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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.

Network56.0.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
56.0.0.0
Broadcast address
56.63.255.255
First usable
56.0.0.1
Last usable
56.63.255.254
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 38000000 · Integer 939524096 to 943718399
Reverse DNS zones
0.56.in-addr.arpa
1.56.in-addr.arpa
2.56.in-addr.arpa
3.56.in-addr.arpa
4.56.in-addr.arpa
5.56.in-addr.arpa
6.56.in-addr.arpa
7.56.in-addr.arpa
8.56.in-addr.arpa
9.56.in-addr.arpa
10.56.in-addr.arpa
11.56.in-addr.arpa
12.56.in-addr.arpa
13.56.in-addr.arpa
14.56.in-addr.arpa
15.56.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
Address00111000.00000000.00000000.0000000056.0.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00111000.00000000.00000000.0000000056.0.0.0
Broadcast00111000.00111111.11111111.1111111156.63.255.255
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)

56.0.0.0/10 makes 4,096 subnets of /22; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
156.0.0.0/2256.0.0.1 to 56.0.3.25456.0.3.2551,022
256.0.4.0/2256.0.4.1 to 56.0.7.25456.0.7.2551,022
356.0.8.0/2256.0.8.1 to 56.0.11.25456.0.11.2551,022
456.0.12.0/2256.0.12.1 to 56.0.15.25456.0.15.2551,022
556.0.16.0/2256.0.16.1 to 56.0.19.25456.0.19.2551,022
656.0.20.0/2256.0.20.1 to 56.0.23.25456.0.23.2551,022
756.0.24.0/2256.0.24.1 to 56.0.27.25456.0.27.2551,022
856.0.28.0/2256.0.28.1 to 56.0.31.25456.0.31.2551,022
956.0.32.0/2256.0.32.1 to 56.0.35.25456.0.35.2551,022
1056.0.36.0/2256.0.36.1 to 56.0.39.25456.0.39.2551,022
1156.0.40.0/2256.0.40.1 to 56.0.43.25456.0.43.2551,022
1256.0.44.0/2256.0.44.1 to 56.0.47.25456.0.47.2551,022
1356.0.48.0/2256.0.48.1 to 56.0.51.25456.0.51.2551,022
1456.0.52.0/2256.0.52.1 to 56.0.55.25456.0.55.2551,022
1556.0.56.0/2256.0.56.1 to 56.0.59.25456.0.59.2551,022
1656.0.60.0/2256.0.60.1 to 56.0.63.25456.0.63.2551,022
1756.0.64.0/2256.0.64.1 to 56.0.67.25456.0.67.2551,022
1856.0.68.0/2256.0.68.1 to 56.0.71.25456.0.71.2551,022
1956.0.72.0/2256.0.72.1 to 56.0.75.25456.0.75.2551,022
2056.0.76.0/2256.0.76.1 to 56.0.79.25456.0.79.2551,022
2156.0.80.0/2256.0.80.1 to 56.0.83.25456.0.83.2551,022
2256.0.84.0/2256.0.84.1 to 56.0.87.25456.0.87.2551,022
2356.0.88.0/2256.0.88.1 to 56.0.91.25456.0.91.2551,022
2456.0.92.0/2256.0.92.1 to 56.0.95.25456.0.95.2551,022
2556.0.96.0/2256.0.96.1 to 56.0.99.25456.0.99.2551,022
2656.0.100.0/2256.0.100.1 to 56.0.103.25456.0.103.2551,022
2756.0.104.0/2256.0.104.1 to 56.0.107.25456.0.107.2551,022
2856.0.108.0/2256.0.108.1 to 56.0.111.25456.0.111.2551,022
2956.0.112.0/2256.0.112.1 to 56.0.115.25456.0.115.2551,022
