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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.

Network84.45.64.0/18
Usable hosts16,382
Subnet mask255.255.192.0
Addresses16,384
Network address
84.45.64.0
Broadcast address
84.45.127.255
First usable
84.45.64.1
Last usable
84.45.127.254
Usable hosts
16,382 (16,384 less the network and broadcast addresses)
Subnet mask
255.255.192.0
Wildcard mask
0.0.63.255 (Cisco ACLs, OSPF)
Prefix length
/18
Type
Public public
Old class
A (default /8)
As numbers
Hex 542D4000 · Integer 1412251648 to 1412268031
Reverse DNS zones
64.45.84.in-addr.arpa
65.45.84.in-addr.arpa
66.45.84.in-addr.arpa
67.45.84.in-addr.arpa
68.45.84.in-addr.arpa
69.45.84.in-addr.arpa
70.45.84.in-addr.arpa
71.45.84.in-addr.arpa
72.45.84.in-addr.arpa
73.45.84.in-addr.arpa
74.45.84.in-addr.arpa
75.45.84.in-addr.arpa
76.45.84.in-addr.arpa
77.45.84.in-addr.arpa
78.45.84.in-addr.arpa
79.45.84.in-addr.arpa
and 48 more
/18 is not on a 8-bit boundary, so it takes 64 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01010100.00101101.01000000.0000000084.45.64.0
Subnet mask11111111.11111111.11000000.00000000255.255.192.0
Network01010100.00101101.01000000.0000000084.45.64.0
Broadcast01010100.00101101.01111111.1111111184.45.127.255
Split into smaller subnets/29
/19 (2)/20 (4)/21 (8)/22 (16)/23 (32)/24 (64)/25 (128)/26 (256)/27 (512)/28 (1,024)/29 (2,048)/30 (4,096)

84.45.64.0/18 makes 2,048 subnets of /29; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
184.45.64.0/2984.45.64.1 to 84.45.64.684.45.64.76
284.45.64.8/2984.45.64.9 to 84.45.64.1484.45.64.156
384.45.64.16/2984.45.64.17 to 84.45.64.2284.45.64.236
484.45.64.24/2984.45.64.25 to 84.45.64.3084.45.64.316
584.45.64.32/2984.45.64.33 to 84.45.64.3884.45.64.396
684.45.64.40/2984.45.64.41 to 84.45.64.4684.45.64.476
784.45.64.48/2984.45.64.49 to 84.45.64.5484.45.64.556
884.45.64.56/2984.45.64.57 to 84.45.64.6284.45.64.636
984.45.64.64/2984.45.64.65 to 84.45.64.7084.45.64.716
1084.45.64.72/2984.45.64.73 to 84.45.64.7884.45.64.796
1184.45.64.80/2984.45.64.81 to 84.45.64.8684.45.64.876
1284.45.64.88/2984.45.64.89 to 84.45.64.9484.45.64.956
1384.45.64.96/2984.45.64.97 to 84.45.64.10284.45.64.1036
1484.45.64.104/2984.45.64.105 to 84.45.64.11084.45.64.1116
1584.45.64.112/2984.45.64.113 to 84.45.64.11884.45.64.1196
1684.45.64.120/2984.45.64.121 to 84.45.64.12684.45.64.1276
1784.45.64.128/2984.45.64.129 to 84.45.64.13484.45.64.1356
1884.45.64.136/2984.45.64.137 to 84.45.64.14284.45.64.1436
1984.45.64.144/2984.45.64.145 to 84.45.64.15084.45.64.1516
2084.45.64.152/2984.45.64.153 to 84.45.64.15884.45.64.1596
2184.45.64.160/2984.45.64.161 to 84.45.64.16684.45.64.1676
2284.45.64.168/2984.45.64.169 to 84.45.64.17484.45.64.1756
