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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.

Network34.36.0.0/18
Usable hosts16,382
Subnet mask255.255.192.0
Addresses16,384
Network address
34.36.0.0
Broadcast address
34.36.63.255
First usable
34.36.0.1
Last usable
34.36.63.254
Usable hosts
16,382 (16,384 less the network and broadcast addresses)
Subnet mask
255.255.192.0
Wildcard mask
0.0.63.255 (Cisco ACLs, OSPF)
Prefix length
/18
Type
Public public
Old class
A (default /8)
As numbers
Hex 22240000 · Integer 572784640 to 572801023
Reverse DNS zones
0.36.34.in-addr.arpa
1.36.34.in-addr.arpa
2.36.34.in-addr.arpa
3.36.34.in-addr.arpa
4.36.34.in-addr.arpa
5.36.34.in-addr.arpa
6.36.34.in-addr.arpa
7.36.34.in-addr.arpa
8.36.34.in-addr.arpa
9.36.34.in-addr.arpa
10.36.34.in-addr.arpa
11.36.34.in-addr.arpa
12.36.34.in-addr.arpa
13.36.34.in-addr.arpa
14.36.34.in-addr.arpa
15.36.34.in-addr.arpa
and 48 more
/18 is not on a 8-bit boundary, so it takes 64 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00100010.00100100.00000000.0000000034.36.0.0
Subnet mask11111111.11111111.11000000.00000000255.255.192.0
Network00100010.00100100.00000000.0000000034.36.0.0
Broadcast00100010.00100100.00111111.1111111134.36.63.255
Split into smaller subnets/26
/19 (2)/20 (4)/21 (8)/22 (16)/23 (32)/24 (64)/25 (128)/26 (256)/27 (512)/28 (1,024)/29 (2,048)/30 (4,096)

34.36.0.0/18 makes 256 subnets of /26.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
134.36.0.0/2634.36.0.1 to 34.36.0.6234.36.0.6362
234.36.0.64/2634.36.0.65 to 34.36.0.12634.36.0.12762
334.36.0.128/2634.36.0.129 to 34.36.0.19034.36.0.19162
434.36.0.192/2634.36.0.193 to 34.36.0.25434.36.0.25562
534.36.1.0/2634.36.1.1 to 34.36.1.6234.36.1.6362
634.36.1.64/2634.36.1.65 to 34.36.1.12634.36.1.12762
734.36.1.128/2634.36.1.129 to 34.36.1.19034.36.1.19162
834.36.1.192/2634.36.1.193 to 34.36.1.25434.36.1.25562
934.36.2.0/2634.36.2.1 to 34.36.2.6234.36.2.6362
1034.36.2.64/2634.36.2.65 to 34.36.2.12634.36.2.12762
1134.36.2.128/2634.36.2.129 to 34.36.2.19034.36.2.19162
1234.36.2.192/2634.36.2.193 to 34.36.2.25434.36.2.25562
1334.36.3.0/2634.36.3.1 to 34.36.3.6234.36.3.6362
1434.36.3.64/2634.36.3.65 to 34.36.3.12634.36.3.12762
1534.36.3.128/2634.36.3.129 to 34.36.3.19034.36.3.19162
1634.36.3.192/2634.36.3.193 to 34.36.3.25434.36.3.25562
1734.36.4.0/2634.36.4.1 to 34.36.4.6234.36.4.6362
1834.36.4.64/2634.36.4.65 to 34.36.4.12634.36.4.12762
1934.36.4.128/2634.36.4.129 to 34.36.4.19034.36.4.19162
2034.36.4.192/2634.36.4.193 to 34.36.4.25434.36.4.25562
2134.36.5.0/2634.36.5.1 to 34.36.5.6234.36.5.6362
2234.36.5.64/2634.36.5.65 to 34.36.5.12634.36.5.12762
2334.36.5.128/2634.36.5.129 to 34.36.5.19034.36.5.19162
