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IP subnet calculator

Type an address with its prefix or mask to see the network, its usable range and masks. Split it into smaller subnets, or look up any prefix in the reference tables.

Network10.0.0.0/11
Usable hosts2,097,150
Subnet mask255.224.0.0
Addresses2,097,152
Network address
10.0.0.0
Broadcast address
10.31.255.255
First usable
10.0.0.1
Last usable
10.31.255.254
Usable hosts
2,097,150 (2,097,152 less the network and broadcast addresses)
Subnet mask
255.224.0.0
Wildcard mask
0.31.255.255 (Cisco ACLs, OSPF)
Prefix length
/11
Type
Private (RFC 1918) 10.0.0.0/8
Office and home networks; not routed on the internet
Old class
A (default /8)
As numbers
Hex 0A000000 · Integer 167772160 to 169869311
Reverse DNS zones
0.10.in-addr.arpa
1.10.in-addr.arpa
2.10.in-addr.arpa
3.10.in-addr.arpa
4.10.in-addr.arpa
5.10.in-addr.arpa
6.10.in-addr.arpa
7.10.in-addr.arpa
8.10.in-addr.arpa
9.10.in-addr.arpa
10.10.in-addr.arpa
11.10.in-addr.arpa
12.10.in-addr.arpa
13.10.in-addr.arpa
14.10.in-addr.arpa
15.10.in-addr.arpa
and 16 more
/11 is not on a 8-bit boundary, so it takes 32 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00001010.00000000.00000000.0000000010.0.0.0
Subnet mask11111111.11100000.00000000.00000000255.224.0.0
Network00001010.00000000.00000000.0000000010.0.0.0
Broadcast00001010.00011111.11111111.1111111110.31.255.255
Split into smaller subnets/21
/12 (2)/13 (4)/14 (8)/15 (16)/16 (32)/17 (64)/18 (128)/19 (256)/20 (512)/21 (1,024)/22 (2,048)/23 (4,096)

10.0.0.0/11 makes 1,024 subnets of /21; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
110.0.0.0/2110.0.0.1 to 10.0.7.25410.0.7.2552,046
210.0.8.0/2110.0.8.1 to 10.0.15.25410.0.15.2552,046
310.0.16.0/2110.0.16.1 to 10.0.23.25410.0.23.2552,046
410.0.24.0/2110.0.24.1 to 10.0.31.25410.0.31.2552,046
510.0.32.0/2110.0.32.1 to 10.0.39.25410.0.39.2552,046
610.0.40.0/2110.0.40.1 to 10.0.47.25410.0.47.2552,046
710.0.48.0/2110.0.48.1 to 10.0.55.25410.0.55.2552,046
810.0.56.0/2110.0.56.1 to 10.0.63.25410.0.63.2552,046
910.0.64.0/2110.0.64.1 to 10.0.71.25410.0.71.2552,046
1010.0.72.0/2110.0.72.1 to 10.0.79.25410.0.79.2552,046
1110.0.80.0/2110.0.80.1 to 10.0.87.25410.0.87.2552,046
1210.0.88.0/2110.0.88.1 to 10.0.95.25410.0.95.2552,046
1310.0.96.0/2110.0.96.1 to 10.0.103.25410.0.103.2552,046
1410.0.104.0/2110.0.104.1 to 10.0.111.25410.0.111.2552,046
1510.0.112.0/2110.0.112.1 to 10.0.119.25410.0.119.2552,046
1610.0.120.0/2110.0.120.1 to 10.0.127.25410.0.127.2552,046
1710.0.128.0/2110.0.128.1 to 10.0.135.25410.0.135.2552,046
1810.0.136.0/2110.0.136.1 to 10.0.143.25410.0.143.2552,046
1910.0.144.0/2110.0.144.1 to 10.0.151.25410.0.151.2552,046
2010.0.152.0/2110.0.152.1 to 10.0.159.25410.0.159.2552,046
