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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.

Network73.76.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
73.76.0.0
Broadcast address
73.77.255.255
First usable
73.76.0.1
Last usable
73.77.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
A (default /8)
As numbers
Hex 494C0000 · Integer 1229717504 to 1229848575
Reverse DNS zones
76.73.in-addr.arpa
77.73.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01001001.01001100.00000000.0000000073.76.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network01001001.01001100.00000000.0000000073.76.0.0
Broadcast01001001.01001101.11111111.1111111173.77.255.255
Split into smaller subnets/26
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

73.76.0.0/15 makes 2,048 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
173.76.0.0/2673.76.0.1 to 73.76.0.6273.76.0.6362
273.76.0.64/2673.76.0.65 to 73.76.0.12673.76.0.12762
373.76.0.128/2673.76.0.129 to 73.76.0.19073.76.0.19162
473.76.0.192/2673.76.0.193 to 73.76.0.25473.76.0.25562
573.76.1.0/2673.76.1.1 to 73.76.1.6273.76.1.6362
673.76.1.64/2673.76.1.65 to 73.76.1.12673.76.1.12762
773.76.1.128/2673.76.1.129 to 73.76.1.19073.76.1.19162
873.76.1.192/2673.76.1.193 to 73.76.1.25473.76.1.25562
973.76.2.0/2673.76.2.1 to 73.76.2.6273.76.2.6362
1073.76.2.64/2673.76.2.65 to 73.76.2.12673.76.2.12762
1173.76.2.128/2673.76.2.129 to 73.76.2.19073.76.2.19162
1273.76.2.192/2673.76.2.193 to 73.76.2.25473.76.2.25562
1373.76.3.0/2673.76.3.1 to 73.76.3.6273.76.3.6362
1473.76.3.64/2673.76.3.65 to 73.76.3.12673.76.3.12762
1573.76.3.128/2673.76.3.129 to 73.76.3.19073.76.3.19162
1673.76.3.192/2673.76.3.193 to 73.76.3.25473.76.3.25562
1773.76.4.0/2673.76.4.1 to 73.76.4.6273.76.4.6362
1873.76.4.64/2673.76.4.65 to 73.76.4.12673.76.4.12762
1973.76.4.128/2673.76.4.129 to 73.76.4.19073.76.4.19162
2073.76.4.192/2673.76.4.193 to 73.76.4.25473.76.4.25562
2173.76.5.0/2673.76.5.1 to 73.76.5.6273.76.5.6362
2273.76.5.64/2673.76.5.65 to 73.76.5.12673.76.5.12762
2373.76.5.128/2673.76.5.129 to 73.76.5.19073.76.5.19162
2473.76.5.192/2673.76.5.193 to 73.76.5.25473.76.5.25562
2573.76.6.0/2673.76.6.1 to 73.76.6.6273.76.6.6362
2673.76.6.64/2673.76.6.65 to 73.76.6.12673.76.6.12762
2773.76.6.128/2673.76.6.129 to 73.76.6.19073.76.6.19162
2873.76.6.192/2673.76.6.193 to 73.76.6.25473.76.6.25562
2973.76.7.0/2673.76.7.1 to 73.76.7.6273.76.7.6362
3073.76.7.64/2673.76.7.65 to 73.76.7.12673.76.7.12762
3173.76.7.128/2673.76.7.129 to 73.76.7.19073.76.7.19162
3273.76.7.192/2673.76.7.193 to 73.76.7.25473.76.7.25562
3373.76.8.0/2673.76.8.1 to 73.76.8.6273.76.8.6362
