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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.

Network43.89.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
43.89.0.0
Broadcast address
43.89.127.255
First usable
43.89.0.1
Last usable
43.89.127.254
Usable hosts
32,766 (32,768 less the network and broadcast addresses)
Subnet mask
255.255.128.0
Wildcard mask
0.0.127.255 (Cisco ACLs, OSPF)
Prefix length
/17
Type
Public public
Old class
A (default /8)
As numbers
Hex 2B590000 · Integer 727252992 to 727285759
Reverse DNS zones
0.89.43.in-addr.arpa
1.89.43.in-addr.arpa
2.89.43.in-addr.arpa
3.89.43.in-addr.arpa
4.89.43.in-addr.arpa
5.89.43.in-addr.arpa
6.89.43.in-addr.arpa
7.89.43.in-addr.arpa
8.89.43.in-addr.arpa
9.89.43.in-addr.arpa
10.89.43.in-addr.arpa
11.89.43.in-addr.arpa
12.89.43.in-addr.arpa
13.89.43.in-addr.arpa
14.89.43.in-addr.arpa
15.89.43.in-addr.arpa
and 112 more
/17 is not on a 8-bit boundary, so it takes 128 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00101011.01011001.00000000.0000000043.89.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network00101011.01011001.00000000.0000000043.89.0.0
Broadcast00101011.01011001.01111111.1111111143.89.127.255
Split into smaller subnets/26
/18 (2)/19 (4)/20 (8)/21 (16)/22 (32)/23 (64)/24 (128)/25 (256)/26 (512)/27 (1,024)/28 (2,048)/29 (4,096)

43.89.0.0/17 makes 512 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
143.89.0.0/2643.89.0.1 to 43.89.0.6243.89.0.6362
243.89.0.64/2643.89.0.65 to 43.89.0.12643.89.0.12762
343.89.0.128/2643.89.0.129 to 43.89.0.19043.89.0.19162
443.89.0.192/2643.89.0.193 to 43.89.0.25443.89.0.25562
543.89.1.0/2643.89.1.1 to 43.89.1.6243.89.1.6362
643.89.1.64/2643.89.1.65 to 43.89.1.12643.89.1.12762
743.89.1.128/2643.89.1.129 to 43.89.1.19043.89.1.19162
843.89.1.192/2643.89.1.193 to 43.89.1.25443.89.1.25562
943.89.2.0/2643.89.2.1 to 43.89.2.6243.89.2.6362
1043.89.2.64/2643.89.2.65 to 43.89.2.12643.89.2.12762
1143.89.2.128/2643.89.2.129 to 43.89.2.19043.89.2.19162
1243.89.2.192/2643.89.2.193 to 43.89.2.25443.89.2.25562
1343.89.3.0/2643.89.3.1 to 43.89.3.6243.89.3.6362
1443.89.3.64/2643.89.3.65 to 43.89.3.12643.89.3.12762
1543.89.3.128/2643.89.3.129 to 43.89.3.19043.89.3.19162
1643.89.3.192/2643.89.3.193 to 43.89.3.25443.89.3.25562
1743.89.4.0/2643.89.4.1 to 43.89.4.6243.89.4.6362
1843.89.4.64/2643.89.4.65 to 43.89.4.12643.89.4.12762
1943.89.4.128/2643.89.4.129 to 43.89.4.19043.89.4.19162
2043.89.4.192/2643.89.4.193 to 43.89.4.25443.89.4.25562
2143.89.5.0/2643.89.5.1 to 43.89.5.6243.89.5.6362
2243.89.5.64/2643.89.5.65 to 43.89.5.12643.89.5.12762
2343.89.5.128/2643.89.5.129 to 43.89.5.19043.89.5.19162
2443.89.5.192/2643.89.5.193 to 43.89.5.25443.89.5.25562
