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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.

Network64.48.64.0/18
Usable hosts16,382
Subnet mask255.255.192.0
Addresses16,384
Network address
64.48.64.0
Broadcast address
64.48.127.255
First usable
64.48.64.1
Last usable
64.48.127.254
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 40304000 · Integer 1076903936 to 1076920319
Reverse DNS zones
64.48.64.in-addr.arpa
65.48.64.in-addr.arpa
66.48.64.in-addr.arpa
67.48.64.in-addr.arpa
68.48.64.in-addr.arpa
69.48.64.in-addr.arpa
70.48.64.in-addr.arpa
71.48.64.in-addr.arpa
72.48.64.in-addr.arpa
73.48.64.in-addr.arpa
74.48.64.in-addr.arpa
75.48.64.in-addr.arpa
76.48.64.in-addr.arpa
77.48.64.in-addr.arpa
78.48.64.in-addr.arpa
79.48.64.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
Address01000000.00110000.01000000.0000000064.48.64.0
Subnet mask11111111.11111111.11000000.00000000255.255.192.0
Network01000000.00110000.01000000.0000000064.48.64.0
Broadcast01000000.00110000.01111111.1111111164.48.127.255
Split into smaller subnets/26
/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)

64.48.64.0/18 makes 256 subnets of /26.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
164.48.64.0/2664.48.64.1 to 64.48.64.6264.48.64.6362
264.48.64.64/2664.48.64.65 to 64.48.64.12664.48.64.12762
364.48.64.128/2664.48.64.129 to 64.48.64.19064.48.64.19162
464.48.64.192/2664.48.64.193 to 64.48.64.25464.48.64.25562
564.48.65.0/2664.48.65.1 to 64.48.65.6264.48.65.6362
664.48.65.64/2664.48.65.65 to 64.48.65.12664.48.65.12762
764.48.65.128/2664.48.65.129 to 64.48.65.19064.48.65.19162
864.48.65.192/2664.48.65.193 to 64.48.65.25464.48.65.25562
964.48.66.0/2664.48.66.1 to 64.48.66.6264.48.66.6362
1064.48.66.64/2664.48.66.65 to 64.48.66.12664.48.66.12762
1164.48.66.128/2664.48.66.129 to 64.48.66.19064.48.66.19162
1264.48.66.192/2664.48.66.193 to 64.48.66.25464.48.66.25562
1364.48.67.0/2664.48.67.1 to 64.48.67.6264.48.67.6362
1464.48.67.64/2664.48.67.65 to 64.48.67.12664.48.67.12762
1564.48.67.128/2664.48.67.129 to 64.48.67.19064.48.67.19162
1664.48.67.192/2664.48.67.193 to 64.48.67.25464.48.67.25562
1764.48.68.0/2664.48.68.1 to 64.48.68.6264.48.68.6362
1864.48.68.64/2664.48.68.65 to 64.48.68.12664.48.68.12762
1964.48.68.128/2664.48.68.129 to 64.48.68.19064.48.68.19162
2064.48.68.192/2664.48.68.193 to 64.48.68.25464.48.68.25562
2164.48.69.0/2664.48.69.1 to 64.48.69.6264.48.69.6362
2264.48.69.64/2664.48.69.65 to 64.48.69.12664.48.69.12762
2364.48.69.128/2664.48.69.129 to 64.48.69.19064.48.69.19162
2464.48.69.192/2664.48.69.193 to 64.48.69.25464.48.69.25562
2564.48.70.0/2664.48.70.1 to 64.48.70.6264.48.70.6362
2664.48.70.64/2664.48.70.65 to 64.48.70.12664.48.70.12762
2764.48.70.128/2664.48.70.129 to 64.48.70.19064.48.70.19162
