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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)10.18.128.0/17
network10.18.128.0/17
broadcast10.18.255.255
first host10.18.128.1
last host10.18.255.254
subnet mask255.255.128.0
wildcard0.0.127.255
addresses32,768
usable hosts32,766
classA
ipcalc 10.18.128.0/17
address00001010.00010010.10000000.00000000
subnet mask11111111.11111111.10000000.00000000
network00001010.00010010.10000000.00000000
broadcast00001010.00010010.11111111.11111111
green = network part, grey = host part
hex0x0a128000
decimal168984576
reverse dns0.128.18.10.in-addr.arpa
ipv4-mapped::ffff:a12:8000

/17 split into /23 · 64 subnets

close ×
#networkhost rangebroadcast
110.18.128.0/2310.18.128.1 – 10.18.129.25410.18.129.255
210.18.130.0/2310.18.130.1 – 10.18.131.25410.18.131.255
310.18.132.0/2310.18.132.1 – 10.18.133.25410.18.133.255
410.18.134.0/2310.18.134.1 – 10.18.135.25410.18.135.255
510.18.136.0/2310.18.136.1 – 10.18.137.25410.18.137.255
610.18.138.0/2310.18.138.1 – 10.18.139.25410.18.139.255
710.18.140.0/2310.18.140.1 – 10.18.141.25410.18.141.255
810.18.142.0/2310.18.142.1 – 10.18.143.25410.18.143.255
910.18.144.0/2310.18.144.1 – 10.18.145.25410.18.145.255
1010.18.146.0/2310.18.146.1 – 10.18.147.25410.18.147.255
1110.18.148.0/2310.18.148.1 – 10.18.149.25410.18.149.255
1210.18.150.0/2310.18.150.1 – 10.18.151.25410.18.151.255
1310.18.152.0/2310.18.152.1 – 10.18.153.25410.18.153.255
1410.18.154.0/2310.18.154.1 – 10.18.155.25410.18.155.255
1510.18.156.0/2310.18.156.1 – 10.18.157.25410.18.157.255
1610.18.158.0/2310.18.158.1 – 10.18.159.25410.18.159.255
1710.18.160.0/2310.18.160.1 – 10.18.161.25410.18.161.255
1810.18.162.0/2310.18.162.1 – 10.18.163.25410.18.163.255
1910.18.164.0/2310.18.164.1 – 10.18.165.25410.18.165.255
2010.18.166.0/2310.18.166.1 – 10.18.167.25410.18.167.255
2110.18.168.0/2310.18.168.1 – 10.18.169.25410.18.169.255
2210.18.170.0/2310.18.170.1 – 10.18.171.25410.18.171.255
2310.18.172.0/2310.18.172.1 – 10.18.173.25410.18.173.255
2410.18.174.0/2310.18.174.1 – 10.18.175.25410.18.175.255
2510.18.176.0/2310.18.176.1 – 10.18.177.25410.18.177.255
2610.18.178.0/2310.18.178.1 – 10.18.179.25410.18.179.255
2710.18.180.0/2310.18.180.1 – 10.18.181.25410.18.181.255
2810.18.182.0/2310.18.182.1 – 10.18.183.25410.18.183.255
2910.18.184.0/2310.18.184.1 – 10.18.185.25410.18.185.255
3010.18.186.0/2310.18.186.1 – 10.18.187.25410.18.187.255
3110.18.188.0/2310.18.188.1 – 10.18.189.25410.18.189.255
3210.18.190.0/2310.18.190.1 – 10.18.191.25410.18.191.255
3310.18.192.0/2310.18.192.1 – 10.18.193.25410.18.193.255
3410.18.194.0/2310.18.194.1 – 10.18.195.25410.18.195.255
3510.18.196.0/2310.18.196.1 – 10.18.197.25410.18.197.255
3610.18.198.0/2310.18.198.1 – 10.18.199.25410.18.199.255
3710.18.200.0/2310.18.200.1 – 10.18.201.25410.18.201.255
3810.18.202.0/2310.18.202.1 – 10.18.203.25410.18.203.255
3910.18.204.0/2310.18.204.1 – 10.18.205.25410.18.205.255
4010.18.206.0/2310.18.206.1 – 10.18.207.25410.18.207.255
4110.18.208.0/2310.18.208.1 – 10.18.209.25410.18.209.255
4210.18.210.0/2310.18.210.1 – 10.18.211.25410.18.211.255
4310.18.212.0/2310.18.212.1 – 10.18.213.25410.18.213.255
4410.18.214.0/2310.18.214.1 – 10.18.215.25410.18.215.255
4510.18.216.0/2310.18.216.1 – 10.18.217.25410.18.217.255
4610.18.218.0/2310.18.218.1 – 10.18.219.25410.18.219.255
4710.18.220.0/2310.18.220.1 – 10.18.221.25410.18.221.255
4810.18.222.0/2310.18.222.1 – 10.18.223.25410.18.223.255
4910.18.224.0/2310.18.224.1 – 10.18.225.25410.18.225.255
5010.18.226.0/2310.18.226.1 – 10.18.227.25410.18.227.255
5110.18.228.0/2310.18.228.1 – 10.18.229.25410.18.229.255
5210.18.230.0/2310.18.230.1 – 10.18.231.25410.18.231.255
5310.18.232.0/2310.18.232.1 – 10.18.233.25410.18.233.255
5410.18.234.0/2310.18.234.1 – 10.18.235.25410.18.235.255
5510.18.236.0/2310.18.236.1 – 10.18.237.25410.18.237.255
5610.18.238.0/2310.18.238.1 – 10.18.239.25410.18.239.255
5710.18.240.0/2310.18.240.1 – 10.18.241.25410.18.241.255
5810.18.242.0/2310.18.242.1 – 10.18.243.25410.18.243.255
5910.18.244.0/2310.18.244.1 – 10.18.245.25410.18.245.255
6010.18.246.0/2310.18.246.1 – 10.18.247.25410.18.247.255
6110.18.248.0/2310.18.248.1 – 10.18.249.25410.18.249.255
6210.18.250.0/2310.18.250.1 – 10.18.251.25410.18.251.255
6310.18.252.0/2310.18.252.1 – 10.18.253.25410.18.253.255
6410.18.254.0/2310.18.254.1 – 10.18.255.25410.18.255.255
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 →