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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.

Network23.3.76.0/22
Usable hosts1,022
Subnet mask255.255.252.0
Addresses1,024
Network address
23.3.76.0
Broadcast address
23.3.79.255
First usable
23.3.76.1
Last usable
23.3.79.254
Usable hosts
1,022 (1,024 less the network and broadcast addresses)
Subnet mask
255.255.252.0
Wildcard mask
0.0.3.255 (Cisco ACLs, OSPF)
Prefix length
/22
Type
Public public
Old class
A (default /8)
As numbers
Hex 17034C00 · Integer 386092032 to 386093055
Reverse DNS zones
76.3.23.in-addr.arpa
77.3.23.in-addr.arpa
78.3.23.in-addr.arpa
79.3.23.in-addr.arpa
/22 is not on a 8-bit boundary, so it takes 4 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00010111.00000011.01001100.0000000023.3.76.0
Subnet mask11111111.11111111.11111100.00000000255.255.252.0
Network00010111.00000011.01001100.0000000023.3.76.0
Broadcast00010111.00000011.01001111.1111111123.3.79.255
Split into smaller subnets/30
/23 (2)/24 (4)/25 (8)/26 (16)/27 (32)/28 (64)/29 (128)/30 (256)/31 (512)/32 (1,024)

23.3.76.0/22 makes 256 subnets of /30.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
123.3.76.0/3023.3.76.1 to 23.3.76.223.3.76.32
223.3.76.4/3023.3.76.5 to 23.3.76.623.3.76.72
323.3.76.8/3023.3.76.9 to 23.3.76.1023.3.76.112
423.3.76.12/3023.3.76.13 to 23.3.76.1423.3.76.152
523.3.76.16/3023.3.76.17 to 23.3.76.1823.3.76.192
623.3.76.20/3023.3.76.21 to 23.3.76.2223.3.76.232
723.3.76.24/3023.3.76.25 to 23.3.76.2623.3.76.272
823.3.76.28/3023.3.76.29 to 23.3.76.3023.3.76.312
923.3.76.32/3023.3.76.33 to 23.3.76.3423.3.76.352
1023.3.76.36/3023.3.76.37 to 23.3.76.3823.3.76.392
1123.3.76.40/3023.3.76.41 to 23.3.76.4223.3.76.432
1223.3.76.44/3023.3.76.45 to 23.3.76.4623.3.76.472
1323.3.76.48/3023.3.76.49 to 23.3.76.5023.3.76.512
1423.3.76.52/3023.3.76.53 to 23.3.76.5423.3.76.552
1523.3.76.56/3023.3.76.57 to 23.3.76.5823.3.76.592
1623.3.76.60/3023.3.76.61 to 23.3.76.6223.3.76.632
1723.3.76.64/3023.3.76.65 to 23.3.76.6623.3.76.672
1823.3.76.68/3023.3.76.69 to 23.3.76.7023.3.76.712
1923.3.76.72/3023.3.76.73 to 23.3.76.7423.3.76.752
2023.3.76.76/3023.3.76.77 to 23.3.76.7823.3.76.792
2123.3.76.80/3023.3.76.81 to 23.3.76.8223.3.76.832
2223.3.76.84/3023.3.76.85 to 23.3.76.8623.3.76.872
2323.3.76.88/3023.3.76.89 to 23.3.76.9023.3.76.912
2423.3.76.92/3023.3.76.93 to 23.3.76.9423.3.76.952
2523.3.76.96/3023.3.76.97 to 23.3.76.9823.3.76.992
2623.3.76.100/3023.3.76.101 to 23.3.76.10223.3.76.1032
