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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.

Network35.78.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
35.78.0.0
Broadcast address
35.78.127.255
First usable
35.78.0.1
Last usable
35.78.127.254
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 234E0000 · Integer 592314368 to 592347135
Reverse DNS zones
0.78.35.in-addr.arpa
1.78.35.in-addr.arpa
2.78.35.in-addr.arpa
3.78.35.in-addr.arpa
4.78.35.in-addr.arpa
5.78.35.in-addr.arpa
6.78.35.in-addr.arpa
7.78.35.in-addr.arpa
8.78.35.in-addr.arpa
9.78.35.in-addr.arpa
10.78.35.in-addr.arpa
11.78.35.in-addr.arpa
12.78.35.in-addr.arpa
13.78.35.in-addr.arpa
14.78.35.in-addr.arpa
15.78.35.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
Address00100011.01001110.00000000.0000000035.78.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network00100011.01001110.00000000.0000000035.78.0.0
Broadcast00100011.01001110.01111111.1111111135.78.127.255
Split into smaller subnets/28
/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)

35.78.0.0/17 makes 2,048 subnets of /28; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
135.78.0.0/2835.78.0.1 to 35.78.0.1435.78.0.1514
235.78.0.16/2835.78.0.17 to 35.78.0.3035.78.0.3114
335.78.0.32/2835.78.0.33 to 35.78.0.4635.78.0.4714
435.78.0.48/2835.78.0.49 to 35.78.0.6235.78.0.6314
535.78.0.64/2835.78.0.65 to 35.78.0.7835.78.0.7914
635.78.0.80/2835.78.0.81 to 35.78.0.9435.78.0.9514
735.78.0.96/2835.78.0.97 to 35.78.0.11035.78.0.11114
835.78.0.112/2835.78.0.113 to 35.78.0.12635.78.0.12714
935.78.0.128/2835.78.0.129 to 35.78.0.14235.78.0.14314
1035.78.0.144/2835.78.0.145 to 35.78.0.15835.78.0.15914
1135.78.0.160/2835.78.0.161 to 35.78.0.17435.78.0.17514
1235.78.0.176/2835.78.0.177 to 35.78.0.19035.78.0.19114
1335.78.0.192/2835.78.0.193 to 35.78.0.20635.78.0.20714
1435.78.0.208/2835.78.0.209 to 35.78.0.22235.78.0.22314
1535.78.0.224/2835.78.0.225 to 35.78.0.23835.78.0.23914
1635.78.0.240/2835.78.0.241 to 35.78.0.25435.78.0.25514
1735.78.1.0/2835.78.1.1 to 35.78.1.1435.78.1.1514
1835.78.1.16/2835.78.1.17 to 35.78.1.3035.78.1.3114
1935.78.1.32/2835.78.1.33 to 35.78.1.4635.78.1.4714
2035.78.1.48/2835.78.1.49 to 35.78.1.6235.78.1.6314
2135.78.1.64/2835.78.1.65 to 35.78.1.7835.78.1.7914
2235.78.1.80/2835.78.1.81 to 35.78.1.9435.78.1.9514
2335.78.1.96/2835.78.1.97 to 35.78.1.11035.78.1.11114
2435.78.1.112/2835.78.1.113 to 35.78.1.12635.78.1.12714
2535.78.1.128/2835.78.1.129 to 35.78.1.14235.78.1.14314
2635.78.1.144/2835.78.1.145 to 35.78.1.15835.78.1.15914
2735.78.1.160/2835.78.1.161 to 35.78.1.17435.78.1.17514
