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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.

Network98.7.80.0/20
Usable hosts4,094
Subnet mask255.255.240.0
Addresses4,096
Network address
98.7.80.0
Broadcast address
98.7.95.255
First usable
98.7.80.1
Last usable
98.7.95.254
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 62075000 · Integer 1644646400 to 1644650495
Reverse DNS zones
80.7.98.in-addr.arpa
81.7.98.in-addr.arpa
82.7.98.in-addr.arpa
83.7.98.in-addr.arpa
84.7.98.in-addr.arpa
85.7.98.in-addr.arpa
86.7.98.in-addr.arpa
87.7.98.in-addr.arpa
88.7.98.in-addr.arpa
89.7.98.in-addr.arpa
90.7.98.in-addr.arpa
91.7.98.in-addr.arpa
92.7.98.in-addr.arpa
93.7.98.in-addr.arpa
94.7.98.in-addr.arpa
95.7.98.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
Address01100010.00000111.01010000.0000000098.7.80.0
Subnet mask11111111.11111111.11110000.00000000255.255.240.0
Network01100010.00000111.01010000.0000000098.7.80.0
Broadcast01100010.00000111.01011111.1111111198.7.95.255
Split into smaller subnets/30
/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)

98.7.80.0/20 makes 1,024 subnets of /30; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
198.7.80.0/3098.7.80.1 to 98.7.80.298.7.80.32
298.7.80.4/3098.7.80.5 to 98.7.80.698.7.80.72
398.7.80.8/3098.7.80.9 to 98.7.80.1098.7.80.112
498.7.80.12/3098.7.80.13 to 98.7.80.1498.7.80.152
598.7.80.16/3098.7.80.17 to 98.7.80.1898.7.80.192
698.7.80.20/3098.7.80.21 to 98.7.80.2298.7.80.232
798.7.80.24/3098.7.80.25 to 98.7.80.2698.7.80.272
898.7.80.28/3098.7.80.29 to 98.7.80.3098.7.80.312
998.7.80.32/3098.7.80.33 to 98.7.80.3498.7.80.352
1098.7.80.36/3098.7.80.37 to 98.7.80.3898.7.80.392
1198.7.80.40/3098.7.80.41 to 98.7.80.4298.7.80.432
1298.7.80.44/3098.7.80.45 to 98.7.80.4698.7.80.472
1398.7.80.48/3098.7.80.49 to 98.7.80.5098.7.80.512
1498.7.80.52/3098.7.80.53 to 98.7.80.5498.7.80.552
1598.7.80.56/3098.7.80.57 to 98.7.80.5898.7.80.592
1698.7.80.60/3098.7.80.61 to 98.7.80.6298.7.80.632
1798.7.80.64/3098.7.80.65 to 98.7.80.6698.7.80.672
1898.7.80.68/3098.7.80.69 to 98.7.80.7098.7.80.712
1998.7.80.72/3098.7.80.73 to 98.7.80.7498.7.80.752
2098.7.80.76/3098.7.80.77 to 98.7.80.7898.7.80.792
2198.7.80.80/3098.7.80.81 to 98.7.80.8298.7.80.832
2298.7.80.84/3098.7.80.85 to 98.7.80.8698.7.80.872
2398.7.80.88/3098.7.80.89 to 98.7.80.9098.7.80.912
2498.7.80.92/3098.7.80.93 to 98.7.80.9498.7.80.952
2598.7.80.96/3098.7.80.97 to 98.7.80.9898.7.80.992
2698.7.80.100/3098.7.80.101 to 98.7.80.10298.7.80.1032