2723.3.76.104/3023.3.76.105 to 23.3.76.10623.3.76.1072
2823.3.76.108/3023.3.76.109 to 23.3.76.11023.3.76.1112
2923.3.76.112/3023.3.76.113 to 23.3.76.11423.3.76.1152
3023.3.76.116/3023.3.76.117 to 23.3.76.11823.3.76.1192
3123.3.76.120/3023.3.76.121 to 23.3.76.12223.3.76.1232
3223.3.76.124/3023.3.76.125 to 23.3.76.12623.3.76.1272
3323.3.76.128/3023.3.76.129 to 23.3.76.13023.3.76.1312
3423.3.76.132/3023.3.76.133 to 23.3.76.13423.3.76.1352
3523.3.76.136/3023.3.76.137 to 23.3.76.13823.3.76.1392
3623.3.76.140/3023.3.76.141 to 23.3.76.14223.3.76.1432
3723.3.76.144/3023.3.76.145 to 23.3.76.14623.3.76.1472
3823.3.76.148/3023.3.76.149 to 23.3.76.15023.3.76.1512
3923.3.76.152/3023.3.76.153 to 23.3.76.15423.3.76.1552
4023.3.76.156/3023.3.76.157 to 23.3.76.15823.3.76.1592
4123.3.76.160/3023.3.76.161 to 23.3.76.16223.3.76.1632
4223.3.76.164/3023.3.76.165 to 23.3.76.16623.3.76.1672
4323.3.76.168/3023.3.76.169 to 23.3.76.17023.3.76.1712
4423.3.76.172/3023.3.76.173 to 23.3.76.17423.3.76.1752
4523.3.76.176/3023.3.76.177 to 23.3.76.17823.3.76.1792
4623.3.76.180/3023.3.76.181 to 23.3.76.18223.3.76.1832
4723.3.76.184/3023.3.76.185 to 23.3.76.18623.3.76.1872
4823.3.76.188/3023.3.76.189 to 23.3.76.19023.3.76.1912
4923.3.76.192/3023.3.76.193 to 23.3.76.19423.3.76.1952
5023.3.76.196/3023.3.76.197 to 23.3.76.19823.3.76.1992
5123.3.76.200/3023.3.76.201 to 23.3.76.20223.3.76.2032
5223.3.76.204/3023.3.76.205 to 23.3.76.20623.3.76.2072
5323.3.76.208/3023.3.76.209 to 23.3.76.21023.3.76.2112
5423.3.76.212/3023.3.76.213 to 23.3.76.21423.3.76.2152
5523.3.76.216/3023.3.76.217 to 23.3.76.21823.3.76.2192
5623.3.76.220/3023.3.76.221 to 23.3.76.22223.3.76.2232
5723.3.76.224/3023.3.76.225 to 23.3.76.22623.3.76.2272
5823.3.76.228/3023.3.76.229 to 23.3.76.23023.3.76.2312
5923.3.76.232/3023.3.76.233 to 23.3.76.23423.3.76.2352
6023.3.76.236/3023.3.76.237 to 23.3.76.23823.3.76.2392
6123.3.76.240/3023.3.76.241 to 23.3.76.24223.3.76.2432
6223.3.76.244/3023.3.76.245 to 23.3.76.24623.3.76.2472
6323.3.76.248/3023.3.76.249 to 23.3.76.25023.3.76.2512
6423.3.76.252/3023.3.76.253 to 23.3.76.25423.3.76.2552
6523.3.77.0/3023.3.77.1 to 23.3.77.223.3.77.32
6623.3.77.4/3023.3.77.5 to 23.3.77.623.3.77.72
6723.3.77.8/3023.3.77.9 to 23.3.77.1023.3.77.112
6823.3.77.12/3023.3.77.13 to 23.3.77.1423.3.77.152
6923.3.77.16/3023.3.77.17 to 23.3.77.1823.3.77.192
7023.3.77.20/3023.3.77.21 to 23.3.77.2223.3.77.232
7123.3.77.24/3023.3.77.25 to 23.3.77.2623.3.77.272
7223.3.77.28/3023.3.77.29 to 23.3.77.3023.3.77.312
7323.3.77.32/3023.3.77.33 to 23.3.77.3423.3.77.352
