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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.

Network80.4.48.0/20
Usable hosts4,094
Subnet mask255.255.240.0
Addresses4,096
Network address
80.4.48.0
Broadcast address
80.4.63.255
First usable
80.4.48.1
Last usable
80.4.63.254
Usable hosts
4,094 (4,096 less the network and broadcast addresses)
Subnet mask
255.255.240.0
Wildcard mask
0.0.15.255 (Cisco ACLs, OSPF)
Prefix length
/20
Type
Public public
Old class
A (default /8)
As numbers
Hex 50043000 · Integer 1342451712 to 1342455807
Reverse DNS zones
48.4.80.in-addr.arpa
49.4.80.in-addr.arpa
50.4.80.in-addr.arpa
51.4.80.in-addr.arpa
52.4.80.in-addr.arpa
53.4.80.in-addr.arpa
54.4.80.in-addr.arpa
55.4.80.in-addr.arpa
56.4.80.in-addr.arpa
57.4.80.in-addr.arpa
58.4.80.in-addr.arpa
59.4.80.in-addr.arpa
60.4.80.in-addr.arpa
61.4.80.in-addr.arpa
62.4.80.in-addr.arpa
63.4.80.in-addr.arpa
/20 is not on a 8-bit boundary, so it takes 16 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01010000.00000100.00110000.0000000080.4.48.0
Subnet mask11111111.11111111.11110000.00000000255.255.240.0
Network01010000.00000100.00110000.0000000080.4.48.0
Broadcast01010000.00000100.00111111.1111111180.4.63.255
Split into smaller subnets/28
/21 (2)/22 (4)/23 (8)/24 (16)/25 (32)/26 (64)/27 (128)/28 (256)/29 (512)/30 (1,024)/31 (2,048)/32 (4,096)

80.4.48.0/20 makes 256 subnets of /28.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
180.4.48.0/2880.4.48.1 to 80.4.48.1480.4.48.1514
280.4.48.16/2880.4.48.17 to 80.4.48.3080.4.48.3114
380.4.48.32/2880.4.48.33 to 80.4.48.4680.4.48.4714
480.4.48.48/2880.4.48.49 to 80.4.48.6280.4.48.6314
580.4.48.64/2880.4.48.65 to 80.4.48.7880.4.48.7914
680.4.48.80/2880.4.48.81 to 80.4.48.9480.4.48.9514
780.4.48.96/2880.4.48.97 to 80.4.48.11080.4.48.11114
880.4.48.112/2880.4.48.113 to 80.4.48.12680.4.48.12714
980.4.48.128/2880.4.48.129 to 80.4.48.14280.4.48.14314
1080.4.48.144/2880.4.48.145 to 80.4.48.15880.4.48.15914
1180.4.48.160/2880.4.48.161 to 80.4.48.17480.4.48.17514
1280.4.48.176/2880.4.48.177 to 80.4.48.19080.4.48.19114
1380.4.48.192/2880.4.48.193 to 80.4.48.20680.4.48.20714
1480.4.48.208/2880.4.48.209 to 80.4.48.22280.4.48.22314
1580.4.48.224/2880.4.48.225 to 80.4.48.23880.4.48.23914
1680.4.48.240/2880.4.48.241 to 80.4.48.25480.4.48.25514
1780.4.49.0/2880.4.49.1 to 80.4.49.1480.4.49.1514
1880.4.49.16/2880.4.49.17 to 80.4.49.3080.4.49.3114
1980.4.49.32/2880.4.49.33 to 80.4.49.4680.4.49.4714
2080.4.49.48/2880.4.49.49 to 80.4.49.6280.4.49.6314
2180.4.49.64/2880.4.49.65 to 80.4.49.7880.4.49.7914
2280.4.49.80/2880.4.49.81 to 80.4.49.9480.4.49.9514