2543.89.6.0/2643.89.6.1 to 43.89.6.6243.89.6.6362
2643.89.6.64/2643.89.6.65 to 43.89.6.12643.89.6.12762
2743.89.6.128/2643.89.6.129 to 43.89.6.19043.89.6.19162
2843.89.6.192/2643.89.6.193 to 43.89.6.25443.89.6.25562
2943.89.7.0/2643.89.7.1 to 43.89.7.6243.89.7.6362
3043.89.7.64/2643.89.7.65 to 43.89.7.12643.89.7.12762
3143.89.7.128/2643.89.7.129 to 43.89.7.19043.89.7.19162
3243.89.7.192/2643.89.7.193 to 43.89.7.25443.89.7.25562
3343.89.8.0/2643.89.8.1 to 43.89.8.6243.89.8.6362
3443.89.8.64/2643.89.8.65 to 43.89.8.12643.89.8.12762
3543.89.8.128/2643.89.8.129 to 43.89.8.19043.89.8.19162
3643.89.8.192/2643.89.8.193 to 43.89.8.25443.89.8.25562
3743.89.9.0/2643.89.9.1 to 43.89.9.6243.89.9.6362
3843.89.9.64/2643.89.9.65 to 43.89.9.12643.89.9.12762
3943.89.9.128/2643.89.9.129 to 43.89.9.19043.89.9.19162
4043.89.9.192/2643.89.9.193 to 43.89.9.25443.89.9.25562
4143.89.10.0/2643.89.10.1 to 43.89.10.6243.89.10.6362
4243.89.10.64/2643.89.10.65 to 43.89.10.12643.89.10.12762
4343.89.10.128/2643.89.10.129 to 43.89.10.19043.89.10.19162
4443.89.10.192/2643.89.10.193 to 43.89.10.25443.89.10.25562
4543.89.11.0/2643.89.11.1 to 43.89.11.6243.89.11.6362
4643.89.11.64/2643.89.11.65 to 43.89.11.12643.89.11.12762
4743.89.11.128/2643.89.11.129 to 43.89.11.19043.89.11.19162
4843.89.11.192/2643.89.11.193 to 43.89.11.25443.89.11.25562
4943.89.12.0/2643.89.12.1 to 43.89.12.6243.89.12.6362
5043.89.12.64/2643.89.12.65 to 43.89.12.12643.89.12.12762
5143.89.12.128/2643.89.12.129 to 43.89.12.19043.89.12.19162
5243.89.12.192/2643.89.12.193 to 43.89.12.25443.89.12.25562
5343.89.13.0/2643.89.13.1 to 43.89.13.6243.89.13.6362
5443.89.13.64/2643.89.13.65 to 43.89.13.12643.89.13.12762
5543.89.13.128/2643.89.13.129 to 43.89.13.19043.89.13.19162
5643.89.13.192/2643.89.13.193 to 43.89.13.25443.89.13.25562
5743.89.14.0/2643.89.14.1 to 43.89.14.6243.89.14.6362
5843.89.14.64/2643.89.14.65 to 43.89.14.12643.89.14.12762
5943.89.14.128/2643.89.14.129 to 43.89.14.19043.89.14.19162
6043.89.14.192/2643.89.14.193 to 43.89.14.25443.89.14.25562
6143.89.15.0/2643.89.15.1 to 43.89.15.6243.89.15.6362
6243.89.15.64/2643.89.15.65 to 43.89.15.12643.89.15.12762
6343.89.15.128/2643.89.15.129 to 43.89.15.19043.89.15.19162
6443.89.15.192/2643.89.15.193 to 43.89.15.25443.89.15.25562
6543.89.16.0/2643.89.16.1 to 43.89.16.6243.89.16.6362
6643.89.16.64/2643.89.16.65 to 43.89.16.12643.89.16.12762
6743.89.16.128/2643.89.16.129 to 43.89.16.19043.89.16.19162
6843.89.16.192/2643.89.16.193 to 43.89.16.25443.89.16.25562
6943.89.17.0/2643.89.17.1 to 43.89.17.6243.89.17.6362
7043.89.17.64/2643.89.17.65 to 43.89.17.12643.89.17.12762
7143.89.17.128/2643.89.17.129 to 43.89.17.19043.89.17.19162
7243.89.17.192/2643.89.17.193 to 43.89.17.25443.89.17.25562