3056.0.116.0/2256.0.116.1 to 56.0.119.25456.0.119.2551,022
3156.0.120.0/2256.0.120.1 to 56.0.123.25456.0.123.2551,022
3256.0.124.0/2256.0.124.1 to 56.0.127.25456.0.127.2551,022
3356.0.128.0/2256.0.128.1 to 56.0.131.25456.0.131.2551,022
3456.0.132.0/2256.0.132.1 to 56.0.135.25456.0.135.2551,022
3556.0.136.0/2256.0.136.1 to 56.0.139.25456.0.139.2551,022
3656.0.140.0/2256.0.140.1 to 56.0.143.25456.0.143.2551,022
3756.0.144.0/2256.0.144.1 to 56.0.147.25456.0.147.2551,022
3856.0.148.0/2256.0.148.1 to 56.0.151.25456.0.151.2551,022
3956.0.152.0/2256.0.152.1 to 56.0.155.25456.0.155.2551,022
4056.0.156.0/2256.0.156.1 to 56.0.159.25456.0.159.2551,022
4156.0.160.0/2256.0.160.1 to 56.0.163.25456.0.163.2551,022
4256.0.164.0/2256.0.164.1 to 56.0.167.25456.0.167.2551,022
4356.0.168.0/2256.0.168.1 to 56.0.171.25456.0.171.2551,022
4456.0.172.0/2256.0.172.1 to 56.0.175.25456.0.175.2551,022
4556.0.176.0/2256.0.176.1 to 56.0.179.25456.0.179.2551,022
4656.0.180.0/2256.0.180.1 to 56.0.183.25456.0.183.2551,022
4756.0.184.0/2256.0.184.1 to 56.0.187.25456.0.187.2551,022
4856.0.188.0/2256.0.188.1 to 56.0.191.25456.0.191.2551,022
4956.0.192.0/2256.0.192.1 to 56.0.195.25456.0.195.2551,022
5056.0.196.0/2256.0.196.1 to 56.0.199.25456.0.199.2551,022
5156.0.200.0/2256.0.200.1 to 56.0.203.25456.0.203.2551,022
5256.0.204.0/2256.0.204.1 to 56.0.207.25456.0.207.2551,022
5356.0.208.0/2256.0.208.1 to 56.0.211.25456.0.211.2551,022
5456.0.212.0/2256.0.212.1 to 56.0.215.25456.0.215.2551,022
5556.0.216.0/2256.0.216.1 to 56.0.219.25456.0.219.2551,022
5656.0.220.0/2256.0.220.1 to 56.0.223.25456.0.223.2551,022
5756.0.224.0/2256.0.224.1 to 56.0.227.25456.0.227.2551,022
5856.0.228.0/2256.0.228.1 to 56.0.231.25456.0.231.2551,022
5956.0.232.0/2256.0.232.1 to 56.0.235.25456.0.235.2551,022
6056.0.236.0/2256.0.236.1 to 56.0.239.25456.0.239.2551,022
6156.0.240.0/2256.0.240.1 to 56.0.243.25456.0.243.2551,022
6256.0.244.0/2256.0.244.1 to 56.0.247.25456.0.247.2551,022
6356.0.248.0/2256.0.248.1 to 56.0.251.25456.0.251.2551,022
6456.0.252.0/2256.0.252.1 to 56.0.255.25456.0.255.2551,022
6556.1.0.0/2256.1.0.1 to 56.1.3.25456.1.3.2551,022
6656.1.4.0/2256.1.4.1 to 56.1.7.25456.1.7.2551,022
6756.1.8.0/2256.1.8.1 to 56.1.11.25456.1.11.2551,022
6856.1.12.0/2256.1.12.1 to 56.1.15.25456.1.15.2551,022
6956.1.16.0/2256.1.16.1 to 56.1.19.25456.1.19.2551,022
7056.1.20.0/2256.1.20.1 to 56.1.23.25456.1.23.2551,022
7156.1.24.0/2256.1.24.1 to 56.1.27.25456.1.27.2551,022
7256.1.28.0/2256.1.28.1 to 56.1.31.25456.1.31.2551,022
7356.1.32.0/2256.1.32.1 to 56.1.35.25456.1.35.2551,022
7456.1.36.0/2256.1.36.1 to 56.1.39.25456.1.39.2551,022
7556.1.40.0/2256.1.40.1 to 56.1.43.25456.1.43.2551,022
