ip
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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
private IP (RFC 1918)10.31.128.0/17
network10.31.128.0/17
broadcast10.31.255.255
first host10.31.128.1
last host10.31.255.254
subnet mask255.255.128.0
wildcard0.0.127.255
addresses32,768
usable hosts32,766
classA
ipcalc 10.31.128.0/17
address00001010.00011111.10000000.00000000
subnet mask11111111.11111111.10000000.00000000
network00001010.00011111.10000000.00000000
broadcast00001010.00011111.11111111.11111111
green = network part, grey = host part
hex0x0a1f8000
decimal169836544
reverse dns0.128.31.10.in-addr.arpa
ipv4-mapped::ffff:a1f:8000

/17 split into /23 · 64 subnets

close ×
#networkhost rangebroadcast
110.31.128.0/2310.31.128.1 – 10.31.129.25410.31.129.255
210.31.130.0/2310.31.130.1 – 10.31.131.25410.31.131.255
310.31.132.0/2310.31.132.1 – 10.31.133.25410.31.133.255
410.31.134.0/2310.31.134.1 – 10.31.135.25410.31.135.255
510.31.136.0/2310.31.136.1 – 10.31.137.25410.31.137.255
610.31.138.0/2310.31.138.1 – 10.31.139.25410.31.139.255
710.31.140.0/2310.31.140.1 – 10.31.141.25410.31.141.255
810.31.142.0/2310.31.142.1 – 10.31.143.25410.31.143.255
910.31.144.0/2310.31.144.1 – 10.31.145.25410.31.145.255
1010.31.146.0/2310.31.146.1 – 10.31.147.25410.31.147.255
1110.31.148.0/2310.31.148.1 – 10.31.149.25410.31.149.255
1210.31.150.0/2310.31.150.1 – 10.31.151.25410.31.151.255
1310.31.152.0/2310.31.152.1 – 10.31.153.25410.31.153.255
1410.31.154.0/2310.31.154.1 – 10.31.155.25410.31.155.255
1510.31.156.0/2310.31.156.1 – 10.31.157.25410.31.157.255
1610.31.158.0/2310.31.158.1 – 10.31.159.25410.31.159.255
1710.31.160.0/2310.31.160.1 – 10.31.161.25410.31.161.255
1810.31.162.0/2310.31.162.1 – 10.31.163.25410.31.163.255
1910.31.164.0/2310.31.164.1 – 10.31.165.25410.31.165.255
2010.31.166.0/2310.31.166.1 – 10.31.167.25410.31.167.255
2110.31.168.0/2310.31.168.1 – 10.31.169.25410.31.169.255
2210.31.170.0/2310.31.170.1 – 10.31.171.25410.31.171.255
2310.31.172.0/2310.31.172.1 – 10.31.173.25410.31.173.255
2410.31.174.0/2310.31.174.1 – 10.31.175.25410.31.175.255
2510.31.176.0/2310.31.176.1 – 10.31.177.25410.31.177.255
2610.31.178.0/2310.31.178.1 – 10.31.179.25410.31.179.255
2710.31.180.0/2310.31.180.1 – 10.31.181.25410.31.181.255
2810.31.182.0/2310.31.182.1 – 10.31.183.25410.31.183.255
2910.31.184.0/2310.31.184.1 – 10.31.185.25410.31.185.255
3010.31.186.0/2310.31.186.1 – 10.31.187.25410.31.187.255
3110.31.188.0/2310.31.188.1 – 10.31.189.25410.31.189.255
3210.31.190.0/2310.31.190.1 – 10.31.191.25410.31.191.255
3310.31.192.0/2310.31.192.1 – 10.31.193.25410.31.193.255
3410.31.194.0/2310.31.194.1 – 10.31.195.25410.31.195.255
3510.31.196.0/2310.31.196.1 – 10.31.197.25410.31.197.255
3610.31.198.0/2310.31.198.1 – 10.31.199.25410.31.199.255
3710.31.200.0/2310.31.200.1 – 10.31.201.25410.31.201.255
3810.31.202.0/2310.31.202.1 – 10.31.203.25410.31.203.255
3910.31.204.0/2310.31.204.1 – 10.31.205.25410.31.205.255
4010.31.206.0/2310.31.206.1 – 10.31.207.25410.31.207.255
4110.31.208.0/2310.31.208.1 – 10.31.209.25410.31.209.255
4210.31.210.0/2310.31.210.1 – 10.31.211.25410.31.211.255
4310.31.212.0/2310.31.212.1 – 10.31.213.25410.31.213.255
4410.31.214.0/2310.31.214.1 – 10.31.215.25410.31.215.255
4510.31.216.0/2310.31.216.1 – 10.31.217.25410.31.217.255
4610.31.218.0/2310.31.218.1 – 10.31.219.25410.31.219.255
4710.31.220.0/2310.31.220.1 – 10.31.221.25410.31.221.255
4810.31.222.0/2310.31.222.1 – 10.31.223.25410.31.223.255
4910.31.224.0/2310.31.224.1 – 10.31.225.25410.31.225.255
5010.31.226.0/2310.31.226.1 – 10.31.227.25410.31.227.255
5110.31.228.0/2310.31.228.1 – 10.31.229.25410.31.229.255
5210.31.230.0/2310.31.230.1 – 10.31.231.25410.31.231.255
5310.31.232.0/2310.31.232.1 – 10.31.233.25410.31.233.255
5410.31.234.0/2310.31.234.1 – 10.31.235.25410.31.235.255
5510.31.236.0/2310.31.236.1 – 10.31.237.25410.31.237.255
5610.31.238.0/2310.31.238.1 – 10.31.239.25410.31.239.255
5710.31.240.0/2310.31.240.1 – 10.31.241.25410.31.241.255
5810.31.242.0/2310.31.242.1 – 10.31.243.25410.31.243.255
5910.31.244.0/2310.31.244.1 – 10.31.245.25410.31.245.255
6010.31.246.0/2310.31.246.1 – 10.31.247.25410.31.247.255
6110.31.248.0/2310.31.248.1 – 10.31.249.25410.31.249.255
6210.31.250.0/2310.31.250.1 – 10.31.251.25410.31.251.255
6310.31.252.0/2310.31.252.1 – 10.31.253.25410.31.253.255
6410.31.254.0/2310.31.254.1 – 10.31.255.25410.31.255.255
01 / table

IPv4 CIDR prefix table.

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

prefixsubnet maskaddresseshostsin your /17
/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-
/17255.255.128.032,76832,7661
/18255.255.192.016,38416,3822 split →
/19255.255.224.08,1928,1904 split →
/20255.255.240.04,0964,0948 split →
/21255.255.248.02,0482,04616 split →
/22255.255.252.01,0241,02232 split →
/23255.255.254.051251064 split →
/24255.255.255.0256254128 split →
/25255.255.255.128128126256 split →
/26255.255.255.1926462512 split →
/27255.255.255.22432301,024 split →
/28255.255.255.24016142,048 split →
/29255.255.255.248864,096 split →
/30255.255.255.252428,192 split →
/31255.255.255.2542216,384 split →
/32255.255.255.2551132,768 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 →