.111
8810.7.77.112/2810.7.77.113 – 10.7.77.12610.7.77.127
8910.7.77.128/2810.7.77.129 – 10.7.77.14210.7.77.143
9010.7.77.144/2810.7.77.145 – 10.7.77.15810.7.77.159
9110.7.77.160/2810.7.77.161 – 10.7.77.17410.7.77.175
9210.7.77.176/2810.7.77.177 – 10.7.77.19010.7.77.191
9310.7.77.192/2810.7.77.193 – 10.7.77.20610.7.77.207
9410.7.77.208/2810.7.77.209 – 10.7.77.22210.7.77.223
9510.7.77.224/2810.7.77.225 – 10.7.77.23810.7.77.239
9610.7.77.240/2810.7.77.241 – 10.7.77.25410.7.77.255
9710.7.78.0/2810.7.78.1 – 10.7.78.1410.7.78.15
9810.7.78.16/2810.7.78.17 – 10.7.78.3010.7.78.31
9910.7.78.32/2810.7.78.33 – 10.7.78.4610.7.78.47
10010.7.78.48/2810.7.78.49 – 10.7.78.6210.7.78.63
10110.7.78.64/2810.7.78.65 – 10.7.78.7810.7.78.79
10210.7.78.80/2810.7.78.81 – 10.7.78.9410.7.78.95
10310.7.78.96/2810.7.78.97 – 10.7.78.11010.7.78.111
10410.7.78.112/2810.7.78.113 – 10.7.78.12610.7.78.127
10510.7.78.128/2810.7.78.129 – 10.7.78.14210.7.78.143
10610.7.78.144/2810.7.78.145 – 10.7.78.15810.7.78.159
10710.7.78.160/2810.7.78.161 – 10.7.78.17410.7.78.175
10810.7.78.176/2810.7.78.177 – 10.7.78.19010.7.78.191
10910.7.78.192/2810.7.78.193 – 10.7.78.20610.7.78.207
11010.7.78.208/2810.7.78.209 – 10.7.78.22210.7.78.223
11110.7.78.224/2810.7.78.225 – 10.7.78.23810.7.78.239
11210.7.78.240/2810.7.78.241 – 10.7.78.25410.7.78.255
11310.7.79.0/2810.7.79.1 – 10.7.79.1410.7.79.15
11410.7.79.16/2810.7.79.17 – 10.7.79.3010.7.79.31
11510.7.79.32/2810.7.79.33 – 10.7.79.4610.7.79.47
11610.7.79.48/2810.7.79.49 – 10.7.79.6210.7.79.63
11710.7.79.64/2810.7.79.65 – 10.7.79.7810.7.79.79
11810.7.79.80/2810.7.79.81 – 10.7.79.9410.7.79.95
11910.7.79.96/2810.7.79.97 – 10.7.79.11010.7.79.111
12010.7.79.112/2810.7.79.113 – 10.7.79.12610.7.79.127
12110.7.79.128/2810.7.79.129 – 10.7.79.14210.7.79.143
12210.7.79.144/2810.7.79.145 – 10.7.79.15810.7.79.159
12310.7.79.160/2810.7.79.161 – 10.7.79.17410.7.79.175
12410.7.79.176/2810.7.79.177 – 10.7.79.19010.7.79.191
12510.7.79.192/2810.7.79.193 – 10.7.79.20610.7.79.207
12610.7.79.208/2810.7.79.209 – 10.7.79.22210.7.79.223
12710.7.79.224/2810.7.79.225 – 10.7.79.23810.7.79.239
12810.7.79.240/2810.7.79.241 – 10.7.79.25410.7.79.255
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 →