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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.

Network70.4.96.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
70.4.96.0
Broadcast address
70.4.127.255
First usable
70.4.96.1
Last usable
70.4.127.254
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 46046000 · Integer 1174691840 to 1174700031
Reverse DNS zones
96.4.70.in-addr.arpa
97.4.70.in-addr.arpa
98.4.70.in-addr.arpa
99.4.70.in-addr.arpa
100.4.70.in-addr.arpa
101.4.70.in-addr.arpa
102.4.70.in-addr.arpa
103.4.70.in-addr.arpa
104.4.70.in-addr.arpa
105.4.70.in-addr.arpa
106.4.70.in-addr.arpa
107.4.70.in-addr.arpa
108.4.70.in-addr.arpa
109.4.70.in-addr.arpa
110.4.70.in-addr.arpa
111.4.70.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
Address01000110.00000100.01100000.0000000070.4.96.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network01000110.00000100.01100000.0000000070.4.96.0
Broadcast01000110.00000100.01111111.1111111170.4.127.255
Split into smaller subnets/27
/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)

70.4.96.0/19 makes 256 subnets of /27.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
170.4.96.0/2770.4.96.1 to 70.4.96.3070.4.96.3130
270.4.96.32/2770.4.96.33 to 70.4.96.6270.4.96.6330
370.4.96.64/2770.4.96.65 to 70.4.96.9470.4.96.9530
470.4.96.96/2770.4.96.97 to 70.4.96.12670.4.96.12730
570.4.96.128/2770.4.96.129 to 70.4.96.15870.4.96.15930
670.4.96.160/2770.4.96.161 to 70.4.96.19070.4.96.19130
770.4.96.192/2770.4.96.193 to 70.4.96.22270.4.96.22330
870.4.96.224/2770.4.96.225 to 70.4.96.25470.4.96.25530
970.4.97.0/2770.4.97.1 to 70.4.97.3070.4.97.3130
1070.4.97.32/2770.4.97.33 to 70.4.97.6270.4.97.6330
1170.4.97.64/2770.4.97.65 to 70.4.97.9470.4.97.9530
1270.4.97.96/2770.4.97.97 to 70.4.97.12670.4.97.12730
1370.4.97.128/2770.4.97.129 to 70.4.97.15870.4.97.15930
1470.4.97.160/2770.4.97.161 to 70.4.97.19070.4.97.19130
1570.4.97.192/2770.4.97.193 to 70.4.97.22270.4.97.22330
1670.4.97.224/2770.4.97.225 to 70.4.97.25470.4.97.25530
1770.4.98.0/2770.4.98.1 to 70.4.98.3070.4.98.3130
1870.4.98.32/2770.4.98.33 to 70.4.98.6270.4.98.6330
1970.4.98.64/2770.4.98.65 to 70.4.98.9470.4.98.9530
2070.4.98.96/2770.4.98.97 to 70.4.98.12670.4.98.12730
2170.4.98.128/2770.4.98.129 to 70.4.98.15870.4.98.15930
2270.4.98.160/2770.4.98.161 to 70.4.98.19070.4.98.19130
2370.4.98.192/2770.4.98.193 to 70.4.98.22270.4.98.22330
2470.4.98.224/2770.4.98.225 to 70.4.98.25470.4.98.25530
2570.4.99.0/2770.4.99.1 to 70.4.99.3070.4.99.3130
2670.4.99.32/2770.4.99.33 to 70.4.99.6270.4.99.6330
2770.4.99.64/2770.4.99.65 to 70.4.99.9470.4.99.9530
2870.4.99.96/2770.4.99.97 to 70.4.99.12670.4.99.12730