2434.36.5.192/2634.36.5.193 to 34.36.5.25434.36.5.25562
2534.36.6.0/2634.36.6.1 to 34.36.6.6234.36.6.6362
2634.36.6.64/2634.36.6.65 to 34.36.6.12634.36.6.12762
2734.36.6.128/2634.36.6.129 to 34.36.6.19034.36.6.19162
2834.36.6.192/2634.36.6.193 to 34.36.6.25434.36.6.25562
2934.36.7.0/2634.36.7.1 to 34.36.7.6234.36.7.6362
3034.36.7.64/2634.36.7.65 to 34.36.7.12634.36.7.12762
3134.36.7.128/2634.36.7.129 to 34.36.7.19034.36.7.19162
3234.36.7.192/2634.36.7.193 to 34.36.7.25434.36.7.25562
3334.36.8.0/2634.36.8.1 to 34.36.8.6234.36.8.6362
3434.36.8.64/2634.36.8.65 to 34.36.8.12634.36.8.12762
3534.36.8.128/2634.36.8.129 to 34.36.8.19034.36.8.19162
3634.36.8.192/2634.36.8.193 to 34.36.8.25434.36.8.25562
3734.36.9.0/2634.36.9.1 to 34.36.9.6234.36.9.6362
3834.36.9.64/2634.36.9.65 to 34.36.9.12634.36.9.12762
3934.36.9.128/2634.36.9.129 to 34.36.9.19034.36.9.19162
4034.36.9.192/2634.36.9.193 to 34.36.9.25434.36.9.25562
4134.36.10.0/2634.36.10.1 to 34.36.10.6234.36.10.6362
4234.36.10.64/2634.36.10.65 to 34.36.10.12634.36.10.12762
4334.36.10.128/2634.36.10.129 to 34.36.10.19034.36.10.19162
4434.36.10.192/2634.36.10.193 to 34.36.10.25434.36.10.25562
4534.36.11.0/2634.36.11.1 to 34.36.11.6234.36.11.6362
4634.36.11.64/2634.36.11.65 to 34.36.11.12634.36.11.12762
4734.36.11.128/2634.36.11.129 to 34.36.11.19034.36.11.19162
4834.36.11.192/2634.36.11.193 to 34.36.11.25434.36.11.25562
4934.36.12.0/2634.36.12.1 to 34.36.12.6234.36.12.6362
5034.36.12.64/2634.36.12.65 to 34.36.12.12634.36.12.12762
5134.36.12.128/2634.36.12.129 to 34.36.12.19034.36.12.19162
5234.36.12.192/2634.36.12.193 to 34.36.12.25434.36.12.25562
5334.36.13.0/2634.36.13.1 to 34.36.13.6234.36.13.6362
5434.36.13.64/2634.36.13.65 to 34.36.13.12634.36.13.12762
5534.36.13.128/2634.36.13.129 to 34.36.13.19034.36.13.19162
5634.36.13.192/2634.36.13.193 to 34.36.13.25434.36.13.25562
5734.36.14.0/2634.36.14.1 to 34.36.14.6234.36.14.6362
5834.36.14.64/2634.36.14.65 to 34.36.14.12634.36.14.12762
5934.36.14.128/2634.36.14.129 to 34.36.14.19034.36.14.19162
6034.36.14.192/2634.36.14.193 to 34.36.14.25434.36.14.25562
6134.36.15.0/2634.36.15.1 to 34.36.15.6234.36.15.6362
6234.36.15.64/2634.36.15.65 to 34.36.15.12634.36.15.12762
6334.36.15.128/2634.36.15.129 to 34.36.15.19034.36.15.19162
6434.36.15.192/2634.36.15.193 to 34.36.15.25434.36.15.25562
6534.36.16.0/2634.36.16.1 to 34.36.16.6234.36.16.6362
6634.36.16.64/2634.36.16.65 to 34.36.16.12634.36.16.12762
6734.36.16.128/2634.36.16.129 to 34.36.16.19034.36.16.19162
6834.36.16.192/2634.36.16.193 to 34.36.16.25434.36.16.25562
6934.36.17.0/2634.36.17.1 to 34.36.17.6234.36.17.6362
7034.36.17.64/2634.36.17.65 to 34.36.17.12634.36.17.12762
7134.36.17.128/2634.36.17.129 to 34.36.17.19034.36.17.19162
7234.36.17.192/2634.36.17.193 to 34.36.17.25434.36.17.25562
