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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.

Network36.0.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
36.0.0.0
Broadcast address
36.63.255.255
First usable
36.0.0.1
Last usable
36.63.255.254
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 24000000 · Integer 603979776 to 608174079
Reverse DNS zones
0.36.in-addr.arpa
1.36.in-addr.arpa
2.36.in-addr.arpa
3.36.in-addr.arpa
4.36.in-addr.arpa
5.36.in-addr.arpa
6.36.in-addr.arpa
7.36.in-addr.arpa
8.36.in-addr.arpa
9.36.in-addr.arpa
10.36.in-addr.arpa
11.36.in-addr.arpa
12.36.in-addr.arpa
13.36.in-addr.arpa
14.36.in-addr.arpa
15.36.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
Address00100100.00000000.00000000.0000000036.0.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00100100.00000000.00000000.0000000036.0.0.0
Broadcast00100100.00111111.11111111.1111111136.63.255.255
Split into smaller subnets/20
/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)

36.0.0.0/10 makes 1,024 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
136.0.0.0/2036.0.0.1 to 36.0.15.25436.0.15.2554,094
236.0.16.0/2036.0.16.1 to 36.0.31.25436.0.31.2554,094
336.0.32.0/2036.0.32.1 to 36.0.47.25436.0.47.2554,094
436.0.48.0/2036.0.48.1 to 36.0.63.25436.0.63.2554,094
536.0.64.0/2036.0.64.1 to 36.0.79.25436.0.79.2554,094
636.0.80.0/2036.0.80.1 to 36.0.95.25436.0.95.2554,094
736.0.96.0/2036.0.96.1 to 36.0.111.25436.0.111.2554,094
836.0.112.0/2036.0.112.1 to 36.0.127.25436.0.127.2554,094
936.0.128.0/2036.0.128.1 to 36.0.143.25436.0.143.2554,094
1036.0.144.0/2036.0.144.1 to 36.0.159.25436.0.159.2554,094
1136.0.160.0/2036.0.160.1 to 36.0.175.25436.0.175.2554,094
1236.0.176.0/2036.0.176.1 to 36.0.191.25436.0.191.2554,094
1336.0.192.0/2036.0.192.1 to 36.0.207.25436.0.207.2554,094
1436.0.208.0/2036.0.208.1 to 36.0.223.25436.0.223.2554,094
1536.0.224.0/2036.0.224.1 to 36.0.239.25436.0.239.2554,094
1636.0.240.0/2036.0.240.1 to 36.0.255.25436.0.255.2554,094
1736.1.0.0/2036.1.0.1 to 36.1.15.25436.1.15.2554,094
1836.1.16.0/2036.1.16.1 to 36.1.31.25436.1.31.2554,094
1936.1.32.0/2036.1.32.1 to 36.1.47.25436.1.47.2554,094
2036.1.48.0/2036.1.48.1 to 36.1.63.25436.1.63.2554,094
2136.1.64.0/2036.1.64.1 to 36.1.79.25436.1.79.2554,094
2236.1.80.0/2036.1.80.1 to 36.1.95.25436.1.95.2554,094
2336.1.96.0/2036.1.96.1 to 36.1.111.25436.1.111.2554,094
2436.1.112.0/2036.1.112.1 to 36.1.127.25436.1.127.2554,094
2536.1.128.0/2036.1.128.1 to 36.1.143.25436.1.143.2554,094
2636.1.144.0/2036.1.144.1 to 36.1.159.25436.1.159.2554,094
2736.1.160.0/2036.1.160.1 to 36.1.175.25436.1.175.2554,094
2836.1.176.0/2036.1.176.1 to 36.1.191.25436.1.191.2554,094
2936.1.192.0/2036.1.192.1 to 36.1.207.25436.1.207.2554,094