7423.3.77.36/3023.3.77.37 to 23.3.77.3823.3.77.392
7523.3.77.40/3023.3.77.41 to 23.3.77.4223.3.77.432
7623.3.77.44/3023.3.77.45 to 23.3.77.4623.3.77.472
7723.3.77.48/3023.3.77.49 to 23.3.77.5023.3.77.512
7823.3.77.52/3023.3.77.53 to 23.3.77.5423.3.77.552
7923.3.77.56/3023.3.77.57 to 23.3.77.5823.3.77.592
8023.3.77.60/3023.3.77.61 to 23.3.77.6223.3.77.632
8123.3.77.64/3023.3.77.65 to 23.3.77.6623.3.77.672
8223.3.77.68/3023.3.77.69 to 23.3.77.7023.3.77.712
8323.3.77.72/3023.3.77.73 to 23.3.77.7423.3.77.752
8423.3.77.76/3023.3.77.77 to 23.3.77.7823.3.77.792
8523.3.77.80/3023.3.77.81 to 23.3.77.8223.3.77.832
8623.3.77.84/3023.3.77.85 to 23.3.77.8623.3.77.872
8723.3.77.88/3023.3.77.89 to 23.3.77.9023.3.77.912
8823.3.77.92/3023.3.77.93 to 23.3.77.9423.3.77.952
8923.3.77.96/3023.3.77.97 to 23.3.77.9823.3.77.992
9023.3.77.100/3023.3.77.101 to 23.3.77.10223.3.77.1032
9123.3.77.104/3023.3.77.105 to 23.3.77.10623.3.77.1072
9223.3.77.108/3023.3.77.109 to 23.3.77.11023.3.77.1112
9323.3.77.112/3023.3.77.113 to 23.3.77.11423.3.77.1152
9423.3.77.116/3023.3.77.117 to 23.3.77.11823.3.77.1192
9523.3.77.120/3023.3.77.121 to 23.3.77.12223.3.77.1232
9623.3.77.124/3023.3.77.125 to 23.3.77.12623.3.77.1272
9723.3.77.128/3023.3.77.129 to 23.3.77.13023.3.77.1312
9823.3.77.132/3023.3.77.133 to 23.3.77.13423.3.77.1352
9923.3.77.136/3023.3.77.137 to 23.3.77.13823.3.77.1392
10023.3.77.140/3023.3.77.141 to 23.3.77.14223.3.77.1432
10123.3.77.144/3023.3.77.145 to 23.3.77.14623.3.77.1472
10223.3.77.148/3023.3.77.149 to 23.3.77.15023.3.77.1512
10323.3.77.152/3023.3.77.153 to 23.3.77.15423.3.77.1552
10423.3.77.156/3023.3.77.157 to 23.3.77.15823.3.77.1592
10523.3.77.160/3023.3.77.161 to 23.3.77.16223.3.77.1632
10623.3.77.164/3023.3.77.165 to 23.3.77.16623.3.77.1672
10723.3.77.168/3023.3.77.169 to 23.3.77.17023.3.77.1712
10823.3.77.172/3023.3.77.173 to 23.3.77.17423.3.77.1752
10923.3.77.176/3023.3.77.177 to 23.3.77.17823.3.77.1792
11023.3.77.180/3023.3.77.181 to 23.3.77.18223.3.77.1832
11123.3.77.184/3023.3.77.185 to 23.3.77.18623.3.77.1872
11223.3.77.188/3023.3.77.189 to 23.3.77.19023.3.77.1912
11323.3.77.192/3023.3.77.193 to 23.3.77.19423.3.77.1952
11423.3.77.196/3023.3.77.197 to 23.3.77.19823.3.77.1992
11523.3.77.200/3023.3.77.201 to 23.3.77.20223.3.77.2032
11623.3.77.204/3023.3.77.205 to 23.3.77.20623.3.77.2072
11723.3.77.208/3023.3.77.209 to 23.3.77.21023.3.77.2112
11823.3.77.212/3023.3.77.213 to 23.3.77.21423.3.77.2152
11923.3.77.216/3023.3.77.217 to 23.3.77.21823.3.77.2192