2798.7.80.104/3098.7.80.105 to 98.7.80.10698.7.80.1072
2898.7.80.108/3098.7.80.109 to 98.7.80.11098.7.80.1112
2998.7.80.112/3098.7.80.113 to 98.7.80.11498.7.80.1152
3098.7.80.116/3098.7.80.117 to 98.7.80.11898.7.80.1192
3198.7.80.120/3098.7.80.121 to 98.7.80.12298.7.80.1232
3298.7.80.124/3098.7.80.125 to 98.7.80.12698.7.80.1272
3398.7.80.128/3098.7.80.129 to 98.7.80.13098.7.80.1312
3498.7.80.132/3098.7.80.133 to 98.7.80.13498.7.80.1352
3598.7.80.136/3098.7.80.137 to 98.7.80.13898.7.80.1392
3698.7.80.140/3098.7.80.141 to 98.7.80.14298.7.80.1432
3798.7.80.144/3098.7.80.145 to 98.7.80.14698.7.80.1472
3898.7.80.148/3098.7.80.149 to 98.7.80.15098.7.80.1512
3998.7.80.152/3098.7.80.153 to 98.7.80.15498.7.80.1552
4098.7.80.156/3098.7.80.157 to 98.7.80.15898.7.80.1592
4198.7.80.160/3098.7.80.161 to 98.7.80.16298.7.80.1632
4298.7.80.164/3098.7.80.165 to 98.7.80.16698.7.80.1672
4398.7.80.168/3098.7.80.169 to 98.7.80.17098.7.80.1712
4498.7.80.172/3098.7.80.173 to 98.7.80.17498.7.80.1752
4598.7.80.176/3098.7.80.177 to 98.7.80.17898.7.80.1792
4698.7.80.180/3098.7.80.181 to 98.7.80.18298.7.80.1832
4798.7.80.184/3098.7.80.185 to 98.7.80.18698.7.80.1872
4898.7.80.188/3098.7.80.189 to 98.7.80.19098.7.80.1912
4998.7.80.192/3098.7.80.193 to 98.7.80.19498.7.80.1952
5098.7.80.196/3098.7.80.197 to 98.7.80.19898.7.80.1992
5198.7.80.200/3098.7.80.201 to 98.7.80.20298.7.80.2032
5298.7.80.204/3098.7.80.205 to 98.7.80.20698.7.80.2072
5398.7.80.208/3098.7.80.209 to 98.7.80.21098.7.80.2112
5498.7.80.212/3098.7.80.213 to 98.7.80.21498.7.80.2152
5598.7.80.216/3098.7.80.217 to 98.7.80.21898.7.80.2192
5698.7.80.220/3098.7.80.221 to 98.7.80.22298.7.80.2232
5798.7.80.224/3098.7.80.225 to 98.7.80.22698.7.80.2272
5898.7.80.228/3098.7.80.229 to 98.7.80.23098.7.80.2312
5998.7.80.232/3098.7.80.233 to 98.7.80.23498.7.80.2352
6098.7.80.236/3098.7.80.237 to 98.7.80.23898.7.80.2392
6198.7.80.240/3098.7.80.241 to 98.7.80.24298.7.80.2432
6298.7.80.244/3098.7.80.245 to 98.7.80.24698.7.80.2472
6398.7.80.248/3098.7.80.249 to 98.7.80.25098.7.80.2512
6498.7.80.252/3098.7.80.253 to 98.7.80.25498.7.80.2552
6598.7.81.0/3098.7.81.1 to 98.7.81.298.7.81.32
6698.7.81.4/3098.7.81.5 to 98.7.81.698.7.81.72
6798.7.81.8/3098.7.81.9 to 98.7.81.1098.7.81.112
6898.7.81.12/3098.7.81.13 to 98.7.81.1498.7.81.152
6998.7.81.16/3098.7.81.17 to 98.7.81.1898.7.81.192
7098.7.81.20/3098.7.81.21 to 98.7.81.2298.7.81.232
7198.7.81.24/3098.7.81.25 to 98.7.81.2698.7.81.272
7298.7.81.28/3098.7.81.29 to 98.7.81.3098.7.81.312
7398.7.81.32/3098.7.81.33 to 98.7.81.3498.7.81.352