2380.4.49.96/2880.4.49.97 to 80.4.49.11080.4.49.11114
2480.4.49.112/2880.4.49.113 to 80.4.49.12680.4.49.12714
2580.4.49.128/2880.4.49.129 to 80.4.49.14280.4.49.14314
2680.4.49.144/2880.4.49.145 to 80.4.49.15880.4.49.15914
2780.4.49.160/2880.4.49.161 to 80.4.49.17480.4.49.17514
2880.4.49.176/2880.4.49.177 to 80.4.49.19080.4.49.19114
2980.4.49.192/2880.4.49.193 to 80.4.49.20680.4.49.20714
3080.4.49.208/2880.4.49.209 to 80.4.49.22280.4.49.22314
3180.4.49.224/2880.4.49.225 to 80.4.49.23880.4.49.23914
3280.4.49.240/2880.4.49.241 to 80.4.49.25480.4.49.25514
3380.4.50.0/2880.4.50.1 to 80.4.50.1480.4.50.1514
3480.4.50.16/2880.4.50.17 to 80.4.50.3080.4.50.3114
3580.4.50.32/2880.4.50.33 to 80.4.50.4680.4.50.4714
3680.4.50.48/2880.4.50.49 to 80.4.50.6280.4.50.6314
3780.4.50.64/2880.4.50.65 to 80.4.50.7880.4.50.7914
3880.4.50.80/2880.4.50.81 to 80.4.50.9480.4.50.9514
3980.4.50.96/2880.4.50.97 to 80.4.50.11080.4.50.11114
4080.4.50.112/2880.4.50.113 to 80.4.50.12680.4.50.12714
4180.4.50.128/2880.4.50.129 to 80.4.50.14280.4.50.14314
4280.4.50.144/2880.4.50.145 to 80.4.50.15880.4.50.15914
4380.4.50.160/2880.4.50.161 to 80.4.50.17480.4.50.17514
4480.4.50.176/2880.4.50.177 to 80.4.50.19080.4.50.19114
4580.4.50.192/2880.4.50.193 to 80.4.50.20680.4.50.20714
4680.4.50.208/2880.4.50.209 to 80.4.50.22280.4.50.22314
4780.4.50.224/2880.4.50.225 to 80.4.50.23880.4.50.23914
4880.4.50.240/2880.4.50.241 to 80.4.50.25480.4.50.25514
4980.4.51.0/2880.4.51.1 to 80.4.51.1480.4.51.1514
5080.4.51.16/2880.4.51.17 to 80.4.51.3080.4.51.3114
5180.4.51.32/2880.4.51.33 to 80.4.51.4680.4.51.4714
5280.4.51.48/2880.4.51.49 to 80.4.51.6280.4.51.6314
5380.4.51.64/2880.4.51.65 to 80.4.51.7880.4.51.7914
5480.4.51.80/2880.4.51.81 to 80.4.51.9480.4.51.9514
5580.4.51.96/2880.4.51.97 to 80.4.51.11080.4.51.11114
5680.4.51.112/2880.4.51.113 to 80.4.51.12680.4.51.12714
5780.4.51.128/2880.4.51.129 to 80.4.51.14280.4.51.14314
5880.4.51.144/2880.4.51.145 to 80.4.51.15880.4.51.15914
5980.4.51.160/2880.4.51.161 to 80.4.51.17480.4.51.17514
6080.4.51.176/2880.4.51.177 to 80.4.51.19080.4.51.19114
6180.4.51.192/2880.4.51.193 to 80.4.51.20680.4.51.20714
6280.4.51.208/2880.4.51.209 to 80.4.51.22280.4.51.22314
6380.4.51.224/2880.4.51.225 to 80.4.51.23880.4.51.23914
6480.4.51.240/2880.4.51.241 to 80.4.51.25480.4.51.25514
6580.4.52.0/2880.4.52.1 to 80.4.52.1480.4.52.1514
6680.4.52.16/2880.4.52.17 to 80.4.52.3080.4.52.3114
6780.4.52.32/2880.4.52.33 to 80.4.52.4680.4.52.4714
6880.4.52.48/2880.4.52.49 to 80.4.52.6280.4.52.6314
6980.4.52.64/2880.4.52.65 to 80.4.52.7880.4.52.7914
