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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)10.11.240.0/20
network10.11.240.0/20
broadcast10.11.255.255
first host10.11.240.1
last host10.11.255.254
subnet mask255.255.240.0
wildcard0.0.15.255
addresses4,096
usable hosts4,094
classA
ipcalc 10.11.240.0/20
address00001010.00001011.11110000.00000000
subnet mask11111111.11111111.11110000.00000000
network00001010.00001011.11110000.00000000
broadcast00001010.00001011.11111111.11111111
green = network part, grey = host part
hex0x0a0bf000
decimal168554496
reverse dns0.240.11.10.in-addr.arpa
ipv4-mapped::ffff:a0b:f000

/20 split into /25 · 32 subnets

close ×
#networkhost rangebroadcast
110.11.240.0/2510.11.240.1 – 10.11.240.12610.11.240.127
210.11.240.128/2510.11.240.129 – 10.11.240.25410.11.240.255
310.11.241.0/2510.11.241.1 – 10.11.241.12610.11.241.127
410.11.241.128/2510.11.241.129 – 10.11.241.25410.11.241.255
510.11.242.0/2510.11.242.1 – 10.11.242.12610.11.242.127
610.11.242.128/2510.11.242.129 – 10.11.242.25410.11.242.255
710.11.243.0/2510.11.243.1 – 10.11.243.12610.11.243.127
810.11.243.128/2510.11.243.129 – 10.11.243.25410.11.243.255
910.11.244.0/2510.11.244.1 – 10.11.244.12610.11.244.127
1010.11.244.128/2510.11.244.129 – 10.11.244.25410.11.244.255
1110.11.245.0/2510.11.245.1 – 10.11.245.12610.11.245.127
1210.11.245.128/2510.11.245.129 – 10.11.245.25410.11.245.255
1310.11.246.0/2510.11.246.1 – 10.11.246.12610.11.246.127
1410.11.246.128/2510.11.246.129 – 10.11.246.25410.11.246.255
1510.11.247.0/2510.11.247.1 – 10.11.247.12610.11.247.127
1610.11.247.128/2510.11.247.129 – 10.11.247.25410.11.247.255
1710.11.248.0/2510.11.248.1 – 10.11.248.12610.11.248.127
1810.11.248.128/2510.11.248.129 – 10.11.248.25410.11.248.255
1910.11.249.0/2510.11.249.1 – 10.11.249.12610.11.249.127
2010.11.249.128/2510.11.249.129 – 10.11.249.25410.11.249.255
2110.11.250.0/2510.11.250.1 – 10.11.250.12610.11.250.127
2210.11.250.128/2510.11.250.129 – 10.11.250.25410.11.250.255
2310.11.251.0/2510.11.251.1 – 10.11.251.12610.11.251.127
2410.11.251.128/2510.11.251.129 – 10.11.251.25410.11.251.255
2510.11.252.0/2510.11.252.1 – 10.11.252.12610.11.252.127
2610.11.252.128/2510.11.252.129 – 10.11.252.25410.11.252.255
2710.11.253.0/2510.11.253.1 – 10.11.253.12610.11.253.127
2810.11.253.128/2510.11.253.129 – 10.11.253.25410.11.253.255
2910.11.254.0/2510.11.254.1 – 10.11.254.12610.11.254.127
3010.11.254.128/2510.11.254.129 – 10.11.254.25410.11.254.255
3110.11.255.0/2510.11.255.1 – 10.11.255.12610.11.255.127
3210.11.255.128/2510.11.255.129 – 10.11.255.25410.11.255.255
01 / table

IPv4 CIDR prefix table.

Click a prefix longer than your network to split it into subnets.

prefixsubnet maskaddresseshostsin your /20
/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-
/20255.255.240.04,0964,0941
/21255.255.248.02,0482,0462 split →
/22255.255.252.01,0241,0224 split →
/23255.255.254.05125108 split →
/24255.255.255.025625416 split →
/25255.255.255.12812812632 split →
/26255.255.255.192646264 split →
/27255.255.255.2243230128 split →
/28255.255.255.2401614256 split →
/29255.255.255.24886512 split →
/30255.255.255.252421,024 split →
/31255.255.255.254222,048 split →
/32255.255.255.255114,096 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 →