2835.78.1.176/2835.78.1.177 to 35.78.1.19035.78.1.19114
2935.78.1.192/2835.78.1.193 to 35.78.1.20635.78.1.20714
3035.78.1.208/2835.78.1.209 to 35.78.1.22235.78.1.22314
3135.78.1.224/2835.78.1.225 to 35.78.1.23835.78.1.23914
3235.78.1.240/2835.78.1.241 to 35.78.1.25435.78.1.25514
3335.78.2.0/2835.78.2.1 to 35.78.2.1435.78.2.1514
3435.78.2.16/2835.78.2.17 to 35.78.2.3035.78.2.3114
3535.78.2.32/2835.78.2.33 to 35.78.2.4635.78.2.4714
3635.78.2.48/2835.78.2.49 to 35.78.2.6235.78.2.6314
3735.78.2.64/2835.78.2.65 to 35.78.2.7835.78.2.7914
3835.78.2.80/2835.78.2.81 to 35.78.2.9435.78.2.9514
3935.78.2.96/2835.78.2.97 to 35.78.2.11035.78.2.11114
4035.78.2.112/2835.78.2.113 to 35.78.2.12635.78.2.12714
4135.78.2.128/2835.78.2.129 to 35.78.2.14235.78.2.14314
4235.78.2.144/2835.78.2.145 to 35.78.2.15835.78.2.15914
4335.78.2.160/2835.78.2.161 to 35.78.2.17435.78.2.17514
4435.78.2.176/2835.78.2.177 to 35.78.2.19035.78.2.19114
4535.78.2.192/2835.78.2.193 to 35.78.2.20635.78.2.20714
4635.78.2.208/2835.78.2.209 to 35.78.2.22235.78.2.22314
4735.78.2.224/2835.78.2.225 to 35.78.2.23835.78.2.23914
4835.78.2.240/2835.78.2.241 to 35.78.2.25435.78.2.25514
4935.78.3.0/2835.78.3.1 to 35.78.3.1435.78.3.1514
5035.78.3.16/2835.78.3.17 to 35.78.3.3035.78.3.3114
5135.78.3.32/2835.78.3.33 to 35.78.3.4635.78.3.4714
5235.78.3.48/2835.78.3.49 to 35.78.3.6235.78.3.6314
5335.78.3.64/2835.78.3.65 to 35.78.3.7835.78.3.7914
5435.78.3.80/2835.78.3.81 to 35.78.3.9435.78.3.9514
5535.78.3.96/2835.78.3.97 to 35.78.3.11035.78.3.11114
5635.78.3.112/2835.78.3.113 to 35.78.3.12635.78.3.12714
5735.78.3.128/2835.78.3.129 to 35.78.3.14235.78.3.14314
5835.78.3.144/2835.78.3.145 to 35.78.3.15835.78.3.15914
5935.78.3.160/2835.78.3.161 to 35.78.3.17435.78.3.17514
6035.78.3.176/2835.78.3.177 to 35.78.3.19035.78.3.19114
6135.78.3.192/2835.78.3.193 to 35.78.3.20635.78.3.20714
6235.78.3.208/2835.78.3.209 to 35.78.3.22235.78.3.22314
6335.78.3.224/2835.78.3.225 to 35.78.3.23835.78.3.23914
6435.78.3.240/2835.78.3.241 to 35.78.3.25435.78.3.25514
6535.78.4.0/2835.78.4.1 to 35.78.4.1435.78.4.1514
6635.78.4.16/2835.78.4.17 to 35.78.4.3035.78.4.3114
6735.78.4.32/2835.78.4.33 to 35.78.4.4635.78.4.4714
6835.78.4.48/2835.78.4.49 to 35.78.4.6235.78.4.6314
6935.78.4.64/2835.78.4.65 to 35.78.4.7835.78.4.7914
7035.78.4.80/2835.78.4.81 to 35.78.4.9435.78.4.9514
7135.78.4.96/2835.78.4.97 to 35.78.4.11035.78.4.11114
7235.78.4.112/2835.78.4.113 to 35.78.4.12635.78.4.12714
7335.78.4.128/2835.78.4.129 to 35.78.4.14235.78.4.14314
7435.78.4.144/2835.78.4.145 to 35.78.4.15835.78.4.15914
7535.78.4.160/2835.78.4.161 to 35.78.4.17435.78.4.17514
