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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.

Network63.0.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
63.0.0.0
Broadcast address
63.63.255.255
First usable
63.0.0.1
Last usable
63.63.255.254
Usable hosts
4,194,302 (4,194,304 less the network and broadcast addresses)
Subnet mask
255.192.0.0
Wildcard mask
0.63.255.255 (Cisco ACLs, OSPF)
Prefix length
/10
Type
Public public
Old class
A (default /8)
As numbers
Hex 3F000000 · Integer 1056964608 to 1061158911
Reverse DNS zones
0.63.in-addr.arpa
1.63.in-addr.arpa
2.63.in-addr.arpa
3.63.in-addr.arpa
4.63.in-addr.arpa
5.63.in-addr.arpa
6.63.in-addr.arpa
7.63.in-addr.arpa
8.63.in-addr.arpa
9.63.in-addr.arpa
10.63.in-addr.arpa
11.63.in-addr.arpa
12.63.in-addr.arpa
13.63.in-addr.arpa
14.63.in-addr.arpa
15.63.in-addr.arpa
and 48 more
/10 is not on a 8-bit boundary, so it takes 64 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00111111.00000000.00000000.0000000063.0.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00111111.00000000.00000000.0000000063.0.0.0
Broadcast00111111.00111111.11111111.1111111163.63.255.255
Split into smaller subnets/22
/11 (2)/12 (4)/13 (8)/14 (16)/15 (32)/16 (64)/17 (128)/18 (256)/19 (512)/20 (1,024)/21 (2,048)/22 (4,096)

63.0.0.0/10 makes 4,096 subnets of /22; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
163.0.0.0/2263.0.0.1 to 63.0.3.25463.0.3.2551,022
263.0.4.0/2263.0.4.1 to 63.0.7.25463.0.7.2551,022
363.0.8.0/2263.0.8.1 to 63.0.11.25463.0.11.2551,022
463.0.12.0/2263.0.12.1 to 63.0.15.25463.0.15.2551,022
563.0.16.0/2263.0.16.1 to 63.0.19.25463.0.19.2551,022
663.0.20.0/2263.0.20.1 to 63.0.23.25463.0.23.2551,022
763.0.24.0/2263.0.24.1 to 63.0.27.25463.0.27.2551,022
863.0.28.0/2263.0.28.1 to 63.0.31.25463.0.31.2551,022
963.0.32.0/2263.0.32.1 to 63.0.35.25463.0.35.2551,022
1063.0.36.0/2263.0.36.1 to 63.0.39.25463.0.39.2551,022
1163.0.40.0/2263.0.40.1 to 63.0.43.25463.0.43.2551,022
1263.0.44.0/2263.0.44.1 to 63.0.47.25463.0.47.2551,022
1363.0.48.0/2263.0.48.1 to 63.0.51.25463.0.51.2551,022
1463.0.52.0/2263.0.52.1 to 63.0.55.25463.0.55.2551,022
1563.0.56.0/2263.0.56.1 to 63.0.59.25463.0.59.2551,022
1663.0.60.0/2263.0.60.1 to 63.0.63.25463.0.63.2551,022
1763.0.64.0/2263.0.64.1 to 63.0.67.25463.0.67.2551,022
1863.0.68.0/2263.0.68.1 to 63.0.71.25463.0.71.2551,022
1963.0.72.0/2263.0.72.1 to 63.0.75.25463.0.75.2551,022
2063.0.76.0/2263.0.76.1 to 63.0.79.25463.0.79.2551,022
2163.0.80.0/2263.0.80.1 to 63.0.83.25463.0.83.2551,022
2263.0.84.0/2263.0.84.1 to 63.0.87.25463.0.87.2551,022
2363.0.88.0/2263.0.88.1 to 63.0.91.25463.0.91.2551,022
2463.0.92.0/2263.0.92.1 to 63.0.95.25463.0.95.2551,022