2970.4.99.128/2770.4.99.129 to 70.4.99.15870.4.99.15930
3070.4.99.160/2770.4.99.161 to 70.4.99.19070.4.99.19130
3170.4.99.192/2770.4.99.193 to 70.4.99.22270.4.99.22330
3270.4.99.224/2770.4.99.225 to 70.4.99.25470.4.99.25530
3370.4.100.0/2770.4.100.1 to 70.4.100.3070.4.100.3130
3470.4.100.32/2770.4.100.33 to 70.4.100.6270.4.100.6330
3570.4.100.64/2770.4.100.65 to 70.4.100.9470.4.100.9530
3670.4.100.96/2770.4.100.97 to 70.4.100.12670.4.100.12730
3770.4.100.128/2770.4.100.129 to 70.4.100.15870.4.100.15930
3870.4.100.160/2770.4.100.161 to 70.4.100.19070.4.100.19130
3970.4.100.192/2770.4.100.193 to 70.4.100.22270.4.100.22330
4070.4.100.224/2770.4.100.225 to 70.4.100.25470.4.100.25530
4170.4.101.0/2770.4.101.1 to 70.4.101.3070.4.101.3130
4270.4.101.32/2770.4.101.33 to 70.4.101.6270.4.101.6330
4370.4.101.64/2770.4.101.65 to 70.4.101.9470.4.101.9530
4470.4.101.96/2770.4.101.97 to 70.4.101.12670.4.101.12730
4570.4.101.128/2770.4.101.129 to 70.4.101.15870.4.101.15930
4670.4.101.160/2770.4.101.161 to 70.4.101.19070.4.101.19130
4770.4.101.192/2770.4.101.193 to 70.4.101.22270.4.101.22330
4870.4.101.224/2770.4.101.225 to 70.4.101.25470.4.101.25530
4970.4.102.0/2770.4.102.1 to 70.4.102.3070.4.102.3130
5070.4.102.32/2770.4.102.33 to 70.4.102.6270.4.102.6330
5170.4.102.64/2770.4.102.65 to 70.4.102.9470.4.102.9530
5270.4.102.96/2770.4.102.97 to 70.4.102.12670.4.102.12730
5370.4.102.128/2770.4.102.129 to 70.4.102.15870.4.102.15930
5470.4.102.160/2770.4.102.161 to 70.4.102.19070.4.102.19130
5570.4.102.192/2770.4.102.193 to 70.4.102.22270.4.102.22330
5670.4.102.224/2770.4.102.225 to 70.4.102.25470.4.102.25530
5770.4.103.0/2770.4.103.1 to 70.4.103.3070.4.103.3130
5870.4.103.32/2770.4.103.33 to 70.4.103.6270.4.103.6330
5970.4.103.64/2770.4.103.65 to 70.4.103.9470.4.103.9530
6070.4.103.96/2770.4.103.97 to 70.4.103.12670.4.103.12730
6170.4.103.128/2770.4.103.129 to 70.4.103.15870.4.103.15930
6270.4.103.160/2770.4.103.161 to 70.4.103.19070.4.103.19130
6370.4.103.192/2770.4.103.193 to 70.4.103.22270.4.103.22330
6470.4.103.224/2770.4.103.225 to 70.4.103.25470.4.103.25530
6570.4.104.0/2770.4.104.1 to 70.4.104.3070.4.104.3130
6670.4.104.32/2770.4.104.33 to 70.4.104.6270.4.104.6330
6770.4.104.64/2770.4.104.65 to 70.4.104.9470.4.104.9530
6870.4.104.96/2770.4.104.97 to 70.4.104.12670.4.104.12730
6970.4.104.128/2770.4.104.129 to 70.4.104.15870.4.104.15930
7070.4.104.160/2770.4.104.161 to 70.4.104.19070.4.104.19130
7170.4.104.192/2770.4.104.193 to 70.4.104.22270.4.104.22330
7270.4.104.224/2770.4.104.225 to 70.4.104.25470.4.104.25530
7370.4.105.0/2770.4.105.1 to 70.4.105.3070.4.105.3130
7470.4.105.32/2770.4.105.33 to 70.4.105.6270.4.105.6330
7570.4.105.64/2770.4.105.65 to 70.4.105.9470.4.105.9530