3473.76.8.64/2673.76.8.65 to 73.76.8.12673.76.8.12762
3573.76.8.128/2673.76.8.129 to 73.76.8.19073.76.8.19162
3673.76.8.192/2673.76.8.193 to 73.76.8.25473.76.8.25562
3773.76.9.0/2673.76.9.1 to 73.76.9.6273.76.9.6362
3873.76.9.64/2673.76.9.65 to 73.76.9.12673.76.9.12762
3973.76.9.128/2673.76.9.129 to 73.76.9.19073.76.9.19162
4073.76.9.192/2673.76.9.193 to 73.76.9.25473.76.9.25562
4173.76.10.0/2673.76.10.1 to 73.76.10.6273.76.10.6362
4273.76.10.64/2673.76.10.65 to 73.76.10.12673.76.10.12762
4373.76.10.128/2673.76.10.129 to 73.76.10.19073.76.10.19162
4473.76.10.192/2673.76.10.193 to 73.76.10.25473.76.10.25562
4573.76.11.0/2673.76.11.1 to 73.76.11.6273.76.11.6362
4673.76.11.64/2673.76.11.65 to 73.76.11.12673.76.11.12762
4773.76.11.128/2673.76.11.129 to 73.76.11.19073.76.11.19162
4873.76.11.192/2673.76.11.193 to 73.76.11.25473.76.11.25562
4973.76.12.0/2673.76.12.1 to 73.76.12.6273.76.12.6362
5073.76.12.64/2673.76.12.65 to 73.76.12.12673.76.12.12762
5173.76.12.128/2673.76.12.129 to 73.76.12.19073.76.12.19162
5273.76.12.192/2673.76.12.193 to 73.76.12.25473.76.12.25562
5373.76.13.0/2673.76.13.1 to 73.76.13.6273.76.13.6362
5473.76.13.64/2673.76.13.65 to 73.76.13.12673.76.13.12762
5573.76.13.128/2673.76.13.129 to 73.76.13.19073.76.13.19162
5673.76.13.192/2673.76.13.193 to 73.76.13.25473.76.13.25562
5773.76.14.0/2673.76.14.1 to 73.76.14.6273.76.14.6362
5873.76.14.64/2673.76.14.65 to 73.76.14.12673.76.14.12762
5973.76.14.128/2673.76.14.129 to 73.76.14.19073.76.14.19162
6073.76.14.192/2673.76.14.193 to 73.76.14.25473.76.14.25562
6173.76.15.0/2673.76.15.1 to 73.76.15.6273.76.15.6362
6273.76.15.64/2673.76.15.65 to 73.76.15.12673.76.15.12762
6373.76.15.128/2673.76.15.129 to 73.76.15.19073.76.15.19162
6473.76.15.192/2673.76.15.193 to 73.76.15.25473.76.15.25562
6573.76.16.0/2673.76.16.1 to 73.76.16.6273.76.16.6362
6673.76.16.64/2673.76.16.65 to 73.76.16.12673.76.16.12762
6773.76.16.128/2673.76.16.129 to 73.76.16.19073.76.16.19162
6873.76.16.192/2673.76.16.193 to 73.76.16.25473.76.16.25562
6973.76.17.0/2673.76.17.1 to 73.76.17.6273.76.17.6362
7073.76.17.64/2673.76.17.65 to 73.76.17.12673.76.17.12762
7173.76.17.128/2673.76.17.129 to 73.76.17.19073.76.17.19162
7273.76.17.192/2673.76.17.193 to 73.76.17.25473.76.17.25562
7373.76.18.0/2673.76.18.1 to 73.76.18.6273.76.18.6362
7473.76.18.64/2673.76.18.65 to 73.76.18.12673.76.18.12762
7573.76.18.128/2673.76.18.129 to 73.76.18.19073.76.18.19162
7673.76.18.192/2673.76.18.193 to 73.76.18.25473.76.18.25562
7773.76.19.0/2673.76.19.1 to 73.76.19.6273.76.19.6362
7873.76.19.64/2673.76.19.65 to 73.76.19.12673.76.19.12762
7973.76.19.128/2673.76.19.129 to 73.76.19.19073.76.19.19162
