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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.

Network16.3.96.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
16.3.96.0
Broadcast address
16.3.127.255
First usable
16.3.96.1
Last usable
16.3.127.254
Usable hosts
8,190 (8,192 less the network and broadcast addresses)
Subnet mask
255.255.224.0
Wildcard mask
0.0.31.255 (Cisco ACLs, OSPF)
Prefix length
/19
Type
Public public
Old class
A (default /8)
As numbers
Hex 10036000 · Integer 268656640 to 268664831
Reverse DNS zones
96.3.16.in-addr.arpa
97.3.16.in-addr.arpa
98.3.16.in-addr.arpa
99.3.16.in-addr.arpa
100.3.16.in-addr.arpa
101.3.16.in-addr.arpa
102.3.16.in-addr.arpa
103.3.16.in-addr.arpa
104.3.16.in-addr.arpa
105.3.16.in-addr.arpa
106.3.16.in-addr.arpa
107.3.16.in-addr.arpa
108.3.16.in-addr.arpa
109.3.16.in-addr.arpa
110.3.16.in-addr.arpa
111.3.16.in-addr.arpa
and 16 more
/19 is not on a 8-bit boundary, so it takes 32 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00010000.00000011.01100000.0000000016.3.96.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network00010000.00000011.01100000.0000000016.3.96.0
Broadcast00010000.00000011.01111111.1111111116.3.127.255
Split into smaller subnets/28
/20 (2)/21 (4)/22 (8)/23 (16)/24 (32)/25 (64)/26 (128)/27 (256)/28 (512)/29 (1,024)/30 (2,048)/31 (4,096)

16.3.96.0/19 makes 512 subnets of /28; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
116.3.96.0/2816.3.96.1 to 16.3.96.1416.3.96.1514
216.3.96.16/2816.3.96.17 to 16.3.96.3016.3.96.3114
316.3.96.32/2816.3.96.33 to 16.3.96.4616.3.96.4714
416.3.96.48/2816.3.96.49 to 16.3.96.6216.3.96.6314
516.3.96.64/2816.3.96.65 to 16.3.96.7816.3.96.7914
616.3.96.80/2816.3.96.81 to 16.3.96.9416.3.96.9514
716.3.96.96/2816.3.96.97 to 16.3.96.11016.3.96.11114
816.3.96.112/2816.3.96.113 to 16.3.96.12616.3.96.12714
916.3.96.128/2816.3.96.129 to 16.3.96.14216.3.96.14314
1016.3.96.144/2816.3.96.145 to 16.3.96.15816.3.96.15914
1116.3.96.160/2816.3.96.161 to 16.3.96.17416.3.96.17514
1216.3.96.176/2816.3.96.177 to 16.3.96.19016.3.96.19114
1316.3.96.192/2816.3.96.193 to 16.3.96.20616.3.96.20714
1416.3.96.208/2816.3.96.209 to 16.3.96.22216.3.96.22314
1516.3.96.224/2816.3.96.225 to 16.3.96.23816.3.96.23914
1616.3.96.240/2816.3.96.241 to 16.3.96.25416.3.96.25514
1716.3.97.0/2816.3.97.1 to 16.3.97.1416.3.97.1514
1816.3.97.16/2816.3.97.17 to 16.3.97.3016.3.97.3114
1916.3.97.32/2816.3.97.33 to 16.3.97.4616.3.97.4714
2016.3.97.48/2816.3.97.49 to 16.3.97.6216.3.97.6314
2116.3.97.64/2816.3.97.65 to 16.3.97.7816.3.97.7914
2216.3.97.80/2816.3.97.81 to 16.3.97.9416.3.97.9514
2316.3.97.96/2816.3.97.97 to 16.3.97.11016.3.97.11114
2416.3.97.112/2816.3.97.113 to 16.3.97.12616.3.97.12714
