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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)10.7.224.0/21
network10.7.224.0/21
broadcast10.7.231.255
first host10.7.224.1
last host10.7.231.254
subnet mask255.255.248.0
wildcard0.0.7.255
addresses2,048
usable hosts2,046
classA
ipcalc 10.7.224.0/21
address00001010.00000111.11100000.00000000
subnet mask11111111.11111111.11111000.00000000
network00001010.00000111.11100000.00000000
broadcast00001010.00000111.11100111.11111111
green = network part, grey = host part
hex0x0a07e000
decimal168288256
reverse dns0.224.7.10.in-addr.arpa
ipv4-mapped::ffff:a07:e000

/21 split into /26 · 32 subnets

close ×
#networkhost rangebroadcast
110.7.224.0/2610.7.224.1 – 10.7.224.6210.7.224.63
210.7.224.64/2610.7.224.65 – 10.7.224.12610.7.224.127
310.7.224.128/2610.7.224.129 – 10.7.224.19010.7.224.191
410.7.224.192/2610.7.224.193 – 10.7.224.25410.7.224.255
510.7.225.0/2610.7.225.1 – 10.7.225.6210.7.225.63
610.7.225.64/2610.7.225.65 – 10.7.225.12610.7.225.127
710.7.225.128/2610.7.225.129 – 10.7.225.19010.7.225.191
810.7.225.192/2610.7.225.193 – 10.7.225.25410.7.225.255
910.7.226.0/2610.7.226.1 – 10.7.226.6210.7.226.63
1010.7.226.64/2610.7.226.65 – 10.7.226.12610.7.226.127
1110.7.226.128/2610.7.226.129 – 10.7.226.19010.7.226.191
1210.7.226.192/2610.7.226.193 – 10.7.226.25410.7.226.255
1310.7.227.0/2610.7.227.1 – 10.7.227.6210.7.227.63
1410.7.227.64/2610.7.227.65 – 10.7.227.12610.7.227.127
1510.7.227.128/2610.7.227.129 – 10.7.227.19010.7.227.191
1610.7.227.192/2610.7.227.193 – 10.7.227.25410.7.227.255
1710.7.228.0/2610.7.228.1 – 10.7.228.6210.7.228.63
1810.7.228.64/2610.7.228.65 – 10.7.228.12610.7.228.127
1910.7.228.128/2610.7.228.129 – 10.7.228.19010.7.228.191
2010.7.228.192/2610.7.228.193 – 10.7.228.25410.7.228.255
2110.7.229.0/2610.7.229.1 – 10.7.229.6210.7.229.63
2210.7.229.64/2610.7.229.65 – 10.7.229.12610.7.229.127
2310.7.229.128/2610.7.229.129 – 10.7.229.19010.7.229.191
2410.7.229.192/2610.7.229.193 – 10.7.229.25410.7.229.255
2510.7.230.0/2610.7.230.1 – 10.7.230.6210.7.230.63
2610.7.230.64/2610.7.230.65 – 10.7.230.12610.7.230.127
2710.7.230.128/2610.7.230.129 – 10.7.230.19010.7.230.191
2810.7.230.192/2610.7.230.193 – 10.7.230.25410.7.230.255
2910.7.231.0/2610.7.231.1 – 10.7.231.6210.7.231.63
3010.7.231.64/2610.7.231.65 – 10.7.231.12610.7.231.127
3110.7.231.128/2610.7.231.129 – 10.7.231.19010.7.231.191
3210.7.231.192/2610.7.231.193 – 10.7.231.25410.7.231.255
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 →