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)10.87.232.0/21
network10.87.232.0/21
broadcast10.87.239.255
first host10.87.232.1
last host10.87.239.254
subnet mask255.255.248.0
wildcard0.0.7.255
addresses2,048
usable hosts2,046
classA
ipcalc 10.87.232.0/21
address00001010.01010111.11101000.00000000
subnet mask11111111.11111111.11111000.00000000
network00001010.01010111.11101000.00000000
broadcast00001010.01010111.11101111.11111111
green = network part, grey = host part
hex0x0a57e800
decimal173533184
reverse dns0.232.87.10.in-addr.arpa
ipv4-mapped::ffff:a57:e800

/21 split into /28 · 128 subnets

close ×
#networkhost rangebroadcast
110.87.232.0/2810.87.232.1 – 10.87.232.1410.87.232.15
210.87.232.16/2810.87.232.17 – 10.87.232.3010.87.232.31
310.87.232.32/2810.87.232.33 – 10.87.232.4610.87.232.47
410.87.232.48/2810.87.232.49 – 10.87.232.6210.87.232.63
510.87.232.64/2810.87.232.65 – 10.87.232.7810.87.232.79
610.87.232.80/2810.87.232.81 – 10.87.232.9410.87.232.95
710.87.232.96/2810.87.232.97 – 10.87.232.11010.87.232.111
810.87.232.112/2810.87.232.113 – 10.87.232.12610.87.232.127
910.87.232.128/2810.87.232.129 – 10.87.232.14210.87.232.143
1010.87.232.144/2810.87.232.145 – 10.87.232.15810.87.232.159
1110.87.232.160/2810.87.232.161 – 10.87.232.17410.87.232.175
1210.87.232.176/2810.87.232.177 – 10.87.232.19010.87.232.191
1310.87.232.192/2810.87.232.193 – 10.87.232.20610.87.232.207
1410.87.232.208/2810.87.232.209 – 10.87.232.22210.87.232.223
1510.87.232.224/2810.87.232.225 – 10.87.232.23810.87.232.239
1610.87.232.240/2810.87.232.241 – 10.87.232.25410.87.232.255
1710.87.233.0/2810.87.233.1 – 10.87.233.1410.87.233.15
1810.87.233.16/2810.87.233.17 – 10.87.233.3010.87.233.31
1910.87.233.32/2810.87.233.33 – 10.87.233.4610.87.233.47
2010.87.233.48/2810.87.233.49 – 10.87.233.6210.87.233.63
2110.87.233.64/2810.87.233.65 – 10.87.233.7810.87.233.79
2210.87.233.80/2810.87.233.81 – 10.87.233.9410.87.233.95
2310.87.233.96/2810.87.233.97 – 10.87.233.11010.87.233.111
2410.87.233.112/2810.87.233.113 – 10.87.233.12610.87.233.127
2510.87.233.128/2810.87.233.129 – 10.87.233.14210.87.233.143
2610.87.233.144/2810.87.233.145 – 10.87.233.15810.87.233.159
2710.87.233.160/2810.87.233.161 – 10.87.233.17410.87.233.175
2810.87.233.176/2810.87.233.177 – 10.87.233.19010.87.233.191
2910.87.233.192/2810.87.233.193 – 10.87.233.20610.87.233.207
3010.87.233.208/2810.87.233.209 – 10.87.233.22210.87.233.223
3110.87.233.224/2810.87.233.225 – 10.87.233.23810.87.233.239
3210.87.233.240/2810.87.233.241 – 10.87.233.25410.87.233.255
3310.87.234.0/2810.87.234.1 – 10.87.234.1410.87.234.15
3410.87.234.16/2810.87.234.17 – 10.87.234.3010.87.234.31
3510.87.234.32/2810.87.234.33 – 10.87.234.4610.87.234.47
3610.87.234.48/2810.87.234.49 – 10.87.234.6210.87.234.63