2384.45.64.176/2984.45.64.177 to 84.45.64.18284.45.64.1836
2484.45.64.184/2984.45.64.185 to 84.45.64.19084.45.64.1916
2584.45.64.192/2984.45.64.193 to 84.45.64.19884.45.64.1996
2684.45.64.200/2984.45.64.201 to 84.45.64.20684.45.64.2076
2784.45.64.208/2984.45.64.209 to 84.45.64.21484.45.64.2156
2884.45.64.216/2984.45.64.217 to 84.45.64.22284.45.64.2236
2984.45.64.224/2984.45.64.225 to 84.45.64.23084.45.64.2316
3084.45.64.232/2984.45.64.233 to 84.45.64.23884.45.64.2396
3184.45.64.240/2984.45.64.241 to 84.45.64.24684.45.64.2476
3284.45.64.248/2984.45.64.249 to 84.45.64.25484.45.64.2556
3384.45.65.0/2984.45.65.1 to 84.45.65.684.45.65.76
3484.45.65.8/2984.45.65.9 to 84.45.65.1484.45.65.156
3584.45.65.16/2984.45.65.17 to 84.45.65.2284.45.65.236
3684.45.65.24/2984.45.65.25 to 84.45.65.3084.45.65.316
3784.45.65.32/2984.45.65.33 to 84.45.65.3884.45.65.396
3884.45.65.40/2984.45.65.41 to 84.45.65.4684.45.65.476
3984.45.65.48/2984.45.65.49 to 84.45.65.5484.45.65.556
4084.45.65.56/2984.45.65.57 to 84.45.65.6284.45.65.636
4184.45.65.64/2984.45.65.65 to 84.45.65.7084.45.65.716
4284.45.65.72/2984.45.65.73 to 84.45.65.7884.45.65.796
4384.45.65.80/2984.45.65.81 to 84.45.65.8684.45.65.876
4484.45.65.88/2984.45.65.89 to 84.45.65.9484.45.65.956
4584.45.65.96/2984.45.65.97 to 84.45.65.10284.45.65.1036
4684.45.65.104/2984.45.65.105 to 84.45.65.11084.45.65.1116
4784.45.65.112/2984.45.65.113 to 84.45.65.11884.45.65.1196
4884.45.65.120/2984.45.65.121 to 84.45.65.12684.45.65.1276
4984.45.65.128/2984.45.65.129 to 84.45.65.13484.45.65.1356
5084.45.65.136/2984.45.65.137 to 84.45.65.14284.45.65.1436
5184.45.65.144/2984.45.65.145 to 84.45.65.15084.45.65.1516
5284.45.65.152/2984.45.65.153 to 84.45.65.15884.45.65.1596
5384.45.65.160/2984.45.65.161 to 84.45.65.16684.45.65.1676
5484.45.65.168/2984.45.65.169 to 84.45.65.17484.45.65.1756
5584.45.65.176/2984.45.65.177 to 84.45.65.18284.45.65.1836
5684.45.65.184/2984.45.65.185 to 84.45.65.19084.45.65.1916
5784.45.65.192/2984.45.65.193 to 84.45.65.19884.45.65.1996
5884.45.65.200/2984.45.65.201 to 84.45.65.20684.45.65.2076
5984.45.65.208/2984.45.65.209 to 84.45.65.21484.45.65.2156
6084.45.65.216/2984.45.65.217 to 84.45.65.22284.45.65.2236
6184.45.65.224/2984.45.65.225 to 84.45.65.23084.45.65.2316
6284.45.65.232/2984.45.65.233 to 84.45.65.23884.45.65.2396
6384.45.65.240/2984.45.65.241 to 84.45.65.24684.45.65.2476
6484.45.65.248/2984.45.65.249 to 84.45.65.25484.45.65.2556
6584.45.66.0/2984.45.66.1 to 84.45.66.684.45.66.76
6684.45.66.8/2984.45.66.9 to 84.45.66.1484.45.66.156
6784.45.66.16/2984.45.66.17 to 84.45.66.2284.45.66.236
6884.45.66.24/2984.45.66.25 to 84.45.66.3084.45.66.316
6984.45.66.32/2984.45.66.33 to 84.45.66.3884.45.66.396
7084.45.66.40/2984.45.66.41 to 84.45.66.4684.45.66.476
