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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)10.18.0.0/19
network10.18.0.0/19
broadcast10.18.31.255
first host10.18.0.1
last host10.18.31.254
subnet mask255.255.224.0
wildcard0.0.31.255
addresses8,192
usable hosts8,190
classA
ipcalc 10.18.0.0/19
address00001010.00010010.00000000.00000000
subnet mask11111111.11111111.11100000.00000000
network00001010.00010010.00000000.00000000
broadcast00001010.00010010.00011111.11111111
green = network part, grey = host part
hex0x0a120000
decimal168951808
reverse dns0.0.18.10.in-addr.arpa
ipv4-mapped::ffff:a12:0

/19 split into /25 · 64 subnets

close ×
#networkhost rangebroadcast
110.18.0.0/2510.18.0.1 – 10.18.0.12610.18.0.127
210.18.0.128/2510.18.0.129 – 10.18.0.25410.18.0.255
310.18.1.0/2510.18.1.1 – 10.18.1.12610.18.1.127
410.18.1.128/2510.18.1.129 – 10.18.1.25410.18.1.255
510.18.2.0/2510.18.2.1 – 10.18.2.12610.18.2.127
610.18.2.128/2510.18.2.129 – 10.18.2.25410.18.2.255
710.18.3.0/2510.18.3.1 – 10.18.3.12610.18.3.127
810.18.3.128/2510.18.3.129 – 10.18.3.25410.18.3.255
910.18.4.0/2510.18.4.1 – 10.18.4.12610.18.4.127
1010.18.4.128/2510.18.4.129 – 10.18.4.25410.18.4.255
1110.18.5.0/2510.18.5.1 – 10.18.5.12610.18.5.127
1210.18.5.128/2510.18.5.129 – 10.18.5.25410.18.5.255
1310.18.6.0/2510.18.6.1 – 10.18.6.12610.18.6.127
1410.18.6.128/2510.18.6.129 – 10.18.6.25410.18.6.255
1510.18.7.0/2510.18.7.1 – 10.18.7.12610.18.7.127
1610.18.7.128/2510.18.7.129 – 10.18.7.25410.18.7.255
1710.18.8.0/2510.18.8.1 – 10.18.8.12610.18.8.127
1810.18.8.128/2510.18.8.129 – 10.18.8.25410.18.8.255
1910.18.9.0/2510.18.9.1 – 10.18.9.12610.18.9.127
2010.18.9.128/2510.18.9.129 – 10.18.9.25410.18.9.255
2110.18.10.0/2510.18.10.1 – 10.18.10.12610.18.10.127
2210.18.10.128/2510.18.10.129 – 10.18.10.25410.18.10.255
2310.18.11.0/2510.18.11.1 – 10.18.11.12610.18.11.127
2410.18.11.128/2510.18.11.129 – 10.18.11.25410.18.11.255
2510.18.12.0/2510.18.12.1 – 10.18.12.12610.18.12.127
2610.18.12.128/2510.18.12.129 – 10.18.12.25410.18.12.255
2710.18.13.0/2510.18.13.1 – 10.18.13.12610.18.13.127
2810.18.13.128/2510.18.13.129 – 10.18.13.25410.18.13.255
2910.18.14.0/2510.18.14.1 – 10.18.14.12610.18.14.127
3010.18.14.128/2510.18.14.129 – 10.18.14.25410.18.14.255
3110.18.15.0/2510.18.15.1 – 10.18.15.12610.18.15.127
3210.18.15.128/2510.18.15.129 – 10.18.15.25410.18.15.255
3310.18.16.0/2510.18.16.1 – 10.18.16.12610.18.16.127
3410.18.16.128/2510.18.16.129 – 10.18.16.25410.18.16.255
3510.18.17.0/2510.18.17.1 – 10.18.17.12610.18.17.127
3610.18.17.128/2510.18.17.129 – 10.18.17.25410.18.17.255
3710.18.18.0/2510.18.18.1 – 10.18.18.12610.18.18.127
3810.18.18.128/2510.18.18.129 – 10.18.18.25410.18.18.255
3910.18.19.0/2510.18.19.1 – 10.18.19.12610.18.19.127
4010.18.19.128/2510.18.19.129 – 10.18.19.25410.18.19.255
4110.18.20.0/2510.18.20.1 – 10.18.20.12610.18.20.127
4210.18.20.128/2510.18.20.129 – 10.18.20.25410.18.20.255
4310.18.21.0/2510.18.21.1 – 10.18.21.12610.18.21.127
4410.18.21.128/2510.18.21.129 – 10.18.21.25410.18.21.255
4510.18.22.0/2510.18.22.1 – 10.18.22.12610.18.22.127
4610.18.22.128/2510.18.22.129 – 10.18.22.25410.18.22.255
4710.18.23.0/2510.18.23.1 – 10.18.23.12610.18.23.127
4810.18.23.128/2510.18.23.129 – 10.18.23.25410.18.23.255
4910.18.24.0/2510.18.24.1 – 10.18.24.12610.18.24.127
5010.18.24.128/2510.18.24.129 – 10.18.24.25410.18.24.255
5110.18.25.0/2510.18.25.1 – 10.18.25.12610.18.25.127
5210.18.25.128/2510.18.25.129 – 10.18.25.25410.18.25.255
5310.18.26.0/2510.18.26.1 – 10.18.26.12610.18.26.127
5410.18.26.128/2510.18.26.129 – 10.18.26.25410.18.26.255
5510.18.27.0/2510.18.27.1 – 10.18.27.12610.18.27.127
5610.18.27.128/2510.18.27.129 – 10.18.27.25410.18.27.255
5710.18.28.0/2510.18.28.1 – 10.18.28.12610.18.28.127
5810.18.28.128/2510.18.28.129 – 10.18.28.25410.18.28.255
5910.18.29.0/2510.18.29.1 – 10.18.29.12610.18.29.127
6010.18.29.128/2510.18.29.129 – 10.18.29.25410.18.29.255
6110.18.30.0/2510.18.30.1 – 10.18.30.12610.18.30.127
6210.18.30.128/2510.18.30.129 – 10.18.30.25410.18.30.255
6310.18.31.0/2510.18.31.1 – 10.18.31.12610.18.31.127
6410.18.31.128/2510.18.31.129 – 10.18.31.25410.18.31.255
01 / table

IPv4 CIDR prefix table.

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

prefixsubnet maskaddresseshostsin your /19
/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-
/19255.255.224.08,1928,1901
/20255.255.240.04,0964,0942 split →
/21255.255.248.02,0482,0464 split →
/22255.255.252.01,0241,0228 split →
/23255.255.254.051251016 split →
/24255.255.255.025625432 split →
/25255.255.255.12812812664 split →
/26255.255.255.1926462128 split →
/27255.255.255.2243230256 split →
/28255.255.255.2401614512 split →
/29255.255.255.248861,024 split →
/30255.255.255.252422,048 split →
/31255.255.255.254224,096 split →
/32255.255.255.255118,192 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 →