7498.7.81.36/3098.7.81.37 to 98.7.81.3898.7.81.392
7598.7.81.40/3098.7.81.41 to 98.7.81.4298.7.81.432
7698.7.81.44/3098.7.81.45 to 98.7.81.4698.7.81.472
7798.7.81.48/3098.7.81.49 to 98.7.81.5098.7.81.512
7898.7.81.52/3098.7.81.53 to 98.7.81.5498.7.81.552
7998.7.81.56/3098.7.81.57 to 98.7.81.5898.7.81.592
8098.7.81.60/3098.7.81.61 to 98.7.81.6298.7.81.632
8198.7.81.64/3098.7.81.65 to 98.7.81.6698.7.81.672
8298.7.81.68/3098.7.81.69 to 98.7.81.7098.7.81.712
8398.7.81.72/3098.7.81.73 to 98.7.81.7498.7.81.752
8498.7.81.76/3098.7.81.77 to 98.7.81.7898.7.81.792
8598.7.81.80/3098.7.81.81 to 98.7.81.8298.7.81.832
8698.7.81.84/3098.7.81.85 to 98.7.81.8698.7.81.872
8798.7.81.88/3098.7.81.89 to 98.7.81.9098.7.81.912
8898.7.81.92/3098.7.81.93 to 98.7.81.9498.7.81.952
8998.7.81.96/3098.7.81.97 to 98.7.81.9898.7.81.992
9098.7.81.100/3098.7.81.101 to 98.7.81.10298.7.81.1032
9198.7.81.104/3098.7.81.105 to 98.7.81.10698.7.81.1072
9298.7.81.108/3098.7.81.109 to 98.7.81.11098.7.81.1112
9398.7.81.112/3098.7.81.113 to 98.7.81.11498.7.81.1152
9498.7.81.116/3098.7.81.117 to 98.7.81.11898.7.81.1192
9598.7.81.120/3098.7.81.121 to 98.7.81.12298.7.81.1232
9698.7.81.124/3098.7.81.125 to 98.7.81.12698.7.81.1272
9798.7.81.128/3098.7.81.129 to 98.7.81.13098.7.81.1312
9898.7.81.132/3098.7.81.133 to 98.7.81.13498.7.81.1352
9998.7.81.136/3098.7.81.137 to 98.7.81.13898.7.81.1392
10098.7.81.140/3098.7.81.141 to 98.7.81.14298.7.81.1432
10198.7.81.144/3098.7.81.145 to 98.7.81.14698.7.81.1472
10298.7.81.148/3098.7.81.149 to 98.7.81.15098.7.81.1512
10398.7.81.152/3098.7.81.153 to 98.7.81.15498.7.81.1552
10498.7.81.156/3098.7.81.157 to 98.7.81.15898.7.81.1592
10598.7.81.160/3098.7.81.161 to 98.7.81.16298.7.81.1632
10698.7.81.164/3098.7.81.165 to 98.7.81.16698.7.81.1672
10798.7.81.168/3098.7.81.169 to 98.7.81.17098.7.81.1712
10898.7.81.172/3098.7.81.173 to 98.7.81.17498.7.81.1752
10998.7.81.176/3098.7.81.177 to 98.7.81.17898.7.81.1792
11098.7.81.180/3098.7.81.181 to 98.7.81.18298.7.81.1832
11198.7.81.184/3098.7.81.185 to 98.7.81.18698.7.81.1872
11298.7.81.188/3098.7.81.189 to 98.7.81.19098.7.81.1912
11398.7.81.192/3098.7.81.193 to 98.7.81.19498.7.81.1952
11498.7.81.196/3098.7.81.197 to 98.7.81.19898.7.81.1992
11598.7.81.200/3098.7.81.201 to 98.7.81.20298.7.81.2032
11698.7.81.204/3098.7.81.205 to 98.7.81.20698.7.81.2072
11798.7.81.208/3098.7.81.209 to 98.7.81.21098.7.81.2112
11898.7.81.212/3098.7.81.213 to 98.7.81.21498.7.81.2152
11998.7.81.216/3098.7.81.217 to 98.7.81.21898.7.81.2192
