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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)10.1.16.0/20
network10.1.16.0/20
broadcast10.1.31.255
first host10.1.16.1
last host10.1.31.254
subnet mask255.255.240.0
wildcard0.0.15.255
addresses4,096
usable hosts4,094
classA
ipcalc 10.1.16.0/20
address00001010.00000001.00010000.00000000
subnet mask11111111.11111111.11110000.00000000
network00001010.00000001.00010000.00000000
broadcast00001010.00000001.00011111.11111111
green = network part, grey = host part
hex0x0a011000
decimal167841792
reverse dns0.16.1.10.in-addr.arpa
ipv4-mapped::ffff:a01:1000

/20 split into /26 · 64 subnets

close ×
#networkhost rangebroadcast
110.1.16.0/2610.1.16.1 – 10.1.16.6210.1.16.63
210.1.16.64/2610.1.16.65 – 10.1.16.12610.1.16.127
310.1.16.128/2610.1.16.129 – 10.1.16.19010.1.16.191
410.1.16.192/2610.1.16.193 – 10.1.16.25410.1.16.255
510.1.17.0/2610.1.17.1 – 10.1.17.6210.1.17.63
610.1.17.64/2610.1.17.65 – 10.1.17.12610.1.17.127
710.1.17.128/2610.1.17.129 – 10.1.17.19010.1.17.191
810.1.17.192/2610.1.17.193 – 10.1.17.25410.1.17.255
910.1.18.0/2610.1.18.1 – 10.1.18.6210.1.18.63
1010.1.18.64/2610.1.18.65 – 10.1.18.12610.1.18.127
1110.1.18.128/2610.1.18.129 – 10.1.18.19010.1.18.191
1210.1.18.192/2610.1.18.193 – 10.1.18.25410.1.18.255
1310.1.19.0/2610.1.19.1 – 10.1.19.6210.1.19.63
1410.1.19.64/2610.1.19.65 – 10.1.19.12610.1.19.127
1510.1.19.128/2610.1.19.129 – 10.1.19.19010.1.19.191
1610.1.19.192/2610.1.19.193 – 10.1.19.25410.1.19.255
1710.1.20.0/2610.1.20.1 – 10.1.20.6210.1.20.63
1810.1.20.64/2610.1.20.65 – 10.1.20.12610.1.20.127
1910.1.20.128/2610.1.20.129 – 10.1.20.19010.1.20.191
2010.1.20.192/2610.1.20.193 – 10.1.20.25410.1.20.255
2110.1.21.0/2610.1.21.1 – 10.1.21.6210.1.21.63
2210.1.21.64/2610.1.21.65 – 10.1.21.12610.1.21.127
2310.1.21.128/2610.1.21.129 – 10.1.21.19010.1.21.191
2410.1.21.192/2610.1.21.193 – 10.1.21.25410.1.21.255
2510.1.22.0/2610.1.22.1 – 10.1.22.6210.1.22.63
2610.1.22.64/2610.1.22.65 – 10.1.22.12610.1.22.127
2710.1.22.128/2610.1.22.129 – 10.1.22.19010.1.22.191
2810.1.22.192/2610.1.22.193 – 10.1.22.25410.1.22.255
2910.1.23.0/2610.1.23.1 – 10.1.23.6210.1.23.63
3010.1.23.64/2610.1.23.65 – 10.1.23.12610.1.23.127
3110.1.23.128/2610.1.23.129 – 10.1.23.19010.1.23.191
3210.1.23.192/2610.1.23.193 – 10.1.23.25410.1.23.255
3310.1.24.0/2610.1.24.1 – 10.1.24.6210.1.24.63
3410.1.24.64/2610.1.24.65 – 10.1.24.12610.1.24.127
3510.1.24.128/2610.1.24.129 – 10.1.24.19010.1.24.191
3610.1.24.192/2610.1.24.193 – 10.1.24.25410.1.24.255
3710.1.25.0/2610.1.25.1 – 10.1.25.6210.1.25.63
3810.1.25.64/2610.1.25.65 – 10.1.25.12610.1.25.127
3910.1.25.128/2610.1.25.129 – 10.1.25.19010.1.25.191
4010.1.25.192/2610.1.25.193 – 10.1.25.25410.1.25.255
4110.1.26.0/2610.1.26.1 – 10.1.26.6210.1.26.63
4210.1.26.64/2610.1.26.65 – 10.1.26.12610.1.26.127
4310.1.26.128/2610.1.26.129 – 10.1.26.19010.1.26.191
4410.1.26.192/2610.1.26.193 – 10.1.26.25410.1.26.255
4510.1.27.0/2610.1.27.1 – 10.1.27.6210.1.27.63
4610.1.27.64/2610.1.27.65 – 10.1.27.12610.1.27.127
4710.1.27.128/2610.1.27.129 – 10.1.27.19010.1.27.191
4810.1.27.192/2610.1.27.193 – 10.1.27.25410.1.27.255
4910.1.28.0/2610.1.28.1 – 10.1.28.6210.1.28.63
5010.1.28.64/2610.1.28.65 – 10.1.28.12610.1.28.127
5110.1.28.128/2610.1.28.129 – 10.1.28.19010.1.28.191
5210.1.28.192/2610.1.28.193 – 10.1.28.25410.1.28.255
5310.1.29.0/2610.1.29.1 – 10.1.29.6210.1.29.63
5410.1.29.64/2610.1.29.65 – 10.1.29.12610.1.29.127
5510.1.29.128/2610.1.29.129 – 10.1.29.19010.1.29.191
5610.1.29.192/2610.1.29.193 – 10.1.29.25410.1.29.255
5710.1.30.0/2610.1.30.1 – 10.1.30.6210.1.30.63
5810.1.30.64/2610.1.30.65 – 10.1.30.12610.1.30.127
5910.1.30.128/2610.1.30.129 – 10.1.30.19010.1.30.191
6010.1.30.192/2610.1.30.193 – 10.1.30.25410.1.30.255
6110.1.31.0/2610.1.31.1 – 10.1.31.6210.1.31.63
6210.1.31.64/2610.1.31.65 – 10.1.31.12610.1.31.127
6310.1.31.128/2610.1.31.129 – 10.1.31.19010.1.31.191
6410.1.31.192/2610.1.31.193 – 10.1.31.25410.1.31.255
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 →