2110.0.160.0/2110.0.160.1 to 10.0.167.25410.0.167.2552,046
2210.0.168.0/2110.0.168.1 to 10.0.175.25410.0.175.2552,046
2310.0.176.0/2110.0.176.1 to 10.0.183.25410.0.183.2552,046
2410.0.184.0/2110.0.184.1 to 10.0.191.25410.0.191.2552,046
2510.0.192.0/2110.0.192.1 to 10.0.199.25410.0.199.2552,046
2610.0.200.0/2110.0.200.1 to 10.0.207.25410.0.207.2552,046
2710.0.208.0/2110.0.208.1 to 10.0.215.25410.0.215.2552,046
2810.0.216.0/2110.0.216.1 to 10.0.223.25410.0.223.2552,046
2910.0.224.0/2110.0.224.1 to 10.0.231.25410.0.231.2552,046
3010.0.232.0/2110.0.232.1 to 10.0.239.25410.0.239.2552,046
3110.0.240.0/2110.0.240.1 to 10.0.247.25410.0.247.2552,046
3210.0.248.0/2110.0.248.1 to 10.0.255.25410.0.255.2552,046
3310.1.0.0/2110.1.0.1 to 10.1.7.25410.1.7.2552,046
3410.1.8.0/2110.1.8.1 to 10.1.15.25410.1.15.2552,046
3510.1.16.0/2110.1.16.1 to 10.1.23.25410.1.23.2552,046
3610.1.24.0/2110.1.24.1 to 10.1.31.25410.1.31.2552,046
3710.1.32.0/2110.1.32.1 to 10.1.39.25410.1.39.2552,046
3810.1.40.0/2110.1.40.1 to 10.1.47.25410.1.47.2552,046
3910.1.48.0/2110.1.48.1 to 10.1.55.25410.1.55.2552,046
4010.1.56.0/2110.1.56.1 to 10.1.63.25410.1.63.2552,046
4110.1.64.0/2110.1.64.1 to 10.1.71.25410.1.71.2552,046
4210.1.72.0/2110.1.72.1 to 10.1.79.25410.1.79.2552,046
4310.1.80.0/2110.1.80.1 to 10.1.87.25410.1.87.2552,046
4410.1.88.0/2110.1.88.1 to 10.1.95.25410.1.95.2552,046
4510.1.96.0/2110.1.96.1 to 10.1.103.25410.1.103.2552,046
4610.1.104.0/2110.1.104.1 to 10.1.111.25410.1.111.2552,046
4710.1.112.0/2110.1.112.1 to 10.1.119.25410.1.119.2552,046
4810.1.120.0/2110.1.120.1 to 10.1.127.25410.1.127.2552,046
4910.1.128.0/2110.1.128.1 to 10.1.135.25410.1.135.2552,046
5010.1.136.0/2110.1.136.1 to 10.1.143.25410.1.143.2552,046
5110.1.144.0/2110.1.144.1 to 10.1.151.25410.1.151.2552,046
5210.1.152.0/2110.1.152.1 to 10.1.159.25410.1.159.2552,046
5310.1.160.0/2110.1.160.1 to 10.1.167.25410.1.167.2552,046
5410.1.168.0/2110.1.168.1 to 10.1.175.25410.1.175.2552,046
5510.1.176.0/2110.1.176.1 to 10.1.183.25410.1.183.2552,046
5610.1.184.0/2110.1.184.1 to 10.1.191.25410.1.191.2552,046
5710.1.192.0/2110.1.192.1 to 10.1.199.25410.1.199.2552,046
5810.1.200.0/2110.1.200.1 to 10.1.207.25410.1.207.2552,046
5910.1.208.0/2110.1.208.1 to 10.1.215.25410.1.215.2552,046
6010.1.216.0/2110.1.216.1 to 10.1.223.25410.1.223.2552,046
6110.1.224.0/2110.1.224.1 to 10.1.231.25410.1.231.2552,046
6210.1.232.0/2110.1.232.1 to 10.1.239.25410.1.239.2552,046
6310.1.240.0/2110.1.240.1 to 10.1.247.25410.1.247.2552,046
6410.1.248.0/2110.1.248.1 to 10.1.255.25410.1.255.2552,046
6510.2.0.0/2110.2.0.1 to 10.2.7.25410.2.7.2552,046
6610.2.8.0/2110.2.8.1 to 10.2.15.25410.2.15.2552,046
6710.2.16.0/2110.2.16.1 to 10.2.23.25410.2.23.2552,046
6810.2.24.0/2110.2.24.1 to 10.2.31.25410.2.31.2552,046
