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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.

Network54.64.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
54.64.0.0
Broadcast address
54.127.255.255
First usable
54.64.0.1
Last usable
54.127.255.254
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 36400000 · Integer 910163968 to 914358271
Reverse DNS zones
64.54.in-addr.arpa
65.54.in-addr.arpa
66.54.in-addr.arpa
67.54.in-addr.arpa
68.54.in-addr.arpa
69.54.in-addr.arpa
70.54.in-addr.arpa
71.54.in-addr.arpa
72.54.in-addr.arpa
73.54.in-addr.arpa
74.54.in-addr.arpa
75.54.in-addr.arpa
76.54.in-addr.arpa
77.54.in-addr.arpa
78.54.in-addr.arpa
79.54.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
Address00110110.01000000.00000000.0000000054.64.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00110110.01000000.00000000.0000000054.64.0.0
Broadcast00110110.01111111.11111111.1111111154.127.255.255
Split into smaller subnets/21
/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)

54.64.0.0/10 makes 2,048 subnets of /21; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
154.64.0.0/2154.64.0.1 to 54.64.7.25454.64.7.2552,046
254.64.8.0/2154.64.8.1 to 54.64.15.25454.64.15.2552,046
354.64.16.0/2154.64.16.1 to 54.64.23.25454.64.23.2552,046
454.64.24.0/2154.64.24.1 to 54.64.31.25454.64.31.2552,046
554.64.32.0/2154.64.32.1 to 54.64.39.25454.64.39.2552,046
654.64.40.0/2154.64.40.1 to 54.64.47.25454.64.47.2552,046
754.64.48.0/2154.64.48.1 to 54.64.55.25454.64.55.2552,046
854.64.56.0/2154.64.56.1 to 54.64.63.25454.64.63.2552,046
954.64.64.0/2154.64.64.1 to 54.64.71.25454.64.71.2552,046
1054.64.72.0/2154.64.72.1 to 54.64.79.25454.64.79.2552,046
1154.64.80.0/2154.64.80.1 to 54.64.87.25454.64.87.2552,046
1254.64.88.0/2154.64.88.1 to 54.64.95.25454.64.95.2552,046
1354.64.96.0/2154.64.96.1 to 54.64.103.25454.64.103.2552,046
1454.64.104.0/2154.64.104.1 to 54.64.111.25454.64.111.2552,046
1554.64.112.0/2154.64.112.1 to 54.64.119.25454.64.119.2552,046
1654.64.120.0/2154.64.120.1 to 54.64.127.25454.64.127.2552,046
1754.64.128.0/2154.64.128.1 to 54.64.135.25454.64.135.2552,046
1854.64.136.0/2154.64.136.1 to 54.64.143.25454.64.143.2552,046
1954.64.144.0/2154.64.144.1 to 54.64.151.25454.64.151.2552,046
2054.64.152.0/2154.64.152.1 to 54.64.159.25454.64.159.2552,046
2154.64.160.0/2154.64.160.1 to 54.64.167.25454.64.167.2552,046
2254.64.168.0/2154.64.168.1 to 54.64.175.25454.64.175.2552,046
2354.64.176.0/2154.64.176.1 to 54.64.183.25454.64.183.2552,046
2454.64.184.0/2154.64.184.1 to 54.64.191.25454.64.191.2552,046
2554.64.192.0/2154.64.192.1 to 54.64.199.25454.64.199.2552,046
2654.64.200.0/2154.64.200.1 to 54.64.207.25454.64.207.2552,046
2754.64.208.0/2154.64.208.1 to 54.64.215.25454.64.215.2552,046
2854.64.216.0/2154.64.216.1 to 54.64.223.25454.64.223.2552,046