7656.1.44.0/2256.1.44.1 to 56.1.47.25456.1.47.2551,022
7756.1.48.0/2256.1.48.1 to 56.1.51.25456.1.51.2551,022
7856.1.52.0/2256.1.52.1 to 56.1.55.25456.1.55.2551,022
7956.1.56.0/2256.1.56.1 to 56.1.59.25456.1.59.2551,022
8056.1.60.0/2256.1.60.1 to 56.1.63.25456.1.63.2551,022
8156.1.64.0/2256.1.64.1 to 56.1.67.25456.1.67.2551,022
8256.1.68.0/2256.1.68.1 to 56.1.71.25456.1.71.2551,022
8356.1.72.0/2256.1.72.1 to 56.1.75.25456.1.75.2551,022
8456.1.76.0/2256.1.76.1 to 56.1.79.25456.1.79.2551,022
8556.1.80.0/2256.1.80.1 to 56.1.83.25456.1.83.2551,022
8656.1.84.0/2256.1.84.1 to 56.1.87.25456.1.87.2551,022
8756.1.88.0/2256.1.88.1 to 56.1.91.25456.1.91.2551,022
8856.1.92.0/2256.1.92.1 to 56.1.95.25456.1.95.2551,022
8956.1.96.0/2256.1.96.1 to 56.1.99.25456.1.99.2551,022
9056.1.100.0/2256.1.100.1 to 56.1.103.25456.1.103.2551,022
9156.1.104.0/2256.1.104.1 to 56.1.107.25456.1.107.2551,022
9256.1.108.0/2256.1.108.1 to 56.1.111.25456.1.111.2551,022
9356.1.112.0/2256.1.112.1 to 56.1.115.25456.1.115.2551,022
9456.1.116.0/2256.1.116.1 to 56.1.119.25456.1.119.2551,022
9556.1.120.0/2256.1.120.1 to 56.1.123.25456.1.123.2551,022
9656.1.124.0/2256.1.124.1 to 56.1.127.25456.1.127.2551,022
9756.1.128.0/2256.1.128.1 to 56.1.131.25456.1.131.2551,022
9856.1.132.0/2256.1.132.1 to 56.1.135.25456.1.135.2551,022
9956.1.136.0/2256.1.136.1 to 56.1.139.25456.1.139.2551,022
10056.1.140.0/2256.1.140.1 to 56.1.143.25456.1.143.2551,022
10156.1.144.0/2256.1.144.1 to 56.1.147.25456.1.147.2551,022
10256.1.148.0/2256.1.148.1 to 56.1.151.25456.1.151.2551,022
10356.1.152.0/2256.1.152.1 to 56.1.155.25456.1.155.2551,022
10456.1.156.0/2256.1.156.1 to 56.1.159.25456.1.159.2551,022
10556.1.160.0/2256.1.160.1 to 56.1.163.25456.1.163.2551,022
10656.1.164.0/2256.1.164.1 to 56.1.167.25456.1.167.2551,022
10756.1.168.0/2256.1.168.1 to 56.1.171.25456.1.171.2551,022
10856.1.172.0/2256.1.172.1 to 56.1.175.25456.1.175.2551,022
10956.1.176.0/2256.1.176.1 to 56.1.179.25456.1.179.2551,022
11056.1.180.0/2256.1.180.1 to 56.1.183.25456.1.183.2551,022
11156.1.184.0/2256.1.184.1 to 56.1.187.25456.1.187.2551,022
11256.1.188.0/2256.1.188.1 to 56.1.191.25456.1.191.2551,022
11356.1.192.0/2256.1.192.1 to 56.1.195.25456.1.195.2551,022
11456.1.196.0/2256.1.196.1 to 56.1.199.25456.1.199.2551,022
11556.1.200.0/2256.1.200.1 to 56.1.203.25456.1.203.2551,022
11656.1.204.0/2256.1.204.1 to 56.1.207.25456.1.207.2551,022
11756.1.208.0/2256.1.208.1 to 56.1.211.25456.1.211.2551,022
11856.1.212.0/2256.1.212.1 to 56.1.215.25456.1.215.2551,022
11956.1.216.0/2256.1.216.1 to 56.1.219.25456.1.219.2551,022
12056.1.220.0/2256.1.220.1 to 56.1.223.25456.1.223.2551,022