7184.45.66.48/2984.45.66.49 to 84.45.66.5484.45.66.556
7284.45.66.56/2984.45.66.57 to 84.45.66.6284.45.66.636
7384.45.66.64/2984.45.66.65 to 84.45.66.7084.45.66.716
7484.45.66.72/2984.45.66.73 to 84.45.66.7884.45.66.796
7584.45.66.80/2984.45.66.81 to 84.45.66.8684.45.66.876
7684.45.66.88/2984.45.66.89 to 84.45.66.9484.45.66.956
7784.45.66.96/2984.45.66.97 to 84.45.66.10284.45.66.1036
7884.45.66.104/2984.45.66.105 to 84.45.66.11084.45.66.1116
7984.45.66.112/2984.45.66.113 to 84.45.66.11884.45.66.1196
8084.45.66.120/2984.45.66.121 to 84.45.66.12684.45.66.1276
8184.45.66.128/2984.45.66.129 to 84.45.66.13484.45.66.1356
8284.45.66.136/2984.45.66.137 to 84.45.66.14284.45.66.1436
8384.45.66.144/2984.45.66.145 to 84.45.66.15084.45.66.1516
8484.45.66.152/2984.45.66.153 to 84.45.66.15884.45.66.1596
8584.45.66.160/2984.45.66.161 to 84.45.66.16684.45.66.1676
8684.45.66.168/2984.45.66.169 to 84.45.66.17484.45.66.1756
8784.45.66.176/2984.45.66.177 to 84.45.66.18284.45.66.1836
8884.45.66.184/2984.45.66.185 to 84.45.66.19084.45.66.1916
8984.45.66.192/2984.45.66.193 to 84.45.66.19884.45.66.1996
9084.45.66.200/2984.45.66.201 to 84.45.66.20684.45.66.2076
9184.45.66.208/2984.45.66.209 to 84.45.66.21484.45.66.2156
9284.45.66.216/2984.45.66.217 to 84.45.66.22284.45.66.2236
9384.45.66.224/2984.45.66.225 to 84.45.66.23084.45.66.2316
9484.45.66.232/2984.45.66.233 to 84.45.66.23884.45.66.2396
9584.45.66.240/2984.45.66.241 to 84.45.66.24684.45.66.2476
9684.45.66.248/2984.45.66.249 to 84.45.66.25484.45.66.2556
9784.45.67.0/2984.45.67.1 to 84.45.67.684.45.67.76
9884.45.67.8/2984.45.67.9 to 84.45.67.1484.45.67.156
9984.45.67.16/2984.45.67.17 to 84.45.67.2284.45.67.236
10084.45.67.24/2984.45.67.25 to 84.45.67.3084.45.67.316
10184.45.67.32/2984.45.67.33 to 84.45.67.3884.45.67.396
10284.45.67.40/2984.45.67.41 to 84.45.67.4684.45.67.476
10384.45.67.48/2984.45.67.49 to 84.45.67.5484.45.67.556
10484.45.67.56/2984.45.67.57 to 84.45.67.6284.45.67.636
10584.45.67.64/2984.45.67.65 to 84.45.67.7084.45.67.716
10684.45.67.72/2984.45.67.73 to 84.45.67.7884.45.67.796
10784.45.67.80/2984.45.67.81 to 84.45.67.8684.45.67.876
10884.45.67.88/2984.45.67.89 to 84.45.67.9484.45.67.956
10984.45.67.96/2984.45.67.97 to 84.45.67.10284.45.67.1036
11084.45.67.104/2984.45.67.105 to 84.45.67.11084.45.67.1116
11184.45.67.112/2984.45.67.113 to 84.45.67.11884.45.67.1196
11284.45.67.120/2984.45.67.121 to 84.45.67.12684.45.67.1276
11384.45.67.128/2984.45.67.129 to 84.45.67.13484.45.67.1356
11484.45.67.136/2984.45.67.137 to 84.45.67.14284.45.67.1436
11584.45.67.144/2984.45.67.145 to 84.45.67.15084.45.67.1516
11684.45.67.152/2984.45.67.153 to 84.45.67.15884.45.67.1596
11784.45.67.160/2984.45.67.161 to 84.45.67.16684.45.67.1676