2954.64.224.0/2154.64.224.1 to 54.64.231.25454.64.231.2552,046
3054.64.232.0/2154.64.232.1 to 54.64.239.25454.64.239.2552,046
3154.64.240.0/2154.64.240.1 to 54.64.247.25454.64.247.2552,046
3254.64.248.0/2154.64.248.1 to 54.64.255.25454.64.255.2552,046
3354.65.0.0/2154.65.0.1 to 54.65.7.25454.65.7.2552,046
3454.65.8.0/2154.65.8.1 to 54.65.15.25454.65.15.2552,046
3554.65.16.0/2154.65.16.1 to 54.65.23.25454.65.23.2552,046
3654.65.24.0/2154.65.24.1 to 54.65.31.25454.65.31.2552,046
3754.65.32.0/2154.65.32.1 to 54.65.39.25454.65.39.2552,046
3854.65.40.0/2154.65.40.1 to 54.65.47.25454.65.47.2552,046
3954.65.48.0/2154.65.48.1 to 54.65.55.25454.65.55.2552,046
4054.65.56.0/2154.65.56.1 to 54.65.63.25454.65.63.2552,046
4154.65.64.0/2154.65.64.1 to 54.65.71.25454.65.71.2552,046
4254.65.72.0/2154.65.72.1 to 54.65.79.25454.65.79.2552,046
4354.65.80.0/2154.65.80.1 to 54.65.87.25454.65.87.2552,046
4454.65.88.0/2154.65.88.1 to 54.65.95.25454.65.95.2552,046
4554.65.96.0/2154.65.96.1 to 54.65.103.25454.65.103.2552,046
4654.65.104.0/2154.65.104.1 to 54.65.111.25454.65.111.2552,046
4754.65.112.0/2154.65.112.1 to 54.65.119.25454.65.119.2552,046
4854.65.120.0/2154.65.120.1 to 54.65.127.25454.65.127.2552,046
4954.65.128.0/2154.65.128.1 to 54.65.135.25454.65.135.2552,046
5054.65.136.0/2154.65.136.1 to 54.65.143.25454.65.143.2552,046
5154.65.144.0/2154.65.144.1 to 54.65.151.25454.65.151.2552,046
5254.65.152.0/2154.65.152.1 to 54.65.159.25454.65.159.2552,046
5354.65.160.0/2154.65.160.1 to 54.65.167.25454.65.167.2552,046
5454.65.168.0/2154.65.168.1 to 54.65.175.25454.65.175.2552,046
5554.65.176.0/2154.65.176.1 to 54.65.183.25454.65.183.2552,046
5654.65.184.0/2154.65.184.1 to 54.65.191.25454.65.191.2552,046
5754.65.192.0/2154.65.192.1 to 54.65.199.25454.65.199.2552,046
5854.65.200.0/2154.65.200.1 to 54.65.207.25454.65.207.2552,046
5954.65.208.0/2154.65.208.1 to 54.65.215.25454.65.215.2552,046
6054.65.216.0/2154.65.216.1 to 54.65.223.25454.65.223.2552,046
6154.65.224.0/2154.65.224.1 to 54.65.231.25454.65.231.2552,046
6254.65.232.0/2154.65.232.1 to 54.65.239.25454.65.239.2552,046
6354.65.240.0/2154.65.240.1 to 54.65.247.25454.65.247.2552,046
6454.65.248.0/2154.65.248.1 to 54.65.255.25454.65.255.2552,046
6554.66.0.0/2154.66.0.1 to 54.66.7.25454.66.7.2552,046
6654.66.8.0/2154.66.8.1 to 54.66.15.25454.66.15.2552,046
6754.66.16.0/2154.66.16.1 to 54.66.23.25454.66.23.2552,046
6854.66.24.0/2154.66.24.1 to 54.66.31.25454.66.31.2552,046
6954.66.32.0/2154.66.32.1 to 54.66.39.25454.66.39.2552,046
7054.66.40.0/2154.66.40.1 to 54.66.47.25454.66.47.2552,046
7154.66.48.0/2154.66.48.1 to 54.66.55.25454.66.55.2552,046
7254.66.56.0/2154.66.56.1 to 54.66.63.25454.66.63.2552,046
7354.66.64.0/2154.66.64.1 to 54.66.71.25454.66.71.2552,046
7454.66.72.0/2154.66.72.1 to 54.66.79.25454.66.79.2552,046
7554.66.80.0/2154.66.80.1 to 54.66.87.25454.66.87.2552,046