7635.78.4.176/2835.78.4.177 to 35.78.4.19035.78.4.19114
7735.78.4.192/2835.78.4.193 to 35.78.4.20635.78.4.20714
7835.78.4.208/2835.78.4.209 to 35.78.4.22235.78.4.22314
7935.78.4.224/2835.78.4.225 to 35.78.4.23835.78.4.23914
8035.78.4.240/2835.78.4.241 to 35.78.4.25435.78.4.25514
8135.78.5.0/2835.78.5.1 to 35.78.5.1435.78.5.1514
8235.78.5.16/2835.78.5.17 to 35.78.5.3035.78.5.3114
8335.78.5.32/2835.78.5.33 to 35.78.5.4635.78.5.4714
8435.78.5.48/2835.78.5.49 to 35.78.5.6235.78.5.6314
8535.78.5.64/2835.78.5.65 to 35.78.5.7835.78.5.7914
8635.78.5.80/2835.78.5.81 to 35.78.5.9435.78.5.9514
8735.78.5.96/2835.78.5.97 to 35.78.5.11035.78.5.11114
8835.78.5.112/2835.78.5.113 to 35.78.5.12635.78.5.12714
8935.78.5.128/2835.78.5.129 to 35.78.5.14235.78.5.14314
9035.78.5.144/2835.78.5.145 to 35.78.5.15835.78.5.15914
9135.78.5.160/2835.78.5.161 to 35.78.5.17435.78.5.17514
9235.78.5.176/2835.78.5.177 to 35.78.5.19035.78.5.19114
9335.78.5.192/2835.78.5.193 to 35.78.5.20635.78.5.20714
9435.78.5.208/2835.78.5.209 to 35.78.5.22235.78.5.22314
9535.78.5.224/2835.78.5.225 to 35.78.5.23835.78.5.23914
9635.78.5.240/2835.78.5.241 to 35.78.5.25435.78.5.25514
9735.78.6.0/2835.78.6.1 to 35.78.6.1435.78.6.1514
9835.78.6.16/2835.78.6.17 to 35.78.6.3035.78.6.3114
9935.78.6.32/2835.78.6.33 to 35.78.6.4635.78.6.4714
10035.78.6.48/2835.78.6.49 to 35.78.6.6235.78.6.6314
10135.78.6.64/2835.78.6.65 to 35.78.6.7835.78.6.7914
10235.78.6.80/2835.78.6.81 to 35.78.6.9435.78.6.9514
10335.78.6.96/2835.78.6.97 to 35.78.6.11035.78.6.11114
10435.78.6.112/2835.78.6.113 to 35.78.6.12635.78.6.12714
10535.78.6.128/2835.78.6.129 to 35.78.6.14235.78.6.14314
10635.78.6.144/2835.78.6.145 to 35.78.6.15835.78.6.15914
10735.78.6.160/2835.78.6.161 to 35.78.6.17435.78.6.17514
10835.78.6.176/2835.78.6.177 to 35.78.6.19035.78.6.19114
10935.78.6.192/2835.78.6.193 to 35.78.6.20635.78.6.20714
11035.78.6.208/2835.78.6.209 to 35.78.6.22235.78.6.22314
11135.78.6.224/2835.78.6.225 to 35.78.6.23835.78.6.23914
11235.78.6.240/2835.78.6.241 to 35.78.6.25435.78.6.25514
11335.78.7.0/2835.78.7.1 to 35.78.7.1435.78.7.1514
11435.78.7.16/2835.78.7.17 to 35.78.7.3035.78.7.3114
11535.78.7.32/2835.78.7.33 to 35.78.7.4635.78.7.4714
11635.78.7.48/2835.78.7.49 to 35.78.7.6235.78.7.6314
11735.78.7.64/2835.78.7.65 to 35.78.7.7835.78.7.7914
11835.78.7.80/2835.78.7.81 to 35.78.7.9435.78.7.9514
11935.78.7.96/2835.78.7.97 to 35.78.7.11035.78.7.11114
12035.78.7.112/2835.78.7.113 to 35.78.7.12635.78.7.12714
12135.78.7.128/2835.78.7.129 to 35.78.7.14235.78.7.14314
12235.78.7.144/2835.78.7.145 to 35.78.7.15835.78.7.15914
12335.78.7.160/2835.78.7.161 to 35.78.7.17435.78.7.17514