11884.45.67.168/2984.45.67.169 to 84.45.67.17484.45.67.1756
11984.45.67.176/2984.45.67.177 to 84.45.67.18284.45.67.1836
12084.45.67.184/2984.45.67.185 to 84.45.67.19084.45.67.1916
12184.45.67.192/2984.45.67.193 to 84.45.67.19884.45.67.1996
12284.45.67.200/2984.45.67.201 to 84.45.67.20684.45.67.2076
12384.45.67.208/2984.45.67.209 to 84.45.67.21484.45.67.2156
12484.45.67.216/2984.45.67.217 to 84.45.67.22284.45.67.2236
12584.45.67.224/2984.45.67.225 to 84.45.67.23084.45.67.2316
12684.45.67.232/2984.45.67.233 to 84.45.67.23884.45.67.2396
12784.45.67.240/2984.45.67.241 to 84.45.67.24684.45.67.2476
12884.45.67.248/2984.45.67.249 to 84.45.67.25484.45.67.2556
12984.45.68.0/2984.45.68.1 to 84.45.68.684.45.68.76
13084.45.68.8/2984.45.68.9 to 84.45.68.1484.45.68.156
13184.45.68.16/2984.45.68.17 to 84.45.68.2284.45.68.236
13284.45.68.24/2984.45.68.25 to 84.45.68.3084.45.68.316
13384.45.68.32/2984.45.68.33 to 84.45.68.3884.45.68.396
13484.45.68.40/2984.45.68.41 to 84.45.68.4684.45.68.476
13584.45.68.48/2984.45.68.49 to 84.45.68.5484.45.68.556
13684.45.68.56/2984.45.68.57 to 84.45.68.6284.45.68.636
13784.45.68.64/2984.45.68.65 to 84.45.68.7084.45.68.716
13884.45.68.72/2984.45.68.73 to 84.45.68.7884.45.68.796
13984.45.68.80/2984.45.68.81 to 84.45.68.8684.45.68.876
14084.45.68.88/2984.45.68.89 to 84.45.68.9484.45.68.956
14184.45.68.96/2984.45.68.97 to 84.45.68.10284.45.68.1036
14284.45.68.104/2984.45.68.105 to 84.45.68.11084.45.68.1116
14384.45.68.112/2984.45.68.113 to 84.45.68.11884.45.68.1196
14484.45.68.120/2984.45.68.121 to 84.45.68.12684.45.68.1276
14584.45.68.128/2984.45.68.129 to 84.45.68.13484.45.68.1356
14684.45.68.136/2984.45.68.137 to 84.45.68.14284.45.68.1436
14784.45.68.144/2984.45.68.145 to 84.45.68.15084.45.68.1516
14884.45.68.152/2984.45.68.153 to 84.45.68.15884.45.68.1596
14984.45.68.160/2984.45.68.161 to 84.45.68.16684.45.68.1676
15084.45.68.168/2984.45.68.169 to 84.45.68.17484.45.68.1756
15184.45.68.176/2984.45.68.177 to 84.45.68.18284.45.68.1836
15284.45.68.184/2984.45.68.185 to 84.45.68.19084.45.68.1916
15384.45.68.192/2984.45.68.193 to 84.45.68.19884.45.68.1996
15484.45.68.200/2984.45.68.201 to 84.45.68.20684.45.68.2076
15584.45.68.208/2984.45.68.209 to 84.45.68.21484.45.68.2156
15684.45.68.216/2984.45.68.217 to 84.45.68.22284.45.68.2236
15784.45.68.224/2984.45.68.225 to 84.45.68.23084.45.68.2316
15884.45.68.232/2984.45.68.233 to 84.45.68.23884.45.68.2396
15984.45.68.240/2984.45.68.241 to 84.45.68.24684.45.68.2476
16084.45.68.248/2984.45.68.249 to 84.45.68.25484.45.68.2556
16184.45.69.0/2984.45.69.1 to 84.45.69.684.45.69.76
16284.45.69.8/2984.45.69.9 to 84.45.69.1484.45.69.156
16384.45.69.16/2984.45.69.17 to 84.45.69.2284.45.69.236
16484.45.69.24/2984.45.69.25 to 84.45.69.3084.45.69.316