7654.66.88.0/2154.66.88.1 to 54.66.95.25454.66.95.2552,046
7754.66.96.0/2154.66.96.1 to 54.66.103.25454.66.103.2552,046
7854.66.104.0/2154.66.104.1 to 54.66.111.25454.66.111.2552,046
7954.66.112.0/2154.66.112.1 to 54.66.119.25454.66.119.2552,046
8054.66.120.0/2154.66.120.1 to 54.66.127.25454.66.127.2552,046
8154.66.128.0/2154.66.128.1 to 54.66.135.25454.66.135.2552,046
8254.66.136.0/2154.66.136.1 to 54.66.143.25454.66.143.2552,046
8354.66.144.0/2154.66.144.1 to 54.66.151.25454.66.151.2552,046
8454.66.152.0/2154.66.152.1 to 54.66.159.25454.66.159.2552,046
8554.66.160.0/2154.66.160.1 to 54.66.167.25454.66.167.2552,046
8654.66.168.0/2154.66.168.1 to 54.66.175.25454.66.175.2552,046
8754.66.176.0/2154.66.176.1 to 54.66.183.25454.66.183.2552,046
8854.66.184.0/2154.66.184.1 to 54.66.191.25454.66.191.2552,046
8954.66.192.0/2154.66.192.1 to 54.66.199.25454.66.199.2552,046
9054.66.200.0/2154.66.200.1 to 54.66.207.25454.66.207.2552,046
9154.66.208.0/2154.66.208.1 to 54.66.215.25454.66.215.2552,046
9254.66.216.0/2154.66.216.1 to 54.66.223.25454.66.223.2552,046
9354.66.224.0/2154.66.224.1 to 54.66.231.25454.66.231.2552,046
9454.66.232.0/2154.66.232.1 to 54.66.239.25454.66.239.2552,046
9554.66.240.0/2154.66.240.1 to 54.66.247.25454.66.247.2552,046
9654.66.248.0/2154.66.248.1 to 54.66.255.25454.66.255.2552,046
9754.67.0.0/2154.67.0.1 to 54.67.7.25454.67.7.2552,046
9854.67.8.0/2154.67.8.1 to 54.67.15.25454.67.15.2552,046
9954.67.16.0/2154.67.16.1 to 54.67.23.25454.67.23.2552,046
10054.67.24.0/2154.67.24.1 to 54.67.31.25454.67.31.2552,046
10154.67.32.0/2154.67.32.1 to 54.67.39.25454.67.39.2552,046
10254.67.40.0/2154.67.40.1 to 54.67.47.25454.67.47.2552,046
10354.67.48.0/2154.67.48.1 to 54.67.55.25454.67.55.2552,046
10454.67.56.0/2154.67.56.1 to 54.67.63.25454.67.63.2552,046
10554.67.64.0/2154.67.64.1 to 54.67.71.25454.67.71.2552,046
10654.67.72.0/2154.67.72.1 to 54.67.79.25454.67.79.2552,046
10754.67.80.0/2154.67.80.1 to 54.67.87.25454.67.87.2552,046
10854.67.88.0/2154.67.88.1 to 54.67.95.25454.67.95.2552,046
10954.67.96.0/2154.67.96.1 to 54.67.103.25454.67.103.2552,046
11054.67.104.0/2154.67.104.1 to 54.67.111.25454.67.111.2552,046
11154.67.112.0/2154.67.112.1 to 54.67.119.25454.67.119.2552,046
11254.67.120.0/2154.67.120.1 to 54.67.127.25454.67.127.2552,046
11354.67.128.0/2154.67.128.1 to 54.67.135.25454.67.135.2552,046
11454.67.136.0/2154.67.136.1 to 54.67.143.25454.67.143.2552,046
11554.67.144.0/2154.67.144.1 to 54.67.151.25454.67.151.2552,046
11654.67.152.0/2154.67.152.1 to 54.67.159.25454.67.159.2552,046
11754.67.160.0/2154.67.160.1 to 54.67.167.25454.67.167.2552,046
11854.67.168.0/2154.67.168.1 to 54.67.175.25454.67.175.2552,046
11954.67.176.0/2154.67.176.1 to 54.67.183.25454.67.183.2552,046
12054.67.184.0/2154.67.184.1 to 54.67.191.25454.67.191.2552,046
12154.67.192.0/2154.67.192.1 to 54.67.199.25454.67.199.2552,046