7343.89.18.0/2643.89.18.1 to 43.89.18.6243.89.18.6362
7443.89.18.64/2643.89.18.65 to 43.89.18.12643.89.18.12762
7543.89.18.128/2643.89.18.129 to 43.89.18.19043.89.18.19162
7643.89.18.192/2643.89.18.193 to 43.89.18.25443.89.18.25562
7743.89.19.0/2643.89.19.1 to 43.89.19.6243.89.19.6362
7843.89.19.64/2643.89.19.65 to 43.89.19.12643.89.19.12762
7943.89.19.128/2643.89.19.129 to 43.89.19.19043.89.19.19162
8043.89.19.192/2643.89.19.193 to 43.89.19.25443.89.19.25562
8143.89.20.0/2643.89.20.1 to 43.89.20.6243.89.20.6362
8243.89.20.64/2643.89.20.65 to 43.89.20.12643.89.20.12762
8343.89.20.128/2643.89.20.129 to 43.89.20.19043.89.20.19162
8443.89.20.192/2643.89.20.193 to 43.89.20.25443.89.20.25562
8543.89.21.0/2643.89.21.1 to 43.89.21.6243.89.21.6362
8643.89.21.64/2643.89.21.65 to 43.89.21.12643.89.21.12762
8743.89.21.128/2643.89.21.129 to 43.89.21.19043.89.21.19162
8843.89.21.192/2643.89.21.193 to 43.89.21.25443.89.21.25562
8943.89.22.0/2643.89.22.1 to 43.89.22.6243.89.22.6362
9043.89.22.64/2643.89.22.65 to 43.89.22.12643.89.22.12762
9143.89.22.128/2643.89.22.129 to 43.89.22.19043.89.22.19162
9243.89.22.192/2643.89.22.193 to 43.89.22.25443.89.22.25562
9343.89.23.0/2643.89.23.1 to 43.89.23.6243.89.23.6362
9443.89.23.64/2643.89.23.65 to 43.89.23.12643.89.23.12762
9543.89.23.128/2643.89.23.129 to 43.89.23.19043.89.23.19162
9643.89.23.192/2643.89.23.193 to 43.89.23.25443.89.23.25562
9743.89.24.0/2643.89.24.1 to 43.89.24.6243.89.24.6362
9843.89.24.64/2643.89.24.65 to 43.89.24.12643.89.24.12762
9943.89.24.128/2643.89.24.129 to 43.89.24.19043.89.24.19162
10043.89.24.192/2643.89.24.193 to 43.89.24.25443.89.24.25562
10143.89.25.0/2643.89.25.1 to 43.89.25.6243.89.25.6362
10243.89.25.64/2643.89.25.65 to 43.89.25.12643.89.25.12762
10343.89.25.128/2643.89.25.129 to 43.89.25.19043.89.25.19162
10443.89.25.192/2643.89.25.193 to 43.89.25.25443.89.25.25562
10543.89.26.0/2643.89.26.1 to 43.89.26.6243.89.26.6362
10643.89.26.64/2643.89.26.65 to 43.89.26.12643.89.26.12762
10743.89.26.128/2643.89.26.129 to 43.89.26.19043.89.26.19162
10843.89.26.192/2643.89.26.193 to 43.89.26.25443.89.26.25562
10943.89.27.0/2643.89.27.1 to 43.89.27.6243.89.27.6362
11043.89.27.64/2643.89.27.65 to 43.89.27.12643.89.27.12762
11143.89.27.128/2643.89.27.129 to 43.89.27.19043.89.27.19162
11243.89.27.192/2643.89.27.193 to 43.89.27.25443.89.27.25562
11343.89.28.0/2643.89.28.1 to 43.89.28.6243.89.28.6362
11443.89.28.64/2643.89.28.65 to 43.89.28.12643.89.28.12762
11543.89.28.128/2643.89.28.129 to 43.89.28.19043.89.28.19162
11643.89.28.192/2643.89.28.193 to 43.89.28.25443.89.28.25562
11743.89.29.0/2643.89.29.1 to 43.89.29.6243.89.29.6362
11843.89.29.64/2643.89.29.65 to 43.89.29.12643.89.29.12762
11943.89.29.128/2643.89.29.129 to 43.89.29.19043.89.29.19162