2864.48.70.192/2664.48.70.193 to 64.48.70.25464.48.70.25562
2964.48.71.0/2664.48.71.1 to 64.48.71.6264.48.71.6362
3064.48.71.64/2664.48.71.65 to 64.48.71.12664.48.71.12762
3164.48.71.128/2664.48.71.129 to 64.48.71.19064.48.71.19162
3264.48.71.192/2664.48.71.193 to 64.48.71.25464.48.71.25562
3364.48.72.0/2664.48.72.1 to 64.48.72.6264.48.72.6362
3464.48.72.64/2664.48.72.65 to 64.48.72.12664.48.72.12762
3564.48.72.128/2664.48.72.129 to 64.48.72.19064.48.72.19162
3664.48.72.192/2664.48.72.193 to 64.48.72.25464.48.72.25562
3764.48.73.0/2664.48.73.1 to 64.48.73.6264.48.73.6362
3864.48.73.64/2664.48.73.65 to 64.48.73.12664.48.73.12762
3964.48.73.128/2664.48.73.129 to 64.48.73.19064.48.73.19162
4064.48.73.192/2664.48.73.193 to 64.48.73.25464.48.73.25562
4164.48.74.0/2664.48.74.1 to 64.48.74.6264.48.74.6362
4264.48.74.64/2664.48.74.65 to 64.48.74.12664.48.74.12762
4364.48.74.128/2664.48.74.129 to 64.48.74.19064.48.74.19162
4464.48.74.192/2664.48.74.193 to 64.48.74.25464.48.74.25562
4564.48.75.0/2664.48.75.1 to 64.48.75.6264.48.75.6362
4664.48.75.64/2664.48.75.65 to 64.48.75.12664.48.75.12762
4764.48.75.128/2664.48.75.129 to 64.48.75.19064.48.75.19162
4864.48.75.192/2664.48.75.193 to 64.48.75.25464.48.75.25562
4964.48.76.0/2664.48.76.1 to 64.48.76.6264.48.76.6362
5064.48.76.64/2664.48.76.65 to 64.48.76.12664.48.76.12762
5164.48.76.128/2664.48.76.129 to 64.48.76.19064.48.76.19162
5264.48.76.192/2664.48.76.193 to 64.48.76.25464.48.76.25562
5364.48.77.0/2664.48.77.1 to 64.48.77.6264.48.77.6362
5464.48.77.64/2664.48.77.65 to 64.48.77.12664.48.77.12762
5564.48.77.128/2664.48.77.129 to 64.48.77.19064.48.77.19162
5664.48.77.192/2664.48.77.193 to 64.48.77.25464.48.77.25562
5764.48.78.0/2664.48.78.1 to 64.48.78.6264.48.78.6362
5864.48.78.64/2664.48.78.65 to 64.48.78.12664.48.78.12762
5964.48.78.128/2664.48.78.129 to 64.48.78.19064.48.78.19162
6064.48.78.192/2664.48.78.193 to 64.48.78.25464.48.78.25562
6164.48.79.0/2664.48.79.1 to 64.48.79.6264.48.79.6362
6264.48.79.64/2664.48.79.65 to 64.48.79.12664.48.79.12762
6364.48.79.128/2664.48.79.129 to 64.48.79.19064.48.79.19162
6464.48.79.192/2664.48.79.193 to 64.48.79.25464.48.79.25562
6564.48.80.0/2664.48.80.1 to 64.48.80.6264.48.80.6362
6664.48.80.64/2664.48.80.65 to 64.48.80.12664.48.80.12762
6764.48.80.128/2664.48.80.129 to 64.48.80.19064.48.80.19162
6864.48.80.192/2664.48.80.193 to 64.48.80.25464.48.80.25562
6964.48.81.0/2664.48.81.1 to 64.48.81.6264.48.81.6362
7064.48.81.64/2664.48.81.65 to 64.48.81.12664.48.81.12762
7164.48.81.128/2664.48.81.129 to 64.48.81.19064.48.81.19162
7264.48.81.192/2664.48.81.193 to 64.48.81.25464.48.81.25562
7364.48.82.0/2664.48.82.1 to 64.48.82.6264.48.82.6362
7464.48.82.64/2664.48.82.65 to 64.48.82.12664.48.82.12762
7564.48.82.128/2664.48.82.129 to 64.48.82.19064.48.82.19162