12254.67.200.0/2154.67.200.1 to 54.67.207.25454.67.207.2552,046
12354.67.208.0/2154.67.208.1 to 54.67.215.25454.67.215.2552,046
12454.67.216.0/2154.67.216.1 to 54.67.223.25454.67.223.2552,046
12554.67.224.0/2154.67.224.1 to 54.67.231.25454.67.231.2552,046
12654.67.232.0/2154.67.232.1 to 54.67.239.25454.67.239.2552,046
12754.67.240.0/2154.67.240.1 to 54.67.247.25454.67.247.2552,046
12854.67.248.0/2154.67.248.1 to 54.67.255.25454.67.255.2552,046
12954.68.0.0/2154.68.0.1 to 54.68.7.25454.68.7.2552,046
13054.68.8.0/2154.68.8.1 to 54.68.15.25454.68.15.2552,046
13154.68.16.0/2154.68.16.1 to 54.68.23.25454.68.23.2552,046
13254.68.24.0/2154.68.24.1 to 54.68.31.25454.68.31.2552,046
13354.68.32.0/2154.68.32.1 to 54.68.39.25454.68.39.2552,046
13454.68.40.0/2154.68.40.1 to 54.68.47.25454.68.47.2552,046
13554.68.48.0/2154.68.48.1 to 54.68.55.25454.68.55.2552,046
13654.68.56.0/2154.68.56.1 to 54.68.63.25454.68.63.2552,046
13754.68.64.0/2154.68.64.1 to 54.68.71.25454.68.71.2552,046
13854.68.72.0/2154.68.72.1 to 54.68.79.25454.68.79.2552,046
13954.68.80.0/2154.68.80.1 to 54.68.87.25454.68.87.2552,046
14054.68.88.0/2154.68.88.1 to 54.68.95.25454.68.95.2552,046
14154.68.96.0/2154.68.96.1 to 54.68.103.25454.68.103.2552,046
14254.68.104.0/2154.68.104.1 to 54.68.111.25454.68.111.2552,046
14354.68.112.0/2154.68.112.1 to 54.68.119.25454.68.119.2552,046
14454.68.120.0/2154.68.120.1 to 54.68.127.25454.68.127.2552,046
14554.68.128.0/2154.68.128.1 to 54.68.135.25454.68.135.2552,046
14654.68.136.0/2154.68.136.1 to 54.68.143.25454.68.143.2552,046
14754.68.144.0/2154.68.144.1 to 54.68.151.25454.68.151.2552,046
14854.68.152.0/2154.68.152.1 to 54.68.159.25454.68.159.2552,046
14954.68.160.0/2154.68.160.1 to 54.68.167.25454.68.167.2552,046
15054.68.168.0/2154.68.168.1 to 54.68.175.25454.68.175.2552,046
15154.68.176.0/2154.68.176.1 to 54.68.183.25454.68.183.2552,046
15254.68.184.0/2154.68.184.1 to 54.68.191.25454.68.191.2552,046
15354.68.192.0/2154.68.192.1 to 54.68.199.25454.68.199.2552,046
15454.68.200.0/2154.68.200.1 to 54.68.207.25454.68.207.2552,046
15554.68.208.0/2154.68.208.1 to 54.68.215.25454.68.215.2552,046
15654.68.216.0/2154.68.216.1 to 54.68.223.25454.68.223.2552,046
15754.68.224.0/2154.68.224.1 to 54.68.231.25454.68.231.2552,046
15854.68.232.0/2154.68.232.1 to 54.68.239.25454.68.239.2552,046
15954.68.240.0/2154.68.240.1 to 54.68.247.25454.68.247.2552,046
16054.68.248.0/2154.68.248.1 to 54.68.255.25454.68.255.2552,046
16154.69.0.0/2154.69.0.1 to 54.69.7.25454.69.7.2552,046
16254.69.8.0/2154.69.8.1 to 54.69.15.25454.69.15.2552,046
16354.69.16.0/2154.69.16.1 to 54.69.23.25454.69.23.2552,046
16454.69.24.0/2154.69.24.1 to 54.69.31.25454.69.31.2552,046
16554.69.32.0/2154.69.32.1 to 54.69.39.25454.69.39.2552,046
16654.69.40.0/2154.69.40.1 to 54.69.47.25454.69.47.2552,046