12435.78.7.176/2835.78.7.177 to 35.78.7.19035.78.7.19114
12535.78.7.192/2835.78.7.193 to 35.78.7.20635.78.7.20714
12635.78.7.208/2835.78.7.209 to 35.78.7.22235.78.7.22314
12735.78.7.224/2835.78.7.225 to 35.78.7.23835.78.7.23914
12835.78.7.240/2835.78.7.241 to 35.78.7.25435.78.7.25514
12935.78.8.0/2835.78.8.1 to 35.78.8.1435.78.8.1514
13035.78.8.16/2835.78.8.17 to 35.78.8.3035.78.8.3114
13135.78.8.32/2835.78.8.33 to 35.78.8.4635.78.8.4714
13235.78.8.48/2835.78.8.49 to 35.78.8.6235.78.8.6314
13335.78.8.64/2835.78.8.65 to 35.78.8.7835.78.8.7914
13435.78.8.80/2835.78.8.81 to 35.78.8.9435.78.8.9514
13535.78.8.96/2835.78.8.97 to 35.78.8.11035.78.8.11114
13635.78.8.112/2835.78.8.113 to 35.78.8.12635.78.8.12714
13735.78.8.128/2835.78.8.129 to 35.78.8.14235.78.8.14314
13835.78.8.144/2835.78.8.145 to 35.78.8.15835.78.8.15914
13935.78.8.160/2835.78.8.161 to 35.78.8.17435.78.8.17514
14035.78.8.176/2835.78.8.177 to 35.78.8.19035.78.8.19114
14135.78.8.192/2835.78.8.193 to 35.78.8.20635.78.8.20714
14235.78.8.208/2835.78.8.209 to 35.78.8.22235.78.8.22314
14335.78.8.224/2835.78.8.225 to 35.78.8.23835.78.8.23914
14435.78.8.240/2835.78.8.241 to 35.78.8.25435.78.8.25514
14535.78.9.0/2835.78.9.1 to 35.78.9.1435.78.9.1514
14635.78.9.16/2835.78.9.17 to 35.78.9.3035.78.9.3114
14735.78.9.32/2835.78.9.33 to 35.78.9.4635.78.9.4714
14835.78.9.48/2835.78.9.49 to 35.78.9.6235.78.9.6314
14935.78.9.64/2835.78.9.65 to 35.78.9.7835.78.9.7914
15035.78.9.80/2835.78.9.81 to 35.78.9.9435.78.9.9514
15135.78.9.96/2835.78.9.97 to 35.78.9.11035.78.9.11114
15235.78.9.112/2835.78.9.113 to 35.78.9.12635.78.9.12714
15335.78.9.128/2835.78.9.129 to 35.78.9.14235.78.9.14314
15435.78.9.144/2835.78.9.145 to 35.78.9.15835.78.9.15914
15535.78.9.160/2835.78.9.161 to 35.78.9.17435.78.9.17514
15635.78.9.176/2835.78.9.177 to 35.78.9.19035.78.9.19114
15735.78.9.192/2835.78.9.193 to 35.78.9.20635.78.9.20714
15835.78.9.208/2835.78.9.209 to 35.78.9.22235.78.9.22314
15935.78.9.224/2835.78.9.225 to 35.78.9.23835.78.9.23914
16035.78.9.240/2835.78.9.241 to 35.78.9.25435.78.9.25514
16135.78.10.0/2835.78.10.1 to 35.78.10.1435.78.10.1514
16235.78.10.16/2835.78.10.17 to 35.78.10.3035.78.10.3114
16335.78.10.32/2835.78.10.33 to 35.78.10.4635.78.10.4714
16435.78.10.48/2835.78.10.49 to 35.78.10.6235.78.10.6314
16535.78.10.64/2835.78.10.65 to 35.78.10.7835.78.10.7914
16635.78.10.80/2835.78.10.81 to 35.78.10.9435.78.10.9514
16735.78.10.96/2835.78.10.97 to 35.78.10.11035.78.10.11114
16835.78.10.112/2835.78.10.113 to 35.78.10.12635.78.10.12714
16935.78.10.128/2835.78.10.129 to 35.78.10.14235.78.10.14314