8073.76.19.192/2673.76.19.193 to 73.76.19.25473.76.19.25562
8173.76.20.0/2673.76.20.1 to 73.76.20.6273.76.20.6362
8273.76.20.64/2673.76.20.65 to 73.76.20.12673.76.20.12762
8373.76.20.128/2673.76.20.129 to 73.76.20.19073.76.20.19162
8473.76.20.192/2673.76.20.193 to 73.76.20.25473.76.20.25562
8573.76.21.0/2673.76.21.1 to 73.76.21.6273.76.21.6362
8673.76.21.64/2673.76.21.65 to 73.76.21.12673.76.21.12762
8773.76.21.128/2673.76.21.129 to 73.76.21.19073.76.21.19162
8873.76.21.192/2673.76.21.193 to 73.76.21.25473.76.21.25562
8973.76.22.0/2673.76.22.1 to 73.76.22.6273.76.22.6362
9073.76.22.64/2673.76.22.65 to 73.76.22.12673.76.22.12762
9173.76.22.128/2673.76.22.129 to 73.76.22.19073.76.22.19162
9273.76.22.192/2673.76.22.193 to 73.76.22.25473.76.22.25562
9373.76.23.0/2673.76.23.1 to 73.76.23.6273.76.23.6362
9473.76.23.64/2673.76.23.65 to 73.76.23.12673.76.23.12762
9573.76.23.128/2673.76.23.129 to 73.76.23.19073.76.23.19162
9673.76.23.192/2673.76.23.193 to 73.76.23.25473.76.23.25562
9773.76.24.0/2673.76.24.1 to 73.76.24.6273.76.24.6362
9873.76.24.64/2673.76.24.65 to 73.76.24.12673.76.24.12762
9973.76.24.128/2673.76.24.129 to 73.76.24.19073.76.24.19162
10073.76.24.192/2673.76.24.193 to 73.76.24.25473.76.24.25562
10173.76.25.0/2673.76.25.1 to 73.76.25.6273.76.25.6362
10273.76.25.64/2673.76.25.65 to 73.76.25.12673.76.25.12762
10373.76.25.128/2673.76.25.129 to 73.76.25.19073.76.25.19162
10473.76.25.192/2673.76.25.193 to 73.76.25.25473.76.25.25562
10573.76.26.0/2673.76.26.1 to 73.76.26.6273.76.26.6362
10673.76.26.64/2673.76.26.65 to 73.76.26.12673.76.26.12762
10773.76.26.128/2673.76.26.129 to 73.76.26.19073.76.26.19162
10873.76.26.192/2673.76.26.193 to 73.76.26.25473.76.26.25562
10973.76.27.0/2673.76.27.1 to 73.76.27.6273.76.27.6362
11073.76.27.64/2673.76.27.65 to 73.76.27.12673.76.27.12762
11173.76.27.128/2673.76.27.129 to 73.76.27.19073.76.27.19162
11273.76.27.192/2673.76.27.193 to 73.76.27.25473.76.27.25562
11373.76.28.0/2673.76.28.1 to 73.76.28.6273.76.28.6362
11473.76.28.64/2673.76.28.65 to 73.76.28.12673.76.28.12762
11573.76.28.128/2673.76.28.129 to 73.76.28.19073.76.28.19162
11673.76.28.192/2673.76.28.193 to 73.76.28.25473.76.28.25562
11773.76.29.0/2673.76.29.1 to 73.76.29.6273.76.29.6362
11873.76.29.64/2673.76.29.65 to 73.76.29.12673.76.29.12762
11973.76.29.128/2673.76.29.129 to 73.76.29.19073.76.29.19162
12073.76.29.192/2673.76.29.193 to 73.76.29.25473.76.29.25562
12173.76.30.0/2673.76.30.1 to 73.76.30.6273.76.30.6362
12273.76.30.64/2673.76.30.65 to 73.76.30.12673.76.30.12762
12373.76.30.128/2673.76.30.129 to 73.76.30.19073.76.30.19162
12473.76.30.192/2673.76.30.193 to 73.76.30.25473.76.30.25562