7664.48.82.192/2664.48.82.193 to 64.48.82.25464.48.82.25562
7764.48.83.0/2664.48.83.1 to 64.48.83.6264.48.83.6362
7864.48.83.64/2664.48.83.65 to 64.48.83.12664.48.83.12762
7964.48.83.128/2664.48.83.129 to 64.48.83.19064.48.83.19162
8064.48.83.192/2664.48.83.193 to 64.48.83.25464.48.83.25562
8164.48.84.0/2664.48.84.1 to 64.48.84.6264.48.84.6362
8264.48.84.64/2664.48.84.65 to 64.48.84.12664.48.84.12762
8364.48.84.128/2664.48.84.129 to 64.48.84.19064.48.84.19162
8464.48.84.192/2664.48.84.193 to 64.48.84.25464.48.84.25562
8564.48.85.0/2664.48.85.1 to 64.48.85.6264.48.85.6362
8664.48.85.64/2664.48.85.65 to 64.48.85.12664.48.85.12762
8764.48.85.128/2664.48.85.129 to 64.48.85.19064.48.85.19162
8864.48.85.192/2664.48.85.193 to 64.48.85.25464.48.85.25562
8964.48.86.0/2664.48.86.1 to 64.48.86.6264.48.86.6362
9064.48.86.64/2664.48.86.65 to 64.48.86.12664.48.86.12762
9164.48.86.128/2664.48.86.129 to 64.48.86.19064.48.86.19162
9264.48.86.192/2664.48.86.193 to 64.48.86.25464.48.86.25562
9364.48.87.0/2664.48.87.1 to 64.48.87.6264.48.87.6362
9464.48.87.64/2664.48.87.65 to 64.48.87.12664.48.87.12762
9564.48.87.128/2664.48.87.129 to 64.48.87.19064.48.87.19162
9664.48.87.192/2664.48.87.193 to 64.48.87.25464.48.87.25562
9764.48.88.0/2664.48.88.1 to 64.48.88.6264.48.88.6362
9864.48.88.64/2664.48.88.65 to 64.48.88.12664.48.88.12762
9964.48.88.128/2664.48.88.129 to 64.48.88.19064.48.88.19162
10064.48.88.192/2664.48.88.193 to 64.48.88.25464.48.88.25562
10164.48.89.0/2664.48.89.1 to 64.48.89.6264.48.89.6362
10264.48.89.64/2664.48.89.65 to 64.48.89.12664.48.89.12762
10364.48.89.128/2664.48.89.129 to 64.48.89.19064.48.89.19162
10464.48.89.192/2664.48.89.193 to 64.48.89.25464.48.89.25562
10564.48.90.0/2664.48.90.1 to 64.48.90.6264.48.90.6362
10664.48.90.64/2664.48.90.65 to 64.48.90.12664.48.90.12762
10764.48.90.128/2664.48.90.129 to 64.48.90.19064.48.90.19162
10864.48.90.192/2664.48.90.193 to 64.48.90.25464.48.90.25562
10964.48.91.0/2664.48.91.1 to 64.48.91.6264.48.91.6362
11064.48.91.64/2664.48.91.65 to 64.48.91.12664.48.91.12762
11164.48.91.128/2664.48.91.129 to 64.48.91.19064.48.91.19162
11264.48.91.192/2664.48.91.193 to 64.48.91.25464.48.91.25562
11364.48.92.0/2664.48.92.1 to 64.48.92.6264.48.92.6362
11464.48.92.64/2664.48.92.65 to 64.48.92.12664.48.92.12762
11564.48.92.128/2664.48.92.129 to 64.48.92.19064.48.92.19162
11664.48.92.192/2664.48.92.193 to 64.48.92.25464.48.92.25562
11764.48.93.0/2664.48.93.1 to 64.48.93.6264.48.93.6362
11864.48.93.64/2664.48.93.65 to 64.48.93.12664.48.93.12762
11964.48.93.128/2664.48.93.129 to 64.48.93.19064.48.93.19162
12064.48.93.192/2664.48.93.193 to 64.48.93.25464.48.93.25562
12164.48.94.0/2664.48.94.1 to 64.48.94.6264.48.94.6362
12264.48.94.64/2664.48.94.65 to 64.48.94.12664.48.94.12762
12364.48.94.128/2664.48.94.129 to 64.48.94.19064.48.94.19162