17035.78.10.144/2835.78.10.145 to 35.78.10.15835.78.10.15914
17135.78.10.160/2835.78.10.161 to 35.78.10.17435.78.10.17514
17235.78.10.176/2835.78.10.177 to 35.78.10.19035.78.10.19114
17335.78.10.192/2835.78.10.193 to 35.78.10.20635.78.10.20714
17435.78.10.208/2835.78.10.209 to 35.78.10.22235.78.10.22314
17535.78.10.224/2835.78.10.225 to 35.78.10.23835.78.10.23914
17635.78.10.240/2835.78.10.241 to 35.78.10.25435.78.10.25514
17735.78.11.0/2835.78.11.1 to 35.78.11.1435.78.11.1514
17835.78.11.16/2835.78.11.17 to 35.78.11.3035.78.11.3114
17935.78.11.32/2835.78.11.33 to 35.78.11.4635.78.11.4714
18035.78.11.48/2835.78.11.49 to 35.78.11.6235.78.11.6314
18135.78.11.64/2835.78.11.65 to 35.78.11.7835.78.11.7914
18235.78.11.80/2835.78.11.81 to 35.78.11.9435.78.11.9514
18335.78.11.96/2835.78.11.97 to 35.78.11.11035.78.11.11114
18435.78.11.112/2835.78.11.113 to 35.78.11.12635.78.11.12714
18535.78.11.128/2835.78.11.129 to 35.78.11.14235.78.11.14314
18635.78.11.144/2835.78.11.145 to 35.78.11.15835.78.11.15914
18735.78.11.160/2835.78.11.161 to 35.78.11.17435.78.11.17514
18835.78.11.176/2835.78.11.177 to 35.78.11.19035.78.11.19114
18935.78.11.192/2835.78.11.193 to 35.78.11.20635.78.11.20714
19035.78.11.208/2835.78.11.209 to 35.78.11.22235.78.11.22314
19135.78.11.224/2835.78.11.225 to 35.78.11.23835.78.11.23914
19235.78.11.240/2835.78.11.241 to 35.78.11.25435.78.11.25514
19335.78.12.0/2835.78.12.1 to 35.78.12.1435.78.12.1514
19435.78.12.16/2835.78.12.17 to 35.78.12.3035.78.12.3114
19535.78.12.32/2835.78.12.33 to 35.78.12.4635.78.12.4714
19635.78.12.48/2835.78.12.49 to 35.78.12.6235.78.12.6314
19735.78.12.64/2835.78.12.65 to 35.78.12.7835.78.12.7914
19835.78.12.80/2835.78.12.81 to 35.78.12.9435.78.12.9514
19935.78.12.96/2835.78.12.97 to 35.78.12.11035.78.12.11114
20035.78.12.112/2835.78.12.113 to 35.78.12.12635.78.12.12714
20135.78.12.128/2835.78.12.129 to 35.78.12.14235.78.12.14314
20235.78.12.144/2835.78.12.145 to 35.78.12.15835.78.12.15914
20335.78.12.160/2835.78.12.161 to 35.78.12.17435.78.12.17514
20435.78.12.176/2835.78.12.177 to 35.78.12.19035.78.12.19114
20535.78.12.192/2835.78.12.193 to 35.78.12.20635.78.12.20714
20635.78.12.208/2835.78.12.209 to 35.78.12.22235.78.12.22314
20735.78.12.224/2835.78.12.225 to 35.78.12.23835.78.12.23914
20835.78.12.240/2835.78.12.241 to 35.78.12.25435.78.12.25514
20935.78.13.0/2835.78.13.1 to 35.78.13.1435.78.13.1514
21035.78.13.16/2835.78.13.17 to 35.78.13.3035.78.13.3114
21135.78.13.32/2835.78.13.33 to 35.78.13.4635.78.13.4714
21235.78.13.48/2835.78.13.49 to 35.78.13.6235.78.13.6314
21335.78.13.64/2835.78.13.65 to 35.78.13.7835.78.13.7914