6910.2.32.0/2110.2.32.1 to 10.2.39.25410.2.39.2552,046
7010.2.40.0/2110.2.40.1 to 10.2.47.25410.2.47.2552,046
7110.2.48.0/2110.2.48.1 to 10.2.55.25410.2.55.2552,046
7210.2.56.0/2110.2.56.1 to 10.2.63.25410.2.63.2552,046
7310.2.64.0/2110.2.64.1 to 10.2.71.25410.2.71.2552,046
7410.2.72.0/2110.2.72.1 to 10.2.79.25410.2.79.2552,046
7510.2.80.0/2110.2.80.1 to 10.2.87.25410.2.87.2552,046
7610.2.88.0/2110.2.88.1 to 10.2.95.25410.2.95.2552,046
7710.2.96.0/2110.2.96.1 to 10.2.103.25410.2.103.2552,046
7810.2.104.0/2110.2.104.1 to 10.2.111.25410.2.111.2552,046
7910.2.112.0/2110.2.112.1 to 10.2.119.25410.2.119.2552,046
8010.2.120.0/2110.2.120.1 to 10.2.127.25410.2.127.2552,046
8110.2.128.0/2110.2.128.1 to 10.2.135.25410.2.135.2552,046
8210.2.136.0/2110.2.136.1 to 10.2.143.25410.2.143.2552,046
8310.2.144.0/2110.2.144.1 to 10.2.151.25410.2.151.2552,046
8410.2.152.0/2110.2.152.1 to 10.2.159.25410.2.159.2552,046
8510.2.160.0/2110.2.160.1 to 10.2.167.25410.2.167.2552,046
8610.2.168.0/2110.2.168.1 to 10.2.175.25410.2.175.2552,046
8710.2.176.0/2110.2.176.1 to 10.2.183.25410.2.183.2552,046
8810.2.184.0/2110.2.184.1 to 10.2.191.25410.2.191.2552,046
8910.2.192.0/2110.2.192.1 to 10.2.199.25410.2.199.2552,046
9010.2.200.0/2110.2.200.1 to 10.2.207.25410.2.207.2552,046
9110.2.208.0/2110.2.208.1 to 10.2.215.25410.2.215.2552,046
9210.2.216.0/2110.2.216.1 to 10.2.223.25410.2.223.2552,046
9310.2.224.0/2110.2.224.1 to 10.2.231.25410.2.231.2552,046
9410.2.232.0/2110.2.232.1 to 10.2.239.25410.2.239.2552,046
9510.2.240.0/2110.2.240.1 to 10.2.247.25410.2.247.2552,046
9610.2.248.0/2110.2.248.1 to 10.2.255.25410.2.255.2552,046
9710.3.0.0/2110.3.0.1 to 10.3.7.25410.3.7.2552,046
9810.3.8.0/2110.3.8.1 to 10.3.15.25410.3.15.2552,046
9910.3.16.0/2110.3.16.1 to 10.3.23.25410.3.23.2552,046
10010.3.24.0/2110.3.24.1 to 10.3.31.25410.3.31.2552,046
10110.3.32.0/2110.3.32.1 to 10.3.39.25410.3.39.2552,046
10210.3.40.0/2110.3.40.1 to 10.3.47.25410.3.47.2552,046
10310.3.48.0/2110.3.48.1 to 10.3.55.25410.3.55.2552,046
10410.3.56.0/2110.3.56.1 to 10.3.63.25410.3.63.2552,046
10510.3.64.0/2110.3.64.1 to 10.3.71.25410.3.71.2552,046
10610.3.72.0/2110.3.72.1 to 10.3.79.25410.3.79.2552,046
10710.3.80.0/2110.3.80.1 to 10.3.87.25410.3.87.2552,046
10810.3.88.0/2110.3.88.1 to 10.3.95.25410.3.95.2552,046
10910.3.96.0/2110.3.96.1 to 10.3.103.25410.3.103.2552,046
11010.3.104.0/2110.3.104.1 to 10.3.111.25410.3.111.2552,046
11110.3.112.0/2110.3.112.1 to 10.3.119.25410.3.119.2552,046
11210.3.120.0/2110.3.120.1 to 10.3.127.25410.3.127.2552,046
11310.3.128.0/2110.3.128.1 to 10.3.135.25410.3.135.2552,046
11410.3.136.0/2110.3.136.1 to 10.3.143.25410.3.143.2552,046
11510.3.144.0/2110.3.144.1 to 10.3.151.25410.3.151.2552,046
11610.3.152.0/2110.3.152.1 to 10.3.159.25410.3.159.2552,046