3036.1.208.0/2036.1.208.1 to 36.1.223.25436.1.223.2554,094
3136.1.224.0/2036.1.224.1 to 36.1.239.25436.1.239.2554,094
3236.1.240.0/2036.1.240.1 to 36.1.255.25436.1.255.2554,094
3336.2.0.0/2036.2.0.1 to 36.2.15.25436.2.15.2554,094
3436.2.16.0/2036.2.16.1 to 36.2.31.25436.2.31.2554,094
3536.2.32.0/2036.2.32.1 to 36.2.47.25436.2.47.2554,094
3636.2.48.0/2036.2.48.1 to 36.2.63.25436.2.63.2554,094
3736.2.64.0/2036.2.64.1 to 36.2.79.25436.2.79.2554,094
3836.2.80.0/2036.2.80.1 to 36.2.95.25436.2.95.2554,094
3936.2.96.0/2036.2.96.1 to 36.2.111.25436.2.111.2554,094
4036.2.112.0/2036.2.112.1 to 36.2.127.25436.2.127.2554,094
4136.2.128.0/2036.2.128.1 to 36.2.143.25436.2.143.2554,094
4236.2.144.0/2036.2.144.1 to 36.2.159.25436.2.159.2554,094
4336.2.160.0/2036.2.160.1 to 36.2.175.25436.2.175.2554,094
4436.2.176.0/2036.2.176.1 to 36.2.191.25436.2.191.2554,094
4536.2.192.0/2036.2.192.1 to 36.2.207.25436.2.207.2554,094
4636.2.208.0/2036.2.208.1 to 36.2.223.25436.2.223.2554,094
4736.2.224.0/2036.2.224.1 to 36.2.239.25436.2.239.2554,094
4836.2.240.0/2036.2.240.1 to 36.2.255.25436.2.255.2554,094
4936.3.0.0/2036.3.0.1 to 36.3.15.25436.3.15.2554,094
5036.3.16.0/2036.3.16.1 to 36.3.31.25436.3.31.2554,094
5136.3.32.0/2036.3.32.1 to 36.3.47.25436.3.47.2554,094
5236.3.48.0/2036.3.48.1 to 36.3.63.25436.3.63.2554,094
5336.3.64.0/2036.3.64.1 to 36.3.79.25436.3.79.2554,094
5436.3.80.0/2036.3.80.1 to 36.3.95.25436.3.95.2554,094
5536.3.96.0/2036.3.96.1 to 36.3.111.25436.3.111.2554,094
5636.3.112.0/2036.3.112.1 to 36.3.127.25436.3.127.2554,094
5736.3.128.0/2036.3.128.1 to 36.3.143.25436.3.143.2554,094
5836.3.144.0/2036.3.144.1 to 36.3.159.25436.3.159.2554,094
5936.3.160.0/2036.3.160.1 to 36.3.175.25436.3.175.2554,094
6036.3.176.0/2036.3.176.1 to 36.3.191.25436.3.191.2554,094
6136.3.192.0/2036.3.192.1 to 36.3.207.25436.3.207.2554,094
6236.3.208.0/2036.3.208.1 to 36.3.223.25436.3.223.2554,094
6336.3.224.0/2036.3.224.1 to 36.3.239.25436.3.239.2554,094
6436.3.240.0/2036.3.240.1 to 36.3.255.25436.3.255.2554,094
6536.4.0.0/2036.4.0.1 to 36.4.15.25436.4.15.2554,094
6636.4.16.0/2036.4.16.1 to 36.4.31.25436.4.31.2554,094
6736.4.32.0/2036.4.32.1 to 36.4.47.25436.4.47.2554,094
6836.4.48.0/2036.4.48.1 to 36.4.63.25436.4.63.2554,094
6936.4.64.0/2036.4.64.1 to 36.4.79.25436.4.79.2554,094
7036.4.80.0/2036.4.80.1 to 36.4.95.25436.4.95.2554,094
7136.4.96.0/2036.4.96.1 to 36.4.111.25436.4.111.2554,094
7236.4.112.0/2036.4.112.1 to 36.4.127.25436.4.127.2554,094
7336.4.128.0/2036.4.128.1 to 36.4.143.25436.4.143.2554,094
7436.4.144.0/2036.4.144.1 to 36.4.159.25436.4.159.2554,094
7536.4.160.0/2036.4.160.1 to 36.4.175.25436.4.175.2554,094
7636.4.176.0/2036.4.176.1 to 36.4.191.25436.4.191.2554,094