7080.4.52.80/2880.4.52.81 to 80.4.52.9480.4.52.9514
7180.4.52.96/2880.4.52.97 to 80.4.52.11080.4.52.11114
7280.4.52.112/2880.4.52.113 to 80.4.52.12680.4.52.12714
7380.4.52.128/2880.4.52.129 to 80.4.52.14280.4.52.14314
7480.4.52.144/2880.4.52.145 to 80.4.52.15880.4.52.15914
7580.4.52.160/2880.4.52.161 to 80.4.52.17480.4.52.17514
7680.4.52.176/2880.4.52.177 to 80.4.52.19080.4.52.19114
7780.4.52.192/2880.4.52.193 to 80.4.52.20680.4.52.20714
7880.4.52.208/2880.4.52.209 to 80.4.52.22280.4.52.22314
7980.4.52.224/2880.4.52.225 to 80.4.52.23880.4.52.23914
8080.4.52.240/2880.4.52.241 to 80.4.52.25480.4.52.25514
8180.4.53.0/2880.4.53.1 to 80.4.53.1480.4.53.1514
8280.4.53.16/2880.4.53.17 to 80.4.53.3080.4.53.3114
8380.4.53.32/2880.4.53.33 to 80.4.53.4680.4.53.4714
8480.4.53.48/2880.4.53.49 to 80.4.53.6280.4.53.6314
8580.4.53.64/2880.4.53.65 to 80.4.53.7880.4.53.7914
8680.4.53.80/2880.4.53.81 to 80.4.53.9480.4.53.9514
8780.4.53.96/2880.4.53.97 to 80.4.53.11080.4.53.11114
8880.4.53.112/2880.4.53.113 to 80.4.53.12680.4.53.12714
8980.4.53.128/2880.4.53.129 to 80.4.53.14280.4.53.14314
9080.4.53.144/2880.4.53.145 to 80.4.53.15880.4.53.15914
9180.4.53.160/2880.4.53.161 to 80.4.53.17480.4.53.17514
9280.4.53.176/2880.4.53.177 to 80.4.53.19080.4.53.19114
9380.4.53.192/2880.4.53.193 to 80.4.53.20680.4.53.20714
9480.4.53.208/2880.4.53.209 to 80.4.53.22280.4.53.22314
9580.4.53.224/2880.4.53.225 to 80.4.53.23880.4.53.23914
9680.4.53.240/2880.4.53.241 to 80.4.53.25480.4.53.25514
9780.4.54.0/2880.4.54.1 to 80.4.54.1480.4.54.1514
9880.4.54.16/2880.4.54.17 to 80.4.54.3080.4.54.3114
9980.4.54.32/2880.4.54.33 to 80.4.54.4680.4.54.4714
10080.4.54.48/2880.4.54.49 to 80.4.54.6280.4.54.6314
10180.4.54.64/2880.4.54.65 to 80.4.54.7880.4.54.7914
10280.4.54.80/2880.4.54.81 to 80.4.54.9480.4.54.9514
10380.4.54.96/2880.4.54.97 to 80.4.54.11080.4.54.11114
10480.4.54.112/2880.4.54.113 to 80.4.54.12680.4.54.12714
10580.4.54.128/2880.4.54.129 to 80.4.54.14280.4.54.14314
10680.4.54.144/2880.4.54.145 to 80.4.54.15880.4.54.15914
10780.4.54.160/2880.4.54.161 to 80.4.54.17480.4.54.17514
10880.4.54.176/2880.4.54.177 to 80.4.54.19080.4.54.19114
10980.4.54.192/2880.4.54.193 to 80.4.54.20680.4.54.20714
11080.4.54.208/2880.4.54.209 to 80.4.54.22280.4.54.22314
11180.4.54.224/2880.4.54.225 to 80.4.54.23880.4.54.23914
11280.4.54.240/2880.4.54.241 to 80.4.54.25480.4.54.25514
11380.4.55.0/2880.4.55.1 to 80.4.55.1480.4.55.1514
11480.4.55.16/2880.4.55.17 to 80.4.55.3080.4.55.3114
11580.4.55.32/2880.4.55.33 to 80.4.55.4680.4.55.4714
11680.4.55.48/2880.4.55.49 to 80.4.55.6280.4.55.6314
11780.4.55.64/2880.4.55.65 to 80.4.55.7880.4.55.7914