12573.76.31.0/2673.76.31.1 to 73.76.31.6273.76.31.6362
12673.76.31.64/2673.76.31.65 to 73.76.31.12673.76.31.12762
12773.76.31.128/2673.76.31.129 to 73.76.31.19073.76.31.19162
12873.76.31.192/2673.76.31.193 to 73.76.31.25473.76.31.25562
12973.76.32.0/2673.76.32.1 to 73.76.32.6273.76.32.6362
13073.76.32.64/2673.76.32.65 to 73.76.32.12673.76.32.12762
13173.76.32.128/2673.76.32.129 to 73.76.32.19073.76.32.19162
13273.76.32.192/2673.76.32.193 to 73.76.32.25473.76.32.25562
13373.76.33.0/2673.76.33.1 to 73.76.33.6273.76.33.6362
13473.76.33.64/2673.76.33.65 to 73.76.33.12673.76.33.12762
13573.76.33.128/2673.76.33.129 to 73.76.33.19073.76.33.19162
13673.76.33.192/2673.76.33.193 to 73.76.33.25473.76.33.25562
13773.76.34.0/2673.76.34.1 to 73.76.34.6273.76.34.6362
13873.76.34.64/2673.76.34.65 to 73.76.34.12673.76.34.12762
13973.76.34.128/2673.76.34.129 to 73.76.34.19073.76.34.19162
14073.76.34.192/2673.76.34.193 to 73.76.34.25473.76.34.25562
14173.76.35.0/2673.76.35.1 to 73.76.35.6273.76.35.6362
14273.76.35.64/2673.76.35.65 to 73.76.35.12673.76.35.12762
14373.76.35.128/2673.76.35.129 to 73.76.35.19073.76.35.19162
14473.76.35.192/2673.76.35.193 to 73.76.35.25473.76.35.25562
14573.76.36.0/2673.76.36.1 to 73.76.36.6273.76.36.6362
14673.76.36.64/2673.76.36.65 to 73.76.36.12673.76.36.12762
14773.76.36.128/2673.76.36.129 to 73.76.36.19073.76.36.19162
14873.76.36.192/2673.76.36.193 to 73.76.36.25473.76.36.25562
14973.76.37.0/2673.76.37.1 to 73.76.37.6273.76.37.6362
15073.76.37.64/2673.76.37.65 to 73.76.37.12673.76.37.12762
15173.76.37.128/2673.76.37.129 to 73.76.37.19073.76.37.19162
15273.76.37.192/2673.76.37.193 to 73.76.37.25473.76.37.25562
15373.76.38.0/2673.76.38.1 to 73.76.38.6273.76.38.6362
15473.76.38.64/2673.76.38.65 to 73.76.38.12673.76.38.12762
15573.76.38.128/2673.76.38.129 to 73.76.38.19073.76.38.19162
15673.76.38.192/2673.76.38.193 to 73.76.38.25473.76.38.25562
15773.76.39.0/2673.76.39.1 to 73.76.39.6273.76.39.6362
15873.76.39.64/2673.76.39.65 to 73.76.39.12673.76.39.12762
15973.76.39.128/2673.76.39.129 to 73.76.39.19073.76.39.19162
16073.76.39.192/2673.76.39.193 to 73.76.39.25473.76.39.25562
16173.76.40.0/2673.76.40.1 to 73.76.40.6273.76.40.6362
16273.76.40.64/2673.76.40.65 to 73.76.40.12673.76.40.12762
16373.76.40.128/2673.76.40.129 to 73.76.40.19073.76.40.19162
16473.76.40.192/2673.76.40.193 to 73.76.40.25473.76.40.25562
16573.76.41.0/2673.76.41.1 to 73.76.41.6273.76.41.6362
16673.76.41.64/2673.76.41.65 to 73.76.41.12673.76.41.12762
16773.76.41.128/2673.76.41.129 to 73.76.41.19073.76.41.19162
16873.76.41.192/2673.76.41.193 to 73.76.41.25473.76.41.25562