7736.4.192.0/2036.4.192.1 to 36.4.207.25436.4.207.2554,094
7836.4.208.0/2036.4.208.1 to 36.4.223.25436.4.223.2554,094
7936.4.224.0/2036.4.224.1 to 36.4.239.25436.4.239.2554,094
8036.4.240.0/2036.4.240.1 to 36.4.255.25436.4.255.2554,094
8136.5.0.0/2036.5.0.1 to 36.5.15.25436.5.15.2554,094
8236.5.16.0/2036.5.16.1 to 36.5.31.25436.5.31.2554,094
8336.5.32.0/2036.5.32.1 to 36.5.47.25436.5.47.2554,094
8436.5.48.0/2036.5.48.1 to 36.5.63.25436.5.63.2554,094
8536.5.64.0/2036.5.64.1 to 36.5.79.25436.5.79.2554,094
8636.5.80.0/2036.5.80.1 to 36.5.95.25436.5.95.2554,094
8736.5.96.0/2036.5.96.1 to 36.5.111.25436.5.111.2554,094
8836.5.112.0/2036.5.112.1 to 36.5.127.25436.5.127.2554,094
8936.5.128.0/2036.5.128.1 to 36.5.143.25436.5.143.2554,094
9036.5.144.0/2036.5.144.1 to 36.5.159.25436.5.159.2554,094
9136.5.160.0/2036.5.160.1 to 36.5.175.25436.5.175.2554,094
9236.5.176.0/2036.5.176.1 to 36.5.191.25436.5.191.2554,094
9336.5.192.0/2036.5.192.1 to 36.5.207.25436.5.207.2554,094
9436.5.208.0/2036.5.208.1 to 36.5.223.25436.5.223.2554,094
9536.5.224.0/2036.5.224.1 to 36.5.239.25436.5.239.2554,094
9636.5.240.0/2036.5.240.1 to 36.5.255.25436.5.255.2554,094
9736.6.0.0/2036.6.0.1 to 36.6.15.25436.6.15.2554,094
9836.6.16.0/2036.6.16.1 to 36.6.31.25436.6.31.2554,094
9936.6.32.0/2036.6.32.1 to 36.6.47.25436.6.47.2554,094
10036.6.48.0/2036.6.48.1 to 36.6.63.25436.6.63.2554,094
10136.6.64.0/2036.6.64.1 to 36.6.79.25436.6.79.2554,094
10236.6.80.0/2036.6.80.1 to 36.6.95.25436.6.95.2554,094
10336.6.96.0/2036.6.96.1 to 36.6.111.25436.6.111.2554,094
10436.6.112.0/2036.6.112.1 to 36.6.127.25436.6.127.2554,094
10536.6.128.0/2036.6.128.1 to 36.6.143.25436.6.143.2554,094
10636.6.144.0/2036.6.144.1 to 36.6.159.25436.6.159.2554,094
10736.6.160.0/2036.6.160.1 to 36.6.175.25436.6.175.2554,094
10836.6.176.0/2036.6.176.1 to 36.6.191.25436.6.191.2554,094
10936.6.192.0/2036.6.192.1 to 36.6.207.25436.6.207.2554,094
11036.6.208.0/2036.6.208.1 to 36.6.223.25436.6.223.2554,094
11136.6.224.0/2036.6.224.1 to 36.6.239.25436.6.239.2554,094
11236.6.240.0/2036.6.240.1 to 36.6.255.25436.6.255.2554,094
11336.7.0.0/2036.7.0.1 to 36.7.15.25436.7.15.2554,094
11436.7.16.0/2036.7.16.1 to 36.7.31.25436.7.31.2554,094
11536.7.32.0/2036.7.32.1 to 36.7.47.25436.7.47.2554,094
11636.7.48.0/2036.7.48.1 to 36.7.63.25436.7.63.2554,094
11736.7.64.0/2036.7.64.1 to 36.7.79.25436.7.79.2554,094
11836.7.80.0/2036.7.80.1 to 36.7.95.25436.7.95.2554,094
11936.7.96.0/2036.7.96.1 to 36.7.111.25436.7.111.2554,094
12036.7.112.0/2036.7.112.1 to 36.7.127.25436.7.127.2554,094
12136.7.128.0/2036.7.128.1 to 36.7.143.25436.7.143.2554,094
12236.7.144.0/2036.7.144.1 to 36.7.159.25436.7.159.2554,094
12336.7.160.0/2036.7.160.1 to 36.7.175.25436.7.175.2554,094
12436.7.176.0/2036.7.176.1 to 36.7.191.25436.7.191.2554,094