12156.1.224.0/2256.1.224.1 to 56.1.227.25456.1.227.2551,022
12256.1.228.0/2256.1.228.1 to 56.1.231.25456.1.231.2551,022
12356.1.232.0/2256.1.232.1 to 56.1.235.25456.1.235.2551,022
12456.1.236.0/2256.1.236.1 to 56.1.239.25456.1.239.2551,022
12556.1.240.0/2256.1.240.1 to 56.1.243.25456.1.243.2551,022
12656.1.244.0/2256.1.244.1 to 56.1.247.25456.1.247.2551,022
12756.1.248.0/2256.1.248.1 to 56.1.251.25456.1.251.2551,022
12856.1.252.0/2256.1.252.1 to 56.1.255.25456.1.255.2551,022
12956.2.0.0/2256.2.0.1 to 56.2.3.25456.2.3.2551,022
13056.2.4.0/2256.2.4.1 to 56.2.7.25456.2.7.2551,022
13156.2.8.0/2256.2.8.1 to 56.2.11.25456.2.11.2551,022
13256.2.12.0/2256.2.12.1 to 56.2.15.25456.2.15.2551,022
13356.2.16.0/2256.2.16.1 to 56.2.19.25456.2.19.2551,022
13456.2.20.0/2256.2.20.1 to 56.2.23.25456.2.23.2551,022
13556.2.24.0/2256.2.24.1 to 56.2.27.25456.2.27.2551,022
13656.2.28.0/2256.2.28.1 to 56.2.31.25456.2.31.2551,022
13756.2.32.0/2256.2.32.1 to 56.2.35.25456.2.35.2551,022
13856.2.36.0/2256.2.36.1 to 56.2.39.25456.2.39.2551,022
13956.2.40.0/2256.2.40.1 to 56.2.43.25456.2.43.2551,022
14056.2.44.0/2256.2.44.1 to 56.2.47.25456.2.47.2551,022
14156.2.48.0/2256.2.48.1 to 56.2.51.25456.2.51.2551,022
14256.2.52.0/2256.2.52.1 to 56.2.55.25456.2.55.2551,022
14356.2.56.0/2256.2.56.1 to 56.2.59.25456.2.59.2551,022
14456.2.60.0/2256.2.60.1 to 56.2.63.25456.2.63.2551,022
14556.2.64.0/2256.2.64.1 to 56.2.67.25456.2.67.2551,022
14656.2.68.0/2256.2.68.1 to 56.2.71.25456.2.71.2551,022
14756.2.72.0/2256.2.72.1 to 56.2.75.25456.2.75.2551,022
14856.2.76.0/2256.2.76.1 to 56.2.79.25456.2.79.2551,022
14956.2.80.0/2256.2.80.1 to 56.2.83.25456.2.83.2551,022
15056.2.84.0/2256.2.84.1 to 56.2.87.25456.2.87.2551,022
15156.2.88.0/2256.2.88.1 to 56.2.91.25456.2.91.2551,022
15256.2.92.0/2256.2.92.1 to 56.2.95.25456.2.95.2551,022
15356.2.96.0/2256.2.96.1 to 56.2.99.25456.2.99.2551,022
15456.2.100.0/2256.2.100.1 to 56.2.103.25456.2.103.2551,022
15556.2.104.0/2256.2.104.1 to 56.2.107.25456.2.107.2551,022
15656.2.108.0/2256.2.108.1 to 56.2.111.25456.2.111.2551,022
15756.2.112.0/2256.2.112.1 to 56.2.115.25456.2.115.2551,022
15856.2.116.0/2256.2.116.1 to 56.2.119.25456.2.119.2551,022
15956.2.120.0/2256.2.120.1 to 56.2.123.25456.2.123.2551,022
16056.2.124.0/2256.2.124.1 to 56.2.127.25456.2.127.2551,022
16156.2.128.0/2256.2.128.1 to 56.2.131.25456.2.131.2551,022
16256.2.132.0/2256.2.132.1 to 56.2.135.25456.2.135.2551,022
16356.2.136.0/2256.2.136.1 to 56.2.139.25456.2.139.2551,022
16456.2.140.0/2256.2.140.1 to 56.2.143.25456.2.143.2551,022
16556.2.144.0/2256.2.144.1 to 56.2.147.25456.2.147.2551,022
16656.2.148.0/2256.2.148.1 to 56.2.151.25456.2.151.2551,022
16756.2.152.0/2256.2.152.1 to 56.2.155.25456.2.155.2551,022