16584.45.69.32/2984.45.69.33 to 84.45.69.3884.45.69.396
16684.45.69.40/2984.45.69.41 to 84.45.69.4684.45.69.476
16784.45.69.48/2984.45.69.49 to 84.45.69.5484.45.69.556
16884.45.69.56/2984.45.69.57 to 84.45.69.6284.45.69.636
16984.45.69.64/2984.45.69.65 to 84.45.69.7084.45.69.716
17084.45.69.72/2984.45.69.73 to 84.45.69.7884.45.69.796
17184.45.69.80/2984.45.69.81 to 84.45.69.8684.45.69.876
17284.45.69.88/2984.45.69.89 to 84.45.69.9484.45.69.956
17384.45.69.96/2984.45.69.97 to 84.45.69.10284.45.69.1036
17484.45.69.104/2984.45.69.105 to 84.45.69.11084.45.69.1116
17584.45.69.112/2984.45.69.113 to 84.45.69.11884.45.69.1196
17684.45.69.120/2984.45.69.121 to 84.45.69.12684.45.69.1276
17784.45.69.128/2984.45.69.129 to 84.45.69.13484.45.69.1356
17884.45.69.136/2984.45.69.137 to 84.45.69.14284.45.69.1436
17984.45.69.144/2984.45.69.145 to 84.45.69.15084.45.69.1516
18084.45.69.152/2984.45.69.153 to 84.45.69.15884.45.69.1596
18184.45.69.160/2984.45.69.161 to 84.45.69.16684.45.69.1676
18284.45.69.168/2984.45.69.169 to 84.45.69.17484.45.69.1756
18384.45.69.176/2984.45.69.177 to 84.45.69.18284.45.69.1836
18484.45.69.184/2984.45.69.185 to 84.45.69.19084.45.69.1916
18584.45.69.192/2984.45.69.193 to 84.45.69.19884.45.69.1996
18684.45.69.200/2984.45.69.201 to 84.45.69.20684.45.69.2076
18784.45.69.208/2984.45.69.209 to 84.45.69.21484.45.69.2156
18884.45.69.216/2984.45.69.217 to 84.45.69.22284.45.69.2236
18984.45.69.224/2984.45.69.225 to 84.45.69.23084.45.69.2316
19084.45.69.232/2984.45.69.233 to 84.45.69.23884.45.69.2396
19184.45.69.240/2984.45.69.241 to 84.45.69.24684.45.69.2476
19284.45.69.248/2984.45.69.249 to 84.45.69.25484.45.69.2556
19384.45.70.0/2984.45.70.1 to 84.45.70.684.45.70.76
19484.45.70.8/2984.45.70.9 to 84.45.70.1484.45.70.156
19584.45.70.16/2984.45.70.17 to 84.45.70.2284.45.70.236
19684.45.70.24/2984.45.70.25 to 84.45.70.3084.45.70.316
19784.45.70.32/2984.45.70.33 to 84.45.70.3884.45.70.396
19884.45.70.40/2984.45.70.41 to 84.45.70.4684.45.70.476
19984.45.70.48/2984.45.70.49 to 84.45.70.5484.45.70.556
20084.45.70.56/2984.45.70.57 to 84.45.70.6284.45.70.636
20184.45.70.64/2984.45.70.65 to 84.45.70.7084.45.70.716
20284.45.70.72/2984.45.70.73 to 84.45.70.7884.45.70.796
20384.45.70.80/2984.45.70.81 to 84.45.70.8684.45.70.876
20484.45.70.88/2984.45.70.89 to 84.45.70.9484.45.70.956
20584.45.70.96/2984.45.70.97 to 84.45.70.10284.45.70.1036
20684.45.70.104/2984.45.70.105 to 84.45.70.11084.45.70.1116
20784.45.70.112/2984.45.70.113 to 84.45.70.11884.45.70.1196
20884.45.70.120/2984.45.70.121 to 84.45.70.12684.45.70.1276
20984.45.70.128/2984.45.70.129 to 84.45.70.13484.45.70.1356
21084.45.70.136/2984.45.70.137 to 84.45.70.14284.45.70.1436
21184.45.70.144/2984.45.70.145 to 84.45.70.15084.45.70.1516