12098.7.81.220/3098.7.81.221 to 98.7.81.22298.7.81.2232
12198.7.81.224/3098.7.81.225 to 98.7.81.22698.7.81.2272
12298.7.81.228/3098.7.81.229 to 98.7.81.23098.7.81.2312
12398.7.81.232/3098.7.81.233 to 98.7.81.23498.7.81.2352
12498.7.81.236/3098.7.81.237 to 98.7.81.23898.7.81.2392
12598.7.81.240/3098.7.81.241 to 98.7.81.24298.7.81.2432
12698.7.81.244/3098.7.81.245 to 98.7.81.24698.7.81.2472
12798.7.81.248/3098.7.81.249 to 98.7.81.25098.7.81.2512
12898.7.81.252/3098.7.81.253 to 98.7.81.25498.7.81.2552
12998.7.82.0/3098.7.82.1 to 98.7.82.298.7.82.32
13098.7.82.4/3098.7.82.5 to 98.7.82.698.7.82.72
13198.7.82.8/3098.7.82.9 to 98.7.82.1098.7.82.112
13298.7.82.12/3098.7.82.13 to 98.7.82.1498.7.82.152
13398.7.82.16/3098.7.82.17 to 98.7.82.1898.7.82.192
13498.7.82.20/3098.7.82.21 to 98.7.82.2298.7.82.232
13598.7.82.24/3098.7.82.25 to 98.7.82.2698.7.82.272
13698.7.82.28/3098.7.82.29 to 98.7.82.3098.7.82.312
13798.7.82.32/3098.7.82.33 to 98.7.82.3498.7.82.352
13898.7.82.36/3098.7.82.37 to 98.7.82.3898.7.82.392
13998.7.82.40/3098.7.82.41 to 98.7.82.4298.7.82.432
14098.7.82.44/3098.7.82.45 to 98.7.82.4698.7.82.472
14198.7.82.48/3098.7.82.49 to 98.7.82.5098.7.82.512
14298.7.82.52/3098.7.82.53 to 98.7.82.5498.7.82.552
14398.7.82.56/3098.7.82.57 to 98.7.82.5898.7.82.592
14498.7.82.60/3098.7.82.61 to 98.7.82.6298.7.82.632
14598.7.82.64/3098.7.82.65 to 98.7.82.6698.7.82.672
14698.7.82.68/3098.7.82.69 to 98.7.82.7098.7.82.712
14798.7.82.72/3098.7.82.73 to 98.7.82.7498.7.82.752
14898.7.82.76/3098.7.82.77 to 98.7.82.7898.7.82.792
14998.7.82.80/3098.7.82.81 to 98.7.82.8298.7.82.832
15098.7.82.84/3098.7.82.85 to 98.7.82.8698.7.82.872
15198.7.82.88/3098.7.82.89 to 98.7.82.9098.7.82.912
15298.7.82.92/3098.7.82.93 to 98.7.82.9498.7.82.952
15398.7.82.96/3098.7.82.97 to 98.7.82.9898.7.82.992
15498.7.82.100/3098.7.82.101 to 98.7.82.10298.7.82.1032
15598.7.82.104/3098.7.82.105 to 98.7.82.10698.7.82.1072
15698.7.82.108/3098.7.82.109 to 98.7.82.11098.7.82.1112
15798.7.82.112/3098.7.82.113 to 98.7.82.11498.7.82.1152
15898.7.82.116/3098.7.82.117 to 98.7.82.11898.7.82.1192
15998.7.82.120/3098.7.82.121 to 98.7.82.12298.7.82.1232
16098.7.82.124/3098.7.82.125 to 98.7.82.12698.7.82.1272
16198.7.82.128/3098.7.82.129 to 98.7.82.13098.7.82.1312
16298.7.82.132/3098.7.82.133 to 98.7.82.13498.7.82.1352
16398.7.82.136/3098.7.82.137 to 98.7.82.13898.7.82.1392
16498.7.82.140/3098.7.82.141 to 98.7.82.14298.7.82.1432
16598.7.82.144/3098.7.82.145 to 98.7.82.14698.7.82.1472
16698.7.82.148/3098.7.82.149 to 98.7.82.15098.7.82.1512