2563.0.96.0/2263.0.96.1 to 63.0.99.25463.0.99.2551,022
2663.0.100.0/2263.0.100.1 to 63.0.103.25463.0.103.2551,022
2763.0.104.0/2263.0.104.1 to 63.0.107.25463.0.107.2551,022
2863.0.108.0/2263.0.108.1 to 63.0.111.25463.0.111.2551,022
2963.0.112.0/2263.0.112.1 to 63.0.115.25463.0.115.2551,022
3063.0.116.0/2263.0.116.1 to 63.0.119.25463.0.119.2551,022
3163.0.120.0/2263.0.120.1 to 63.0.123.25463.0.123.2551,022
3263.0.124.0/2263.0.124.1 to 63.0.127.25463.0.127.2551,022
3363.0.128.0/2263.0.128.1 to 63.0.131.25463.0.131.2551,022
3463.0.132.0/2263.0.132.1 to 63.0.135.25463.0.135.2551,022
3563.0.136.0/2263.0.136.1 to 63.0.139.25463.0.139.2551,022
3663.0.140.0/2263.0.140.1 to 63.0.143.25463.0.143.2551,022
3763.0.144.0/2263.0.144.1 to 63.0.147.25463.0.147.2551,022
3863.0.148.0/2263.0.148.1 to 63.0.151.25463.0.151.2551,022
3963.0.152.0/2263.0.152.1 to 63.0.155.25463.0.155.2551,022
4063.0.156.0/2263.0.156.1 to 63.0.159.25463.0.159.2551,022
4163.0.160.0/2263.0.160.1 to 63.0.163.25463.0.163.2551,022
4263.0.164.0/2263.0.164.1 to 63.0.167.25463.0.167.2551,022
4363.0.168.0/2263.0.168.1 to 63.0.171.25463.0.171.2551,022
4463.0.172.0/2263.0.172.1 to 63.0.175.25463.0.175.2551,022
4563.0.176.0/2263.0.176.1 to 63.0.179.25463.0.179.2551,022
4663.0.180.0/2263.0.180.1 to 63.0.183.25463.0.183.2551,022
4763.0.184.0/2263.0.184.1 to 63.0.187.25463.0.187.2551,022
4863.0.188.0/2263.0.188.1 to 63.0.191.25463.0.191.2551,022
4963.0.192.0/2263.0.192.1 to 63.0.195.25463.0.195.2551,022
5063.0.196.0/2263.0.196.1 to 63.0.199.25463.0.199.2551,022
5163.0.200.0/2263.0.200.1 to 63.0.203.25463.0.203.2551,022
5263.0.204.0/2263.0.204.1 to 63.0.207.25463.0.207.2551,022
5363.0.208.0/2263.0.208.1 to 63.0.211.25463.0.211.2551,022
5463.0.212.0/2263.0.212.1 to 63.0.215.25463.0.215.2551,022
5563.0.216.0/2263.0.216.1 to 63.0.219.25463.0.219.2551,022
5663.0.220.0/2263.0.220.1 to 63.0.223.25463.0.223.2551,022
5763.0.224.0/2263.0.224.1 to 63.0.227.25463.0.227.2551,022
5863.0.228.0/2263.0.228.1 to 63.0.231.25463.0.231.2551,022
5963.0.232.0/2263.0.232.1 to 63.0.235.25463.0.235.2551,022
6063.0.236.0/2263.0.236.1 to 63.0.239.25463.0.239.2551,022
6163.0.240.0/2263.0.240.1 to 63.0.243.25463.0.243.2551,022
6263.0.244.0/2263.0.244.1 to 63.0.247.25463.0.247.2551,022
6363.0.248.0/2263.0.248.1 to 63.0.251.25463.0.251.2551,022
6463.0.252.0/2263.0.252.1 to 63.0.255.25463.0.255.2551,022
6563.1.0.0/2263.1.0.1 to 63.1.3.25463.1.3.2551,022
6663.1.4.0/2263.1.4.1 to 63.1.7.25463.1.7.2551,022
6763.1.8.0/2263.1.8.1 to 63.1.11.25463.1.11.2551,022
6863.1.12.0/2263.1.12.1 to 63.1.15.25463.1.15.2551,022
6963.1.16.0/2263.1.16.1 to 63.1.19.25463.1.19.2551,022
7063.1.20.0/2263.1.20.1 to 63.1.23.25463.1.23.2551,022
7163.1.24.0/2263.1.24.1 to 63.1.27.25463.1.27.2551,022