11880.4.55.80/2880.4.55.81 to 80.4.55.9480.4.55.9514
11980.4.55.96/2880.4.55.97 to 80.4.55.11080.4.55.11114
12080.4.55.112/2880.4.55.113 to 80.4.55.12680.4.55.12714
12180.4.55.128/2880.4.55.129 to 80.4.55.14280.4.55.14314
12280.4.55.144/2880.4.55.145 to 80.4.55.15880.4.55.15914
12380.4.55.160/2880.4.55.161 to 80.4.55.17480.4.55.17514
12480.4.55.176/2880.4.55.177 to 80.4.55.19080.4.55.19114
12580.4.55.192/2880.4.55.193 to 80.4.55.20680.4.55.20714
12680.4.55.208/2880.4.55.209 to 80.4.55.22280.4.55.22314
12780.4.55.224/2880.4.55.225 to 80.4.55.23880.4.55.23914
12880.4.55.240/2880.4.55.241 to 80.4.55.25480.4.55.25514
12980.4.56.0/2880.4.56.1 to 80.4.56.1480.4.56.1514
13080.4.56.16/2880.4.56.17 to 80.4.56.3080.4.56.3114
13180.4.56.32/2880.4.56.33 to 80.4.56.4680.4.56.4714
13280.4.56.48/2880.4.56.49 to 80.4.56.6280.4.56.6314
13380.4.56.64/2880.4.56.65 to 80.4.56.7880.4.56.7914
13480.4.56.80/2880.4.56.81 to 80.4.56.9480.4.56.9514
13580.4.56.96/2880.4.56.97 to 80.4.56.11080.4.56.11114
13680.4.56.112/2880.4.56.113 to 80.4.56.12680.4.56.12714
13780.4.56.128/2880.4.56.129 to 80.4.56.14280.4.56.14314
13880.4.56.144/2880.4.56.145 to 80.4.56.15880.4.56.15914
13980.4.56.160/2880.4.56.161 to 80.4.56.17480.4.56.17514
14080.4.56.176/2880.4.56.177 to 80.4.56.19080.4.56.19114
14180.4.56.192/2880.4.56.193 to 80.4.56.20680.4.56.20714
14280.4.56.208/2880.4.56.209 to 80.4.56.22280.4.56.22314
14380.4.56.224/2880.4.56.225 to 80.4.56.23880.4.56.23914
14480.4.56.240/2880.4.56.241 to 80.4.56.25480.4.56.25514
14580.4.57.0/2880.4.57.1 to 80.4.57.1480.4.57.1514
14680.4.57.16/2880.4.57.17 to 80.4.57.3080.4.57.3114
14780.4.57.32/2880.4.57.33 to 80.4.57.4680.4.57.4714
14880.4.57.48/2880.4.57.49 to 80.4.57.6280.4.57.6314
14980.4.57.64/2880.4.57.65 to 80.4.57.7880.4.57.7914
15080.4.57.80/2880.4.57.81 to 80.4.57.9480.4.57.9514
15180.4.57.96/2880.4.57.97 to 80.4.57.11080.4.57.11114
15280.4.57.112/2880.4.57.113 to 80.4.57.12680.4.57.12714
15380.4.57.128/2880.4.57.129 to 80.4.57.14280.4.57.14314
15480.4.57.144/2880.4.57.145 to 80.4.57.15880.4.57.15914
15580.4.57.160/2880.4.57.161 to 80.4.57.17480.4.57.17514
15680.4.57.176/2880.4.57.177 to 80.4.57.19080.4.57.19114
15780.4.57.192/2880.4.57.193 to 80.4.57.20680.4.57.20714
15880.4.57.208/2880.4.57.209 to 80.4.57.22280.4.57.22314
15980.4.57.224/2880.4.57.225 to 80.4.57.23880.4.57.23914
16080.4.57.240/2880.4.57.241 to 80.4.57.25480.4.57.25514
16180.4.58.0/2880.4.58.1 to 80.4.58.1480.4.58.1514
16280.4.58.16/2880.4.58.17 to 80.4.58.3080.4.58.3114
16380.4.58.32/2880.4.58.33 to 80.4.58.4680.4.58.4714
