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)10.78.32.0/21
network10.78.32.0/21
broadcast10.78.39.255
first host10.78.32.1
last host10.78.39.254
subnet mask255.255.248.0
wildcard0.0.7.255
addresses2,048
usable hosts2,046
classA
ipcalc 10.78.32.0/21
address00001010.01001110.00100000.00000000
subnet mask11111111.11111111.11111000.00000000
network00001010.01001110.00100000.00000000
broadcast00001010.01001110.00100111.11111111
green = network part, grey = host part
hex0x0a4e2000
decimal172892160
reverse dns0.32.78.10.in-addr.arpa
ipv4-mapped::ffff:a4e:2000

/21 split into /28 · 128 subnets

close ×
#networkhost rangebroadcast
110.78.32.0/2810.78.32.1 – 10.78.32.1410.78.32.15
210.78.32.16/2810.78.32.17 – 10.78.32.3010.78.32.31
310.78.32.32/2810.78.32.33 – 10.78.32.4610.78.32.47
410.78.32.48/2810.78.32.49 – 10.78.32.6210.78.32.63
510.78.32.64/2810.78.32.65 – 10.78.32.7810.78.32.79
610.78.32.80/2810.78.32.81 – 10.78.32.9410.78.32.95
710.78.32.96/2810.78.32.97 – 10.78.32.11010.78.32.111
810.78.32.112/2810.78.32.113 – 10.78.32.12610.78.32.127
910.78.32.128/2810.78.32.129 – 10.78.32.14210.78.32.143
1010.78.32.144/2810.78.32.145 – 10.78.32.15810.78.32.159
1110.78.32.160/2810.78.32.161 – 10.78.32.17410.78.32.175
1210.78.32.176/2810.78.32.177 – 10.78.32.19010.78.32.191
1310.78.32.192/2810.78.32.193 – 10.78.32.20610.78.32.207
1410.78.32.208/2810.78.32.209 – 10.78.32.22210.78.32.223
1510.78.32.224/2810.78.32.225 – 10.78.32.23810.78.32.239
1610.78.32.240/2810.78.32.241 – 10.78.32.25410.78.32.255
1710.78.33.0/2810.78.33.1 – 10.78.33.1410.78.33.15
1810.78.33.16/2810.78.33.17 – 10.78.33.3010.78.33.31
1910.78.33.32/2810.78.33.33 – 10.78.33.4610.78.33.47
2010.78.33.48/2810.78.33.49 – 10.78.33.6210.78.33.63
2110.78.33.64/2810.78.33.65 – 10.78.33.7810.78.33.79
2210.78.33.80/2810.78.33.81 – 10.78.33.9410.78.33.95
2310.78.33.96/2810.78.33.97 – 10.78.33.11010.78.33.111
2410.78.33.112/2810.78.33.113 – 10.78.33.12610.78.33.127
2510.78.33.128/2810.78.33.129 – 10.78.33.14210.78.33.143
2610.78.33.144/2810.78.33.145 – 10.78.33.15810.78.33.159
2710.78.33.160/2810.78.33.161 – 10.78.33.17410.78.33.175
2810.78.33.176/2810.78.33.177 – 10.78.33.19010.78.33.191
2910.78.33.192/2810.78.33.193 – 10.78.33.20610.78.33.207
3010.78.33.208/2810.78.33.209 – 10.78.33.22210.78.33.223
3110.78.33.224/2810.78.33.225 – 10.78.33.23810.78.33.239
3210.78.33.240/2810.78.33.241 – 10.78.33.25410.78.33.255
3310.78.34.0/2810.78.34.1 – 10.78.34.1410.78.34.15
3410.78.34.16/2810.78.34.17 – 10.78.34.3010.78.34.31
3510.78.34.32/2810.78.34.33 – 10.78.34.4610.78.34.47
3610.78.34.48/2810.78.34.49 – 10.78.34.6210.78.34.63