7334.36.18.0/2634.36.18.1 to 34.36.18.6234.36.18.6362
7434.36.18.64/2634.36.18.65 to 34.36.18.12634.36.18.12762
7534.36.18.128/2634.36.18.129 to 34.36.18.19034.36.18.19162
7634.36.18.192/2634.36.18.193 to 34.36.18.25434.36.18.25562
7734.36.19.0/2634.36.19.1 to 34.36.19.6234.36.19.6362
7834.36.19.64/2634.36.19.65 to 34.36.19.12634.36.19.12762
7934.36.19.128/2634.36.19.129 to 34.36.19.19034.36.19.19162
8034.36.19.192/2634.36.19.193 to 34.36.19.25434.36.19.25562
8134.36.20.0/2634.36.20.1 to 34.36.20.6234.36.20.6362
8234.36.20.64/2634.36.20.65 to 34.36.20.12634.36.20.12762
8334.36.20.128/2634.36.20.129 to 34.36.20.19034.36.20.19162
8434.36.20.192/2634.36.20.193 to 34.36.20.25434.36.20.25562
8534.36.21.0/2634.36.21.1 to 34.36.21.6234.36.21.6362
8634.36.21.64/2634.36.21.65 to 34.36.21.12634.36.21.12762
8734.36.21.128/2634.36.21.129 to 34.36.21.19034.36.21.19162
8834.36.21.192/2634.36.21.193 to 34.36.21.25434.36.21.25562
8934.36.22.0/2634.36.22.1 to 34.36.22.6234.36.22.6362
9034.36.22.64/2634.36.22.65 to 34.36.22.12634.36.22.12762
9134.36.22.128/2634.36.22.129 to 34.36.22.19034.36.22.19162
9234.36.22.192/2634.36.22.193 to 34.36.22.25434.36.22.25562
9334.36.23.0/2634.36.23.1 to 34.36.23.6234.36.23.6362
9434.36.23.64/2634.36.23.65 to 34.36.23.12634.36.23.12762
9534.36.23.128/2634.36.23.129 to 34.36.23.19034.36.23.19162
9634.36.23.192/2634.36.23.193 to 34.36.23.25434.36.23.25562
9734.36.24.0/2634.36.24.1 to 34.36.24.6234.36.24.6362
9834.36.24.64/2634.36.24.65 to 34.36.24.12634.36.24.12762
9934.36.24.128/2634.36.24.129 to 34.36.24.19034.36.24.19162
10034.36.24.192/2634.36.24.193 to 34.36.24.25434.36.24.25562
10134.36.25.0/2634.36.25.1 to 34.36.25.6234.36.25.6362
10234.36.25.64/2634.36.25.65 to 34.36.25.12634.36.25.12762
10334.36.25.128/2634.36.25.129 to 34.36.25.19034.36.25.19162
10434.36.25.192/2634.36.25.193 to 34.36.25.25434.36.25.25562
10534.36.26.0/2634.36.26.1 to 34.36.26.6234.36.26.6362
10634.36.26.64/2634.36.26.65 to 34.36.26.12634.36.26.12762
10734.36.26.128/2634.36.26.129 to 34.36.26.19034.36.26.19162
10834.36.26.192/2634.36.26.193 to 34.36.26.25434.36.26.25562
10934.36.27.0/2634.36.27.1 to 34.36.27.6234.36.27.6362
11034.36.27.64/2634.36.27.65 to 34.36.27.12634.36.27.12762
11134.36.27.128/2634.36.27.129 to 34.36.27.19034.36.27.19162
11234.36.27.192/2634.36.27.193 to 34.36.27.25434.36.27.25562
11334.36.28.0/2634.36.28.1 to 34.36.28.6234.36.28.6362
11434.36.28.64/2634.36.28.65 to 34.36.28.12634.36.28.12762
11534.36.28.128/2634.36.28.129 to 34.36.28.19034.36.28.19162
11634.36.28.192/2634.36.28.193 to 34.36.28.25434.36.28.25562
11734.36.29.0/2634.36.29.1 to 34.36.29.6234.36.29.6362
11834.36.29.64/2634.36.29.65 to 34.36.29.12634.36.29.12762