2516.3.97.128/2816.3.97.129 to 16.3.97.14216.3.97.14314
2616.3.97.144/2816.3.97.145 to 16.3.97.15816.3.97.15914
2716.3.97.160/2816.3.97.161 to 16.3.97.17416.3.97.17514
2816.3.97.176/2816.3.97.177 to 16.3.97.19016.3.97.19114
2916.3.97.192/2816.3.97.193 to 16.3.97.20616.3.97.20714
3016.3.97.208/2816.3.97.209 to 16.3.97.22216.3.97.22314
3116.3.97.224/2816.3.97.225 to 16.3.97.23816.3.97.23914
3216.3.97.240/2816.3.97.241 to 16.3.97.25416.3.97.25514
3316.3.98.0/2816.3.98.1 to 16.3.98.1416.3.98.1514
3416.3.98.16/2816.3.98.17 to 16.3.98.3016.3.98.3114
3516.3.98.32/2816.3.98.33 to 16.3.98.4616.3.98.4714
3616.3.98.48/2816.3.98.49 to 16.3.98.6216.3.98.6314
3716.3.98.64/2816.3.98.65 to 16.3.98.7816.3.98.7914
3816.3.98.80/2816.3.98.81 to 16.3.98.9416.3.98.9514
3916.3.98.96/2816.3.98.97 to 16.3.98.11016.3.98.11114
4016.3.98.112/2816.3.98.113 to 16.3.98.12616.3.98.12714
4116.3.98.128/2816.3.98.129 to 16.3.98.14216.3.98.14314
4216.3.98.144/2816.3.98.145 to 16.3.98.15816.3.98.15914
4316.3.98.160/2816.3.98.161 to 16.3.98.17416.3.98.17514
4416.3.98.176/2816.3.98.177 to 16.3.98.19016.3.98.19114
4516.3.98.192/2816.3.98.193 to 16.3.98.20616.3.98.20714
4616.3.98.208/2816.3.98.209 to 16.3.98.22216.3.98.22314
4716.3.98.224/2816.3.98.225 to 16.3.98.23816.3.98.23914
4816.3.98.240/2816.3.98.241 to 16.3.98.25416.3.98.25514
4916.3.99.0/2816.3.99.1 to 16.3.99.1416.3.99.1514
5016.3.99.16/2816.3.99.17 to 16.3.99.3016.3.99.3114
5116.3.99.32/2816.3.99.33 to 16.3.99.4616.3.99.4714
5216.3.99.48/2816.3.99.49 to 16.3.99.6216.3.99.6314
5316.3.99.64/2816.3.99.65 to 16.3.99.7816.3.99.7914
5416.3.99.80/2816.3.99.81 to 16.3.99.9416.3.99.9514
5516.3.99.96/2816.3.99.97 to 16.3.99.11016.3.99.11114
5616.3.99.112/2816.3.99.113 to 16.3.99.12616.3.99.12714
5716.3.99.128/2816.3.99.129 to 16.3.99.14216.3.99.14314
5816.3.99.144/2816.3.99.145 to 16.3.99.15816.3.99.15914
5916.3.99.160/2816.3.99.161 to 16.3.99.17416.3.99.17514
6016.3.99.176/2816.3.99.177 to 16.3.99.19016.3.99.19114
6116.3.99.192/2816.3.99.193 to 16.3.99.20616.3.99.20714
6216.3.99.208/2816.3.99.209 to 16.3.99.22216.3.99.22314
6316.3.99.224/2816.3.99.225 to 16.3.99.23816.3.99.23914
6416.3.99.240/2816.3.99.241 to 16.3.99.25416.3.99.25514
6516.3.100.0/2816.3.100.1 to 16.3.100.1416.3.100.1514
6616.3.100.16/2816.3.100.17 to 16.3.100.3016.3.100.3114
6716.3.100.32/2816.3.100.33 to 16.3.100.4616.3.100.4714
6816.3.100.48/2816.3.100.49 to 16.3.100.6216.3.100.6314
6916.3.100.64/2816.3.100.65 to 16.3.100.7816.3.100.7914
7016.3.100.80/2816.3.100.81 to 16.3.100.9416.3.100.9514
7116.3.100.96/2816.3.100.97 to 16.3.100.11016.3.100.11114
7216.3.100.112/2816.3.100.113 to 16.3.100.12616.3.100.12714
7316.3.100.128/2816.3.100.129 to 16.3.100.14216.3.100.14314