12043.89.29.192/2643.89.29.193 to 43.89.29.25443.89.29.25562
12143.89.30.0/2643.89.30.1 to 43.89.30.6243.89.30.6362
12243.89.30.64/2643.89.30.65 to 43.89.30.12643.89.30.12762
12343.89.30.128/2643.89.30.129 to 43.89.30.19043.89.30.19162
12443.89.30.192/2643.89.30.193 to 43.89.30.25443.89.30.25562
12543.89.31.0/2643.89.31.1 to 43.89.31.6243.89.31.6362
12643.89.31.64/2643.89.31.65 to 43.89.31.12643.89.31.12762
12743.89.31.128/2643.89.31.129 to 43.89.31.19043.89.31.19162
12843.89.31.192/2643.89.31.193 to 43.89.31.25443.89.31.25562
12943.89.32.0/2643.89.32.1 to 43.89.32.6243.89.32.6362
13043.89.32.64/2643.89.32.65 to 43.89.32.12643.89.32.12762
13143.89.32.128/2643.89.32.129 to 43.89.32.19043.89.32.19162
13243.89.32.192/2643.89.32.193 to 43.89.32.25443.89.32.25562
13343.89.33.0/2643.89.33.1 to 43.89.33.6243.89.33.6362
13443.89.33.64/2643.89.33.65 to 43.89.33.12643.89.33.12762
13543.89.33.128/2643.89.33.129 to 43.89.33.19043.89.33.19162
13643.89.33.192/2643.89.33.193 to 43.89.33.25443.89.33.25562
13743.89.34.0/2643.89.34.1 to 43.89.34.6243.89.34.6362
13843.89.34.64/2643.89.34.65 to 43.89.34.12643.89.34.12762
13943.89.34.128/2643.89.34.129 to 43.89.34.19043.89.34.19162
14043.89.34.192/2643.89.34.193 to 43.89.34.25443.89.34.25562
14143.89.35.0/2643.89.35.1 to 43.89.35.6243.89.35.6362
14243.89.35.64/2643.89.35.65 to 43.89.35.12643.89.35.12762
14343.89.35.128/2643.89.35.129 to 43.89.35.19043.89.35.19162
14443.89.35.192/2643.89.35.193 to 43.89.35.25443.89.35.25562
14543.89.36.0/2643.89.36.1 to 43.89.36.6243.89.36.6362
14643.89.36.64/2643.89.36.65 to 43.89.36.12643.89.36.12762
14743.89.36.128/2643.89.36.129 to 43.89.36.19043.89.36.19162
14843.89.36.192/2643.89.36.193 to 43.89.36.25443.89.36.25562
14943.89.37.0/2643.89.37.1 to 43.89.37.6243.89.37.6362
15043.89.37.64/2643.89.37.65 to 43.89.37.12643.89.37.12762
15143.89.37.128/2643.89.37.129 to 43.89.37.19043.89.37.19162
15243.89.37.192/2643.89.37.193 to 43.89.37.25443.89.37.25562
15343.89.38.0/2643.89.38.1 to 43.89.38.6243.89.38.6362
15443.89.38.64/2643.89.38.65 to 43.89.38.12643.89.38.12762
15543.89.38.128/2643.89.38.129 to 43.89.38.19043.89.38.19162
15643.89.38.192/2643.89.38.193 to 43.89.38.25443.89.38.25562
15743.89.39.0/2643.89.39.1 to 43.89.39.6243.89.39.6362
15843.89.39.64/2643.89.39.65 to 43.89.39.12643.89.39.12762
15943.89.39.128/2643.89.39.129 to 43.89.39.19043.89.39.19162
16043.89.39.192/2643.89.39.193 to 43.89.39.25443.89.39.25562
16143.89.40.0/2643.89.40.1 to 43.89.40.6243.89.40.6362
16243.89.40.64/2643.89.40.65 to 43.89.40.12643.89.40.12762
16343.89.40.128/2643.89.40.129 to 43.89.40.19043.89.40.19162
16443.89.40.192/2643.89.40.193 to 43.89.40.25443.89.40.25562
16543.89.41.0/2643.89.41.1 to 43.89.41.6243.89.41.6362