16798.7.82.152/3098.7.82.153 to 98.7.82.15498.7.82.1552
16898.7.82.156/3098.7.82.157 to 98.7.82.15898.7.82.1592
16998.7.82.160/3098.7.82.161 to 98.7.82.16298.7.82.1632
17098.7.82.164/3098.7.82.165 to 98.7.82.16698.7.82.1672
17198.7.82.168/3098.7.82.169 to 98.7.82.17098.7.82.1712
17298.7.82.172/3098.7.82.173 to 98.7.82.17498.7.82.1752
17398.7.82.176/3098.7.82.177 to 98.7.82.17898.7.82.1792
17498.7.82.180/3098.7.82.181 to 98.7.82.18298.7.82.1832
17598.7.82.184/3098.7.82.185 to 98.7.82.18698.7.82.1872
17698.7.82.188/3098.7.82.189 to 98.7.82.19098.7.82.1912
17798.7.82.192/3098.7.82.193 to 98.7.82.19498.7.82.1952
17898.7.82.196/3098.7.82.197 to 98.7.82.19898.7.82.1992
17998.7.82.200/3098.7.82.201 to 98.7.82.20298.7.82.2032
18098.7.82.204/3098.7.82.205 to 98.7.82.20698.7.82.2072
18198.7.82.208/3098.7.82.209 to 98.7.82.21098.7.82.2112
18298.7.82.212/3098.7.82.213 to 98.7.82.21498.7.82.2152
18398.7.82.216/3098.7.82.217 to 98.7.82.21898.7.82.2192
18498.7.82.220/3098.7.82.221 to 98.7.82.22298.7.82.2232
18598.7.82.224/3098.7.82.225 to 98.7.82.22698.7.82.2272
18698.7.82.228/3098.7.82.229 to 98.7.82.23098.7.82.2312
18798.7.82.232/3098.7.82.233 to 98.7.82.23498.7.82.2352
18898.7.82.236/3098.7.82.237 to 98.7.82.23898.7.82.2392
18998.7.82.240/3098.7.82.241 to 98.7.82.24298.7.82.2432
19098.7.82.244/3098.7.82.245 to 98.7.82.24698.7.82.2472
19198.7.82.248/3098.7.82.249 to 98.7.82.25098.7.82.2512
19298.7.82.252/3098.7.82.253 to 98.7.82.25498.7.82.2552
19398.7.83.0/3098.7.83.1 to 98.7.83.298.7.83.32
19498.7.83.4/3098.7.83.5 to 98.7.83.698.7.83.72
19598.7.83.8/3098.7.83.9 to 98.7.83.1098.7.83.112
19698.7.83.12/3098.7.83.13 to 98.7.83.1498.7.83.152
19798.7.83.16/3098.7.83.17 to 98.7.83.1898.7.83.192
19898.7.83.20/3098.7.83.21 to 98.7.83.2298.7.83.232
19998.7.83.24/3098.7.83.25 to 98.7.83.2698.7.83.272
20098.7.83.28/3098.7.83.29 to 98.7.83.3098.7.83.312
20198.7.83.32/3098.7.83.33 to 98.7.83.3498.7.83.352
20298.7.83.36/3098.7.83.37 to 98.7.83.3898.7.83.392
20398.7.83.40/3098.7.83.41 to 98.7.83.4298.7.83.432
20498.7.83.44/3098.7.83.45 to 98.7.83.4698.7.83.472
20598.7.83.48/3098.7.83.49 to 98.7.83.5098.7.83.512
20698.7.83.52/3098.7.83.53 to 98.7.83.5498.7.83.552
20798.7.83.56/3098.7.83.57 to 98.7.83.5898.7.83.592
20898.7.83.60/3098.7.83.61 to 98.7.83.6298.7.83.632
20998.7.83.64/3098.7.83.65 to 98.7.83.6698.7.83.672
21098.7.83.68/3098.7.83.69 to 98.7.83.7098.7.83.712
21198.7.83.72/3098.7.83.73 to 98.7.83.7498.7.83.752
21298.7.83.76/3098.7.83.77 to 98.7.83.7898.7.83.792