7263.1.28.0/2263.1.28.1 to 63.1.31.25463.1.31.2551,022
7363.1.32.0/2263.1.32.1 to 63.1.35.25463.1.35.2551,022
7463.1.36.0/2263.1.36.1 to 63.1.39.25463.1.39.2551,022
7563.1.40.0/2263.1.40.1 to 63.1.43.25463.1.43.2551,022
7663.1.44.0/2263.1.44.1 to 63.1.47.25463.1.47.2551,022
7763.1.48.0/2263.1.48.1 to 63.1.51.25463.1.51.2551,022
7863.1.52.0/2263.1.52.1 to 63.1.55.25463.1.55.2551,022
7963.1.56.0/2263.1.56.1 to 63.1.59.25463.1.59.2551,022
8063.1.60.0/2263.1.60.1 to 63.1.63.25463.1.63.2551,022
8163.1.64.0/2263.1.64.1 to 63.1.67.25463.1.67.2551,022
8263.1.68.0/2263.1.68.1 to 63.1.71.25463.1.71.2551,022
8363.1.72.0/2263.1.72.1 to 63.1.75.25463.1.75.2551,022
8463.1.76.0/2263.1.76.1 to 63.1.79.25463.1.79.2551,022
8563.1.80.0/2263.1.80.1 to 63.1.83.25463.1.83.2551,022
8663.1.84.0/2263.1.84.1 to 63.1.87.25463.1.87.2551,022
8763.1.88.0/2263.1.88.1 to 63.1.91.25463.1.91.2551,022
8863.1.92.0/2263.1.92.1 to 63.1.95.25463.1.95.2551,022
8963.1.96.0/2263.1.96.1 to 63.1.99.25463.1.99.2551,022
9063.1.100.0/2263.1.100.1 to 63.1.103.25463.1.103.2551,022
9163.1.104.0/2263.1.104.1 to 63.1.107.25463.1.107.2551,022
9263.1.108.0/2263.1.108.1 to 63.1.111.25463.1.111.2551,022
9363.1.112.0/2263.1.112.1 to 63.1.115.25463.1.115.2551,022
9463.1.116.0/2263.1.116.1 to 63.1.119.25463.1.119.2551,022
9563.1.120.0/2263.1.120.1 to 63.1.123.25463.1.123.2551,022
9663.1.124.0/2263.1.124.1 to 63.1.127.25463.1.127.2551,022
9763.1.128.0/2263.1.128.1 to 63.1.131.25463.1.131.2551,022
9863.1.132.0/2263.1.132.1 to 63.1.135.25463.1.135.2551,022
9963.1.136.0/2263.1.136.1 to 63.1.139.25463.1.139.2551,022
10063.1.140.0/2263.1.140.1 to 63.1.143.25463.1.143.2551,022
10163.1.144.0/2263.1.144.1 to 63.1.147.25463.1.147.2551,022
10263.1.148.0/2263.1.148.1 to 63.1.151.25463.1.151.2551,022
10363.1.152.0/2263.1.152.1 to 63.1.155.25463.1.155.2551,022
10463.1.156.0/2263.1.156.1 to 63.1.159.25463.1.159.2551,022
10563.1.160.0/2263.1.160.1 to 63.1.163.25463.1.163.2551,022
10663.1.164.0/2263.1.164.1 to 63.1.167.25463.1.167.2551,022
10763.1.168.0/2263.1.168.1 to 63.1.171.25463.1.171.2551,022
10863.1.172.0/2263.1.172.1 to 63.1.175.25463.1.175.2551,022
10963.1.176.0/2263.1.176.1 to 63.1.179.25463.1.179.2551,022
11063.1.180.0/2263.1.180.1 to 63.1.183.25463.1.183.2551,022
11163.1.184.0/2263.1.184.1 to 63.1.187.25463.1.187.2551,022
11263.1.188.0/2263.1.188.1 to 63.1.191.25463.1.191.2551,022
11363.1.192.0/2263.1.192.1 to 63.1.195.25463.1.195.2551,022
11463.1.196.0/2263.1.196.1 to 63.1.199.25463.1.199.2551,022
11563.1.200.0/2263.1.200.1 to 63.1.203.25463.1.203.2551,022
11663.1.204.0/2263.1.204.1 to 63.1.207.25463.1.207.2551,022
11763.1.208.0/2263.1.208.1 to 63.1.211.25463.1.211.2551,022
11863.1.212.0/2263.1.212.1 to 63.1.215.25463.1.215.2551,022