11934.36.29.128/2634.36.29.129 to 34.36.29.19034.36.29.19162
12034.36.29.192/2634.36.29.193 to 34.36.29.25434.36.29.25562
12134.36.30.0/2634.36.30.1 to 34.36.30.6234.36.30.6362
12234.36.30.64/2634.36.30.65 to 34.36.30.12634.36.30.12762
12334.36.30.128/2634.36.30.129 to 34.36.30.19034.36.30.19162
12434.36.30.192/2634.36.30.193 to 34.36.30.25434.36.30.25562
12534.36.31.0/2634.36.31.1 to 34.36.31.6234.36.31.6362
12634.36.31.64/2634.36.31.65 to 34.36.31.12634.36.31.12762
12734.36.31.128/2634.36.31.129 to 34.36.31.19034.36.31.19162
12834.36.31.192/2634.36.31.193 to 34.36.31.25434.36.31.25562
12934.36.32.0/2634.36.32.1 to 34.36.32.6234.36.32.6362
13034.36.32.64/2634.36.32.65 to 34.36.32.12634.36.32.12762
13134.36.32.128/2634.36.32.129 to 34.36.32.19034.36.32.19162
13234.36.32.192/2634.36.32.193 to 34.36.32.25434.36.32.25562
13334.36.33.0/2634.36.33.1 to 34.36.33.6234.36.33.6362
13434.36.33.64/2634.36.33.65 to 34.36.33.12634.36.33.12762
13534.36.33.128/2634.36.33.129 to 34.36.33.19034.36.33.19162
13634.36.33.192/2634.36.33.193 to 34.36.33.25434.36.33.25562
13734.36.34.0/2634.36.34.1 to 34.36.34.6234.36.34.6362
13834.36.34.64/2634.36.34.65 to 34.36.34.12634.36.34.12762
13934.36.34.128/2634.36.34.129 to 34.36.34.19034.36.34.19162
14034.36.34.192/2634.36.34.193 to 34.36.34.25434.36.34.25562
14134.36.35.0/2634.36.35.1 to 34.36.35.6234.36.35.6362
14234.36.35.64/2634.36.35.65 to 34.36.35.12634.36.35.12762
14334.36.35.128/2634.36.35.129 to 34.36.35.19034.36.35.19162
14434.36.35.192/2634.36.35.193 to 34.36.35.25434.36.35.25562
14534.36.36.0/2634.36.36.1 to 34.36.36.6234.36.36.6362
14634.36.36.64/2634.36.36.65 to 34.36.36.12634.36.36.12762
14734.36.36.128/2634.36.36.129 to 34.36.36.19034.36.36.19162
14834.36.36.192/2634.36.36.193 to 34.36.36.25434.36.36.25562
14934.36.37.0/2634.36.37.1 to 34.36.37.6234.36.37.6362
15034.36.37.64/2634.36.37.65 to 34.36.37.12634.36.37.12762
15134.36.37.128/2634.36.37.129 to 34.36.37.19034.36.37.19162
15234.36.37.192/2634.36.37.193 to 34.36.37.25434.36.37.25562
15334.36.38.0/2634.36.38.1 to 34.36.38.6234.36.38.6362
15434.36.38.64/2634.36.38.65 to 34.36.38.12634.36.38.12762
15534.36.38.128/2634.36.38.129 to 34.36.38.19034.36.38.19162
15634.36.38.192/2634.36.38.193 to 34.36.38.25434.36.38.25562
15734.36.39.0/2634.36.39.1 to 34.36.39.6234.36.39.6362
15834.36.39.64/2634.36.39.65 to 34.36.39.12634.36.39.12762
15934.36.39.128/2634.36.39.129 to 34.36.39.19034.36.39.19162
16034.36.39.192/2634.36.39.193 to 34.36.39.25434.36.39.25562
16134.36.40.0/2634.36.40.1 to 34.36.40.6234.36.40.6362
16234.36.40.64/2634.36.40.65 to 34.36.40.12634.36.40.12762
16334.36.40.128/2634.36.40.129 to 34.36.40.19034.36.40.19162
16434.36.40.192/2634.36.40.193 to 34.36.40.25434.36.40.25562
16534.36.41.0/2634.36.41.1 to 34.36.41.6234.36.41.6362