16856.2.156.0/2256.2.156.1 to 56.2.159.25456.2.159.2551,022
16956.2.160.0/2256.2.160.1 to 56.2.163.25456.2.163.2551,022
17056.2.164.0/2256.2.164.1 to 56.2.167.25456.2.167.2551,022
17156.2.168.0/2256.2.168.1 to 56.2.171.25456.2.171.2551,022
17256.2.172.0/2256.2.172.1 to 56.2.175.25456.2.175.2551,022
17356.2.176.0/2256.2.176.1 to 56.2.179.25456.2.179.2551,022
17456.2.180.0/2256.2.180.1 to 56.2.183.25456.2.183.2551,022
17556.2.184.0/2256.2.184.1 to 56.2.187.25456.2.187.2551,022
17656.2.188.0/2256.2.188.1 to 56.2.191.25456.2.191.2551,022
17756.2.192.0/2256.2.192.1 to 56.2.195.25456.2.195.2551,022
17856.2.196.0/2256.2.196.1 to 56.2.199.25456.2.199.2551,022
17956.2.200.0/2256.2.200.1 to 56.2.203.25456.2.203.2551,022
18056.2.204.0/2256.2.204.1 to 56.2.207.25456.2.207.2551,022
18156.2.208.0/2256.2.208.1 to 56.2.211.25456.2.211.2551,022
18256.2.212.0/2256.2.212.1 to 56.2.215.25456.2.215.2551,022
18356.2.216.0/2256.2.216.1 to 56.2.219.25456.2.219.2551,022
18456.2.220.0/2256.2.220.1 to 56.2.223.25456.2.223.2551,022
18556.2.224.0/2256.2.224.1 to 56.2.227.25456.2.227.2551,022
18656.2.228.0/2256.2.228.1 to 56.2.231.25456.2.231.2551,022
18756.2.232.0/2256.2.232.1 to 56.2.235.25456.2.235.2551,022
18856.2.236.0/2256.2.236.1 to 56.2.239.25456.2.239.2551,022
18956.2.240.0/2256.2.240.1 to 56.2.243.25456.2.243.2551,022
19056.2.244.0/2256.2.244.1 to 56.2.247.25456.2.247.2551,022
19156.2.248.0/2256.2.248.1 to 56.2.251.25456.2.251.2551,022
19256.2.252.0/2256.2.252.1 to 56.2.255.25456.2.255.2551,022
19356.3.0.0/2256.3.0.1 to 56.3.3.25456.3.3.2551,022
19456.3.4.0/2256.3.4.1 to 56.3.7.25456.3.7.2551,022
19556.3.8.0/2256.3.8.1 to 56.3.11.25456.3.11.2551,022
19656.3.12.0/2256.3.12.1 to 56.3.15.25456.3.15.2551,022
19756.3.16.0/2256.3.16.1 to 56.3.19.25456.3.19.2551,022
19856.3.20.0/2256.3.20.1 to 56.3.23.25456.3.23.2551,022
19956.3.24.0/2256.3.24.1 to 56.3.27.25456.3.27.2551,022
20056.3.28.0/2256.3.28.1 to 56.3.31.25456.3.31.2551,022
20156.3.32.0/2256.3.32.1 to 56.3.35.25456.3.35.2551,022
20256.3.36.0/2256.3.36.1 to 56.3.39.25456.3.39.2551,022
20356.3.40.0/2256.3.40.1 to 56.3.43.25456.3.43.2551,022
20456.3.44.0/2256.3.44.1 to 56.3.47.25456.3.47.2551,022
20556.3.48.0/2256.3.48.1 to 56.3.51.25456.3.51.2551,022
20656.3.52.0/2256.3.52.1 to 56.3.55.25456.3.55.2551,022
20756.3.56.0/2256.3.56.1 to 56.3.59.25456.3.59.2551,022
20856.3.60.0/2256.3.60.1 to 56.3.63.25456.3.63.2551,022
20956.3.64.0/2256.3.64.1 to 56.3.67.25456.3.67.2551,022
21056.3.68.0/2256.3.68.1 to 56.3.71.25456.3.71.2551,022
21156.3.72.0/2256.3.72.1 to 56.3.75.25456.3.75.2551,022
21256.3.76.0/2256.3.76.1 to 56.3.79.25456.3.79.2551,022