12536.7.192.0/2036.7.192.1 to 36.7.207.25436.7.207.2554,094
12636.7.208.0/2036.7.208.1 to 36.7.223.25436.7.223.2554,094
12736.7.224.0/2036.7.224.1 to 36.7.239.25436.7.239.2554,094
12836.7.240.0/2036.7.240.1 to 36.7.255.25436.7.255.2554,094
12936.8.0.0/2036.8.0.1 to 36.8.15.25436.8.15.2554,094
13036.8.16.0/2036.8.16.1 to 36.8.31.25436.8.31.2554,094
13136.8.32.0/2036.8.32.1 to 36.8.47.25436.8.47.2554,094
13236.8.48.0/2036.8.48.1 to 36.8.63.25436.8.63.2554,094
13336.8.64.0/2036.8.64.1 to 36.8.79.25436.8.79.2554,094
13436.8.80.0/2036.8.80.1 to 36.8.95.25436.8.95.2554,094
13536.8.96.0/2036.8.96.1 to 36.8.111.25436.8.111.2554,094
13636.8.112.0/2036.8.112.1 to 36.8.127.25436.8.127.2554,094
13736.8.128.0/2036.8.128.1 to 36.8.143.25436.8.143.2554,094
13836.8.144.0/2036.8.144.1 to 36.8.159.25436.8.159.2554,094
13936.8.160.0/2036.8.160.1 to 36.8.175.25436.8.175.2554,094
14036.8.176.0/2036.8.176.1 to 36.8.191.25436.8.191.2554,094
14136.8.192.0/2036.8.192.1 to 36.8.207.25436.8.207.2554,094
14236.8.208.0/2036.8.208.1 to 36.8.223.25436.8.223.2554,094
14336.8.224.0/2036.8.224.1 to 36.8.239.25436.8.239.2554,094
14436.8.240.0/2036.8.240.1 to 36.8.255.25436.8.255.2554,094
14536.9.0.0/2036.9.0.1 to 36.9.15.25436.9.15.2554,094
14636.9.16.0/2036.9.16.1 to 36.9.31.25436.9.31.2554,094
14736.9.32.0/2036.9.32.1 to 36.9.47.25436.9.47.2554,094
14836.9.48.0/2036.9.48.1 to 36.9.63.25436.9.63.2554,094
14936.9.64.0/2036.9.64.1 to 36.9.79.25436.9.79.2554,094
15036.9.80.0/2036.9.80.1 to 36.9.95.25436.9.95.2554,094
15136.9.96.0/2036.9.96.1 to 36.9.111.25436.9.111.2554,094
15236.9.112.0/2036.9.112.1 to 36.9.127.25436.9.127.2554,094
15336.9.128.0/2036.9.128.1 to 36.9.143.25436.9.143.2554,094
15436.9.144.0/2036.9.144.1 to 36.9.159.25436.9.159.2554,094
15536.9.160.0/2036.9.160.1 to 36.9.175.25436.9.175.2554,094
15636.9.176.0/2036.9.176.1 to 36.9.191.25436.9.191.2554,094
15736.9.192.0/2036.9.192.1 to 36.9.207.25436.9.207.2554,094
15836.9.208.0/2036.9.208.1 to 36.9.223.25436.9.223.2554,094
15936.9.224.0/2036.9.224.1 to 36.9.239.25436.9.239.2554,094
16036.9.240.0/2036.9.240.1 to 36.9.255.25436.9.255.2554,094
16136.10.0.0/2036.10.0.1 to 36.10.15.25436.10.15.2554,094
16236.10.16.0/2036.10.16.1 to 36.10.31.25436.10.31.2554,094
16336.10.32.0/2036.10.32.1 to 36.10.47.25436.10.47.2554,094
16436.10.48.0/2036.10.48.1 to 36.10.63.25436.10.63.2554,094
16536.10.64.0/2036.10.64.1 to 36.10.79.25436.10.79.2554,094
16636.10.80.0/2036.10.80.1 to 36.10.95.25436.10.95.2554,094
16736.10.96.0/2036.10.96.1 to 36.10.111.25436.10.111.2554,094
16836.10.112.0/2036.10.112.1 to 36.10.127.25436.10.127.2554,094
16936.10.128.0/2036.10.128.1 to 36.10.143.25436.10.143.2554,094
17036.10.144.0/2036.10.144.1 to 36.10.159.25436.10.159.2554,094