7416.3.100.144/2816.3.100.145 to 16.3.100.15816.3.100.15914
7516.3.100.160/2816.3.100.161 to 16.3.100.17416.3.100.17514
7616.3.100.176/2816.3.100.177 to 16.3.100.19016.3.100.19114
7716.3.100.192/2816.3.100.193 to 16.3.100.20616.3.100.20714
7816.3.100.208/2816.3.100.209 to 16.3.100.22216.3.100.22314
7916.3.100.224/2816.3.100.225 to 16.3.100.23816.3.100.23914
8016.3.100.240/2816.3.100.241 to 16.3.100.25416.3.100.25514
8116.3.101.0/2816.3.101.1 to 16.3.101.1416.3.101.1514
8216.3.101.16/2816.3.101.17 to 16.3.101.3016.3.101.3114
8316.3.101.32/2816.3.101.33 to 16.3.101.4616.3.101.4714
8416.3.101.48/2816.3.101.49 to 16.3.101.6216.3.101.6314
8516.3.101.64/2816.3.101.65 to 16.3.101.7816.3.101.7914
8616.3.101.80/2816.3.101.81 to 16.3.101.9416.3.101.9514
8716.3.101.96/2816.3.101.97 to 16.3.101.11016.3.101.11114
8816.3.101.112/2816.3.101.113 to 16.3.101.12616.3.101.12714
8916.3.101.128/2816.3.101.129 to 16.3.101.14216.3.101.14314
9016.3.101.144/2816.3.101.145 to 16.3.101.15816.3.101.15914
9116.3.101.160/2816.3.101.161 to 16.3.101.17416.3.101.17514
9216.3.101.176/2816.3.101.177 to 16.3.101.19016.3.101.19114
9316.3.101.192/2816.3.101.193 to 16.3.101.20616.3.101.20714
9416.3.101.208/2816.3.101.209 to 16.3.101.22216.3.101.22314
9516.3.101.224/2816.3.101.225 to 16.3.101.23816.3.101.23914
9616.3.101.240/2816.3.101.241 to 16.3.101.25416.3.101.25514
9716.3.102.0/2816.3.102.1 to 16.3.102.1416.3.102.1514
9816.3.102.16/2816.3.102.17 to 16.3.102.3016.3.102.3114
9916.3.102.32/2816.3.102.33 to 16.3.102.4616.3.102.4714
10016.3.102.48/2816.3.102.49 to 16.3.102.6216.3.102.6314
10116.3.102.64/2816.3.102.65 to 16.3.102.7816.3.102.7914
10216.3.102.80/2816.3.102.81 to 16.3.102.9416.3.102.9514
10316.3.102.96/2816.3.102.97 to 16.3.102.11016.3.102.11114
10416.3.102.112/2816.3.102.113 to 16.3.102.12616.3.102.12714
10516.3.102.128/2816.3.102.129 to 16.3.102.14216.3.102.14314
10616.3.102.144/2816.3.102.145 to 16.3.102.15816.3.102.15914
10716.3.102.160/2816.3.102.161 to 16.3.102.17416.3.102.17514
10816.3.102.176/2816.3.102.177 to 16.3.102.19016.3.102.19114
10916.3.102.192/2816.3.102.193 to 16.3.102.20616.3.102.20714
11016.3.102.208/2816.3.102.209 to 16.3.102.22216.3.102.22314
11116.3.102.224/2816.3.102.225 to 16.3.102.23816.3.102.23914
11216.3.102.240/2816.3.102.241 to 16.3.102.25416.3.102.25514
11316.3.103.0/2816.3.103.1 to 16.3.103.1416.3.103.1514
11416.3.103.16/2816.3.103.17 to 16.3.103.3016.3.103.3114
11516.3.103.32/2816.3.103.33 to 16.3.103.4616.3.103.4714
11616.3.103.48/2816.3.103.49 to 16.3.103.6216.3.103.6314
11716.3.103.64/2816.3.103.65 to 16.3.103.7816.3.103.7914
11816.3.103.80/2816.3.103.81 to 16.3.103.9416.3.103.9514
11916.3.103.96/2816.3.103.97 to 16.3.103.11016.3.103.11114
12016.3.103.112/2816.3.103.113 to 16.3.103.12616.3.103.12714