16480.4.58.48/2880.4.58.49 to 80.4.58.6280.4.58.6314
16580.4.58.64/2880.4.58.65 to 80.4.58.7880.4.58.7914
16680.4.58.80/2880.4.58.81 to 80.4.58.9480.4.58.9514
16780.4.58.96/2880.4.58.97 to 80.4.58.11080.4.58.11114
16880.4.58.112/2880.4.58.113 to 80.4.58.12680.4.58.12714
16980.4.58.128/2880.4.58.129 to 80.4.58.14280.4.58.14314
17080.4.58.144/2880.4.58.145 to 80.4.58.15880.4.58.15914
17180.4.58.160/2880.4.58.161 to 80.4.58.17480.4.58.17514
17280.4.58.176/2880.4.58.177 to 80.4.58.19080.4.58.19114
17380.4.58.192/2880.4.58.193 to 80.4.58.20680.4.58.20714
17480.4.58.208/2880.4.58.209 to 80.4.58.22280.4.58.22314
17580.4.58.224/2880.4.58.225 to 80.4.58.23880.4.58.23914
17680.4.58.240/2880.4.58.241 to 80.4.58.25480.4.58.25514
17780.4.59.0/2880.4.59.1 to 80.4.59.1480.4.59.1514
17880.4.59.16/2880.4.59.17 to 80.4.59.3080.4.59.3114
17980.4.59.32/2880.4.59.33 to 80.4.59.4680.4.59.4714
18080.4.59.48/2880.4.59.49 to 80.4.59.6280.4.59.6314
18180.4.59.64/2880.4.59.65 to 80.4.59.7880.4.59.7914
18280.4.59.80/2880.4.59.81 to 80.4.59.9480.4.59.9514
18380.4.59.96/2880.4.59.97 to 80.4.59.11080.4.59.11114
18480.4.59.112/2880.4.59.113 to 80.4.59.12680.4.59.12714
18580.4.59.128/2880.4.59.129 to 80.4.59.14280.4.59.14314
18680.4.59.144/2880.4.59.145 to 80.4.59.15880.4.59.15914
18780.4.59.160/2880.4.59.161 to 80.4.59.17480.4.59.17514
18880.4.59.176/2880.4.59.177 to 80.4.59.19080.4.59.19114
18980.4.59.192/2880.4.59.193 to 80.4.59.20680.4.59.20714
19080.4.59.208/2880.4.59.209 to 80.4.59.22280.4.59.22314
19180.4.59.224/2880.4.59.225 to 80.4.59.23880.4.59.23914
19280.4.59.240/2880.4.59.241 to 80.4.59.25480.4.59.25514
19380.4.60.0/2880.4.60.1 to 80.4.60.1480.4.60.1514
19480.4.60.16/2880.4.60.17 to 80.4.60.3080.4.60.3114
19580.4.60.32/2880.4.60.33 to 80.4.60.4680.4.60.4714
19680.4.60.48/2880.4.60.49 to 80.4.60.6280.4.60.6314
19780.4.60.64/2880.4.60.65 to 80.4.60.7880.4.60.7914
19880.4.60.80/2880.4.60.81 to 80.4.60.9480.4.60.9514
19980.4.60.96/2880.4.60.97 to 80.4.60.11080.4.60.11114
20080.4.60.112/2880.4.60.113 to 80.4.60.12680.4.60.12714
20180.4.60.128/2880.4.60.129 to 80.4.60.14280.4.60.14314
20280.4.60.144/2880.4.60.145 to 80.4.60.15880.4.60.15914
20380.4.60.160/2880.4.60.161 to 80.4.60.17480.4.60.17514
20480.4.60.176/2880.4.60.177 to 80.4.60.19080.4.60.19114
20580.4.60.192/2880.4.60.193 to 80.4.60.20680.4.60.20714
20680.4.60.208/2880.4.60.209 to 80.4.60.22280.4.60.22314
20780.4.60.224/2880.4.60.225 to 80.4.60.23880.4.60.23914
20880.4.60.240/2880.4.60.241 to 80.4.60.25480.4.60.25514
20980.4.61.0/2880.4.61.1 to 80.4.61.1480.4.61.1514
21080.4.61.16/2880.4.61.17 to 80.4.61.3080.4.61.3114