16634.36.41.64/2634.36.41.65 to 34.36.41.12634.36.41.12762
16734.36.41.128/2634.36.41.129 to 34.36.41.19034.36.41.19162
16834.36.41.192/2634.36.41.193 to 34.36.41.25434.36.41.25562
16934.36.42.0/2634.36.42.1 to 34.36.42.6234.36.42.6362
17034.36.42.64/2634.36.42.65 to 34.36.42.12634.36.42.12762
17134.36.42.128/2634.36.42.129 to 34.36.42.19034.36.42.19162
17234.36.42.192/2634.36.42.193 to 34.36.42.25434.36.42.25562
17334.36.43.0/2634.36.43.1 to 34.36.43.6234.36.43.6362
17434.36.43.64/2634.36.43.65 to 34.36.43.12634.36.43.12762
17534.36.43.128/2634.36.43.129 to 34.36.43.19034.36.43.19162
17634.36.43.192/2634.36.43.193 to 34.36.43.25434.36.43.25562
17734.36.44.0/2634.36.44.1 to 34.36.44.6234.36.44.6362
17834.36.44.64/2634.36.44.65 to 34.36.44.12634.36.44.12762
17934.36.44.128/2634.36.44.129 to 34.36.44.19034.36.44.19162
18034.36.44.192/2634.36.44.193 to 34.36.44.25434.36.44.25562
18134.36.45.0/2634.36.45.1 to 34.36.45.6234.36.45.6362
18234.36.45.64/2634.36.45.65 to 34.36.45.12634.36.45.12762
18334.36.45.128/2634.36.45.129 to 34.36.45.19034.36.45.19162
18434.36.45.192/2634.36.45.193 to 34.36.45.25434.36.45.25562
18534.36.46.0/2634.36.46.1 to 34.36.46.6234.36.46.6362
18634.36.46.64/2634.36.46.65 to 34.36.46.12634.36.46.12762
18734.36.46.128/2634.36.46.129 to 34.36.46.19034.36.46.19162
18834.36.46.192/2634.36.46.193 to 34.36.46.25434.36.46.25562
18934.36.47.0/2634.36.47.1 to 34.36.47.6234.36.47.6362
19034.36.47.64/2634.36.47.65 to 34.36.47.12634.36.47.12762
19134.36.47.128/2634.36.47.129 to 34.36.47.19034.36.47.19162
19234.36.47.192/2634.36.47.193 to 34.36.47.25434.36.47.25562
19334.36.48.0/2634.36.48.1 to 34.36.48.6234.36.48.6362
19434.36.48.64/2634.36.48.65 to 34.36.48.12634.36.48.12762
19534.36.48.128/2634.36.48.129 to 34.36.48.19034.36.48.19162
19634.36.48.192/2634.36.48.193 to 34.36.48.25434.36.48.25562
19734.36.49.0/2634.36.49.1 to 34.36.49.6234.36.49.6362
19834.36.49.64/2634.36.49.65 to 34.36.49.12634.36.49.12762
19934.36.49.128/2634.36.49.129 to 34.36.49.19034.36.49.19162
20034.36.49.192/2634.36.49.193 to 34.36.49.25434.36.49.25562
20134.36.50.0/2634.36.50.1 to 34.36.50.6234.36.50.6362
20234.36.50.64/2634.36.50.65 to 34.36.50.12634.36.50.12762
20334.36.50.128/2634.36.50.129 to 34.36.50.19034.36.50.19162
20434.36.50.192/2634.36.50.193 to 34.36.50.25434.36.50.25562
20534.36.51.0/2634.36.51.1 to 34.36.51.6234.36.51.6362
20634.36.51.64/2634.36.51.65 to 34.36.51.12634.36.51.12762
20734.36.51.128/2634.36.51.129 to 34.36.51.19034.36.51.19162
20834.36.51.192/2634.36.51.193 to 34.36.51.25434.36.51.25562
20934.36.52.0/2634.36.52.1 to 34.36.52.6234.36.52.6362
21034.36.52.64/2634.36.52.65 to 34.36.52.12634.36.52.12762
21134.36.52.128/2634.36.52.129 to 34.36.52.19034.36.52.19162