16973.76.42.0/2673.76.42.1 to 73.76.42.6273.76.42.6362
17073.76.42.64/2673.76.42.65 to 73.76.42.12673.76.42.12762
17173.76.42.128/2673.76.42.129 to 73.76.42.19073.76.42.19162
17273.76.42.192/2673.76.42.193 to 73.76.42.25473.76.42.25562
17373.76.43.0/2673.76.43.1 to 73.76.43.6273.76.43.6362
17473.76.43.64/2673.76.43.65 to 73.76.43.12673.76.43.12762
17573.76.43.128/2673.76.43.129 to 73.76.43.19073.76.43.19162
17673.76.43.192/2673.76.43.193 to 73.76.43.25473.76.43.25562
17773.76.44.0/2673.76.44.1 to 73.76.44.6273.76.44.6362
17873.76.44.64/2673.76.44.65 to 73.76.44.12673.76.44.12762
17973.76.44.128/2673.76.44.129 to 73.76.44.19073.76.44.19162
18073.76.44.192/2673.76.44.193 to 73.76.44.25473.76.44.25562
18173.76.45.0/2673.76.45.1 to 73.76.45.6273.76.45.6362
18273.76.45.64/2673.76.45.65 to 73.76.45.12673.76.45.12762
18373.76.45.128/2673.76.45.129 to 73.76.45.19073.76.45.19162
18473.76.45.192/2673.76.45.193 to 73.76.45.25473.76.45.25562
18573.76.46.0/2673.76.46.1 to 73.76.46.6273.76.46.6362
18673.76.46.64/2673.76.46.65 to 73.76.46.12673.76.46.12762
18773.76.46.128/2673.76.46.129 to 73.76.46.19073.76.46.19162
18873.76.46.192/2673.76.46.193 to 73.76.46.25473.76.46.25562
18973.76.47.0/2673.76.47.1 to 73.76.47.6273.76.47.6362
19073.76.47.64/2673.76.47.65 to 73.76.47.12673.76.47.12762
19173.76.47.128/2673.76.47.129 to 73.76.47.19073.76.47.19162
19273.76.47.192/2673.76.47.193 to 73.76.47.25473.76.47.25562
19373.76.48.0/2673.76.48.1 to 73.76.48.6273.76.48.6362
19473.76.48.64/2673.76.48.65 to 73.76.48.12673.76.48.12762
19573.76.48.128/2673.76.48.129 to 73.76.48.19073.76.48.19162
19673.76.48.192/2673.76.48.193 to 73.76.48.25473.76.48.25562
19773.76.49.0/2673.76.49.1 to 73.76.49.6273.76.49.6362
19873.76.49.64/2673.76.49.65 to 73.76.49.12673.76.49.12762
19973.76.49.128/2673.76.49.129 to 73.76.49.19073.76.49.19162
20073.76.49.192/2673.76.49.193 to 73.76.49.25473.76.49.25562
20173.76.50.0/2673.76.50.1 to 73.76.50.6273.76.50.6362
20273.76.50.64/2673.76.50.65 to 73.76.50.12673.76.50.12762
20373.76.50.128/2673.76.50.129 to 73.76.50.19073.76.50.19162
20473.76.50.192/2673.76.50.193 to 73.76.50.25473.76.50.25562
20573.76.51.0/2673.76.51.1 to 73.76.51.6273.76.51.6362
20673.76.51.64/2673.76.51.65 to 73.76.51.12673.76.51.12762
20773.76.51.128/2673.76.51.129 to 73.76.51.19073.76.51.19162
20873.76.51.192/2673.76.51.193 to 73.76.51.25473.76.51.25562
20973.76.52.0/2673.76.52.1 to 73.76.52.6273.76.52.6362
21073.76.52.64/2673.76.52.65 to 73.76.52.12673.76.52.12762
21173.76.52.128/2673.76.52.129 to 73.76.52.19073.76.52.19162
21273.76.52.192/2673.76.52.193 to 73.76.52.25473.76.52.25562