16643.89.41.64/2643.89.41.65 to 43.89.41.12643.89.41.12762
16743.89.41.128/2643.89.41.129 to 43.89.41.19043.89.41.19162
16843.89.41.192/2643.89.41.193 to 43.89.41.25443.89.41.25562
16943.89.42.0/2643.89.42.1 to 43.89.42.6243.89.42.6362
17043.89.42.64/2643.89.42.65 to 43.89.42.12643.89.42.12762
17143.89.42.128/2643.89.42.129 to 43.89.42.19043.89.42.19162
17243.89.42.192/2643.89.42.193 to 43.89.42.25443.89.42.25562
17343.89.43.0/2643.89.43.1 to 43.89.43.6243.89.43.6362
17443.89.43.64/2643.89.43.65 to 43.89.43.12643.89.43.12762
17543.89.43.128/2643.89.43.129 to 43.89.43.19043.89.43.19162
17643.89.43.192/2643.89.43.193 to 43.89.43.25443.89.43.25562
17743.89.44.0/2643.89.44.1 to 43.89.44.6243.89.44.6362
17843.89.44.64/2643.89.44.65 to 43.89.44.12643.89.44.12762
17943.89.44.128/2643.89.44.129 to 43.89.44.19043.89.44.19162
18043.89.44.192/2643.89.44.193 to 43.89.44.25443.89.44.25562
18143.89.45.0/2643.89.45.1 to 43.89.45.6243.89.45.6362
18243.89.45.64/2643.89.45.65 to 43.89.45.12643.89.45.12762
18343.89.45.128/2643.89.45.129 to 43.89.45.19043.89.45.19162
18443.89.45.192/2643.89.45.193 to 43.89.45.25443.89.45.25562
18543.89.46.0/2643.89.46.1 to 43.89.46.6243.89.46.6362
18643.89.46.64/2643.89.46.65 to 43.89.46.12643.89.46.12762
18743.89.46.128/2643.89.46.129 to 43.89.46.19043.89.46.19162
18843.89.46.192/2643.89.46.193 to 43.89.46.25443.89.46.25562
18943.89.47.0/2643.89.47.1 to 43.89.47.6243.89.47.6362
19043.89.47.64/2643.89.47.65 to 43.89.47.12643.89.47.12762
19143.89.47.128/2643.89.47.129 to 43.89.47.19043.89.47.19162
19243.89.47.192/2643.89.47.193 to 43.89.47.25443.89.47.25562
19343.89.48.0/2643.89.48.1 to 43.89.48.6243.89.48.6362
19443.89.48.64/2643.89.48.65 to 43.89.48.12643.89.48.12762
19543.89.48.128/2643.89.48.129 to 43.89.48.19043.89.48.19162
19643.89.48.192/2643.89.48.193 to 43.89.48.25443.89.48.25562
19743.89.49.0/2643.89.49.1 to 43.89.49.6243.89.49.6362
19843.89.49.64/2643.89.49.65 to 43.89.49.12643.89.49.12762
19943.89.49.128/2643.89.49.129 to 43.89.49.19043.89.49.19162
20043.89.49.192/2643.89.49.193 to 43.89.49.25443.89.49.25562
20143.89.50.0/2643.89.50.1 to 43.89.50.6243.89.50.6362
20243.89.50.64/2643.89.50.65 to 43.89.50.12643.89.50.12762
20343.89.50.128/2643.89.50.129 to 43.89.50.19043.89.50.19162
20443.89.50.192/2643.89.50.193 to 43.89.50.25443.89.50.25562
20543.89.51.0/2643.89.51.1 to 43.89.51.6243.89.51.6362
20643.89.51.64/2643.89.51.65 to 43.89.51.12643.89.51.12762
20743.89.51.128/2643.89.51.129 to 43.89.51.19043.89.51.19162
20843.89.51.192/2643.89.51.193 to 43.89.51.25443.89.51.25562
20943.89.52.0/2643.89.52.1 to 43.89.52.6243.89.52.6362
21043.89.52.64/2643.89.52.65 to 43.89.52.12643.89.52.12762
21143.89.52.128/2643.89.52.129 to 43.89.52.19043.89.52.19162