3710.78.34.64/2810.78.34.65 – 10.78.34.7810.78.34.79
3810.78.34.80/2810.78.34.81 – 10.78.34.9410.78.34.95
3910.78.34.96/2810.78.34.97 – 10.78.34.11010.78.34.111
4010.78.34.112/2810.78.34.113 – 10.78.34.12610.78.34.127
4110.78.34.128/2810.78.34.129 – 10.78.34.14210.78.34.143
4210.78.34.144/2810.78.34.145 – 10.78.34.15810.78.34.159
4310.78.34.160/2810.78.34.161 – 10.78.34.17410.78.34.175
4410.78.34.176/2810.78.34.177 – 10.78.34.19010.78.34.191
4510.78.34.192/2810.78.34.193 – 10.78.34.20610.78.34.207
4610.78.34.208/2810.78.34.209 – 10.78.34.22210.78.34.223
4710.78.34.224/2810.78.34.225 – 10.78.34.23810.78.34.239
4810.78.34.240/2810.78.34.241 – 10.78.34.25410.78.34.255
4910.78.35.0/2810.78.35.1 – 10.78.35.1410.78.35.15
5010.78.35.16/2810.78.35.17 – 10.78.35.3010.78.35.31
5110.78.35.32/2810.78.35.33 – 10.78.35.4610.78.35.47
5210.78.35.48/2810.78.35.49 – 10.78.35.6210.78.35.63
5310.78.35.64/2810.78.35.65 – 10.78.35.7810.78.35.79
5410.78.35.80/2810.78.35.81 – 10.78.35.9410.78.35.95
5510.78.35.96/2810.78.35.97 – 10.78.35.11010.78.35.111
5610.78.35.112/2810.78.35.113 – 10.78.35.12610.78.35.127
5710.78.35.128/2810.78.35.129 – 10.78.35.14210.78.35.143
5810.78.35.144/2810.78.35.145 – 10.78.35.15810.78.35.159
5910.78.35.160/2810.78.35.161 – 10.78.35.17410.78.35.175
6010.78.35.176/2810.78.35.177 – 10.78.35.19010.78.35.191
6110.78.35.192/2810.78.35.193 – 10.78.35.20610.78.35.207
6210.78.35.208/2810.78.35.209 – 10.78.35.22210.78.35.223
6310.78.35.224/2810.78.35.225 – 10.78.35.23810.78.35.239
6410.78.35.240/2810.78.35.241 – 10.78.35.25410.78.35.255
6510.78.36.0/2810.78.36.1 – 10.78.36.1410.78.36.15
6610.78.36.16/2810.78.36.17 – 10.78.36.3010.78.36.31
6710.78.36.32/2810.78.36.33 – 10.78.36.4610.78.36.47
6810.78.36.48/2810.78.36.49 – 10.78.36.6210.78.36.63
6910.78.36.64/2810.78.36.65 – 10.78.36.7810.78.36.79
7010.78.36.80/2810.78.36.81 – 10.78.36.9410.78.36.95
7110.78.36.96/2810.78.36.97 – 10.78.36.11010.78.36.111
7210.78.36.112/2810.78.36.113 – 10.78.36.12610.78.36.127
7310.78.36.128/2810.78.36.129 – 10.78.36.14210.78.36.143
7410.78.36.144/2810.78.36.145 – 10.78.36.15810.78.36.159
7510.78.36.160/2810.78.36.161 – 10.78.36.17410.78.36.175
7610.78.36.176/2810.78.36.177 – 10.78.36.19010.78.36.191
7710.78.36.192/2810.78.36.193 – 10.78.36.20610.78.36.207
7810.78.36.208/2810.78.36.209 – 10.78.36.22210.78.36.223
7910.78.36.224/2810.78.36.225 – 10.78.36.23810.78.36.239
8010.78.36.240/2810.78.36.241 – 10.78.36.25410.78.36.255
8110.78.37.0/2810.78.37.1 – 10.78.37.1410.78.37.15
8210.78.37.16/2810.78.37.17 – 10.78.37.3010.78.37.31
8310.78.37.32/2810.78.37.33 – 10.78.37.4610.78.37.47