11963.1.216.0/2263.1.216.1 to 63.1.219.25463.1.219.2551,022
12063.1.220.0/2263.1.220.1 to 63.1.223.25463.1.223.2551,022
12163.1.224.0/2263.1.224.1 to 63.1.227.25463.1.227.2551,022
12263.1.228.0/2263.1.228.1 to 63.1.231.25463.1.231.2551,022
12363.1.232.0/2263.1.232.1 to 63.1.235.25463.1.235.2551,022
12463.1.236.0/2263.1.236.1 to 63.1.239.25463.1.239.2551,022
12563.1.240.0/2263.1.240.1 to 63.1.243.25463.1.243.2551,022
12663.1.244.0/2263.1.244.1 to 63.1.247.25463.1.247.2551,022
12763.1.248.0/2263.1.248.1 to 63.1.251.25463.1.251.2551,022
12863.1.252.0/2263.1.252.1 to 63.1.255.25463.1.255.2551,022
12963.2.0.0/2263.2.0.1 to 63.2.3.25463.2.3.2551,022
13063.2.4.0/2263.2.4.1 to 63.2.7.25463.2.7.2551,022
13163.2.8.0/2263.2.8.1 to 63.2.11.25463.2.11.2551,022
13263.2.12.0/2263.2.12.1 to 63.2.15.25463.2.15.2551,022
13363.2.16.0/2263.2.16.1 to 63.2.19.25463.2.19.2551,022
13463.2.20.0/2263.2.20.1 to 63.2.23.25463.2.23.2551,022
13563.2.24.0/2263.2.24.1 to 63.2.27.25463.2.27.2551,022
13663.2.28.0/2263.2.28.1 to 63.2.31.25463.2.31.2551,022
13763.2.32.0/2263.2.32.1 to 63.2.35.25463.2.35.2551,022
13863.2.36.0/2263.2.36.1 to 63.2.39.25463.2.39.2551,022
13963.2.40.0/2263.2.40.1 to 63.2.43.25463.2.43.2551,022
14063.2.44.0/2263.2.44.1 to 63.2.47.25463.2.47.2551,022
14163.2.48.0/2263.2.48.1 to 63.2.51.25463.2.51.2551,022
14263.2.52.0/2263.2.52.1 to 63.2.55.25463.2.55.2551,022
14363.2.56.0/2263.2.56.1 to 63.2.59.25463.2.59.2551,022
14463.2.60.0/2263.2.60.1 to 63.2.63.25463.2.63.2551,022
14563.2.64.0/2263.2.64.1 to 63.2.67.25463.2.67.2551,022
14663.2.68.0/2263.2.68.1 to 63.2.71.25463.2.71.2551,022
14763.2.72.0/2263.2.72.1 to 63.2.75.25463.2.75.2551,022
14863.2.76.0/2263.2.76.1 to 63.2.79.25463.2.79.2551,022
14963.2.80.0/2263.2.80.1 to 63.2.83.25463.2.83.2551,022
15063.2.84.0/2263.2.84.1 to 63.2.87.25463.2.87.2551,022
15163.2.88.0/2263.2.88.1 to 63.2.91.25463.2.91.2551,022
15263.2.92.0/2263.2.92.1 to 63.2.95.25463.2.95.2551,022
15363.2.96.0/2263.2.96.1 to 63.2.99.25463.2.99.2551,022
15463.2.100.0/2263.2.100.1 to 63.2.103.25463.2.103.2551,022
15563.2.104.0/2263.2.104.1 to 63.2.107.25463.2.107.2551,022
15663.2.108.0/2263.2.108.1 to 63.2.111.25463.2.111.2551,022
15763.2.112.0/2263.2.112.1 to 63.2.115.25463.2.115.2551,022
15863.2.116.0/2263.2.116.1 to 63.2.119.25463.2.119.2551,022
15963.2.120.0/2263.2.120.1 to 63.2.123.25463.2.123.2551,022
16063.2.124.0/2263.2.124.1 to 63.2.127.25463.2.127.2551,022
16163.2.128.0/2263.2.128.1 to 63.2.131.25463.2.131.2551,022
16263.2.132.0/2263.2.132.1 to 63.2.135.25463.2.135.2551,022
16363.2.136.0/2263.2.136.1 to 63.2.139.25463.2.139.2551,022
16463.2.140.0/2263.2.140.1 to 63.2.143.25463.2.143.2551,022
16563.2.144.0/2263.2.144.1 to 63.2.147.25463.2.147.2551,022