21284.45.70.152/2984.45.70.153 to 84.45.70.15884.45.70.1596
21384.45.70.160/2984.45.70.161 to 84.45.70.16684.45.70.1676
21484.45.70.168/2984.45.70.169 to 84.45.70.17484.45.70.1756
21584.45.70.176/2984.45.70.177 to 84.45.70.18284.45.70.1836
21684.45.70.184/2984.45.70.185 to 84.45.70.19084.45.70.1916
21784.45.70.192/2984.45.70.193 to 84.45.70.19884.45.70.1996
21884.45.70.200/2984.45.70.201 to 84.45.70.20684.45.70.2076
21984.45.70.208/2984.45.70.209 to 84.45.70.21484.45.70.2156
22084.45.70.216/2984.45.70.217 to 84.45.70.22284.45.70.2236
22184.45.70.224/2984.45.70.225 to 84.45.70.23084.45.70.2316
22284.45.70.232/2984.45.70.233 to 84.45.70.23884.45.70.2396
22384.45.70.240/2984.45.70.241 to 84.45.70.24684.45.70.2476
22484.45.70.248/2984.45.70.249 to 84.45.70.25484.45.70.2556
22584.45.71.0/2984.45.71.1 to 84.45.71.684.45.71.76
22684.45.71.8/2984.45.71.9 to 84.45.71.1484.45.71.156
22784.45.71.16/2984.45.71.17 to 84.45.71.2284.45.71.236
22884.45.71.24/2984.45.71.25 to 84.45.71.3084.45.71.316
22984.45.71.32/2984.45.71.33 to 84.45.71.3884.45.71.396
23084.45.71.40/2984.45.71.41 to 84.45.71.4684.45.71.476
23184.45.71.48/2984.45.71.49 to 84.45.71.5484.45.71.556
23284.45.71.56/2984.45.71.57 to 84.45.71.6284.45.71.636
23384.45.71.64/2984.45.71.65 to 84.45.71.7084.45.71.716
23484.45.71.72/2984.45.71.73 to 84.45.71.7884.45.71.796
23584.45.71.80/2984.45.71.81 to 84.45.71.8684.45.71.876
23684.45.71.88/2984.45.71.89 to 84.45.71.9484.45.71.956
23784.45.71.96/2984.45.71.97 to 84.45.71.10284.45.71.1036
23884.45.71.104/2984.45.71.105 to 84.45.71.11084.45.71.1116
23984.45.71.112/2984.45.71.113 to 84.45.71.11884.45.71.1196
24084.45.71.120/2984.45.71.121 to 84.45.71.12684.45.71.1276
24184.45.71.128/2984.45.71.129 to 84.45.71.13484.45.71.1356
24284.45.71.136/2984.45.71.137 to 84.45.71.14284.45.71.1436
24384.45.71.144/2984.45.71.145 to 84.45.71.15084.45.71.1516
24484.45.71.152/2984.45.71.153 to 84.45.71.15884.45.71.1596
24584.45.71.160/2984.45.71.161 to 84.45.71.16684.45.71.1676
24684.45.71.168/2984.45.71.169 to 84.45.71.17484.45.71.1756
24784.45.71.176/2984.45.71.177 to 84.45.71.18284.45.71.1836
24884.45.71.184/2984.45.71.185 to 84.45.71.19084.45.71.1916
24984.45.71.192/2984.45.71.193 to 84.45.71.19884.45.71.1996
25084.45.71.200/2984.45.71.201 to 84.45.71.20684.45.71.2076
25184.45.71.208/2984.45.71.209 to 84.45.71.21484.45.71.2156
25284.45.71.216/2984.45.71.217 to 84.45.71.22284.45.71.2236
25384.45.71.224/2984.45.71.225 to 84.45.71.23084.45.71.2316
25484.45.71.232/2984.45.71.233 to 84.45.71.23884.45.71.2396
25584.45.71.240/2984.45.71.241 to 84.45.71.24684.45.71.2476
25684.45.71.248/2984.45.71.249 to 84.45.71.25484.45.71.2556

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.