8410.78.37.48/2810.78.37.49 – 10.78.37.6210.78.37.63
8510.78.37.64/2810.78.37.65 – 10.78.37.7810.78.37.79
8610.78.37.80/2810.78.37.81 – 10.78.37.9410.78.37.95
8710.78.37.96/2810.78.37.97 – 10.78.37.11010.78.37.111
8810.78.37.112/2810.78.37.113 – 10.78.37.12610.78.37.127
8910.78.37.128/2810.78.37.129 – 10.78.37.14210.78.37.143
9010.78.37.144/2810.78.37.145 – 10.78.37.15810.78.37.159
9110.78.37.160/2810.78.37.161 – 10.78.37.17410.78.37.175
9210.78.37.176/2810.78.37.177 – 10.78.37.19010.78.37.191
9310.78.37.192/2810.78.37.193 – 10.78.37.20610.78.37.207
9410.78.37.208/2810.78.37.209 – 10.78.37.22210.78.37.223
9510.78.37.224/2810.78.37.225 – 10.78.37.23810.78.37.239
9610.78.37.240/2810.78.37.241 – 10.78.37.25410.78.37.255
9710.78.38.0/2810.78.38.1 – 10.78.38.1410.78.38.15
9810.78.38.16/2810.78.38.17 – 10.78.38.3010.78.38.31
9910.78.38.32/2810.78.38.33 – 10.78.38.4610.78.38.47
10010.78.38.48/2810.78.38.49 – 10.78.38.6210.78.38.63
10110.78.38.64/2810.78.38.65 – 10.78.38.7810.78.38.79
10210.78.38.80/2810.78.38.81 – 10.78.38.9410.78.38.95
10310.78.38.96/2810.78.38.97 – 10.78.38.11010.78.38.111
10410.78.38.112/2810.78.38.113 – 10.78.38.12610.78.38.127
10510.78.38.128/2810.78.38.129 – 10.78.38.14210.78.38.143
10610.78.38.144/2810.78.38.145 – 10.78.38.15810.78.38.159
10710.78.38.160/2810.78.38.161 – 10.78.38.17410.78.38.175
10810.78.38.176/2810.78.38.177 – 10.78.38.19010.78.38.191
10910.78.38.192/2810.78.38.193 – 10.78.38.20610.78.38.207
11010.78.38.208/2810.78.38.209 – 10.78.38.22210.78.38.223
11110.78.38.224/2810.78.38.225 – 10.78.38.23810.78.38.239
11210.78.38.240/2810.78.38.241 – 10.78.38.25410.78.38.255
11310.78.39.0/2810.78.39.1 – 10.78.39.1410.78.39.15
11410.78.39.16/2810.78.39.17 – 10.78.39.3010.78.39.31
11510.78.39.32/2810.78.39.33 – 10.78.39.4610.78.39.47
11610.78.39.48/2810.78.39.49 – 10.78.39.6210.78.39.63
11710.78.39.64/2810.78.39.65 – 10.78.39.7810.78.39.79
11810.78.39.80/2810.78.39.81 – 10.78.39.9410.78.39.95
11910.78.39.96/2810.78.39.97 – 10.78.39.11010.78.39.111
12010.78.39.112/2810.78.39.113 – 10.78.39.12610.78.39.127
12110.78.39.128/2810.78.39.129 – 10.78.39.14210.78.39.143
12210.78.39.144/2810.78.39.145 – 10.78.39.15810.78.39.159
12310.78.39.160/2810.78.39.161 – 10.78.39.17410.78.39.175
12410.78.39.176/2810.78.39.177 – 10.78.39.19010.78.39.191
12510.78.39.192/2810.78.39.193 – 10.78.39.20610.78.39.207
12610.78.39.208/2810.78.39.209 – 10.78.39.22210.78.39.223
12710.78.39.224/2810.78.39.225 – 10.78.39.23810.78.39.239
12810.78.39.240/2810.78.39.241 – 10.78.39.25410.78.39.255
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 →