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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.

Network48.63.64.0/18
Usable hosts16,382
Subnet mask255.255.192.0
Addresses16,384
Network address
48.63.64.0
Broadcast address
48.63.127.255
First usable
48.63.64.1
Last usable
48.63.127.254
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 303F4000 · Integer 809451520 to 809467903
Reverse DNS zones
64.63.48.in-addr.arpa
65.63.48.in-addr.arpa
66.63.48.in-addr.arpa
67.63.48.in-addr.arpa
68.63.48.in-addr.arpa
69.63.48.in-addr.arpa
70.63.48.in-addr.arpa
71.63.48.in-addr.arpa
72.63.48.in-addr.arpa
73.63.48.in-addr.arpa
74.63.48.in-addr.arpa
75.63.48.in-addr.arpa
76.63.48.in-addr.arpa
77.63.48.in-addr.arpa
78.63.48.in-addr.arpa
79.63.48.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
Address00110000.00111111.01000000.0000000048.63.64.0
Subnet mask11111111.11111111.11000000.00000000255.255.192.0
Network00110000.00111111.01000000.0000000048.63.64.0
Broadcast00110000.00111111.01111111.1111111148.63.127.255
Split into smaller subnets/30
/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)

48.63.64.0/18 makes 4,096 subnets of /30; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
148.63.64.0/3048.63.64.1 to 48.63.64.248.63.64.32
248.63.64.4/3048.63.64.5 to 48.63.64.648.63.64.72
348.63.64.8/3048.63.64.9 to 48.63.64.1048.63.64.112
448.63.64.12/3048.63.64.13 to 48.63.64.1448.63.64.152
548.63.64.16/3048.63.64.17 to 48.63.64.1848.63.64.192
648.63.64.20/3048.63.64.21 to 48.63.64.2248.63.64.232
748.63.64.24/3048.63.64.25 to 48.63.64.2648.63.64.272
848.63.64.28/3048.63.64.29 to 48.63.64.3048.63.64.312
948.63.64.32/3048.63.64.33 to 48.63.64.3448.63.64.352
1048.63.64.36/3048.63.64.37 to 48.63.64.3848.63.64.392
1148.63.64.40/3048.63.64.41 to 48.63.64.4248.63.64.432
1248.63.64.44/3048.63.64.45 to 48.63.64.4648.63.64.472
1348.63.64.48/3048.63.64.49 to 48.63.64.5048.63.64.512
1448.63.64.52/3048.63.64.53 to 48.63.64.5448.63.64.552
1548.63.64.56/3048.63.64.57 to 48.63.64.5848.63.64.592
1648.63.64.60/3048.63.64.61 to 48.63.64.6248.63.64.632
1748.63.64.64/3048.63.64.65 to 48.63.64.6648.63.64.672
1848.63.64.68/3048.63.64.69 to 48.63.64.7048.63.64.712
1948.63.64.72/3048.63.64.73 to 48.63.64.7448.63.64.752
2048.63.64.76/3048.63.64.77 to 48.63.64.7848.63.64.792
2148.63.64.80/3048.63.64.81 to 48.63.64.8248.63.64.832
2248.63.64.84/3048.63.64.85 to 48.63.64.8648.63.64.872
2348.63.64.88/3048.63.64.89 to 48.63.64.9048.63.64.912
2448.63.64.92/3048.63.64.93 to 48.63.64.9448.63.64.952
2548.63.64.96/3048.63.64.97 to 48.63.64.9848.63.64.992
2648.63.64.100/3048.63.64.101 to 48.63.64.10248.63.64.1032
2748.63.64.104/3048.63.64.105 to 48.63.64.10648.63.64.1072