12023.3.77.220/3023.3.77.221 to 23.3.77.22223.3.77.2232
12123.3.77.224/3023.3.77.225 to 23.3.77.22623.3.77.2272
12223.3.77.228/3023.3.77.229 to 23.3.77.23023.3.77.2312
12323.3.77.232/3023.3.77.233 to 23.3.77.23423.3.77.2352
12423.3.77.236/3023.3.77.237 to 23.3.77.23823.3.77.2392
12523.3.77.240/3023.3.77.241 to 23.3.77.24223.3.77.2432
12623.3.77.244/3023.3.77.245 to 23.3.77.24623.3.77.2472
12723.3.77.248/3023.3.77.249 to 23.3.77.25023.3.77.2512
12823.3.77.252/3023.3.77.253 to 23.3.77.25423.3.77.2552
12923.3.78.0/3023.3.78.1 to 23.3.78.223.3.78.32
13023.3.78.4/3023.3.78.5 to 23.3.78.623.3.78.72
13123.3.78.8/3023.3.78.9 to 23.3.78.1023.3.78.112
13223.3.78.12/3023.3.78.13 to 23.3.78.1423.3.78.152
13323.3.78.16/3023.3.78.17 to 23.3.78.1823.3.78.192
13423.3.78.20/3023.3.78.21 to 23.3.78.2223.3.78.232
13523.3.78.24/3023.3.78.25 to 23.3.78.2623.3.78.272
13623.3.78.28/3023.3.78.29 to 23.3.78.3023.3.78.312
13723.3.78.32/3023.3.78.33 to 23.3.78.3423.3.78.352
13823.3.78.36/3023.3.78.37 to 23.3.78.3823.3.78.392
13923.3.78.40/3023.3.78.41 to 23.3.78.4223.3.78.432
14023.3.78.44/3023.3.78.45 to 23.3.78.4623.3.78.472
14123.3.78.48/3023.3.78.49 to 23.3.78.5023.3.78.512
14223.3.78.52/3023.3.78.53 to 23.3.78.5423.3.78.552
14323.3.78.56/3023.3.78.57 to 23.3.78.5823.3.78.592
14423.3.78.60/3023.3.78.61 to 23.3.78.6223.3.78.632
14523.3.78.64/3023.3.78.65 to 23.3.78.6623.3.78.672
14623.3.78.68/3023.3.78.69 to 23.3.78.7023.3.78.712
14723.3.78.72/3023.3.78.73 to 23.3.78.7423.3.78.752
14823.3.78.76/3023.3.78.77 to 23.3.78.7823.3.78.792
14923.3.78.80/3023.3.78.81 to 23.3.78.8223.3.78.832
15023.3.78.84/3023.3.78.85 to 23.3.78.8623.3.78.872
15123.3.78.88/3023.3.78.89 to 23.3.78.9023.3.78.912
15223.3.78.92/3023.3.78.93 to 23.3.78.9423.3.78.952
15323.3.78.96/3023.3.78.97 to 23.3.78.9823.3.78.992
15423.3.78.100/3023.3.78.101 to 23.3.78.10223.3.78.1032
15523.3.78.104/3023.3.78.105 to 23.3.78.10623.3.78.1072
15623.3.78.108/3023.3.78.109 to 23.3.78.11023.3.78.1112
15723.3.78.112/3023.3.78.113 to 23.3.78.11423.3.78.1152
15823.3.78.116/3023.3.78.117 to 23.3.78.11823.3.78.1192
15923.3.78.120/3023.3.78.121 to 23.3.78.12223.3.78.1232
16023.3.78.124/3023.3.78.125 to 23.3.78.12623.3.78.1272
16123.3.78.128/3023.3.78.129 to 23.3.78.13023.3.78.1312
16223.3.78.132/3023.3.78.133 to 23.3.78.13423.3.78.1352
16323.3.78.136/3023.3.78.137 to 23.3.78.13823.3.78.1392
16423.3.78.140/3023.3.78.141 to 23.3.78.14223.3.78.1432
16523.3.78.144/3023.3.78.145 to 23.3.78.14623.3.78.1472
16623.3.78.148/3023.3.78.149 to 23.3.78.15023.3.78.1512