12116.3.103.128/2816.3.103.129 to 16.3.103.14216.3.103.14314
12216.3.103.144/2816.3.103.145 to 16.3.103.15816.3.103.15914
12316.3.103.160/2816.3.103.161 to 16.3.103.17416.3.103.17514
12416.3.103.176/2816.3.103.177 to 16.3.103.19016.3.103.19114
12516.3.103.192/2816.3.103.193 to 16.3.103.20616.3.103.20714
12616.3.103.208/2816.3.103.209 to 16.3.103.22216.3.103.22314
12716.3.103.224/2816.3.103.225 to 16.3.103.23816.3.103.23914
12816.3.103.240/2816.3.103.241 to 16.3.103.25416.3.103.25514
12916.3.104.0/2816.3.104.1 to 16.3.104.1416.3.104.1514
13016.3.104.16/2816.3.104.17 to 16.3.104.3016.3.104.3114
13116.3.104.32/2816.3.104.33 to 16.3.104.4616.3.104.4714
13216.3.104.48/2816.3.104.49 to 16.3.104.6216.3.104.6314
13316.3.104.64/2816.3.104.65 to 16.3.104.7816.3.104.7914
13416.3.104.80/2816.3.104.81 to 16.3.104.9416.3.104.9514
13516.3.104.96/2816.3.104.97 to 16.3.104.11016.3.104.11114
13616.3.104.112/2816.3.104.113 to 16.3.104.12616.3.104.12714
13716.3.104.128/2816.3.104.129 to 16.3.104.14216.3.104.14314
13816.3.104.144/2816.3.104.145 to 16.3.104.15816.3.104.15914
13916.3.104.160/2816.3.104.161 to 16.3.104.17416.3.104.17514
14016.3.104.176/2816.3.104.177 to 16.3.104.19016.3.104.19114
14116.3.104.192/2816.3.104.193 to 16.3.104.20616.3.104.20714
14216.3.104.208/2816.3.104.209 to 16.3.104.22216.3.104.22314
14316.3.104.224/2816.3.104.225 to 16.3.104.23816.3.104.23914
14416.3.104.240/2816.3.104.241 to 16.3.104.25416.3.104.25514
14516.3.105.0/2816.3.105.1 to 16.3.105.1416.3.105.1514
14616.3.105.16/2816.3.105.17 to 16.3.105.3016.3.105.3114
14716.3.105.32/2816.3.105.33 to 16.3.105.4616.3.105.4714
14816.3.105.48/2816.3.105.49 to 16.3.105.6216.3.105.6314
14916.3.105.64/2816.3.105.65 to 16.3.105.7816.3.105.7914
15016.3.105.80/2816.3.105.81 to 16.3.105.9416.3.105.9514
15116.3.105.96/2816.3.105.97 to 16.3.105.11016.3.105.11114
15216.3.105.112/2816.3.105.113 to 16.3.105.12616.3.105.12714
15316.3.105.128/2816.3.105.129 to 16.3.105.14216.3.105.14314
15416.3.105.144/2816.3.105.145 to 16.3.105.15816.3.105.15914
15516.3.105.160/2816.3.105.161 to 16.3.105.17416.3.105.17514
15616.3.105.176/2816.3.105.177 to 16.3.105.19016.3.105.19114
15716.3.105.192/2816.3.105.193 to 16.3.105.20616.3.105.20714
15816.3.105.208/2816.3.105.209 to 16.3.105.22216.3.105.22314
15916.3.105.224/2816.3.105.225 to 16.3.105.23816.3.105.23914
16016.3.105.240/2816.3.105.241 to 16.3.105.25416.3.105.25514
16116.3.106.0/2816.3.106.1 to 16.3.106.1416.3.106.1514
16216.3.106.16/2816.3.106.17 to 16.3.106.3016.3.106.3114
16316.3.106.32/2816.3.106.33 to 16.3.106.4616.3.106.4714
16416.3.106.48/2816.3.106.49 to 16.3.106.6216.3.106.6314
16516.3.106.64/2816.3.106.65 to 16.3.106.7816.3.106.7914