3710.87.234.64/2810.87.234.65 – 10.87.234.7810.87.234.79
3810.87.234.80/2810.87.234.81 – 10.87.234.9410.87.234.95
3910.87.234.96/2810.87.234.97 – 10.87.234.11010.87.234.111
4010.87.234.112/2810.87.234.113 – 10.87.234.12610.87.234.127
4110.87.234.128/2810.87.234.129 – 10.87.234.14210.87.234.143
4210.87.234.144/2810.87.234.145 – 10.87.234.15810.87.234.159
4310.87.234.160/2810.87.234.161 – 10.87.234.17410.87.234.175
4410.87.234.176/2810.87.234.177 – 10.87.234.19010.87.234.191
4510.87.234.192/2810.87.234.193 – 10.87.234.20610.87.234.207
4610.87.234.208/2810.87.234.209 – 10.87.234.22210.87.234.223
4710.87.234.224/2810.87.234.225 – 10.87.234.23810.87.234.239
4810.87.234.240/2810.87.234.241 – 10.87.234.25410.87.234.255
4910.87.235.0/2810.87.235.1 – 10.87.235.1410.87.235.15
5010.87.235.16/2810.87.235.17 – 10.87.235.3010.87.235.31
5110.87.235.32/2810.87.235.33 – 10.87.235.4610.87.235.47
5210.87.235.48/2810.87.235.49 – 10.87.235.6210.87.235.63
5310.87.235.64/2810.87.235.65 – 10.87.235.7810.87.235.79
5410.87.235.80/2810.87.235.81 – 10.87.235.9410.87.235.95
5510.87.235.96/2810.87.235.97 – 10.87.235.11010.87.235.111
5610.87.235.112/2810.87.235.113 – 10.87.235.12610.87.235.127
5710.87.235.128/2810.87.235.129 – 10.87.235.14210.87.235.143
5810.87.235.144/2810.87.235.145 – 10.87.235.15810.87.235.159
5910.87.235.160/2810.87.235.161 – 10.87.235.17410.87.235.175
6010.87.235.176/2810.87.235.177 – 10.87.235.19010.87.235.191
6110.87.235.192/2810.87.235.193 – 10.87.235.20610.87.235.207
6210.87.235.208/2810.87.235.209 – 10.87.235.22210.87.235.223
6310.87.235.224/2810.87.235.225 – 10.87.235.23810.87.235.239
6410.87.235.240/2810.87.235.241 – 10.87.235.25410.87.235.255
6510.87.236.0/2810.87.236.1 – 10.87.236.1410.87.236.15
6610.87.236.16/2810.87.236.17 – 10.87.236.3010.87.236.31
6710.87.236.32/2810.87.236.33 – 10.87.236.4610.87.236.47
6810.87.236.48/2810.87.236.49 – 10.87.236.6210.87.236.63
6910.87.236.64/2810.87.236.65 – 10.87.236.7810.87.236.79
7010.87.236.80/2810.87.236.81 – 10.87.236.9410.87.236.95
7110.87.236.96/2810.87.236.97 – 10.87.236.11010.87.236.111
7210.87.236.112/2810.87.236.113 – 10.87.236.12610.87.236.127
7310.87.236.128/2810.87.236.129 – 10.87.236.14210.87.236.143
7410.87.236.144/2810.87.236.145 – 10.87.236.15810.87.236.159
7510.87.236.160/2810.87.236.161 – 10.87.236.17410.87.236.175
7610.87.236.176/2810.87.236.177 – 10.87.236.19010.87.236.191
7710.87.236.192/2810.87.236.193 – 10.87.236.20610.87.236.207
7810.87.236.208/2810.87.236.209 – 10.87.236.22210.87.236.223
7910.87.236.224/2810.87.236.225 – 10.87.236.23810.87.236.239
8010.87.236.240/2810.87.236.241 – 10.87.236.25410.87.236.255
8110.87.237.0/2810.87.237.1 – 10.87.237.1410.87.237.15
8210.87.237.16/2810.87.237.17 – 10.87.237.3010.87.237.31
8310.87.237.32/2810.87.237.33 – 10.87.237.4610.87.237.47