16723.3.78.152/3023.3.78.153 to 23.3.78.15423.3.78.1552
16823.3.78.156/3023.3.78.157 to 23.3.78.15823.3.78.1592
16923.3.78.160/3023.3.78.161 to 23.3.78.16223.3.78.1632
17023.3.78.164/3023.3.78.165 to 23.3.78.16623.3.78.1672
17123.3.78.168/3023.3.78.169 to 23.3.78.17023.3.78.1712
17223.3.78.172/3023.3.78.173 to 23.3.78.17423.3.78.1752
17323.3.78.176/3023.3.78.177 to 23.3.78.17823.3.78.1792
17423.3.78.180/3023.3.78.181 to 23.3.78.18223.3.78.1832
17523.3.78.184/3023.3.78.185 to 23.3.78.18623.3.78.1872
17623.3.78.188/3023.3.78.189 to 23.3.78.19023.3.78.1912
17723.3.78.192/3023.3.78.193 to 23.3.78.19423.3.78.1952
17823.3.78.196/3023.3.78.197 to 23.3.78.19823.3.78.1992
17923.3.78.200/3023.3.78.201 to 23.3.78.20223.3.78.2032
18023.3.78.204/3023.3.78.205 to 23.3.78.20623.3.78.2072
18123.3.78.208/3023.3.78.209 to 23.3.78.21023.3.78.2112
18223.3.78.212/3023.3.78.213 to 23.3.78.21423.3.78.2152
18323.3.78.216/3023.3.78.217 to 23.3.78.21823.3.78.2192
18423.3.78.220/3023.3.78.221 to 23.3.78.22223.3.78.2232
18523.3.78.224/3023.3.78.225 to 23.3.78.22623.3.78.2272
18623.3.78.228/3023.3.78.229 to 23.3.78.23023.3.78.2312
18723.3.78.232/3023.3.78.233 to 23.3.78.23423.3.78.2352
18823.3.78.236/3023.3.78.237 to 23.3.78.23823.3.78.2392
18923.3.78.240/3023.3.78.241 to 23.3.78.24223.3.78.2432
19023.3.78.244/3023.3.78.245 to 23.3.78.24623.3.78.2472
19123.3.78.248/3023.3.78.249 to 23.3.78.25023.3.78.2512
19223.3.78.252/3023.3.78.253 to 23.3.78.25423.3.78.2552
19323.3.79.0/3023.3.79.1 to 23.3.79.223.3.79.32
19423.3.79.4/3023.3.79.5 to 23.3.79.623.3.79.72
19523.3.79.8/3023.3.79.9 to 23.3.79.1023.3.79.112
19623.3.79.12/3023.3.79.13 to 23.3.79.1423.3.79.152
19723.3.79.16/3023.3.79.17 to 23.3.79.1823.3.79.192
19823.3.79.20/3023.3.79.21 to 23.3.79.2223.3.79.232
19923.3.79.24/3023.3.79.25 to 23.3.79.2623.3.79.272
20023.3.79.28/3023.3.79.29 to 23.3.79.3023.3.79.312
20123.3.79.32/3023.3.79.33 to 23.3.79.3423.3.79.352
20223.3.79.36/3023.3.79.37 to 23.3.79.3823.3.79.392
20323.3.79.40/3023.3.79.41 to 23.3.79.4223.3.79.432
20423.3.79.44/3023.3.79.45 to 23.3.79.4623.3.79.472
20523.3.79.48/3023.3.79.49 to 23.3.79.5023.3.79.512
20623.3.79.52/3023.3.79.53 to 23.3.79.5423.3.79.552
20723.3.79.56/3023.3.79.57 to 23.3.79.5823.3.79.592
20823.3.79.60/3023.3.79.61 to 23.3.79.6223.3.79.632
20923.3.79.64/3023.3.79.65 to 23.3.79.6623.3.79.672
21023.3.79.68/3023.3.79.69 to 23.3.79.7023.3.79.712
21123.3.79.72/3023.3.79.73 to 23.3.79.7423.3.79.752
21223.3.79.76/3023.3.79.77 to 23.3.79.7823.3.79.792