21234.36.52.192/2634.36.52.193 to 34.36.52.25434.36.52.25562
21334.36.53.0/2634.36.53.1 to 34.36.53.6234.36.53.6362
21434.36.53.64/2634.36.53.65 to 34.36.53.12634.36.53.12762
21534.36.53.128/2634.36.53.129 to 34.36.53.19034.36.53.19162
21634.36.53.192/2634.36.53.193 to 34.36.53.25434.36.53.25562
21734.36.54.0/2634.36.54.1 to 34.36.54.6234.36.54.6362
21834.36.54.64/2634.36.54.65 to 34.36.54.12634.36.54.12762
21934.36.54.128/2634.36.54.129 to 34.36.54.19034.36.54.19162
22034.36.54.192/2634.36.54.193 to 34.36.54.25434.36.54.25562
22134.36.55.0/2634.36.55.1 to 34.36.55.6234.36.55.6362
22234.36.55.64/2634.36.55.65 to 34.36.55.12634.36.55.12762
22334.36.55.128/2634.36.55.129 to 34.36.55.19034.36.55.19162
22434.36.55.192/2634.36.55.193 to 34.36.55.25434.36.55.25562
22534.36.56.0/2634.36.56.1 to 34.36.56.6234.36.56.6362
22634.36.56.64/2634.36.56.65 to 34.36.56.12634.36.56.12762
22734.36.56.128/2634.36.56.129 to 34.36.56.19034.36.56.19162
22834.36.56.192/2634.36.56.193 to 34.36.56.25434.36.56.25562
22934.36.57.0/2634.36.57.1 to 34.36.57.6234.36.57.6362
23034.36.57.64/2634.36.57.65 to 34.36.57.12634.36.57.12762
23134.36.57.128/2634.36.57.129 to 34.36.57.19034.36.57.19162
23234.36.57.192/2634.36.57.193 to 34.36.57.25434.36.57.25562
23334.36.58.0/2634.36.58.1 to 34.36.58.6234.36.58.6362
23434.36.58.64/2634.36.58.65 to 34.36.58.12634.36.58.12762
23534.36.58.128/2634.36.58.129 to 34.36.58.19034.36.58.19162
23634.36.58.192/2634.36.58.193 to 34.36.58.25434.36.58.25562
23734.36.59.0/2634.36.59.1 to 34.36.59.6234.36.59.6362
23834.36.59.64/2634.36.59.65 to 34.36.59.12634.36.59.12762
23934.36.59.128/2634.36.59.129 to 34.36.59.19034.36.59.19162
24034.36.59.192/2634.36.59.193 to 34.36.59.25434.36.59.25562
24134.36.60.0/2634.36.60.1 to 34.36.60.6234.36.60.6362
24234.36.60.64/2634.36.60.65 to 34.36.60.12634.36.60.12762
24334.36.60.128/2634.36.60.129 to 34.36.60.19034.36.60.19162
24434.36.60.192/2634.36.60.193 to 34.36.60.25434.36.60.25562
24534.36.61.0/2634.36.61.1 to 34.36.61.6234.36.61.6362
24634.36.61.64/2634.36.61.65 to 34.36.61.12634.36.61.12762
24734.36.61.128/2634.36.61.129 to 34.36.61.19034.36.61.19162
24834.36.61.192/2634.36.61.193 to 34.36.61.25434.36.61.25562
24934.36.62.0/2634.36.62.1 to 34.36.62.6234.36.62.6362
25034.36.62.64/2634.36.62.65 to 34.36.62.12634.36.62.12762
25134.36.62.128/2634.36.62.129 to 34.36.62.19034.36.62.19162
25234.36.62.192/2634.36.62.193 to 34.36.62.25434.36.62.25562
25334.36.63.0/2634.36.63.1 to 34.36.63.6234.36.63.6362
25434.36.63.64/2634.36.63.65 to 34.36.63.12634.36.63.12762
25534.36.63.128/2634.36.63.129 to 34.36.63.19034.36.63.19162
25634.36.63.192/2634.36.63.193 to 34.36.63.25434.36.63.25562

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.