17136.10.160.0/2036.10.160.1 to 36.10.175.25436.10.175.2554,094
17236.10.176.0/2036.10.176.1 to 36.10.191.25436.10.191.2554,094
17336.10.192.0/2036.10.192.1 to 36.10.207.25436.10.207.2554,094
17436.10.208.0/2036.10.208.1 to 36.10.223.25436.10.223.2554,094
17536.10.224.0/2036.10.224.1 to 36.10.239.25436.10.239.2554,094
17636.10.240.0/2036.10.240.1 to 36.10.255.25436.10.255.2554,094
17736.11.0.0/2036.11.0.1 to 36.11.15.25436.11.15.2554,094
17836.11.16.0/2036.11.16.1 to 36.11.31.25436.11.31.2554,094
17936.11.32.0/2036.11.32.1 to 36.11.47.25436.11.47.2554,094
18036.11.48.0/2036.11.48.1 to 36.11.63.25436.11.63.2554,094
18136.11.64.0/2036.11.64.1 to 36.11.79.25436.11.79.2554,094
18236.11.80.0/2036.11.80.1 to 36.11.95.25436.11.95.2554,094
18336.11.96.0/2036.11.96.1 to 36.11.111.25436.11.111.2554,094
18436.11.112.0/2036.11.112.1 to 36.11.127.25436.11.127.2554,094
18536.11.128.0/2036.11.128.1 to 36.11.143.25436.11.143.2554,094
18636.11.144.0/2036.11.144.1 to 36.11.159.25436.11.159.2554,094
18736.11.160.0/2036.11.160.1 to 36.11.175.25436.11.175.2554,094
18836.11.176.0/2036.11.176.1 to 36.11.191.25436.11.191.2554,094
18936.11.192.0/2036.11.192.1 to 36.11.207.25436.11.207.2554,094
19036.11.208.0/2036.11.208.1 to 36.11.223.25436.11.223.2554,094
19136.11.224.0/2036.11.224.1 to 36.11.239.25436.11.239.2554,094
19236.11.240.0/2036.11.240.1 to 36.11.255.25436.11.255.2554,094
19336.12.0.0/2036.12.0.1 to 36.12.15.25436.12.15.2554,094
19436.12.16.0/2036.12.16.1 to 36.12.31.25436.12.31.2554,094
19536.12.32.0/2036.12.32.1 to 36.12.47.25436.12.47.2554,094
19636.12.48.0/2036.12.48.1 to 36.12.63.25436.12.63.2554,094
19736.12.64.0/2036.12.64.1 to 36.12.79.25436.12.79.2554,094
19836.12.80.0/2036.12.80.1 to 36.12.95.25436.12.95.2554,094
19936.12.96.0/2036.12.96.1 to 36.12.111.25436.12.111.2554,094
20036.12.112.0/2036.12.112.1 to 36.12.127.25436.12.127.2554,094
20136.12.128.0/2036.12.128.1 to 36.12.143.25436.12.143.2554,094
20236.12.144.0/2036.12.144.1 to 36.12.159.25436.12.159.2554,094
20336.12.160.0/2036.12.160.1 to 36.12.175.25436.12.175.2554,094
20436.12.176.0/2036.12.176.1 to 36.12.191.25436.12.191.2554,094
20536.12.192.0/2036.12.192.1 to 36.12.207.25436.12.207.2554,094
20636.12.208.0/2036.12.208.1 to 36.12.223.25436.12.223.2554,094
20736.12.224.0/2036.12.224.1 to 36.12.239.25436.12.239.2554,094
20836.12.240.0/2036.12.240.1 to 36.12.255.25436.12.255.2554,094
20936.13.0.0/2036.13.0.1 to 36.13.15.25436.13.15.2554,094
21036.13.16.0/2036.13.16.1 to 36.13.31.25436.13.31.2554,094
21136.13.32.0/2036.13.32.1 to 36.13.47.25436.13.47.2554,094
21236.13.48.0/2036.13.48.1 to 36.13.63.25436.13.63.2554,094
21336.13.64.0/2036.13.64.1 to 36.13.79.25436.13.79.2554,094
