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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)10.81.0.0/17
network10.81.0.0/17
broadcast10.81.127.255
first host10.81.0.1
last host10.81.127.254
subnet mask255.255.128.0
wildcard0.0.127.255
addresses32,768
usable hosts32,766
classA
ipcalc 10.81.0.0/17
address00001010.01010001.00000000.00000000
subnet mask11111111.11111111.10000000.00000000
network00001010.01010001.00000000.00000000
broadcast00001010.01010001.01111111.11111111
green = network part, grey = host part
hex0x0a510000
decimal173080576
reverse dns0.0.81.10.in-addr.arpa
ipv4-mapped::ffff:a51:0

/17 split into /23 · 64 subnets

close ×
#networkhost rangebroadcast
110.81.0.0/2310.81.0.1 – 10.81.1.25410.81.1.255
210.81.2.0/2310.81.2.1 – 10.81.3.25410.81.3.255
310.81.4.0/2310.81.4.1 – 10.81.5.25410.81.5.255
410.81.6.0/2310.81.6.1 – 10.81.7.25410.81.7.255
510.81.8.0/2310.81.8.1 – 10.81.9.25410.81.9.255
610.81.10.0/2310.81.10.1 – 10.81.11.25410.81.11.255
710.81.12.0/2310.81.12.1 – 10.81.13.25410.81.13.255
810.81.14.0/2310.81.14.1 – 10.81.15.25410.81.15.255
910.81.16.0/2310.81.16.1 – 10.81.17.25410.81.17.255
1010.81.18.0/2310.81.18.1 – 10.81.19.25410.81.19.255
1110.81.20.0/2310.81.20.1 – 10.81.21.25410.81.21.255
1210.81.22.0/2310.81.22.1 – 10.81.23.25410.81.23.255
1310.81.24.0/2310.81.24.1 – 10.81.25.25410.81.25.255
1410.81.26.0/2310.81.26.1 – 10.81.27.25410.81.27.255
1510.81.28.0/2310.81.28.1 – 10.81.29.25410.81.29.255
1610.81.30.0/2310.81.30.1 – 10.81.31.25410.81.31.255
1710.81.32.0/2310.81.32.1 – 10.81.33.25410.81.33.255
1810.81.34.0/2310.81.34.1 – 10.81.35.25410.81.35.255
1910.81.36.0/2310.81.36.1 – 10.81.37.25410.81.37.255
2010.81.38.0/2310.81.38.1 – 10.81.39.25410.81.39.255
2110.81.40.0/2310.81.40.1 – 10.81.41.25410.81.41.255
2210.81.42.0/2310.81.42.1 – 10.81.43.25410.81.43.255
2310.81.44.0/2310.81.44.1 – 10.81.45.25410.81.45.255
2410.81.46.0/2310.81.46.1 – 10.81.47.25410.81.47.255
2510.81.48.0/2310.81.48.1 – 10.81.49.25410.81.49.255
2610.81.50.0/2310.81.50.1 – 10.81.51.25410.81.51.255
2710.81.52.0/2310.81.52.1 – 10.81.53.25410.81.53.255
2810.81.54.0/2310.81.54.1 – 10.81.55.25410.81.55.255
2910.81.56.0/2310.81.56.1 – 10.81.57.25410.81.57.255
3010.81.58.0/2310.81.58.1 – 10.81.59.25410.81.59.255
3110.81.60.0/2310.81.60.1 – 10.81.61.25410.81.61.255
3210.81.62.0/2310.81.62.1 – 10.81.63.25410.81.63.255
3310.81.64.0/2310.81.64.1 – 10.81.65.25410.81.65.255
3410.81.66.0/2310.81.66.1 – 10.81.67.25410.81.67.255
3510.81.68.0/2310.81.68.1 – 10.81.69.25410.81.69.255
3610.81.70.0/2310.81.70.1 – 10.81.71.25410.81.71.255
3710.81.72.0/2310.81.72.1 – 10.81.73.25410.81.73.255
3810.81.74.0/2310.81.74.1 – 10.81.75.25410.81.75.255
3910.81.76.0/2310.81.76.1 – 10.81.77.25410.81.77.255
4010.81.78.0/2310.81.78.1 – 10.81.79.25410.81.79.255
4110.81.80.0/2310.81.80.1 – 10.81.81.25410.81.81.255
4210.81.82.0/2310.81.82.1 – 10.81.83.25410.81.83.255
4310.81.84.0/2310.81.84.1 – 10.81.85.25410.81.85.255
4410.81.86.0/2310.81.86.1 – 10.81.87.25410.81.87.255
4510.81.88.0/2310.81.88.1 – 10.81.89.25410.81.89.255
4610.81.90.0/2310.81.90.1 – 10.81.91.25410.81.91.255
4710.81.92.0/2310.81.92.1 – 10.81.93.25410.81.93.255
4810.81.94.0/2310.81.94.1 – 10.81.95.25410.81.95.255
4910.81.96.0/2310.81.96.1 – 10.81.97.25410.81.97.255
5010.81.98.0/2310.81.98.1 – 10.81.99.25410.81.99.255
5110.81.100.0/2310.81.100.1 – 10.81.101.25410.81.101.255
5210.81.102.0/2310.81.102.1 – 10.81.103.25410.81.103.255
5310.81.104.0/2310.81.104.1 – 10.81.105.25410.81.105.255
5410.81.106.0/2310.81.106.1 – 10.81.107.25410.81.107.255
5510.81.108.0/2310.81.108.1 – 10.81.109.25410.81.109.255
5610.81.110.0/2310.81.110.1 – 10.81.111.25410.81.111.255
5710.81.112.0/2310.81.112.1 – 10.81.113.25410.81.113.255
5810.81.114.0/2310.81.114.1 – 10.81.115.25410.81.115.255
5910.81.116.0/2310.81.116.1 – 10.81.117.25410.81.117.255
6010.81.118.0/2310.81.118.1 – 10.81.119.25410.81.119.255
6110.81.120.0/2310.81.120.1 – 10.81.121.25410.81.121.255
6210.81.122.0/2310.81.122.1 – 10.81.123.25410.81.123.255
6310.81.124.0/2310.81.124.1 – 10.81.125.25410.81.125.255
6410.81.126.0/2310.81.126.1 – 10.81.127.25410.81.127.255
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 →