16616.3.106.80/2816.3.106.81 to 16.3.106.9416.3.106.9514
16716.3.106.96/2816.3.106.97 to 16.3.106.11016.3.106.11114
16816.3.106.112/2816.3.106.113 to 16.3.106.12616.3.106.12714
16916.3.106.128/2816.3.106.129 to 16.3.106.14216.3.106.14314
17016.3.106.144/2816.3.106.145 to 16.3.106.15816.3.106.15914
17116.3.106.160/2816.3.106.161 to 16.3.106.17416.3.106.17514
17216.3.106.176/2816.3.106.177 to 16.3.106.19016.3.106.19114
17316.3.106.192/2816.3.106.193 to 16.3.106.20616.3.106.20714
17416.3.106.208/2816.3.106.209 to 16.3.106.22216.3.106.22314
17516.3.106.224/2816.3.106.225 to 16.3.106.23816.3.106.23914
17616.3.106.240/2816.3.106.241 to 16.3.106.25416.3.106.25514
17716.3.107.0/2816.3.107.1 to 16.3.107.1416.3.107.1514
17816.3.107.16/2816.3.107.17 to 16.3.107.3016.3.107.3114
17916.3.107.32/2816.3.107.33 to 16.3.107.4616.3.107.4714
18016.3.107.48/2816.3.107.49 to 16.3.107.6216.3.107.6314
18116.3.107.64/2816.3.107.65 to 16.3.107.7816.3.107.7914
18216.3.107.80/2816.3.107.81 to 16.3.107.9416.3.107.9514
18316.3.107.96/2816.3.107.97 to 16.3.107.11016.3.107.11114
18416.3.107.112/2816.3.107.113 to 16.3.107.12616.3.107.12714
18516.3.107.128/2816.3.107.129 to 16.3.107.14216.3.107.14314
18616.3.107.144/2816.3.107.145 to 16.3.107.15816.3.107.15914
18716.3.107.160/2816.3.107.161 to 16.3.107.17416.3.107.17514
18816.3.107.176/2816.3.107.177 to 16.3.107.19016.3.107.19114
18916.3.107.192/2816.3.107.193 to 16.3.107.20616.3.107.20714
19016.3.107.208/2816.3.107.209 to 16.3.107.22216.3.107.22314
19116.3.107.224/2816.3.107.225 to 16.3.107.23816.3.107.23914
19216.3.107.240/2816.3.107.241 to 16.3.107.25416.3.107.25514
19316.3.108.0/2816.3.108.1 to 16.3.108.1416.3.108.1514
19416.3.108.16/2816.3.108.17 to 16.3.108.3016.3.108.3114
19516.3.108.32/2816.3.108.33 to 16.3.108.4616.3.108.4714
19616.3.108.48/2816.3.108.49 to 16.3.108.6216.3.108.6314
19716.3.108.64/2816.3.108.65 to 16.3.108.7816.3.108.7914
19816.3.108.80/2816.3.108.81 to 16.3.108.9416.3.108.9514
19916.3.108.96/2816.3.108.97 to 16.3.108.11016.3.108.11114
20016.3.108.112/2816.3.108.113 to 16.3.108.12616.3.108.12714
20116.3.108.128/2816.3.108.129 to 16.3.108.14216.3.108.14314
20216.3.108.144/2816.3.108.145 to 16.3.108.15816.3.108.15914
20316.3.108.160/2816.3.108.161 to 16.3.108.17416.3.108.17514
20416.3.108.176/2816.3.108.177 to 16.3.108.19016.3.108.19114
20516.3.108.192/2816.3.108.193 to 16.3.108.20616.3.108.20714
20616.3.108.208/2816.3.108.209 to 16.3.108.22216.3.108.22314
20716.3.108.224/2816.3.108.225 to 16.3.108.23816.3.108.23914
20816.3.108.240/2816.3.108.241 to 16.3.108.25416.3.108.25514
20916.3.109.0/2816.3.109.1 to 16.3.109.1416.3.109.1514
21016.3.109.16/2816.3.109.17 to 16.3.109.3016.3.109.3114
21116.3.109.32/2816.3.109.33 to 16.3.109.4616.3.109.4714