7670.4.105.96/2770.4.105.97 to 70.4.105.12670.4.105.12730
7770.4.105.128/2770.4.105.129 to 70.4.105.15870.4.105.15930
7870.4.105.160/2770.4.105.161 to 70.4.105.19070.4.105.19130
7970.4.105.192/2770.4.105.193 to 70.4.105.22270.4.105.22330
8070.4.105.224/2770.4.105.225 to 70.4.105.25470.4.105.25530
8170.4.106.0/2770.4.106.1 to 70.4.106.3070.4.106.3130
8270.4.106.32/2770.4.106.33 to 70.4.106.6270.4.106.6330
8370.4.106.64/2770.4.106.65 to 70.4.106.9470.4.106.9530
8470.4.106.96/2770.4.106.97 to 70.4.106.12670.4.106.12730
8570.4.106.128/2770.4.106.129 to 70.4.106.15870.4.106.15930
8670.4.106.160/2770.4.106.161 to 70.4.106.19070.4.106.19130
8770.4.106.192/2770.4.106.193 to 70.4.106.22270.4.106.22330
8870.4.106.224/2770.4.106.225 to 70.4.106.25470.4.106.25530
8970.4.107.0/2770.4.107.1 to 70.4.107.3070.4.107.3130
9070.4.107.32/2770.4.107.33 to 70.4.107.6270.4.107.6330
9170.4.107.64/2770.4.107.65 to 70.4.107.9470.4.107.9530
9270.4.107.96/2770.4.107.97 to 70.4.107.12670.4.107.12730
9370.4.107.128/2770.4.107.129 to 70.4.107.15870.4.107.15930
9470.4.107.160/2770.4.107.161 to 70.4.107.19070.4.107.19130
9570.4.107.192/2770.4.107.193 to 70.4.107.22270.4.107.22330
9670.4.107.224/2770.4.107.225 to 70.4.107.25470.4.107.25530
9770.4.108.0/2770.4.108.1 to 70.4.108.3070.4.108.3130
9870.4.108.32/2770.4.108.33 to 70.4.108.6270.4.108.6330
9970.4.108.64/2770.4.108.65 to 70.4.108.9470.4.108.9530
10070.4.108.96/2770.4.108.97 to 70.4.108.12670.4.108.12730
10170.4.108.128/2770.4.108.129 to 70.4.108.15870.4.108.15930
10270.4.108.160/2770.4.108.161 to 70.4.108.19070.4.108.19130
10370.4.108.192/2770.4.108.193 to 70.4.108.22270.4.108.22330
10470.4.108.224/2770.4.108.225 to 70.4.108.25470.4.108.25530
10570.4.109.0/2770.4.109.1 to 70.4.109.3070.4.109.3130
10670.4.109.32/2770.4.109.33 to 70.4.109.6270.4.109.6330
10770.4.109.64/2770.4.109.65 to 70.4.109.9470.4.109.9530
10870.4.109.96/2770.4.109.97 to 70.4.109.12670.4.109.12730
10970.4.109.128/2770.4.109.129 to 70.4.109.15870.4.109.15930
11070.4.109.160/2770.4.109.161 to 70.4.109.19070.4.109.19130
11170.4.109.192/2770.4.109.193 to 70.4.109.22270.4.109.22330
11270.4.109.224/2770.4.109.225 to 70.4.109.25470.4.109.25530
11370.4.110.0/2770.4.110.1 to 70.4.110.3070.4.110.3130
11470.4.110.32/2770.4.110.33 to 70.4.110.6270.4.110.6330
11570.4.110.64/2770.4.110.65 to 70.4.110.9470.4.110.9530
11670.4.110.96/2770.4.110.97 to 70.4.110.12670.4.110.12730
11770.4.110.128/2770.4.110.129 to 70.4.110.15870.4.110.15930
11870.4.110.160/2770.4.110.161 to 70.4.110.19070.4.110.19130
11970.4.110.192/2770.4.110.193 to 70.4.110.22270.4.110.22330
12070.4.110.224/2770.4.110.225 to 70.4.110.25470.4.110.25530
12170.4.111.0/2770.4.111.1 to 70.4.111.3070.4.111.3130
