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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)10.2.128.0/17
network10.2.128.0/17
broadcast10.2.255.255
first host10.2.128.1
last host10.2.255.254
subnet mask255.255.128.0
wildcard0.0.127.255
addresses32,768
usable hosts32,766
classA
ipcalc 10.2.128.0/17
address00001010.00000010.10000000.00000000
subnet mask11111111.11111111.10000000.00000000
network00001010.00000010.10000000.00000000
broadcast00001010.00000010.11111111.11111111
green = network part, grey = host part
hex0x0a028000
decimal167936000
reverse dns0.128.2.10.in-addr.arpa
ipv4-mapped::ffff:a02:8000

/17 split into /23 · 64 subnets

close ×
#networkhost rangebroadcast
110.2.128.0/2310.2.128.1 – 10.2.129.25410.2.129.255
210.2.130.0/2310.2.130.1 – 10.2.131.25410.2.131.255
310.2.132.0/2310.2.132.1 – 10.2.133.25410.2.133.255
410.2.134.0/2310.2.134.1 – 10.2.135.25410.2.135.255
510.2.136.0/2310.2.136.1 – 10.2.137.25410.2.137.255
610.2.138.0/2310.2.138.1 – 10.2.139.25410.2.139.255
710.2.140.0/2310.2.140.1 – 10.2.141.25410.2.141.255
810.2.142.0/2310.2.142.1 – 10.2.143.25410.2.143.255
910.2.144.0/2310.2.144.1 – 10.2.145.25410.2.145.255
1010.2.146.0/2310.2.146.1 – 10.2.147.25410.2.147.255
1110.2.148.0/2310.2.148.1 – 10.2.149.25410.2.149.255
1210.2.150.0/2310.2.150.1 – 10.2.151.25410.2.151.255
1310.2.152.0/2310.2.152.1 – 10.2.153.25410.2.153.255
1410.2.154.0/2310.2.154.1 – 10.2.155.25410.2.155.255
1510.2.156.0/2310.2.156.1 – 10.2.157.25410.2.157.255
1610.2.158.0/2310.2.158.1 – 10.2.159.25410.2.159.255
1710.2.160.0/2310.2.160.1 – 10.2.161.25410.2.161.255
1810.2.162.0/2310.2.162.1 – 10.2.163.25410.2.163.255
1910.2.164.0/2310.2.164.1 – 10.2.165.25410.2.165.255
2010.2.166.0/2310.2.166.1 – 10.2.167.25410.2.167.255
2110.2.168.0/2310.2.168.1 – 10.2.169.25410.2.169.255
2210.2.170.0/2310.2.170.1 – 10.2.171.25410.2.171.255
2310.2.172.0/2310.2.172.1 – 10.2.173.25410.2.173.255
2410.2.174.0/2310.2.174.1 – 10.2.175.25410.2.175.255
2510.2.176.0/2310.2.176.1 – 10.2.177.25410.2.177.255
2610.2.178.0/2310.2.178.1 – 10.2.179.25410.2.179.255
2710.2.180.0/2310.2.180.1 – 10.2.181.25410.2.181.255
2810.2.182.0/2310.2.182.1 – 10.2.183.25410.2.183.255
2910.2.184.0/2310.2.184.1 – 10.2.185.25410.2.185.255
3010.2.186.0/2310.2.186.1 – 10.2.187.25410.2.187.255
3110.2.188.0/2310.2.188.1 – 10.2.189.25410.2.189.255
3210.2.190.0/2310.2.190.1 – 10.2.191.25410.2.191.255
3310.2.192.0/2310.2.192.1 – 10.2.193.25410.2.193.255
3410.2.194.0/2310.2.194.1 – 10.2.195.25410.2.195.255
3510.2.196.0/2310.2.196.1 – 10.2.197.25410.2.197.255
3610.2.198.0/2310.2.198.1 – 10.2.199.25410.2.199.255
3710.2.200.0/2310.2.200.1 – 10.2.201.25410.2.201.255
3810.2.202.0/2310.2.202.1 – 10.2.203.25410.2.203.255
3910.2.204.0/2310.2.204.1 – 10.2.205.25410.2.205.255
4010.2.206.0/2310.2.206.1 – 10.2.207.25410.2.207.255
4110.2.208.0/2310.2.208.1 – 10.2.209.25410.2.209.255
4210.2.210.0/2310.2.210.1 – 10.2.211.25410.2.211.255
4310.2.212.0/2310.2.212.1 – 10.2.213.25410.2.213.255
4410.2.214.0/2310.2.214.1 – 10.2.215.25410.2.215.255
4510.2.216.0/2310.2.216.1 – 10.2.217.25410.2.217.255
4610.2.218.0/2310.2.218.1 – 10.2.219.25410.2.219.255
4710.2.220.0/2310.2.220.1 – 10.2.221.25410.2.221.255
4810.2.222.0/2310.2.222.1 – 10.2.223.25410.2.223.255
4910.2.224.0/2310.2.224.1 – 10.2.225.25410.2.225.255
5010.2.226.0/2310.2.226.1 – 10.2.227.25410.2.227.255
5110.2.228.0/2310.2.228.1 – 10.2.229.25410.2.229.255
5210.2.230.0/2310.2.230.1 – 10.2.231.25410.2.231.255
5310.2.232.0/2310.2.232.1 – 10.2.233.25410.2.233.255
5410.2.234.0/2310.2.234.1 – 10.2.235.25410.2.235.255
5510.2.236.0/2310.2.236.1 – 10.2.237.25410.2.237.255
5610.2.238.0/2310.2.238.1 – 10.2.239.25410.2.239.255
5710.2.240.0/2310.2.240.1 – 10.2.241.25410.2.241.255
5810.2.242.0/2310.2.242.1 – 10.2.243.25410.2.243.255
5910.2.244.0/2310.2.244.1 – 10.2.245.25410.2.245.255
6010.2.246.0/2310.2.246.1 – 10.2.247.25410.2.247.255
6110.2.248.0/2310.2.248.1 – 10.2.249.25410.2.249.255
6210.2.250.0/2310.2.250.1 – 10.2.251.25410.2.251.255
6310.2.252.0/2310.2.252.1 – 10.2.253.25410.2.253.255
6410.2.254.0/2310.2.254.1 – 10.2.255.25410.2.255.255
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 →