2848.63.64.108/3048.63.64.109 to 48.63.64.11048.63.64.1112
2948.63.64.112/3048.63.64.113 to 48.63.64.11448.63.64.1152
3048.63.64.116/3048.63.64.117 to 48.63.64.11848.63.64.1192
3148.63.64.120/3048.63.64.121 to 48.63.64.12248.63.64.1232
3248.63.64.124/3048.63.64.125 to 48.63.64.12648.63.64.1272
3348.63.64.128/3048.63.64.129 to 48.63.64.13048.63.64.1312
3448.63.64.132/3048.63.64.133 to 48.63.64.13448.63.64.1352
3548.63.64.136/3048.63.64.137 to 48.63.64.13848.63.64.1392
3648.63.64.140/3048.63.64.141 to 48.63.64.14248.63.64.1432
3748.63.64.144/3048.63.64.145 to 48.63.64.14648.63.64.1472
3848.63.64.148/3048.63.64.149 to 48.63.64.15048.63.64.1512
3948.63.64.152/3048.63.64.153 to 48.63.64.15448.63.64.1552
4048.63.64.156/3048.63.64.157 to 48.63.64.15848.63.64.1592
4148.63.64.160/3048.63.64.161 to 48.63.64.16248.63.64.1632
4248.63.64.164/3048.63.64.165 to 48.63.64.16648.63.64.1672
4348.63.64.168/3048.63.64.169 to 48.63.64.17048.63.64.1712
4448.63.64.172/3048.63.64.173 to 48.63.64.17448.63.64.1752
4548.63.64.176/3048.63.64.177 to 48.63.64.17848.63.64.1792
4648.63.64.180/3048.63.64.181 to 48.63.64.18248.63.64.1832
4748.63.64.184/3048.63.64.185 to 48.63.64.18648.63.64.1872
4848.63.64.188/3048.63.64.189 to 48.63.64.19048.63.64.1912
4948.63.64.192/3048.63.64.193 to 48.63.64.19448.63.64.1952
5048.63.64.196/3048.63.64.197 to 48.63.64.19848.63.64.1992
5148.63.64.200/3048.63.64.201 to 48.63.64.20248.63.64.2032
5248.63.64.204/3048.63.64.205 to 48.63.64.20648.63.64.2072
5348.63.64.208/3048.63.64.209 to 48.63.64.21048.63.64.2112
5448.63.64.212/3048.63.64.213 to 48.63.64.21448.63.64.2152
5548.63.64.216/3048.63.64.217 to 48.63.64.21848.63.64.2192
5648.63.64.220/3048.63.64.221 to 48.63.64.22248.63.64.2232
5748.63.64.224/3048.63.64.225 to 48.63.64.22648.63.64.2272
5848.63.64.228/3048.63.64.229 to 48.63.64.23048.63.64.2312
5948.63.64.232/3048.63.64.233 to 48.63.64.23448.63.64.2352
6048.63.64.236/3048.63.64.237 to 48.63.64.23848.63.64.2392
6148.63.64.240/3048.63.64.241 to 48.63.64.24248.63.64.2432
6248.63.64.244/3048.63.64.245 to 48.63.64.24648.63.64.2472
6348.63.64.248/3048.63.64.249 to 48.63.64.25048.63.64.2512
6448.63.64.252/3048.63.64.253 to 48.63.64.25448.63.64.2552
6548.63.65.0/3048.63.65.1 to 48.63.65.248.63.65.32
6648.63.65.4/3048.63.65.5 to 48.63.65.648.63.65.72
6748.63.65.8/3048.63.65.9 to 48.63.65.1048.63.65.112
6848.63.65.12/3048.63.65.13 to 48.63.65.1448.63.65.152
6948.63.65.16/3048.63.65.17 to 48.63.65.1848.63.65.192
7048.63.65.20/3048.63.65.21 to 48.63.65.2248.63.65.232
7148.63.65.24/3048.63.65.25 to 48.63.65.2648.63.65.272
7248.63.65.28/3048.63.65.29 to 48.63.65.3048.63.65.312
7348.63.65.32/3048.63.65.33 to 48.63.65.3448.63.65.352