12270.4.111.32/2770.4.111.33 to 70.4.111.6270.4.111.6330
12370.4.111.64/2770.4.111.65 to 70.4.111.9470.4.111.9530
12470.4.111.96/2770.4.111.97 to 70.4.111.12670.4.111.12730
12570.4.111.128/2770.4.111.129 to 70.4.111.15870.4.111.15930
12670.4.111.160/2770.4.111.161 to 70.4.111.19070.4.111.19130
12770.4.111.192/2770.4.111.193 to 70.4.111.22270.4.111.22330
12870.4.111.224/2770.4.111.225 to 70.4.111.25470.4.111.25530
12970.4.112.0/2770.4.112.1 to 70.4.112.3070.4.112.3130
13070.4.112.32/2770.4.112.33 to 70.4.112.6270.4.112.6330
13170.4.112.64/2770.4.112.65 to 70.4.112.9470.4.112.9530
13270.4.112.96/2770.4.112.97 to 70.4.112.12670.4.112.12730
13370.4.112.128/2770.4.112.129 to 70.4.112.15870.4.112.15930
13470.4.112.160/2770.4.112.161 to 70.4.112.19070.4.112.19130
13570.4.112.192/2770.4.112.193 to 70.4.112.22270.4.112.22330
13670.4.112.224/2770.4.112.225 to 70.4.112.25470.4.112.25530
13770.4.113.0/2770.4.113.1 to 70.4.113.3070.4.113.3130
13870.4.113.32/2770.4.113.33 to 70.4.113.6270.4.113.6330
13970.4.113.64/2770.4.113.65 to 70.4.113.9470.4.113.9530
14070.4.113.96/2770.4.113.97 to 70.4.113.12670.4.113.12730
14170.4.113.128/2770.4.113.129 to 70.4.113.15870.4.113.15930
14270.4.113.160/2770.4.113.161 to 70.4.113.19070.4.113.19130
14370.4.113.192/2770.4.113.193 to 70.4.113.22270.4.113.22330
14470.4.113.224/2770.4.113.225 to 70.4.113.25470.4.113.25530
14570.4.114.0/2770.4.114.1 to 70.4.114.3070.4.114.3130
14670.4.114.32/2770.4.114.33 to 70.4.114.6270.4.114.6330
14770.4.114.64/2770.4.114.65 to 70.4.114.9470.4.114.9530
14870.4.114.96/2770.4.114.97 to 70.4.114.12670.4.114.12730
14970.4.114.128/2770.4.114.129 to 70.4.114.15870.4.114.15930
15070.4.114.160/2770.4.114.161 to 70.4.114.19070.4.114.19130
15170.4.114.192/2770.4.114.193 to 70.4.114.22270.4.114.22330
15270.4.114.224/2770.4.114.225 to 70.4.114.25470.4.114.25530
15370.4.115.0/2770.4.115.1 to 70.4.115.3070.4.115.3130
15470.4.115.32/2770.4.115.33 to 70.4.115.6270.4.115.6330
15570.4.115.64/2770.4.115.65 to 70.4.115.9470.4.115.9530
15670.4.115.96/2770.4.115.97 to 70.4.115.12670.4.115.12730
15770.4.115.128/2770.4.115.129 to 70.4.115.15870.4.115.15930
15870.4.115.160/2770.4.115.161 to 70.4.115.19070.4.115.19130
15970.4.115.192/2770.4.115.193 to 70.4.115.22270.4.115.22330
16070.4.115.224/2770.4.115.225 to 70.4.115.25470.4.115.25530
16170.4.116.0/2770.4.116.1 to 70.4.116.3070.4.116.3130
16270.4.116.32/2770.4.116.33 to 70.4.116.6270.4.116.6330
16370.4.116.64/2770.4.116.65 to 70.4.116.9470.4.116.9530
16470.4.116.96/2770.4.116.97 to 70.4.116.12670.4.116.12730
16570.4.116.128/2770.4.116.129 to 70.4.116.15870.4.116.15930
16670.4.116.160/2770.4.116.161 to 70.4.116.19070.4.116.19130