12464.48.94.192/2664.48.94.193 to 64.48.94.25464.48.94.25562
12564.48.95.0/2664.48.95.1 to 64.48.95.6264.48.95.6362
12664.48.95.64/2664.48.95.65 to 64.48.95.12664.48.95.12762
12764.48.95.128/2664.48.95.129 to 64.48.95.19064.48.95.19162
12864.48.95.192/2664.48.95.193 to 64.48.95.25464.48.95.25562
12964.48.96.0/2664.48.96.1 to 64.48.96.6264.48.96.6362
13064.48.96.64/2664.48.96.65 to 64.48.96.12664.48.96.12762
13164.48.96.128/2664.48.96.129 to 64.48.96.19064.48.96.19162
13264.48.96.192/2664.48.96.193 to 64.48.96.25464.48.96.25562
13364.48.97.0/2664.48.97.1 to 64.48.97.6264.48.97.6362
13464.48.97.64/2664.48.97.65 to 64.48.97.12664.48.97.12762
13564.48.97.128/2664.48.97.129 to 64.48.97.19064.48.97.19162
13664.48.97.192/2664.48.97.193 to 64.48.97.25464.48.97.25562
13764.48.98.0/2664.48.98.1 to 64.48.98.6264.48.98.6362
13864.48.98.64/2664.48.98.65 to 64.48.98.12664.48.98.12762
13964.48.98.128/2664.48.98.129 to 64.48.98.19064.48.98.19162
14064.48.98.192/2664.48.98.193 to 64.48.98.25464.48.98.25562
14164.48.99.0/2664.48.99.1 to 64.48.99.6264.48.99.6362
14264.48.99.64/2664.48.99.65 to 64.48.99.12664.48.99.12762
14364.48.99.128/2664.48.99.129 to 64.48.99.19064.48.99.19162
14464.48.99.192/2664.48.99.193 to 64.48.99.25464.48.99.25562
14564.48.100.0/2664.48.100.1 to 64.48.100.6264.48.100.6362
14664.48.100.64/2664.48.100.65 to 64.48.100.12664.48.100.12762
14764.48.100.128/2664.48.100.129 to 64.48.100.19064.48.100.19162
14864.48.100.192/2664.48.100.193 to 64.48.100.25464.48.100.25562
14964.48.101.0/2664.48.101.1 to 64.48.101.6264.48.101.6362
15064.48.101.64/2664.48.101.65 to 64.48.101.12664.48.101.12762
15164.48.101.128/2664.48.101.129 to 64.48.101.19064.48.101.19162
15264.48.101.192/2664.48.101.193 to 64.48.101.25464.48.101.25562
15364.48.102.0/2664.48.102.1 to 64.48.102.6264.48.102.6362
15464.48.102.64/2664.48.102.65 to 64.48.102.12664.48.102.12762
15564.48.102.128/2664.48.102.129 to 64.48.102.19064.48.102.19162
15664.48.102.192/2664.48.102.193 to 64.48.102.25464.48.102.25562
15764.48.103.0/2664.48.103.1 to 64.48.103.6264.48.103.6362
15864.48.103.64/2664.48.103.65 to 64.48.103.12664.48.103.12762
15964.48.103.128/2664.48.103.129 to 64.48.103.19064.48.103.19162
16064.48.103.192/2664.48.103.193 to 64.48.103.25464.48.103.25562
16164.48.104.0/2664.48.104.1 to 64.48.104.6264.48.104.6362
16264.48.104.64/2664.48.104.65 to 64.48.104.12664.48.104.12762
16364.48.104.128/2664.48.104.129 to 64.48.104.19064.48.104.19162
16464.48.104.192/2664.48.104.193 to 64.48.104.25464.48.104.25562
16564.48.105.0/2664.48.105.1 to 64.48.105.6264.48.105.6362
16664.48.105.64/2664.48.105.65 to 64.48.105.12664.48.105.12762
16764.48.105.128/2664.48.105.129 to 64.48.105.19064.48.105.19162
16864.48.105.192/2664.48.105.193 to 64.48.105.25464.48.105.25562