16663.2.148.0/2263.2.148.1 to 63.2.151.25463.2.151.2551,022
16763.2.152.0/2263.2.152.1 to 63.2.155.25463.2.155.2551,022
16863.2.156.0/2263.2.156.1 to 63.2.159.25463.2.159.2551,022
16963.2.160.0/2263.2.160.1 to 63.2.163.25463.2.163.2551,022
17063.2.164.0/2263.2.164.1 to 63.2.167.25463.2.167.2551,022
17163.2.168.0/2263.2.168.1 to 63.2.171.25463.2.171.2551,022
17263.2.172.0/2263.2.172.1 to 63.2.175.25463.2.175.2551,022
17363.2.176.0/2263.2.176.1 to 63.2.179.25463.2.179.2551,022
17463.2.180.0/2263.2.180.1 to 63.2.183.25463.2.183.2551,022
17563.2.184.0/2263.2.184.1 to 63.2.187.25463.2.187.2551,022
17663.2.188.0/2263.2.188.1 to 63.2.191.25463.2.191.2551,022
17763.2.192.0/2263.2.192.1 to 63.2.195.25463.2.195.2551,022
17863.2.196.0/2263.2.196.1 to 63.2.199.25463.2.199.2551,022
17963.2.200.0/2263.2.200.1 to 63.2.203.25463.2.203.2551,022
18063.2.204.0/2263.2.204.1 to 63.2.207.25463.2.207.2551,022
18163.2.208.0/2263.2.208.1 to 63.2.211.25463.2.211.2551,022
18263.2.212.0/2263.2.212.1 to 63.2.215.25463.2.215.2551,022
18363.2.216.0/2263.2.216.1 to 63.2.219.25463.2.219.2551,022
18463.2.220.0/2263.2.220.1 to 63.2.223.25463.2.223.2551,022
18563.2.224.0/2263.2.224.1 to 63.2.227.25463.2.227.2551,022
18663.2.228.0/2263.2.228.1 to 63.2.231.25463.2.231.2551,022
18763.2.232.0/2263.2.232.1 to 63.2.235.25463.2.235.2551,022
18863.2.236.0/2263.2.236.1 to 63.2.239.25463.2.239.2551,022
18963.2.240.0/2263.2.240.1 to 63.2.243.25463.2.243.2551,022
19063.2.244.0/2263.2.244.1 to 63.2.247.25463.2.247.2551,022
19163.2.248.0/2263.2.248.1 to 63.2.251.25463.2.251.2551,022
19263.2.252.0/2263.2.252.1 to 63.2.255.25463.2.255.2551,022
19363.3.0.0/2263.3.0.1 to 63.3.3.25463.3.3.2551,022
19463.3.4.0/2263.3.4.1 to 63.3.7.25463.3.7.2551,022
19563.3.8.0/2263.3.8.1 to 63.3.11.25463.3.11.2551,022
19663.3.12.0/2263.3.12.1 to 63.3.15.25463.3.15.2551,022
19763.3.16.0/2263.3.16.1 to 63.3.19.25463.3.19.2551,022
19863.3.20.0/2263.3.20.1 to 63.3.23.25463.3.23.2551,022
19963.3.24.0/2263.3.24.1 to 63.3.27.25463.3.27.2551,022
20063.3.28.0/2263.3.28.1 to 63.3.31.25463.3.31.2551,022
20163.3.32.0/2263.3.32.1 to 63.3.35.25463.3.35.2551,022
20263.3.36.0/2263.3.36.1 to 63.3.39.25463.3.39.2551,022
20363.3.40.0/2263.3.40.1 to 63.3.43.25463.3.43.2551,022
20463.3.44.0/2263.3.44.1 to 63.3.47.25463.3.47.2551,022
20563.3.48.0/2263.3.48.1 to 63.3.51.25463.3.51.2551,022
20663.3.52.0/2263.3.52.1 to 63.3.55.25463.3.55.2551,022
20763.3.56.0/2263.3.56.1 to 63.3.59.25463.3.59.2551,022
20863.3.60.0/2263.3.60.1 to 63.3.63.25463.3.63.2551,022
20963.3.64.0/2263.3.64.1 to 63.3.67.25463.3.67.2551,022
21063.3.68.0/2263.3.68.1 to 63.3.71.25463.3.71.2551,022
21163.3.72.0/2263.3.72.1 to 63.3.75.25463.3.75.2551,022