8410.87.237.48/2810.87.237.49 – 10.87.237.6210.87.237.63
8510.87.237.64/2810.87.237.65 – 10.87.237.7810.87.237.79
8610.87.237.80/2810.87.237.81 – 10.87.237.9410.87.237.95
8710.87.237.96/2810.87.237.97 – 10.87.237.11010.87.237.111
8810.87.237.112/2810.87.237.113 – 10.87.237.12610.87.237.127
8910.87.237.128/2810.87.237.129 – 10.87.237.14210.87.237.143
9010.87.237.144/2810.87.237.145 – 10.87.237.15810.87.237.159
9110.87.237.160/2810.87.237.161 – 10.87.237.17410.87.237.175
9210.87.237.176/2810.87.237.177 – 10.87.237.19010.87.237.191
9310.87.237.192/2810.87.237.193 – 10.87.237.20610.87.237.207
9410.87.237.208/2810.87.237.209 – 10.87.237.22210.87.237.223
9510.87.237.224/2810.87.237.225 – 10.87.237.23810.87.237.239
9610.87.237.240/2810.87.237.241 – 10.87.237.25410.87.237.255
9710.87.238.0/2810.87.238.1 – 10.87.238.1410.87.238.15
9810.87.238.16/2810.87.238.17 – 10.87.238.3010.87.238.31
9910.87.238.32/2810.87.238.33 – 10.87.238.4610.87.238.47
10010.87.238.48/2810.87.238.49 – 10.87.238.6210.87.238.63
10110.87.238.64/2810.87.238.65 – 10.87.238.7810.87.238.79
10210.87.238.80/2810.87.238.81 – 10.87.238.9410.87.238.95
10310.87.238.96/2810.87.238.97 – 10.87.238.11010.87.238.111
10410.87.238.112/2810.87.238.113 – 10.87.238.12610.87.238.127
10510.87.238.128/2810.87.238.129 – 10.87.238.14210.87.238.143
10610.87.238.144/2810.87.238.145 – 10.87.238.15810.87.238.159
10710.87.238.160/2810.87.238.161 – 10.87.238.17410.87.238.175
10810.87.238.176/2810.87.238.177 – 10.87.238.19010.87.238.191
10910.87.238.192/2810.87.238.193 – 10.87.238.20610.87.238.207
11010.87.238.208/2810.87.238.209 – 10.87.238.22210.87.238.223
11110.87.238.224/2810.87.238.225 – 10.87.238.23810.87.238.239
11210.87.238.240/2810.87.238.241 – 10.87.238.25410.87.238.255
11310.87.239.0/2810.87.239.1 – 10.87.239.1410.87.239.15
11410.87.239.16/2810.87.239.17 – 10.87.239.3010.87.239.31
11510.87.239.32/2810.87.239.33 – 10.87.239.4610.87.239.47
11610.87.239.48/2810.87.239.49 – 10.87.239.6210.87.239.63
11710.87.239.64/2810.87.239.65 – 10.87.239.7810.87.239.79
11810.87.239.80/2810.87.239.81 – 10.87.239.9410.87.239.95
11910.87.239.96/2810.87.239.97 – 10.87.239.11010.87.239.111
12010.87.239.112/2810.87.239.113 – 10.87.239.12610.87.239.127
12110.87.239.128/2810.87.239.129 – 10.87.239.14210.87.239.143
12210.87.239.144/2810.87.239.145 – 10.87.239.15810.87.239.159
12310.87.239.160/2810.87.239.161 – 10.87.239.17410.87.239.175
12410.87.239.176/2810.87.239.177 – 10.87.239.19010.87.239.191
12510.87.239.192/2810.87.239.193 – 10.87.239.20610.87.239.207
12610.87.239.208/2810.87.239.209 – 10.87.239.22210.87.239.223
12710.87.239.224/2810.87.239.225 – 10.87.239.23810.87.239.239
12810.87.239.240/2810.87.239.241 – 10.87.239.25410.87.239.255
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 →