16754.69.48.0/2154.69.48.1 to 54.69.55.25454.69.55.2552,046
16854.69.56.0/2154.69.56.1 to 54.69.63.25454.69.63.2552,046
16954.69.64.0/2154.69.64.1 to 54.69.71.25454.69.71.2552,046
17054.69.72.0/2154.69.72.1 to 54.69.79.25454.69.79.2552,046
17154.69.80.0/2154.69.80.1 to 54.69.87.25454.69.87.2552,046
17254.69.88.0/2154.69.88.1 to 54.69.95.25454.69.95.2552,046
17354.69.96.0/2154.69.96.1 to 54.69.103.25454.69.103.2552,046
17454.69.104.0/2154.69.104.1 to 54.69.111.25454.69.111.2552,046
17554.69.112.0/2154.69.112.1 to 54.69.119.25454.69.119.2552,046
17654.69.120.0/2154.69.120.1 to 54.69.127.25454.69.127.2552,046
17754.69.128.0/2154.69.128.1 to 54.69.135.25454.69.135.2552,046
17854.69.136.0/2154.69.136.1 to 54.69.143.25454.69.143.2552,046
17954.69.144.0/2154.69.144.1 to 54.69.151.25454.69.151.2552,046
18054.69.152.0/2154.69.152.1 to 54.69.159.25454.69.159.2552,046
18154.69.160.0/2154.69.160.1 to 54.69.167.25454.69.167.2552,046
18254.69.168.0/2154.69.168.1 to 54.69.175.25454.69.175.2552,046
18354.69.176.0/2154.69.176.1 to 54.69.183.25454.69.183.2552,046
18454.69.184.0/2154.69.184.1 to 54.69.191.25454.69.191.2552,046
18554.69.192.0/2154.69.192.1 to 54.69.199.25454.69.199.2552,046
18654.69.200.0/2154.69.200.1 to 54.69.207.25454.69.207.2552,046
18754.69.208.0/2154.69.208.1 to 54.69.215.25454.69.215.2552,046
18854.69.216.0/2154.69.216.1 to 54.69.223.25454.69.223.2552,046
18954.69.224.0/2154.69.224.1 to 54.69.231.25454.69.231.2552,046
19054.69.232.0/2154.69.232.1 to 54.69.239.25454.69.239.2552,046
19154.69.240.0/2154.69.240.1 to 54.69.247.25454.69.247.2552,046
19254.69.248.0/2154.69.248.1 to 54.69.255.25454.69.255.2552,046
19354.70.0.0/2154.70.0.1 to 54.70.7.25454.70.7.2552,046
19454.70.8.0/2154.70.8.1 to 54.70.15.25454.70.15.2552,046
19554.70.16.0/2154.70.16.1 to 54.70.23.25454.70.23.2552,046
19654.70.24.0/2154.70.24.1 to 54.70.31.25454.70.31.2552,046
19754.70.32.0/2154.70.32.1 to 54.70.39.25454.70.39.2552,046
19854.70.40.0/2154.70.40.1 to 54.70.47.25454.70.47.2552,046
19954.70.48.0/2154.70.48.1 to 54.70.55.25454.70.55.2552,046
20054.70.56.0/2154.70.56.1 to 54.70.63.25454.70.63.2552,046
20154.70.64.0/2154.70.64.1 to 54.70.71.25454.70.71.2552,046
20254.70.72.0/2154.70.72.1 to 54.70.79.25454.70.79.2552,046
20354.70.80.0/2154.70.80.1 to 54.70.87.25454.70.87.2552,046
20454.70.88.0/2154.70.88.1 to 54.70.95.25454.70.95.2552,046
20554.70.96.0/2154.70.96.1 to 54.70.103.25454.70.103.2552,046
20654.70.104.0/2154.70.104.1 to 54.70.111.25454.70.111.2552,046
20754.70.112.0/2154.70.112.1 to 54.70.119.25454.70.119.2552,046
20854.70.120.0/2154.70.120.1 to 54.70.127.25454.70.127.2552,046
20954.70.128.0/2154.70.128.1 to 54.70.135.25454.70.135.2552,046
21054.70.136.0/2154.70.136.1 to 54.70.143.25454.70.143.2552,046
21154.70.144.0/2154.70.144.1 to 54.70.151.25454.70.151.2552,046
21254.70.152.0/2154.70.152.1 to 54.70.159.25454.70.159.2552,046