16964.48.106.0/2664.48.106.1 to 64.48.106.6264.48.106.6362
17064.48.106.64/2664.48.106.65 to 64.48.106.12664.48.106.12762
17164.48.106.128/2664.48.106.129 to 64.48.106.19064.48.106.19162
17264.48.106.192/2664.48.106.193 to 64.48.106.25464.48.106.25562
17364.48.107.0/2664.48.107.1 to 64.48.107.6264.48.107.6362
17464.48.107.64/2664.48.107.65 to 64.48.107.12664.48.107.12762
17564.48.107.128/2664.48.107.129 to 64.48.107.19064.48.107.19162
17664.48.107.192/2664.48.107.193 to 64.48.107.25464.48.107.25562
17764.48.108.0/2664.48.108.1 to 64.48.108.6264.48.108.6362
17864.48.108.64/2664.48.108.65 to 64.48.108.12664.48.108.12762
17964.48.108.128/2664.48.108.129 to 64.48.108.19064.48.108.19162
18064.48.108.192/2664.48.108.193 to 64.48.108.25464.48.108.25562
18164.48.109.0/2664.48.109.1 to 64.48.109.6264.48.109.6362
18264.48.109.64/2664.48.109.65 to 64.48.109.12664.48.109.12762
18364.48.109.128/2664.48.109.129 to 64.48.109.19064.48.109.19162
18464.48.109.192/2664.48.109.193 to 64.48.109.25464.48.109.25562
18564.48.110.0/2664.48.110.1 to 64.48.110.6264.48.110.6362
18664.48.110.64/2664.48.110.65 to 64.48.110.12664.48.110.12762
18764.48.110.128/2664.48.110.129 to 64.48.110.19064.48.110.19162
18864.48.110.192/2664.48.110.193 to 64.48.110.25464.48.110.25562
18964.48.111.0/2664.48.111.1 to 64.48.111.6264.48.111.6362
19064.48.111.64/2664.48.111.65 to 64.48.111.12664.48.111.12762
19164.48.111.128/2664.48.111.129 to 64.48.111.19064.48.111.19162
19264.48.111.192/2664.48.111.193 to 64.48.111.25464.48.111.25562
19364.48.112.0/2664.48.112.1 to 64.48.112.6264.48.112.6362
19464.48.112.64/2664.48.112.65 to 64.48.112.12664.48.112.12762
19564.48.112.128/2664.48.112.129 to 64.48.112.19064.48.112.19162
19664.48.112.192/2664.48.112.193 to 64.48.112.25464.48.112.25562
19764.48.113.0/2664.48.113.1 to 64.48.113.6264.48.113.6362
19864.48.113.64/2664.48.113.65 to 64.48.113.12664.48.113.12762
19964.48.113.128/2664.48.113.129 to 64.48.113.19064.48.113.19162
20064.48.113.192/2664.48.113.193 to 64.48.113.25464.48.113.25562
20164.48.114.0/2664.48.114.1 to 64.48.114.6264.48.114.6362
20264.48.114.64/2664.48.114.65 to 64.48.114.12664.48.114.12762
20364.48.114.128/2664.48.114.129 to 64.48.114.19064.48.114.19162
20464.48.114.192/2664.48.114.193 to 64.48.114.25464.48.114.25562
20564.48.115.0/2664.48.115.1 to 64.48.115.6264.48.115.6362
20664.48.115.64/2664.48.115.65 to 64.48.115.12664.48.115.12762
20764.48.115.128/2664.48.115.129 to 64.48.115.19064.48.115.19162
20864.48.115.192/2664.48.115.193 to 64.48.115.25464.48.115.25562
20964.48.116.0/2664.48.116.1 to 64.48.116.6264.48.116.6362
21064.48.116.64/2664.48.116.65 to 64.48.116.12664.48.116.12762
21164.48.116.128/2664.48.116.129 to 64.48.116.19064.48.116.19162
21264.48.116.192/2664.48.116.193 to 64.48.116.25464.48.116.25562
21364.48.117.0/2664.48.117.1 to 64.48.117.6264.48.117.6362