21216.3.109.48/2816.3.109.49 to 16.3.109.6216.3.109.6314
21316.3.109.64/2816.3.109.65 to 16.3.109.7816.3.109.7914
21416.3.109.80/2816.3.109.81 to 16.3.109.9416.3.109.9514
21516.3.109.96/2816.3.109.97 to 16.3.109.11016.3.109.11114
21616.3.109.112/2816.3.109.113 to 16.3.109.12616.3.109.12714
21716.3.109.128/2816.3.109.129 to 16.3.109.14216.3.109.14314
21816.3.109.144/2816.3.109.145 to 16.3.109.15816.3.109.15914
21916.3.109.160/2816.3.109.161 to 16.3.109.17416.3.109.17514
22016.3.109.176/2816.3.109.177 to 16.3.109.19016.3.109.19114
22116.3.109.192/2816.3.109.193 to 16.3.109.20616.3.109.20714
22216.3.109.208/2816.3.109.209 to 16.3.109.22216.3.109.22314
22316.3.109.224/2816.3.109.225 to 16.3.109.23816.3.109.23914
22416.3.109.240/2816.3.109.241 to 16.3.109.25416.3.109.25514
22516.3.110.0/2816.3.110.1 to 16.3.110.1416.3.110.1514
22616.3.110.16/2816.3.110.17 to 16.3.110.3016.3.110.3114
22716.3.110.32/2816.3.110.33 to 16.3.110.4616.3.110.4714
22816.3.110.48/2816.3.110.49 to 16.3.110.6216.3.110.6314
22916.3.110.64/2816.3.110.65 to 16.3.110.7816.3.110.7914
23016.3.110.80/2816.3.110.81 to 16.3.110.9416.3.110.9514
23116.3.110.96/2816.3.110.97 to 16.3.110.11016.3.110.11114
23216.3.110.112/2816.3.110.113 to 16.3.110.12616.3.110.12714
23316.3.110.128/2816.3.110.129 to 16.3.110.14216.3.110.14314
23416.3.110.144/2816.3.110.145 to 16.3.110.15816.3.110.15914
23516.3.110.160/2816.3.110.161 to 16.3.110.17416.3.110.17514
23616.3.110.176/2816.3.110.177 to 16.3.110.19016.3.110.19114
23716.3.110.192/2816.3.110.193 to 16.3.110.20616.3.110.20714
23816.3.110.208/2816.3.110.209 to 16.3.110.22216.3.110.22314
23916.3.110.224/2816.3.110.225 to 16.3.110.23816.3.110.23914
24016.3.110.240/2816.3.110.241 to 16.3.110.25416.3.110.25514
24116.3.111.0/2816.3.111.1 to 16.3.111.1416.3.111.1514
24216.3.111.16/2816.3.111.17 to 16.3.111.3016.3.111.3114
24316.3.111.32/2816.3.111.33 to 16.3.111.4616.3.111.4714
24416.3.111.48/2816.3.111.49 to 16.3.111.6216.3.111.6314
24516.3.111.64/2816.3.111.65 to 16.3.111.7816.3.111.7914
24616.3.111.80/2816.3.111.81 to 16.3.111.9416.3.111.9514
24716.3.111.96/2816.3.111.97 to 16.3.111.11016.3.111.11114
24816.3.111.112/2816.3.111.113 to 16.3.111.12616.3.111.12714
24916.3.111.128/2816.3.111.129 to 16.3.111.14216.3.111.14314
25016.3.111.144/2816.3.111.145 to 16.3.111.15816.3.111.15914
25116.3.111.160/2816.3.111.161 to 16.3.111.17416.3.111.17514
25216.3.111.176/2816.3.111.177 to 16.3.111.19016.3.111.19114
25316.3.111.192/2816.3.111.193 to 16.3.111.20616.3.111.20714
25416.3.111.208/2816.3.111.209 to 16.3.111.22216.3.111.22314
25516.3.111.224/2816.3.111.225 to 16.3.111.23816.3.111.23914
25616.3.111.240/2816.3.111.241 to 16.3.111.25416.3.111.25514

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.