21373.76.53.0/2673.76.53.1 to 73.76.53.6273.76.53.6362
21473.76.53.64/2673.76.53.65 to 73.76.53.12673.76.53.12762
21573.76.53.128/2673.76.53.129 to 73.76.53.19073.76.53.19162
21673.76.53.192/2673.76.53.193 to 73.76.53.25473.76.53.25562
21773.76.54.0/2673.76.54.1 to 73.76.54.6273.76.54.6362
21873.76.54.64/2673.76.54.65 to 73.76.54.12673.76.54.12762
21973.76.54.128/2673.76.54.129 to 73.76.54.19073.76.54.19162
22073.76.54.192/2673.76.54.193 to 73.76.54.25473.76.54.25562
22173.76.55.0/2673.76.55.1 to 73.76.55.6273.76.55.6362
22273.76.55.64/2673.76.55.65 to 73.76.55.12673.76.55.12762
22373.76.55.128/2673.76.55.129 to 73.76.55.19073.76.55.19162
22473.76.55.192/2673.76.55.193 to 73.76.55.25473.76.55.25562
22573.76.56.0/2673.76.56.1 to 73.76.56.6273.76.56.6362
22673.76.56.64/2673.76.56.65 to 73.76.56.12673.76.56.12762
22773.76.56.128/2673.76.56.129 to 73.76.56.19073.76.56.19162
22873.76.56.192/2673.76.56.193 to 73.76.56.25473.76.56.25562
22973.76.57.0/2673.76.57.1 to 73.76.57.6273.76.57.6362
23073.76.57.64/2673.76.57.65 to 73.76.57.12673.76.57.12762
23173.76.57.128/2673.76.57.129 to 73.76.57.19073.76.57.19162
23273.76.57.192/2673.76.57.193 to 73.76.57.25473.76.57.25562
23373.76.58.0/2673.76.58.1 to 73.76.58.6273.76.58.6362
23473.76.58.64/2673.76.58.65 to 73.76.58.12673.76.58.12762
23573.76.58.128/2673.76.58.129 to 73.76.58.19073.76.58.19162
23673.76.58.192/2673.76.58.193 to 73.76.58.25473.76.58.25562
23773.76.59.0/2673.76.59.1 to 73.76.59.6273.76.59.6362
23873.76.59.64/2673.76.59.65 to 73.76.59.12673.76.59.12762
23973.76.59.128/2673.76.59.129 to 73.76.59.19073.76.59.19162
24073.76.59.192/2673.76.59.193 to 73.76.59.25473.76.59.25562
24173.76.60.0/2673.76.60.1 to 73.76.60.6273.76.60.6362
24273.76.60.64/2673.76.60.65 to 73.76.60.12673.76.60.12762
24373.76.60.128/2673.76.60.129 to 73.76.60.19073.76.60.19162
24473.76.60.192/2673.76.60.193 to 73.76.60.25473.76.60.25562
24573.76.61.0/2673.76.61.1 to 73.76.61.6273.76.61.6362
24673.76.61.64/2673.76.61.65 to 73.76.61.12673.76.61.12762
24773.76.61.128/2673.76.61.129 to 73.76.61.19073.76.61.19162
24873.76.61.192/2673.76.61.193 to 73.76.61.25473.76.61.25562
24973.76.62.0/2673.76.62.1 to 73.76.62.6273.76.62.6362
25073.76.62.64/2673.76.62.65 to 73.76.62.12673.76.62.12762
25173.76.62.128/2673.76.62.129 to 73.76.62.19073.76.62.19162
25273.76.62.192/2673.76.62.193 to 73.76.62.25473.76.62.25562
25373.76.63.0/2673.76.63.1 to 73.76.63.6273.76.63.6362
25473.76.63.64/2673.76.63.65 to 73.76.63.12673.76.63.12762
25573.76.63.128/2673.76.63.129 to 73.76.63.19073.76.63.19162
25673.76.63.192/2673.76.63.193 to 73.76.63.25473.76.63.25562

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.