11710.3.160.0/2110.3.160.1 to 10.3.167.25410.3.167.2552,046
11810.3.168.0/2110.3.168.1 to 10.3.175.25410.3.175.2552,046
11910.3.176.0/2110.3.176.1 to 10.3.183.25410.3.183.2552,046
12010.3.184.0/2110.3.184.1 to 10.3.191.25410.3.191.2552,046
12110.3.192.0/2110.3.192.1 to 10.3.199.25410.3.199.2552,046
12210.3.200.0/2110.3.200.1 to 10.3.207.25410.3.207.2552,046
12310.3.208.0/2110.3.208.1 to 10.3.215.25410.3.215.2552,046
12410.3.216.0/2110.3.216.1 to 10.3.223.25410.3.223.2552,046
12510.3.224.0/2110.3.224.1 to 10.3.231.25410.3.231.2552,046
12610.3.232.0/2110.3.232.1 to 10.3.239.25410.3.239.2552,046
12710.3.240.0/2110.3.240.1 to 10.3.247.25410.3.247.2552,046
12810.3.248.0/2110.3.248.1 to 10.3.255.25410.3.255.2552,046
12910.4.0.0/2110.4.0.1 to 10.4.7.25410.4.7.2552,046
13010.4.8.0/2110.4.8.1 to 10.4.15.25410.4.15.2552,046
13110.4.16.0/2110.4.16.1 to 10.4.23.25410.4.23.2552,046
13210.4.24.0/2110.4.24.1 to 10.4.31.25410.4.31.2552,046
13310.4.32.0/2110.4.32.1 to 10.4.39.25410.4.39.2552,046
13410.4.40.0/2110.4.40.1 to 10.4.47.25410.4.47.2552,046
13510.4.48.0/2110.4.48.1 to 10.4.55.25410.4.55.2552,046
13610.4.56.0/2110.4.56.1 to 10.4.63.25410.4.63.2552,046
13710.4.64.0/2110.4.64.1 to 10.4.71.25410.4.71.2552,046
13810.4.72.0/2110.4.72.1 to 10.4.79.25410.4.79.2552,046
13910.4.80.0/2110.4.80.1 to 10.4.87.25410.4.87.2552,046
14010.4.88.0/2110.4.88.1 to 10.4.95.25410.4.95.2552,046
14110.4.96.0/2110.4.96.1 to 10.4.103.25410.4.103.2552,046
14210.4.104.0/2110.4.104.1 to 10.4.111.25410.4.111.2552,046
14310.4.112.0/2110.4.112.1 to 10.4.119.25410.4.119.2552,046
14410.4.120.0/2110.4.120.1 to 10.4.127.25410.4.127.2552,046
14510.4.128.0/2110.4.128.1 to 10.4.135.25410.4.135.2552,046
14610.4.136.0/2110.4.136.1 to 10.4.143.25410.4.143.2552,046
14710.4.144.0/2110.4.144.1 to 10.4.151.25410.4.151.2552,046
14810.4.152.0/2110.4.152.1 to 10.4.159.25410.4.159.2552,046
14910.4.160.0/2110.4.160.1 to 10.4.167.25410.4.167.2552,046
15010.4.168.0/2110.4.168.1 to 10.4.175.25410.4.175.2552,046
15110.4.176.0/2110.4.176.1 to 10.4.183.25410.4.183.2552,046
15210.4.184.0/2110.4.184.1 to 10.4.191.25410.4.191.2552,046
15310.4.192.0/2110.4.192.1 to 10.4.199.25410.4.199.2552,046
15410.4.200.0/2110.4.200.1 to 10.4.207.25410.4.207.2552,046
15510.4.208.0/2110.4.208.1 to 10.4.215.25410.4.215.2552,046
15610.4.216.0/2110.4.216.1 to 10.4.223.25410.4.223.2552,046
15710.4.224.0/2110.4.224.1 to 10.4.231.25410.4.231.2552,046
15810.4.232.0/2110.4.232.1 to 10.4.239.25410.4.239.2552,046
15910.4.240.0/2110.4.240.1 to 10.4.247.25410.4.247.2552,046
16010.4.248.0/2110.4.248.1 to 10.4.255.25410.4.255.2552,046
16110.5.0.0/2110.5.0.1 to 10.5.7.25410.5.7.2552,046
16210.5.8.0/2110.5.8.1 to 10.5.15.25410.5.15.2552,046
16310.5.16.0/2110.5.16.1 to 10.5.23.25410.5.23.2552,046
