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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)10.3.144.0/20
network10.3.144.0/20
broadcast10.3.159.255
first host10.3.144.1
last host10.3.159.254
subnet mask255.255.240.0
wildcard0.0.15.255
addresses4,096
usable hosts4,094
classA
ipcalc 10.3.144.0/20
address00001010.00000011.10010000.00000000
subnet mask11111111.11111111.11110000.00000000
network00001010.00000011.10010000.00000000
broadcast00001010.00000011.10011111.11111111
green = network part, grey = host part
hex0x0a039000
decimal168005632
reverse dns0.144.3.10.in-addr.arpa
ipv4-mapped::ffff:a03:9000

/20 split into /25 · 32 subnets

close ×
#networkhost rangebroadcast
110.3.144.0/2510.3.144.1 – 10.3.144.12610.3.144.127
210.3.144.128/2510.3.144.129 – 10.3.144.25410.3.144.255
310.3.145.0/2510.3.145.1 – 10.3.145.12610.3.145.127
410.3.145.128/2510.3.145.129 – 10.3.145.25410.3.145.255
510.3.146.0/2510.3.146.1 – 10.3.146.12610.3.146.127
610.3.146.128/2510.3.146.129 – 10.3.146.25410.3.146.255
710.3.147.0/2510.3.147.1 – 10.3.147.12610.3.147.127
810.3.147.128/2510.3.147.129 – 10.3.147.25410.3.147.255
910.3.148.0/2510.3.148.1 – 10.3.148.12610.3.148.127
1010.3.148.128/2510.3.148.129 – 10.3.148.25410.3.148.255
1110.3.149.0/2510.3.149.1 – 10.3.149.12610.3.149.127
1210.3.149.128/2510.3.149.129 – 10.3.149.25410.3.149.255
1310.3.150.0/2510.3.150.1 – 10.3.150.12610.3.150.127
1410.3.150.128/2510.3.150.129 – 10.3.150.25410.3.150.255
1510.3.151.0/2510.3.151.1 – 10.3.151.12610.3.151.127
1610.3.151.128/2510.3.151.129 – 10.3.151.25410.3.151.255
1710.3.152.0/2510.3.152.1 – 10.3.152.12610.3.152.127
1810.3.152.128/2510.3.152.129 – 10.3.152.25410.3.152.255
1910.3.153.0/2510.3.153.1 – 10.3.153.12610.3.153.127
2010.3.153.128/2510.3.153.129 – 10.3.153.25410.3.153.255
2110.3.154.0/2510.3.154.1 – 10.3.154.12610.3.154.127
2210.3.154.128/2510.3.154.129 – 10.3.154.25410.3.154.255
2310.3.155.0/2510.3.155.1 – 10.3.155.12610.3.155.127
2410.3.155.128/2510.3.155.129 – 10.3.155.25410.3.155.255
2510.3.156.0/2510.3.156.1 – 10.3.156.12610.3.156.127
2610.3.156.128/2510.3.156.129 – 10.3.156.25410.3.156.255
2710.3.157.0/2510.3.157.1 – 10.3.157.12610.3.157.127
2810.3.157.128/2510.3.157.129 – 10.3.157.25410.3.157.255
2910.3.158.0/2510.3.158.1 – 10.3.158.12610.3.158.127
3010.3.158.128/2510.3.158.129 – 10.3.158.25410.3.158.255
3110.3.159.0/2510.3.159.1 – 10.3.159.12610.3.159.127
3210.3.159.128/2510.3.159.129 – 10.3.159.25410.3.159.255
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 →