16770.4.116.192/2770.4.116.193 to 70.4.116.22270.4.116.22330
16870.4.116.224/2770.4.116.225 to 70.4.116.25470.4.116.25530
16970.4.117.0/2770.4.117.1 to 70.4.117.3070.4.117.3130
17070.4.117.32/2770.4.117.33 to 70.4.117.6270.4.117.6330
17170.4.117.64/2770.4.117.65 to 70.4.117.9470.4.117.9530
17270.4.117.96/2770.4.117.97 to 70.4.117.12670.4.117.12730
17370.4.117.128/2770.4.117.129 to 70.4.117.15870.4.117.15930
17470.4.117.160/2770.4.117.161 to 70.4.117.19070.4.117.19130
17570.4.117.192/2770.4.117.193 to 70.4.117.22270.4.117.22330
17670.4.117.224/2770.4.117.225 to 70.4.117.25470.4.117.25530
17770.4.118.0/2770.4.118.1 to 70.4.118.3070.4.118.3130
17870.4.118.32/2770.4.118.33 to 70.4.118.6270.4.118.6330
17970.4.118.64/2770.4.118.65 to 70.4.118.9470.4.118.9530
18070.4.118.96/2770.4.118.97 to 70.4.118.12670.4.118.12730
18170.4.118.128/2770.4.118.129 to 70.4.118.15870.4.118.15930
18270.4.118.160/2770.4.118.161 to 70.4.118.19070.4.118.19130
18370.4.118.192/2770.4.118.193 to 70.4.118.22270.4.118.22330
18470.4.118.224/2770.4.118.225 to 70.4.118.25470.4.118.25530
18570.4.119.0/2770.4.119.1 to 70.4.119.3070.4.119.3130
18670.4.119.32/2770.4.119.33 to 70.4.119.6270.4.119.6330
18770.4.119.64/2770.4.119.65 to 70.4.119.9470.4.119.9530
18870.4.119.96/2770.4.119.97 to 70.4.119.12670.4.119.12730
18970.4.119.128/2770.4.119.129 to 70.4.119.15870.4.119.15930
19070.4.119.160/2770.4.119.161 to 70.4.119.19070.4.119.19130
19170.4.119.192/2770.4.119.193 to 70.4.119.22270.4.119.22330
19270.4.119.224/2770.4.119.225 to 70.4.119.25470.4.119.25530
19370.4.120.0/2770.4.120.1 to 70.4.120.3070.4.120.3130
19470.4.120.32/2770.4.120.33 to 70.4.120.6270.4.120.6330
19570.4.120.64/2770.4.120.65 to 70.4.120.9470.4.120.9530
19670.4.120.96/2770.4.120.97 to 70.4.120.12670.4.120.12730
19770.4.120.128/2770.4.120.129 to 70.4.120.15870.4.120.15930
19870.4.120.160/2770.4.120.161 to 70.4.120.19070.4.120.19130
19970.4.120.192/2770.4.120.193 to 70.4.120.22270.4.120.22330
20070.4.120.224/2770.4.120.225 to 70.4.120.25470.4.120.25530
20170.4.121.0/2770.4.121.1 to 70.4.121.3070.4.121.3130
20270.4.121.32/2770.4.121.33 to 70.4.121.6270.4.121.6330
20370.4.121.64/2770.4.121.65 to 70.4.121.9470.4.121.9530
20470.4.121.96/2770.4.121.97 to 70.4.121.12670.4.121.12730
20570.4.121.128/2770.4.121.129 to 70.4.121.15870.4.121.15930
20670.4.121.160/2770.4.121.161 to 70.4.121.19070.4.121.19130
20770.4.121.192/2770.4.121.193 to 70.4.121.22270.4.121.22330
20870.4.121.224/2770.4.121.225 to 70.4.121.25470.4.121.25530
20970.4.122.0/2770.4.122.1 to 70.4.122.3070.4.122.3130
21070.4.122.32/2770.4.122.33 to 70.4.122.6270.4.122.6330
21170.4.122.64/2770.4.122.65 to 70.4.122.9470.4.122.9530
21270.4.122.96/2770.4.122.97 to 70.4.122.12670.4.122.12730