21398.7.83.80/3098.7.83.81 to 98.7.83.8298.7.83.832
21498.7.83.84/3098.7.83.85 to 98.7.83.8698.7.83.872
21598.7.83.88/3098.7.83.89 to 98.7.83.9098.7.83.912
21698.7.83.92/3098.7.83.93 to 98.7.83.9498.7.83.952
21798.7.83.96/3098.7.83.97 to 98.7.83.9898.7.83.992
21898.7.83.100/3098.7.83.101 to 98.7.83.10298.7.83.1032
21998.7.83.104/3098.7.83.105 to 98.7.83.10698.7.83.1072
22098.7.83.108/3098.7.83.109 to 98.7.83.11098.7.83.1112
22198.7.83.112/3098.7.83.113 to 98.7.83.11498.7.83.1152
22298.7.83.116/3098.7.83.117 to 98.7.83.11898.7.83.1192
22398.7.83.120/3098.7.83.121 to 98.7.83.12298.7.83.1232
22498.7.83.124/3098.7.83.125 to 98.7.83.12698.7.83.1272
22598.7.83.128/3098.7.83.129 to 98.7.83.13098.7.83.1312
22698.7.83.132/3098.7.83.133 to 98.7.83.13498.7.83.1352
22798.7.83.136/3098.7.83.137 to 98.7.83.13898.7.83.1392
22898.7.83.140/3098.7.83.141 to 98.7.83.14298.7.83.1432
22998.7.83.144/3098.7.83.145 to 98.7.83.14698.7.83.1472
23098.7.83.148/3098.7.83.149 to 98.7.83.15098.7.83.1512
23198.7.83.152/3098.7.83.153 to 98.7.83.15498.7.83.1552
23298.7.83.156/3098.7.83.157 to 98.7.83.15898.7.83.1592
23398.7.83.160/3098.7.83.161 to 98.7.83.16298.7.83.1632
23498.7.83.164/3098.7.83.165 to 98.7.83.16698.7.83.1672
23598.7.83.168/3098.7.83.169 to 98.7.83.17098.7.83.1712
23698.7.83.172/3098.7.83.173 to 98.7.83.17498.7.83.1752
23798.7.83.176/3098.7.83.177 to 98.7.83.17898.7.83.1792
23898.7.83.180/3098.7.83.181 to 98.7.83.18298.7.83.1832
23998.7.83.184/3098.7.83.185 to 98.7.83.18698.7.83.1872
24098.7.83.188/3098.7.83.189 to 98.7.83.19098.7.83.1912
24198.7.83.192/3098.7.83.193 to 98.7.83.19498.7.83.1952
24298.7.83.196/3098.7.83.197 to 98.7.83.19898.7.83.1992
24398.7.83.200/3098.7.83.201 to 98.7.83.20298.7.83.2032
24498.7.83.204/3098.7.83.205 to 98.7.83.20698.7.83.2072
24598.7.83.208/3098.7.83.209 to 98.7.83.21098.7.83.2112
24698.7.83.212/3098.7.83.213 to 98.7.83.21498.7.83.2152
24798.7.83.216/3098.7.83.217 to 98.7.83.21898.7.83.2192
24898.7.83.220/3098.7.83.221 to 98.7.83.22298.7.83.2232
24998.7.83.224/3098.7.83.225 to 98.7.83.22698.7.83.2272
25098.7.83.228/3098.7.83.229 to 98.7.83.23098.7.83.2312
25198.7.83.232/3098.7.83.233 to 98.7.83.23498.7.83.2352
25298.7.83.236/3098.7.83.237 to 98.7.83.23898.7.83.2392
25398.7.83.240/3098.7.83.241 to 98.7.83.24298.7.83.2432
25498.7.83.244/3098.7.83.245 to 98.7.83.24698.7.83.2472
25598.7.83.248/3098.7.83.249 to 98.7.83.25098.7.83.2512
25698.7.83.252/3098.7.83.253 to 98.7.83.25498.7.83.2552

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.