21436.13.80.0/2036.13.80.1 to 36.13.95.25436.13.95.2554,094
21536.13.96.0/2036.13.96.1 to 36.13.111.25436.13.111.2554,094
21636.13.112.0/2036.13.112.1 to 36.13.127.25436.13.127.2554,094
21736.13.128.0/2036.13.128.1 to 36.13.143.25436.13.143.2554,094
21836.13.144.0/2036.13.144.1 to 36.13.159.25436.13.159.2554,094
21936.13.160.0/2036.13.160.1 to 36.13.175.25436.13.175.2554,094
22036.13.176.0/2036.13.176.1 to 36.13.191.25436.13.191.2554,094
22136.13.192.0/2036.13.192.1 to 36.13.207.25436.13.207.2554,094
22236.13.208.0/2036.13.208.1 to 36.13.223.25436.13.223.2554,094
22336.13.224.0/2036.13.224.1 to 36.13.239.25436.13.239.2554,094
22436.13.240.0/2036.13.240.1 to 36.13.255.25436.13.255.2554,094
22536.14.0.0/2036.14.0.1 to 36.14.15.25436.14.15.2554,094
22636.14.16.0/2036.14.16.1 to 36.14.31.25436.14.31.2554,094
22736.14.32.0/2036.14.32.1 to 36.14.47.25436.14.47.2554,094
22836.14.48.0/2036.14.48.1 to 36.14.63.25436.14.63.2554,094
22936.14.64.0/2036.14.64.1 to 36.14.79.25436.14.79.2554,094
23036.14.80.0/2036.14.80.1 to 36.14.95.25436.14.95.2554,094
23136.14.96.0/2036.14.96.1 to 36.14.111.25436.14.111.2554,094
23236.14.112.0/2036.14.112.1 to 36.14.127.25436.14.127.2554,094
23336.14.128.0/2036.14.128.1 to 36.14.143.25436.14.143.2554,094
23436.14.144.0/2036.14.144.1 to 36.14.159.25436.14.159.2554,094
23536.14.160.0/2036.14.160.1 to 36.14.175.25436.14.175.2554,094
23636.14.176.0/2036.14.176.1 to 36.14.191.25436.14.191.2554,094
23736.14.192.0/2036.14.192.1 to 36.14.207.25436.14.207.2554,094
23836.14.208.0/2036.14.208.1 to 36.14.223.25436.14.223.2554,094
23936.14.224.0/2036.14.224.1 to 36.14.239.25436.14.239.2554,094
24036.14.240.0/2036.14.240.1 to 36.14.255.25436.14.255.2554,094
24136.15.0.0/2036.15.0.1 to 36.15.15.25436.15.15.2554,094
24236.15.16.0/2036.15.16.1 to 36.15.31.25436.15.31.2554,094
24336.15.32.0/2036.15.32.1 to 36.15.47.25436.15.47.2554,094
24436.15.48.0/2036.15.48.1 to 36.15.63.25436.15.63.2554,094
24536.15.64.0/2036.15.64.1 to 36.15.79.25436.15.79.2554,094
24636.15.80.0/2036.15.80.1 to 36.15.95.25436.15.95.2554,094
24736.15.96.0/2036.15.96.1 to 36.15.111.25436.15.111.2554,094
24836.15.112.0/2036.15.112.1 to 36.15.127.25436.15.127.2554,094
24936.15.128.0/2036.15.128.1 to 36.15.143.25436.15.143.2554,094
25036.15.144.0/2036.15.144.1 to 36.15.159.25436.15.159.2554,094
25136.15.160.0/2036.15.160.1 to 36.15.175.25436.15.175.2554,094
25236.15.176.0/2036.15.176.1 to 36.15.191.25436.15.191.2554,094
25336.15.192.0/2036.15.192.1 to 36.15.207.25436.15.207.2554,094
25436.15.208.0/2036.15.208.1 to 36.15.223.25436.15.223.2554,094
25536.15.224.0/2036.15.224.1 to 36.15.239.25436.15.239.2554,094
25636.15.240.0/2036.15.240.1 to 36.15.255.25436.15.255.2554,094

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.