21370.4.122.128/2770.4.122.129 to 70.4.122.15870.4.122.15930
21470.4.122.160/2770.4.122.161 to 70.4.122.19070.4.122.19130
21570.4.122.192/2770.4.122.193 to 70.4.122.22270.4.122.22330
21670.4.122.224/2770.4.122.225 to 70.4.122.25470.4.122.25530
21770.4.123.0/2770.4.123.1 to 70.4.123.3070.4.123.3130
21870.4.123.32/2770.4.123.33 to 70.4.123.6270.4.123.6330
21970.4.123.64/2770.4.123.65 to 70.4.123.9470.4.123.9530
22070.4.123.96/2770.4.123.97 to 70.4.123.12670.4.123.12730
22170.4.123.128/2770.4.123.129 to 70.4.123.15870.4.123.15930
22270.4.123.160/2770.4.123.161 to 70.4.123.19070.4.123.19130
22370.4.123.192/2770.4.123.193 to 70.4.123.22270.4.123.22330
22470.4.123.224/2770.4.123.225 to 70.4.123.25470.4.123.25530
22570.4.124.0/2770.4.124.1 to 70.4.124.3070.4.124.3130
22670.4.124.32/2770.4.124.33 to 70.4.124.6270.4.124.6330
22770.4.124.64/2770.4.124.65 to 70.4.124.9470.4.124.9530
22870.4.124.96/2770.4.124.97 to 70.4.124.12670.4.124.12730
22970.4.124.128/2770.4.124.129 to 70.4.124.15870.4.124.15930
23070.4.124.160/2770.4.124.161 to 70.4.124.19070.4.124.19130
23170.4.124.192/2770.4.124.193 to 70.4.124.22270.4.124.22330
23270.4.124.224/2770.4.124.225 to 70.4.124.25470.4.124.25530
23370.4.125.0/2770.4.125.1 to 70.4.125.3070.4.125.3130
23470.4.125.32/2770.4.125.33 to 70.4.125.6270.4.125.6330
23570.4.125.64/2770.4.125.65 to 70.4.125.9470.4.125.9530
23670.4.125.96/2770.4.125.97 to 70.4.125.12670.4.125.12730
23770.4.125.128/2770.4.125.129 to 70.4.125.15870.4.125.15930
23870.4.125.160/2770.4.125.161 to 70.4.125.19070.4.125.19130
23970.4.125.192/2770.4.125.193 to 70.4.125.22270.4.125.22330
24070.4.125.224/2770.4.125.225 to 70.4.125.25470.4.125.25530
24170.4.126.0/2770.4.126.1 to 70.4.126.3070.4.126.3130
24270.4.126.32/2770.4.126.33 to 70.4.126.6270.4.126.6330
24370.4.126.64/2770.4.126.65 to 70.4.126.9470.4.126.9530
24470.4.126.96/2770.4.126.97 to 70.4.126.12670.4.126.12730
24570.4.126.128/2770.4.126.129 to 70.4.126.15870.4.126.15930
24670.4.126.160/2770.4.126.161 to 70.4.126.19070.4.126.19130
24770.4.126.192/2770.4.126.193 to 70.4.126.22270.4.126.22330
24870.4.126.224/2770.4.126.225 to 70.4.126.25470.4.126.25530
24970.4.127.0/2770.4.127.1 to 70.4.127.3070.4.127.3130
25070.4.127.32/2770.4.127.33 to 70.4.127.6270.4.127.6330
25170.4.127.64/2770.4.127.65 to 70.4.127.9470.4.127.9530
25270.4.127.96/2770.4.127.97 to 70.4.127.12670.4.127.12730
25370.4.127.128/2770.4.127.129 to 70.4.127.15870.4.127.15930
25470.4.127.160/2770.4.127.161 to 70.4.127.19070.4.127.19130
25570.4.127.192/2770.4.127.193 to 70.4.127.22270.4.127.22330
25670.4.127.224/2770.4.127.225 to 70.4.127.25470.4.127.25530

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.