21180.4.61.32/2880.4.61.33 to 80.4.61.4680.4.61.4714
21280.4.61.48/2880.4.61.49 to 80.4.61.6280.4.61.6314
21380.4.61.64/2880.4.61.65 to 80.4.61.7880.4.61.7914
21480.4.61.80/2880.4.61.81 to 80.4.61.9480.4.61.9514
21580.4.61.96/2880.4.61.97 to 80.4.61.11080.4.61.11114
21680.4.61.112/2880.4.61.113 to 80.4.61.12680.4.61.12714
21780.4.61.128/2880.4.61.129 to 80.4.61.14280.4.61.14314
21880.4.61.144/2880.4.61.145 to 80.4.61.15880.4.61.15914
21980.4.61.160/2880.4.61.161 to 80.4.61.17480.4.61.17514
22080.4.61.176/2880.4.61.177 to 80.4.61.19080.4.61.19114
22180.4.61.192/2880.4.61.193 to 80.4.61.20680.4.61.20714
22280.4.61.208/2880.4.61.209 to 80.4.61.22280.4.61.22314
22380.4.61.224/2880.4.61.225 to 80.4.61.23880.4.61.23914
22480.4.61.240/2880.4.61.241 to 80.4.61.25480.4.61.25514
22580.4.62.0/2880.4.62.1 to 80.4.62.1480.4.62.1514
22680.4.62.16/2880.4.62.17 to 80.4.62.3080.4.62.3114
22780.4.62.32/2880.4.62.33 to 80.4.62.4680.4.62.4714
22880.4.62.48/2880.4.62.49 to 80.4.62.6280.4.62.6314
22980.4.62.64/2880.4.62.65 to 80.4.62.7880.4.62.7914
23080.4.62.80/2880.4.62.81 to 80.4.62.9480.4.62.9514
23180.4.62.96/2880.4.62.97 to 80.4.62.11080.4.62.11114
23280.4.62.112/2880.4.62.113 to 80.4.62.12680.4.62.12714
23380.4.62.128/2880.4.62.129 to 80.4.62.14280.4.62.14314
23480.4.62.144/2880.4.62.145 to 80.4.62.15880.4.62.15914
23580.4.62.160/2880.4.62.161 to 80.4.62.17480.4.62.17514
23680.4.62.176/2880.4.62.177 to 80.4.62.19080.4.62.19114
23780.4.62.192/2880.4.62.193 to 80.4.62.20680.4.62.20714
23880.4.62.208/2880.4.62.209 to 80.4.62.22280.4.62.22314
23980.4.62.224/2880.4.62.225 to 80.4.62.23880.4.62.23914
24080.4.62.240/2880.4.62.241 to 80.4.62.25480.4.62.25514
24180.4.63.0/2880.4.63.1 to 80.4.63.1480.4.63.1514
24280.4.63.16/2880.4.63.17 to 80.4.63.3080.4.63.3114
24380.4.63.32/2880.4.63.33 to 80.4.63.4680.4.63.4714
24480.4.63.48/2880.4.63.49 to 80.4.63.6280.4.63.6314
24580.4.63.64/2880.4.63.65 to 80.4.63.7880.4.63.7914
24680.4.63.80/2880.4.63.81 to 80.4.63.9480.4.63.9514
24780.4.63.96/2880.4.63.97 to 80.4.63.11080.4.63.11114
24880.4.63.112/2880.4.63.113 to 80.4.63.12680.4.63.12714
24980.4.63.128/2880.4.63.129 to 80.4.63.14280.4.63.14314
25080.4.63.144/2880.4.63.145 to 80.4.63.15880.4.63.15914
25180.4.63.160/2880.4.63.161 to 80.4.63.17480.4.63.17514
25280.4.63.176/2880.4.63.177 to 80.4.63.19080.4.63.19114
25380.4.63.192/2880.4.63.193 to 80.4.63.20680.4.63.20714
25480.4.63.208/2880.4.63.209 to 80.4.63.22280.4.63.22314
25580.4.63.224/2880.4.63.225 to 80.4.63.23880.4.63.23914
25680.4.63.240/2880.4.63.241 to 80.4.63.25480.4.63.25514

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.