21243.89.52.192/2643.89.52.193 to 43.89.52.25443.89.52.25562
21343.89.53.0/2643.89.53.1 to 43.89.53.6243.89.53.6362
21443.89.53.64/2643.89.53.65 to 43.89.53.12643.89.53.12762
21543.89.53.128/2643.89.53.129 to 43.89.53.19043.89.53.19162
21643.89.53.192/2643.89.53.193 to 43.89.53.25443.89.53.25562
21743.89.54.0/2643.89.54.1 to 43.89.54.6243.89.54.6362
21843.89.54.64/2643.89.54.65 to 43.89.54.12643.89.54.12762
21943.89.54.128/2643.89.54.129 to 43.89.54.19043.89.54.19162
22043.89.54.192/2643.89.54.193 to 43.89.54.25443.89.54.25562
22143.89.55.0/2643.89.55.1 to 43.89.55.6243.89.55.6362
22243.89.55.64/2643.89.55.65 to 43.89.55.12643.89.55.12762
22343.89.55.128/2643.89.55.129 to 43.89.55.19043.89.55.19162
22443.89.55.192/2643.89.55.193 to 43.89.55.25443.89.55.25562
22543.89.56.0/2643.89.56.1 to 43.89.56.6243.89.56.6362
22643.89.56.64/2643.89.56.65 to 43.89.56.12643.89.56.12762
22743.89.56.128/2643.89.56.129 to 43.89.56.19043.89.56.19162
22843.89.56.192/2643.89.56.193 to 43.89.56.25443.89.56.25562
22943.89.57.0/2643.89.57.1 to 43.89.57.6243.89.57.6362
23043.89.57.64/2643.89.57.65 to 43.89.57.12643.89.57.12762
23143.89.57.128/2643.89.57.129 to 43.89.57.19043.89.57.19162
23243.89.57.192/2643.89.57.193 to 43.89.57.25443.89.57.25562
23343.89.58.0/2643.89.58.1 to 43.89.58.6243.89.58.6362
23443.89.58.64/2643.89.58.65 to 43.89.58.12643.89.58.12762
23543.89.58.128/2643.89.58.129 to 43.89.58.19043.89.58.19162
23643.89.58.192/2643.89.58.193 to 43.89.58.25443.89.58.25562
23743.89.59.0/2643.89.59.1 to 43.89.59.6243.89.59.6362
23843.89.59.64/2643.89.59.65 to 43.89.59.12643.89.59.12762
23943.89.59.128/2643.89.59.129 to 43.89.59.19043.89.59.19162
24043.89.59.192/2643.89.59.193 to 43.89.59.25443.89.59.25562
24143.89.60.0/2643.89.60.1 to 43.89.60.6243.89.60.6362
24243.89.60.64/2643.89.60.65 to 43.89.60.12643.89.60.12762
24343.89.60.128/2643.89.60.129 to 43.89.60.19043.89.60.19162
24443.89.60.192/2643.89.60.193 to 43.89.60.25443.89.60.25562
24543.89.61.0/2643.89.61.1 to 43.89.61.6243.89.61.6362
24643.89.61.64/2643.89.61.65 to 43.89.61.12643.89.61.12762
24743.89.61.128/2643.89.61.129 to 43.89.61.19043.89.61.19162
24843.89.61.192/2643.89.61.193 to 43.89.61.25443.89.61.25562
24943.89.62.0/2643.89.62.1 to 43.89.62.6243.89.62.6362
25043.89.62.64/2643.89.62.65 to 43.89.62.12643.89.62.12762
25143.89.62.128/2643.89.62.129 to 43.89.62.19043.89.62.19162
25243.89.62.192/2643.89.62.193 to 43.89.62.25443.89.62.25562
25343.89.63.0/2643.89.63.1 to 43.89.63.6243.89.63.6362
25443.89.63.64/2643.89.63.65 to 43.89.63.12643.89.63.12762
25543.89.63.128/2643.89.63.129 to 43.89.63.19043.89.63.19162
25643.89.63.192/2643.89.63.193 to 43.89.63.25443.89.63.25562

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.