21435.78.13.80/2835.78.13.81 to 35.78.13.9435.78.13.9514
21535.78.13.96/2835.78.13.97 to 35.78.13.11035.78.13.11114
21635.78.13.112/2835.78.13.113 to 35.78.13.12635.78.13.12714
21735.78.13.128/2835.78.13.129 to 35.78.13.14235.78.13.14314
21835.78.13.144/2835.78.13.145 to 35.78.13.15835.78.13.15914
21935.78.13.160/2835.78.13.161 to 35.78.13.17435.78.13.17514
22035.78.13.176/2835.78.13.177 to 35.78.13.19035.78.13.19114
22135.78.13.192/2835.78.13.193 to 35.78.13.20635.78.13.20714
22235.78.13.208/2835.78.13.209 to 35.78.13.22235.78.13.22314
22335.78.13.224/2835.78.13.225 to 35.78.13.23835.78.13.23914
22435.78.13.240/2835.78.13.241 to 35.78.13.25435.78.13.25514
22535.78.14.0/2835.78.14.1 to 35.78.14.1435.78.14.1514
22635.78.14.16/2835.78.14.17 to 35.78.14.3035.78.14.3114
22735.78.14.32/2835.78.14.33 to 35.78.14.4635.78.14.4714
22835.78.14.48/2835.78.14.49 to 35.78.14.6235.78.14.6314
22935.78.14.64/2835.78.14.65 to 35.78.14.7835.78.14.7914
23035.78.14.80/2835.78.14.81 to 35.78.14.9435.78.14.9514
23135.78.14.96/2835.78.14.97 to 35.78.14.11035.78.14.11114
23235.78.14.112/2835.78.14.113 to 35.78.14.12635.78.14.12714
23335.78.14.128/2835.78.14.129 to 35.78.14.14235.78.14.14314
23435.78.14.144/2835.78.14.145 to 35.78.14.15835.78.14.15914
23535.78.14.160/2835.78.14.161 to 35.78.14.17435.78.14.17514
23635.78.14.176/2835.78.14.177 to 35.78.14.19035.78.14.19114
23735.78.14.192/2835.78.14.193 to 35.78.14.20635.78.14.20714
23835.78.14.208/2835.78.14.209 to 35.78.14.22235.78.14.22314
23935.78.14.224/2835.78.14.225 to 35.78.14.23835.78.14.23914
24035.78.14.240/2835.78.14.241 to 35.78.14.25435.78.14.25514
24135.78.15.0/2835.78.15.1 to 35.78.15.1435.78.15.1514
24235.78.15.16/2835.78.15.17 to 35.78.15.3035.78.15.3114
24335.78.15.32/2835.78.15.33 to 35.78.15.4635.78.15.4714
24435.78.15.48/2835.78.15.49 to 35.78.15.6235.78.15.6314
24535.78.15.64/2835.78.15.65 to 35.78.15.7835.78.15.7914
24635.78.15.80/2835.78.15.81 to 35.78.15.9435.78.15.9514
24735.78.15.96/2835.78.15.97 to 35.78.15.11035.78.15.11114
24835.78.15.112/2835.78.15.113 to 35.78.15.12635.78.15.12714
24935.78.15.128/2835.78.15.129 to 35.78.15.14235.78.15.14314
25035.78.15.144/2835.78.15.145 to 35.78.15.15835.78.15.15914
25135.78.15.160/2835.78.15.161 to 35.78.15.17435.78.15.17514
25235.78.15.176/2835.78.15.177 to 35.78.15.19035.78.15.19114
25335.78.15.192/2835.78.15.193 to 35.78.15.20635.78.15.20714
25435.78.15.208/2835.78.15.209 to 35.78.15.22235.78.15.22314
25535.78.15.224/2835.78.15.225 to 35.78.15.23835.78.15.23914
25635.78.15.240/2835.78.15.241 to 35.78.15.25435.78.15.25514

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.