16410.5.24.0/2110.5.24.1 to 10.5.31.25410.5.31.2552,046
16510.5.32.0/2110.5.32.1 to 10.5.39.25410.5.39.2552,046
16610.5.40.0/2110.5.40.1 to 10.5.47.25410.5.47.2552,046
16710.5.48.0/2110.5.48.1 to 10.5.55.25410.5.55.2552,046
16810.5.56.0/2110.5.56.1 to 10.5.63.25410.5.63.2552,046
16910.5.64.0/2110.5.64.1 to 10.5.71.25410.5.71.2552,046
17010.5.72.0/2110.5.72.1 to 10.5.79.25410.5.79.2552,046
17110.5.80.0/2110.5.80.1 to 10.5.87.25410.5.87.2552,046
17210.5.88.0/2110.5.88.1 to 10.5.95.25410.5.95.2552,046
17310.5.96.0/2110.5.96.1 to 10.5.103.25410.5.103.2552,046
17410.5.104.0/2110.5.104.1 to 10.5.111.25410.5.111.2552,046
17510.5.112.0/2110.5.112.1 to 10.5.119.25410.5.119.2552,046
17610.5.120.0/2110.5.120.1 to 10.5.127.25410.5.127.2552,046
17710.5.128.0/2110.5.128.1 to 10.5.135.25410.5.135.2552,046
17810.5.136.0/2110.5.136.1 to 10.5.143.25410.5.143.2552,046
17910.5.144.0/2110.5.144.1 to 10.5.151.25410.5.151.2552,046
18010.5.152.0/2110.5.152.1 to 10.5.159.25410.5.159.2552,046
18110.5.160.0/2110.5.160.1 to 10.5.167.25410.5.167.2552,046
18210.5.168.0/2110.5.168.1 to 10.5.175.25410.5.175.2552,046
18310.5.176.0/2110.5.176.1 to 10.5.183.25410.5.183.2552,046
18410.5.184.0/2110.5.184.1 to 10.5.191.25410.5.191.2552,046
18510.5.192.0/2110.5.192.1 to 10.5.199.25410.5.199.2552,046
18610.5.200.0/2110.5.200.1 to 10.5.207.25410.5.207.2552,046
18710.5.208.0/2110.5.208.1 to 10.5.215.25410.5.215.2552,046
18810.5.216.0/2110.5.216.1 to 10.5.223.25410.5.223.2552,046
18910.5.224.0/2110.5.224.1 to 10.5.231.25410.5.231.2552,046
19010.5.232.0/2110.5.232.1 to 10.5.239.25410.5.239.2552,046
19110.5.240.0/2110.5.240.1 to 10.5.247.25410.5.247.2552,046
19210.5.248.0/2110.5.248.1 to 10.5.255.25410.5.255.2552,046
19310.6.0.0/2110.6.0.1 to 10.6.7.25410.6.7.2552,046
19410.6.8.0/2110.6.8.1 to 10.6.15.25410.6.15.2552,046
19510.6.16.0/2110.6.16.1 to 10.6.23.25410.6.23.2552,046
19610.6.24.0/2110.6.24.1 to 10.6.31.25410.6.31.2552,046
19710.6.32.0/2110.6.32.1 to 10.6.39.25410.6.39.2552,046
19810.6.40.0/2110.6.40.1 to 10.6.47.25410.6.47.2552,046
19910.6.48.0/2110.6.48.1 to 10.6.55.25410.6.55.2552,046
20010.6.56.0/2110.6.56.1 to 10.6.63.25410.6.63.2552,046
20110.6.64.0/2110.6.64.1 to 10.6.71.25410.6.71.2552,046
20210.6.72.0/2110.6.72.1 to 10.6.79.25410.6.79.2552,046
20310.6.80.0/2110.6.80.1 to 10.6.87.25410.6.87.2552,046
20410.6.88.0/2110.6.88.1 to 10.6.95.25410.6.95.2552,046
20510.6.96.0/2110.6.96.1 to 10.6.103.25410.6.103.2552,046
20610.6.104.0/2110.6.104.1 to 10.6.111.25410.6.111.2552,046
20710.6.112.0/2110.6.112.1 to 10.6.119.25410.6.119.2552,046
20810.6.120.0/2110.6.120.1 to 10.6.127.25410.6.127.2552,046
20910.6.128.0/2110.6.128.1 to 10.6.135.25410.6.135.2552,046
21010.6.136.0/2110.6.136.1 to 10.6.143.25410.6.143.2552,046