21263.3.76.0/2263.3.76.1 to 63.3.79.25463.3.79.2551,022
21363.3.80.0/2263.3.80.1 to 63.3.83.25463.3.83.2551,022
21463.3.84.0/2263.3.84.1 to 63.3.87.25463.3.87.2551,022
21563.3.88.0/2263.3.88.1 to 63.3.91.25463.3.91.2551,022
21663.3.92.0/2263.3.92.1 to 63.3.95.25463.3.95.2551,022
21763.3.96.0/2263.3.96.1 to 63.3.99.25463.3.99.2551,022
21863.3.100.0/2263.3.100.1 to 63.3.103.25463.3.103.2551,022
21963.3.104.0/2263.3.104.1 to 63.3.107.25463.3.107.2551,022
22063.3.108.0/2263.3.108.1 to 63.3.111.25463.3.111.2551,022
22163.3.112.0/2263.3.112.1 to 63.3.115.25463.3.115.2551,022
22263.3.116.0/2263.3.116.1 to 63.3.119.25463.3.119.2551,022
22363.3.120.0/2263.3.120.1 to 63.3.123.25463.3.123.2551,022
22463.3.124.0/2263.3.124.1 to 63.3.127.25463.3.127.2551,022
22563.3.128.0/2263.3.128.1 to 63.3.131.25463.3.131.2551,022
22663.3.132.0/2263.3.132.1 to 63.3.135.25463.3.135.2551,022
22763.3.136.0/2263.3.136.1 to 63.3.139.25463.3.139.2551,022
22863.3.140.0/2263.3.140.1 to 63.3.143.25463.3.143.2551,022
22963.3.144.0/2263.3.144.1 to 63.3.147.25463.3.147.2551,022
23063.3.148.0/2263.3.148.1 to 63.3.151.25463.3.151.2551,022
23163.3.152.0/2263.3.152.1 to 63.3.155.25463.3.155.2551,022
23263.3.156.0/2263.3.156.1 to 63.3.159.25463.3.159.2551,022
23363.3.160.0/2263.3.160.1 to 63.3.163.25463.3.163.2551,022
23463.3.164.0/2263.3.164.1 to 63.3.167.25463.3.167.2551,022
23563.3.168.0/2263.3.168.1 to 63.3.171.25463.3.171.2551,022
23663.3.172.0/2263.3.172.1 to 63.3.175.25463.3.175.2551,022
23763.3.176.0/2263.3.176.1 to 63.3.179.25463.3.179.2551,022
23863.3.180.0/2263.3.180.1 to 63.3.183.25463.3.183.2551,022
23963.3.184.0/2263.3.184.1 to 63.3.187.25463.3.187.2551,022
24063.3.188.0/2263.3.188.1 to 63.3.191.25463.3.191.2551,022
24163.3.192.0/2263.3.192.1 to 63.3.195.25463.3.195.2551,022
24263.3.196.0/2263.3.196.1 to 63.3.199.25463.3.199.2551,022
24363.3.200.0/2263.3.200.1 to 63.3.203.25463.3.203.2551,022
24463.3.204.0/2263.3.204.1 to 63.3.207.25463.3.207.2551,022
24563.3.208.0/2263.3.208.1 to 63.3.211.25463.3.211.2551,022
24663.3.212.0/2263.3.212.1 to 63.3.215.25463.3.215.2551,022
24763.3.216.0/2263.3.216.1 to 63.3.219.25463.3.219.2551,022
24863.3.220.0/2263.3.220.1 to 63.3.223.25463.3.223.2551,022
24963.3.224.0/2263.3.224.1 to 63.3.227.25463.3.227.2551,022
25063.3.228.0/2263.3.228.1 to 63.3.231.25463.3.231.2551,022
25163.3.232.0/2263.3.232.1 to 63.3.235.25463.3.235.2551,022
25263.3.236.0/2263.3.236.1 to 63.3.239.25463.3.239.2551,022
25363.3.240.0/2263.3.240.1 to 63.3.243.25463.3.243.2551,022
25463.3.244.0/2263.3.244.1 to 63.3.247.25463.3.247.2551,022
25563.3.248.0/2263.3.248.1 to 63.3.251.25463.3.251.2551,022
25663.3.252.0/2263.3.252.1 to 63.3.255.25463.3.255.2551,022

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.