21354.70.160.0/2154.70.160.1 to 54.70.167.25454.70.167.2552,046
21454.70.168.0/2154.70.168.1 to 54.70.175.25454.70.175.2552,046
21554.70.176.0/2154.70.176.1 to 54.70.183.25454.70.183.2552,046
21654.70.184.0/2154.70.184.1 to 54.70.191.25454.70.191.2552,046
21754.70.192.0/2154.70.192.1 to 54.70.199.25454.70.199.2552,046
21854.70.200.0/2154.70.200.1 to 54.70.207.25454.70.207.2552,046
21954.70.208.0/2154.70.208.1 to 54.70.215.25454.70.215.2552,046
22054.70.216.0/2154.70.216.1 to 54.70.223.25454.70.223.2552,046
22154.70.224.0/2154.70.224.1 to 54.70.231.25454.70.231.2552,046
22254.70.232.0/2154.70.232.1 to 54.70.239.25454.70.239.2552,046
22354.70.240.0/2154.70.240.1 to 54.70.247.25454.70.247.2552,046
22454.70.248.0/2154.70.248.1 to 54.70.255.25454.70.255.2552,046
22554.71.0.0/2154.71.0.1 to 54.71.7.25454.71.7.2552,046
22654.71.8.0/2154.71.8.1 to 54.71.15.25454.71.15.2552,046
22754.71.16.0/2154.71.16.1 to 54.71.23.25454.71.23.2552,046
22854.71.24.0/2154.71.24.1 to 54.71.31.25454.71.31.2552,046
22954.71.32.0/2154.71.32.1 to 54.71.39.25454.71.39.2552,046
23054.71.40.0/2154.71.40.1 to 54.71.47.25454.71.47.2552,046
23154.71.48.0/2154.71.48.1 to 54.71.55.25454.71.55.2552,046
23254.71.56.0/2154.71.56.1 to 54.71.63.25454.71.63.2552,046
23354.71.64.0/2154.71.64.1 to 54.71.71.25454.71.71.2552,046
23454.71.72.0/2154.71.72.1 to 54.71.79.25454.71.79.2552,046
23554.71.80.0/2154.71.80.1 to 54.71.87.25454.71.87.2552,046
23654.71.88.0/2154.71.88.1 to 54.71.95.25454.71.95.2552,046
23754.71.96.0/2154.71.96.1 to 54.71.103.25454.71.103.2552,046
23854.71.104.0/2154.71.104.1 to 54.71.111.25454.71.111.2552,046
23954.71.112.0/2154.71.112.1 to 54.71.119.25454.71.119.2552,046
24054.71.120.0/2154.71.120.1 to 54.71.127.25454.71.127.2552,046
24154.71.128.0/2154.71.128.1 to 54.71.135.25454.71.135.2552,046
24254.71.136.0/2154.71.136.1 to 54.71.143.25454.71.143.2552,046
24354.71.144.0/2154.71.144.1 to 54.71.151.25454.71.151.2552,046
24454.71.152.0/2154.71.152.1 to 54.71.159.25454.71.159.2552,046
24554.71.160.0/2154.71.160.1 to 54.71.167.25454.71.167.2552,046
24654.71.168.0/2154.71.168.1 to 54.71.175.25454.71.175.2552,046
24754.71.176.0/2154.71.176.1 to 54.71.183.25454.71.183.2552,046
24854.71.184.0/2154.71.184.1 to 54.71.191.25454.71.191.2552,046
24954.71.192.0/2154.71.192.1 to 54.71.199.25454.71.199.2552,046
25054.71.200.0/2154.71.200.1 to 54.71.207.25454.71.207.2552,046
25154.71.208.0/2154.71.208.1 to 54.71.215.25454.71.215.2552,046
25254.71.216.0/2154.71.216.1 to 54.71.223.25454.71.223.2552,046
25354.71.224.0/2154.71.224.1 to 54.71.231.25454.71.231.2552,046
25454.71.232.0/2154.71.232.1 to 54.71.239.25454.71.239.2552,046
25554.71.240.0/2154.71.240.1 to 54.71.247.25454.71.247.2552,046
25654.71.248.0/2154.71.248.1 to 54.71.255.25454.71.255.2552,046

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.