21356.3.80.0/2256.3.80.1 to 56.3.83.25456.3.83.2551,022
21456.3.84.0/2256.3.84.1 to 56.3.87.25456.3.87.2551,022
21556.3.88.0/2256.3.88.1 to 56.3.91.25456.3.91.2551,022
21656.3.92.0/2256.3.92.1 to 56.3.95.25456.3.95.2551,022
21756.3.96.0/2256.3.96.1 to 56.3.99.25456.3.99.2551,022
21856.3.100.0/2256.3.100.1 to 56.3.103.25456.3.103.2551,022
21956.3.104.0/2256.3.104.1 to 56.3.107.25456.3.107.2551,022
22056.3.108.0/2256.3.108.1 to 56.3.111.25456.3.111.2551,022
22156.3.112.0/2256.3.112.1 to 56.3.115.25456.3.115.2551,022
22256.3.116.0/2256.3.116.1 to 56.3.119.25456.3.119.2551,022
22356.3.120.0/2256.3.120.1 to 56.3.123.25456.3.123.2551,022
22456.3.124.0/2256.3.124.1 to 56.3.127.25456.3.127.2551,022
22556.3.128.0/2256.3.128.1 to 56.3.131.25456.3.131.2551,022
22656.3.132.0/2256.3.132.1 to 56.3.135.25456.3.135.2551,022
22756.3.136.0/2256.3.136.1 to 56.3.139.25456.3.139.2551,022
22856.3.140.0/2256.3.140.1 to 56.3.143.25456.3.143.2551,022
22956.3.144.0/2256.3.144.1 to 56.3.147.25456.3.147.2551,022
23056.3.148.0/2256.3.148.1 to 56.3.151.25456.3.151.2551,022
23156.3.152.0/2256.3.152.1 to 56.3.155.25456.3.155.2551,022
23256.3.156.0/2256.3.156.1 to 56.3.159.25456.3.159.2551,022
23356.3.160.0/2256.3.160.1 to 56.3.163.25456.3.163.2551,022
23456.3.164.0/2256.3.164.1 to 56.3.167.25456.3.167.2551,022
23556.3.168.0/2256.3.168.1 to 56.3.171.25456.3.171.2551,022
23656.3.172.0/2256.3.172.1 to 56.3.175.25456.3.175.2551,022
23756.3.176.0/2256.3.176.1 to 56.3.179.25456.3.179.2551,022
23856.3.180.0/2256.3.180.1 to 56.3.183.25456.3.183.2551,022
23956.3.184.0/2256.3.184.1 to 56.3.187.25456.3.187.2551,022
24056.3.188.0/2256.3.188.1 to 56.3.191.25456.3.191.2551,022
24156.3.192.0/2256.3.192.1 to 56.3.195.25456.3.195.2551,022
24256.3.196.0/2256.3.196.1 to 56.3.199.25456.3.199.2551,022
24356.3.200.0/2256.3.200.1 to 56.3.203.25456.3.203.2551,022
24456.3.204.0/2256.3.204.1 to 56.3.207.25456.3.207.2551,022
24556.3.208.0/2256.3.208.1 to 56.3.211.25456.3.211.2551,022
24656.3.212.0/2256.3.212.1 to 56.3.215.25456.3.215.2551,022
24756.3.216.0/2256.3.216.1 to 56.3.219.25456.3.219.2551,022
24856.3.220.0/2256.3.220.1 to 56.3.223.25456.3.223.2551,022
24956.3.224.0/2256.3.224.1 to 56.3.227.25456.3.227.2551,022
25056.3.228.0/2256.3.228.1 to 56.3.231.25456.3.231.2551,022
25156.3.232.0/2256.3.232.1 to 56.3.235.25456.3.235.2551,022
25256.3.236.0/2256.3.236.1 to 56.3.239.25456.3.239.2551,022
25356.3.240.0/2256.3.240.1 to 56.3.243.25456.3.243.2551,022
25456.3.244.0/2256.3.244.1 to 56.3.247.25456.3.247.2551,022
25556.3.248.0/2256.3.248.1 to 56.3.251.25456.3.251.2551,022
25656.3.252.0/2256.3.252.1 to 56.3.255.25456.3.255.2551,022

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.