21464.48.117.64/2664.48.117.65 to 64.48.117.12664.48.117.12762
21564.48.117.128/2664.48.117.129 to 64.48.117.19064.48.117.19162
21664.48.117.192/2664.48.117.193 to 64.48.117.25464.48.117.25562
21764.48.118.0/2664.48.118.1 to 64.48.118.6264.48.118.6362
21864.48.118.64/2664.48.118.65 to 64.48.118.12664.48.118.12762
21964.48.118.128/2664.48.118.129 to 64.48.118.19064.48.118.19162
22064.48.118.192/2664.48.118.193 to 64.48.118.25464.48.118.25562
22164.48.119.0/2664.48.119.1 to 64.48.119.6264.48.119.6362
22264.48.119.64/2664.48.119.65 to 64.48.119.12664.48.119.12762
22364.48.119.128/2664.48.119.129 to 64.48.119.19064.48.119.19162
22464.48.119.192/2664.48.119.193 to 64.48.119.25464.48.119.25562
22564.48.120.0/2664.48.120.1 to 64.48.120.6264.48.120.6362
22664.48.120.64/2664.48.120.65 to 64.48.120.12664.48.120.12762
22764.48.120.128/2664.48.120.129 to 64.48.120.19064.48.120.19162
22864.48.120.192/2664.48.120.193 to 64.48.120.25464.48.120.25562
22964.48.121.0/2664.48.121.1 to 64.48.121.6264.48.121.6362
23064.48.121.64/2664.48.121.65 to 64.48.121.12664.48.121.12762
23164.48.121.128/2664.48.121.129 to 64.48.121.19064.48.121.19162
23264.48.121.192/2664.48.121.193 to 64.48.121.25464.48.121.25562
23364.48.122.0/2664.48.122.1 to 64.48.122.6264.48.122.6362
23464.48.122.64/2664.48.122.65 to 64.48.122.12664.48.122.12762
23564.48.122.128/2664.48.122.129 to 64.48.122.19064.48.122.19162
23664.48.122.192/2664.48.122.193 to 64.48.122.25464.48.122.25562
23764.48.123.0/2664.48.123.1 to 64.48.123.6264.48.123.6362
23864.48.123.64/2664.48.123.65 to 64.48.123.12664.48.123.12762
23964.48.123.128/2664.48.123.129 to 64.48.123.19064.48.123.19162
24064.48.123.192/2664.48.123.193 to 64.48.123.25464.48.123.25562
24164.48.124.0/2664.48.124.1 to 64.48.124.6264.48.124.6362
24264.48.124.64/2664.48.124.65 to 64.48.124.12664.48.124.12762
24364.48.124.128/2664.48.124.129 to 64.48.124.19064.48.124.19162
24464.48.124.192/2664.48.124.193 to 64.48.124.25464.48.124.25562
24564.48.125.0/2664.48.125.1 to 64.48.125.6264.48.125.6362
24664.48.125.64/2664.48.125.65 to 64.48.125.12664.48.125.12762
24764.48.125.128/2664.48.125.129 to 64.48.125.19064.48.125.19162
24864.48.125.192/2664.48.125.193 to 64.48.125.25464.48.125.25562
24964.48.126.0/2664.48.126.1 to 64.48.126.6264.48.126.6362
25064.48.126.64/2664.48.126.65 to 64.48.126.12664.48.126.12762
25164.48.126.128/2664.48.126.129 to 64.48.126.19064.48.126.19162
25264.48.126.192/2664.48.126.193 to 64.48.126.25464.48.126.25562
25364.48.127.0/2664.48.127.1 to 64.48.127.6264.48.127.6362
25464.48.127.64/2664.48.127.65 to 64.48.127.12664.48.127.12762
25564.48.127.128/2664.48.127.129 to 64.48.127.19064.48.127.19162
25664.48.127.192/2664.48.127.193 to 64.48.127.25464.48.127.25562

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.