21110.6.144.0/2110.6.144.1 to 10.6.151.25410.6.151.2552,046
21210.6.152.0/2110.6.152.1 to 10.6.159.25410.6.159.2552,046
21310.6.160.0/2110.6.160.1 to 10.6.167.25410.6.167.2552,046
21410.6.168.0/2110.6.168.1 to 10.6.175.25410.6.175.2552,046
21510.6.176.0/2110.6.176.1 to 10.6.183.25410.6.183.2552,046
21610.6.184.0/2110.6.184.1 to 10.6.191.25410.6.191.2552,046
21710.6.192.0/2110.6.192.1 to 10.6.199.25410.6.199.2552,046
21810.6.200.0/2110.6.200.1 to 10.6.207.25410.6.207.2552,046
21910.6.208.0/2110.6.208.1 to 10.6.215.25410.6.215.2552,046
22010.6.216.0/2110.6.216.1 to 10.6.223.25410.6.223.2552,046
22110.6.224.0/2110.6.224.1 to 10.6.231.25410.6.231.2552,046
22210.6.232.0/2110.6.232.1 to 10.6.239.25410.6.239.2552,046
22310.6.240.0/2110.6.240.1 to 10.6.247.25410.6.247.2552,046
22410.6.248.0/2110.6.248.1 to 10.6.255.25410.6.255.2552,046
22510.7.0.0/2110.7.0.1 to 10.7.7.25410.7.7.2552,046
22610.7.8.0/2110.7.8.1 to 10.7.15.25410.7.15.2552,046
22710.7.16.0/2110.7.16.1 to 10.7.23.25410.7.23.2552,046
22810.7.24.0/2110.7.24.1 to 10.7.31.25410.7.31.2552,046
22910.7.32.0/2110.7.32.1 to 10.7.39.25410.7.39.2552,046
23010.7.40.0/2110.7.40.1 to 10.7.47.25410.7.47.2552,046
23110.7.48.0/2110.7.48.1 to 10.7.55.25410.7.55.2552,046
23210.7.56.0/2110.7.56.1 to 10.7.63.25410.7.63.2552,046
23310.7.64.0/2110.7.64.1 to 10.7.71.25410.7.71.2552,046
23410.7.72.0/2110.7.72.1 to 10.7.79.25410.7.79.2552,046
23510.7.80.0/2110.7.80.1 to 10.7.87.25410.7.87.2552,046
23610.7.88.0/2110.7.88.1 to 10.7.95.25410.7.95.2552,046
23710.7.96.0/2110.7.96.1 to 10.7.103.25410.7.103.2552,046
23810.7.104.0/2110.7.104.1 to 10.7.111.25410.7.111.2552,046
23910.7.112.0/2110.7.112.1 to 10.7.119.25410.7.119.2552,046
24010.7.120.0/2110.7.120.1 to 10.7.127.25410.7.127.2552,046
24110.7.128.0/2110.7.128.1 to 10.7.135.25410.7.135.2552,046
24210.7.136.0/2110.7.136.1 to 10.7.143.25410.7.143.2552,046
24310.7.144.0/2110.7.144.1 to 10.7.151.25410.7.151.2552,046
24410.7.152.0/2110.7.152.1 to 10.7.159.25410.7.159.2552,046
24510.7.160.0/2110.7.160.1 to 10.7.167.25410.7.167.2552,046
24610.7.168.0/2110.7.168.1 to 10.7.175.25410.7.175.2552,046
24710.7.176.0/2110.7.176.1 to 10.7.183.25410.7.183.2552,046
24810.7.184.0/2110.7.184.1 to 10.7.191.25410.7.191.2552,046
24910.7.192.0/2110.7.192.1 to 10.7.199.25410.7.199.2552,046
25010.7.200.0/2110.7.200.1 to 10.7.207.25410.7.207.2552,046
25110.7.208.0/2110.7.208.1 to 10.7.215.25410.7.215.2552,046
25210.7.216.0/2110.7.216.1 to 10.7.223.25410.7.223.2552,046
25310.7.224.0/2110.7.224.1 to 10.7.231.25410.7.231.2552,046
25410.7.232.0/2110.7.232.1 to 10.7.239.25410.7.239.2552,046
25510.7.240.0/2110.7.240.1 to 10.7.247.25410.7.247.2552,046
25610.7.248.0/2110.7.248.1 to 10.7.255.25410.7.255.2552,046

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.