21323.3.79.80/3023.3.79.81 to 23.3.79.8223.3.79.832
21423.3.79.84/3023.3.79.85 to 23.3.79.8623.3.79.872
21523.3.79.88/3023.3.79.89 to 23.3.79.9023.3.79.912
21623.3.79.92/3023.3.79.93 to 23.3.79.9423.3.79.952
21723.3.79.96/3023.3.79.97 to 23.3.79.9823.3.79.992
21823.3.79.100/3023.3.79.101 to 23.3.79.10223.3.79.1032
21923.3.79.104/3023.3.79.105 to 23.3.79.10623.3.79.1072
22023.3.79.108/3023.3.79.109 to 23.3.79.11023.3.79.1112
22123.3.79.112/3023.3.79.113 to 23.3.79.11423.3.79.1152
22223.3.79.116/3023.3.79.117 to 23.3.79.11823.3.79.1192
22323.3.79.120/3023.3.79.121 to 23.3.79.12223.3.79.1232
22423.3.79.124/3023.3.79.125 to 23.3.79.12623.3.79.1272
22523.3.79.128/3023.3.79.129 to 23.3.79.13023.3.79.1312
22623.3.79.132/3023.3.79.133 to 23.3.79.13423.3.79.1352
22723.3.79.136/3023.3.79.137 to 23.3.79.13823.3.79.1392
22823.3.79.140/3023.3.79.141 to 23.3.79.14223.3.79.1432
22923.3.79.144/3023.3.79.145 to 23.3.79.14623.3.79.1472
23023.3.79.148/3023.3.79.149 to 23.3.79.15023.3.79.1512
23123.3.79.152/3023.3.79.153 to 23.3.79.15423.3.79.1552
23223.3.79.156/3023.3.79.157 to 23.3.79.15823.3.79.1592
23323.3.79.160/3023.3.79.161 to 23.3.79.16223.3.79.1632
23423.3.79.164/3023.3.79.165 to 23.3.79.16623.3.79.1672
23523.3.79.168/3023.3.79.169 to 23.3.79.17023.3.79.1712
23623.3.79.172/3023.3.79.173 to 23.3.79.17423.3.79.1752
23723.3.79.176/3023.3.79.177 to 23.3.79.17823.3.79.1792
23823.3.79.180/3023.3.79.181 to 23.3.79.18223.3.79.1832
23923.3.79.184/3023.3.79.185 to 23.3.79.18623.3.79.1872
24023.3.79.188/3023.3.79.189 to 23.3.79.19023.3.79.1912
24123.3.79.192/3023.3.79.193 to 23.3.79.19423.3.79.1952
24223.3.79.196/3023.3.79.197 to 23.3.79.19823.3.79.1992
24323.3.79.200/3023.3.79.201 to 23.3.79.20223.3.79.2032
24423.3.79.204/3023.3.79.205 to 23.3.79.20623.3.79.2072
24523.3.79.208/3023.3.79.209 to 23.3.79.21023.3.79.2112
24623.3.79.212/3023.3.79.213 to 23.3.79.21423.3.79.2152
24723.3.79.216/3023.3.79.217 to 23.3.79.21823.3.79.2192
24823.3.79.220/3023.3.79.221 to 23.3.79.22223.3.79.2232
24923.3.79.224/3023.3.79.225 to 23.3.79.22623.3.79.2272
25023.3.79.228/3023.3.79.229 to 23.3.79.23023.3.79.2312
25123.3.79.232/3023.3.79.233 to 23.3.79.23423.3.79.2352
25223.3.79.236/3023.3.79.237 to 23.3.79.23823.3.79.2392
25323.3.79.240/3023.3.79.241 to 23.3.79.24223.3.79.2432
25423.3.79.244/3023.3.79.245 to 23.3.79.24623.3.79.2472
25523.3.79.248/3023.3.79.249 to 23.3.79.25023.3.79.2512
25623.3.79.252/3023.3.79.253 to 23.3.79.25423.3.79.2552

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.