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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)10.12.128.0/17
network10.12.128.0/17
broadcast10.12.255.255
first host10.12.128.1
last host10.12.255.254
subnet mask255.255.128.0
wildcard0.0.127.255
addresses32,768
usable hosts32,766
classA
ipcalc 10.12.128.0/17
address00001010.00001100.10000000.00000000
subnet mask11111111.11111111.10000000.00000000
network00001010.00001100.10000000.00000000
broadcast00001010.00001100.11111111.11111111
green = network part, grey = host part
hex0x0a0c8000
decimal168591360
reverse dns0.128.12.10.in-addr.arpa
ipv4-mapped::ffff:a0c:8000

/17 split into /23 · 64 subnets

close ×
#networkhost rangebroadcast
110.12.128.0/2310.12.128.1 – 10.12.129.25410.12.129.255
210.12.130.0/2310.12.130.1 – 10.12.131.25410.12.131.255
310.12.132.0/2310.12.132.1 – 10.12.133.25410.12.133.255
410.12.134.0/2310.12.134.1 – 10.12.135.25410.12.135.255
510.12.136.0/2310.12.136.1 – 10.12.137.25410.12.137.255
610.12.138.0/2310.12.138.1 – 10.12.139.25410.12.139.255
710.12.140.0/2310.12.140.1 – 10.12.141.25410.12.141.255
810.12.142.0/2310.12.142.1 – 10.12.143.25410.12.143.255
910.12.144.0/2310.12.144.1 – 10.12.145.25410.12.145.255
1010.12.146.0/2310.12.146.1 – 10.12.147.25410.12.147.255
1110.12.148.0/2310.12.148.1 – 10.12.149.25410.12.149.255
1210.12.150.0/2310.12.150.1 – 10.12.151.25410.12.151.255
1310.12.152.0/2310.12.152.1 – 10.12.153.25410.12.153.255
1410.12.154.0/2310.12.154.1 – 10.12.155.25410.12.155.255
1510.12.156.0/2310.12.156.1 – 10.12.157.25410.12.157.255
1610.12.158.0/2310.12.158.1 – 10.12.159.25410.12.159.255
1710.12.160.0/2310.12.160.1 – 10.12.161.25410.12.161.255
1810.12.162.0/2310.12.162.1 – 10.12.163.25410.12.163.255
1910.12.164.0/2310.12.164.1 – 10.12.165.25410.12.165.255
2010.12.166.0/2310.12.166.1 – 10.12.167.25410.12.167.255
2110.12.168.0/2310.12.168.1 – 10.12.169.25410.12.169.255
2210.12.170.0/2310.12.170.1 – 10.12.171.25410.12.171.255
2310.12.172.0/2310.12.172.1 – 10.12.173.25410.12.173.255
2410.12.174.0/2310.12.174.1 – 10.12.175.25410.12.175.255
2510.12.176.0/2310.12.176.1 – 10.12.177.25410.12.177.255
2610.12.178.0/2310.12.178.1 – 10.12.179.25410.12.179.255
2710.12.180.0/2310.12.180.1 – 10.12.181.25410.12.181.255
2810.12.182.0/2310.12.182.1 – 10.12.183.25410.12.183.255
2910.12.184.0/2310.12.184.1 – 10.12.185.25410.12.185.255
3010.12.186.0/2310.12.186.1 – 10.12.187.25410.12.187.255
3110.12.188.0/2310.12.188.1 – 10.12.189.25410.12.189.255
3210.12.190.0/2310.12.190.1 – 10.12.191.25410.12.191.255
3310.12.192.0/2310.12.192.1 – 10.12.193.25410.12.193.255
3410.12.194.0/2310.12.194.1 – 10.12.195.25410.12.195.255
3510.12.196.0/2310.12.196.1 – 10.12.197.25410.12.197.255
3610.12.198.0/2310.12.198.1 – 10.12.199.25410.12.199.255
3710.12.200.0/2310.12.200.1 – 10.12.201.25410.12.201.255
3810.12.202.0/2310.12.202.1 – 10.12.203.25410.12.203.255
3910.12.204.0/2310.12.204.1 – 10.12.205.25410.12.205.255
4010.12.206.0/2310.12.206.1 – 10.12.207.25410.12.207.255
4110.12.208.0/2310.12.208.1 – 10.12.209.25410.12.209.255
4210.12.210.0/2310.12.210.1 – 10.12.211.25410.12.211.255
4310.12.212.0/2310.12.212.1 – 10.12.213.25410.12.213.255
4410.12.214.0/2310.12.214.1 – 10.12.215.25410.12.215.255
4510.12.216.0/2310.12.216.1 – 10.12.217.25410.12.217.255
4610.12.218.0/2310.12.218.1 – 10.12.219.25410.12.219.255
4710.12.220.0/2310.12.220.1 – 10.12.221.25410.12.221.255
4810.12.222.0/2310.12.222.1 – 10.12.223.25410.12.223.255
4910.12.224.0/2310.12.224.1 – 10.12.225.25410.12.225.255
5010.12.226.0/2310.12.226.1 – 10.12.227.25410.12.227.255
5110.12.228.0/2310.12.228.1 – 10.12.229.25410.12.229.255
5210.12.230.0/2310.12.230.1 – 10.12.231.25410.12.231.255
5310.12.232.0/2310.12.232.1 – 10.12.233.25410.12.233.255
5410.12.234.0/2310.12.234.1 – 10.12.235.25410.12.235.255
5510.12.236.0/2310.12.236.1 – 10.12.237.25410.12.237.255
5610.12.238.0/2310.12.238.1 – 10.12.239.25410.12.239.255
5710.12.240.0/2310.12.240.1 – 10.12.241.25410.12.241.255
5810.12.242.0/2310.12.242.1 – 10.12.243.25410.12.243.255
5910.12.244.0/2310.12.244.1 – 10.12.245.25410.12.245.255
6010.12.246.0/2310.12.246.1 – 10.12.247.25410.12.247.255
6110.12.248.0/2310.12.248.1 – 10.12.249.25410.12.249.255
6210.12.250.0/2310.12.250.1 – 10.12.251.25410.12.251.255
6310.12.252.0/2310.12.252.1 – 10.12.253.25410.12.253.255
6410.12.254.0/2310.12.254.1 – 10.12.255.25410.12.255.255
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 →