7448.63.65.36/3048.63.65.37 to 48.63.65.3848.63.65.392
7548.63.65.40/3048.63.65.41 to 48.63.65.4248.63.65.432
7648.63.65.44/3048.63.65.45 to 48.63.65.4648.63.65.472
7748.63.65.48/3048.63.65.49 to 48.63.65.5048.63.65.512
7848.63.65.52/3048.63.65.53 to 48.63.65.5448.63.65.552
7948.63.65.56/3048.63.65.57 to 48.63.65.5848.63.65.592
8048.63.65.60/3048.63.65.61 to 48.63.65.6248.63.65.632
8148.63.65.64/3048.63.65.65 to 48.63.65.6648.63.65.672
8248.63.65.68/3048.63.65.69 to 48.63.65.7048.63.65.712
8348.63.65.72/3048.63.65.73 to 48.63.65.7448.63.65.752
8448.63.65.76/3048.63.65.77 to 48.63.65.7848.63.65.792
8548.63.65.80/3048.63.65.81 to 48.63.65.8248.63.65.832
8648.63.65.84/3048.63.65.85 to 48.63.65.8648.63.65.872
8748.63.65.88/3048.63.65.89 to 48.63.65.9048.63.65.912
8848.63.65.92/3048.63.65.93 to 48.63.65.9448.63.65.952
8948.63.65.96/3048.63.65.97 to 48.63.65.9848.63.65.992
9048.63.65.100/3048.63.65.101 to 48.63.65.10248.63.65.1032
9148.63.65.104/3048.63.65.105 to 48.63.65.10648.63.65.1072
9248.63.65.108/3048.63.65.109 to 48.63.65.11048.63.65.1112
9348.63.65.112/3048.63.65.113 to 48.63.65.11448.63.65.1152
9448.63.65.116/3048.63.65.117 to 48.63.65.11848.63.65.1192
9548.63.65.120/3048.63.65.121 to 48.63.65.12248.63.65.1232
9648.63.65.124/3048.63.65.125 to 48.63.65.12648.63.65.1272
9748.63.65.128/3048.63.65.129 to 48.63.65.13048.63.65.1312
9848.63.65.132/3048.63.65.133 to 48.63.65.13448.63.65.1352
9948.63.65.136/3048.63.65.137 to 48.63.65.13848.63.65.1392
10048.63.65.140/3048.63.65.141 to 48.63.65.14248.63.65.1432
10148.63.65.144/3048.63.65.145 to 48.63.65.14648.63.65.1472
10248.63.65.148/3048.63.65.149 to 48.63.65.15048.63.65.1512
10348.63.65.152/3048.63.65.153 to 48.63.65.15448.63.65.1552
10448.63.65.156/3048.63.65.157 to 48.63.65.15848.63.65.1592
10548.63.65.160/3048.63.65.161 to 48.63.65.16248.63.65.1632
10648.63.65.164/3048.63.65.165 to 48.63.65.16648.63.65.1672
10748.63.65.168/3048.63.65.169 to 48.63.65.17048.63.65.1712
10848.63.65.172/3048.63.65.173 to 48.63.65.17448.63.65.1752
10948.63.65.176/3048.63.65.177 to 48.63.65.17848.63.65.1792
11048.63.65.180/3048.63.65.181 to 48.63.65.18248.63.65.1832
11148.63.65.184/3048.63.65.185 to 48.63.65.18648.63.65.1872
11248.63.65.188/3048.63.65.189 to 48.63.65.19048.63.65.1912
11348.63.65.192/3048.63.65.193 to 48.63.65.19448.63.65.1952
11448.63.65.196/3048.63.65.197 to 48.63.65.19848.63.65.1992
11548.63.65.200/3048.63.65.201 to 48.63.65.20248.63.65.2032
11648.63.65.204/3048.63.65.205 to 48.63.65.20648.63.65.2072
11748.63.65.208/3048.63.65.209 to 48.63.65.21048.63.65.2112
11848.63.65.212/3048.63.65.213 to 48.63.65.21448.63.65.2152
11948.63.65.216/3048.63.65.217 to 48.63.65.21848.63.65.2192
12048.63.65.220/3048.63.65.221 to 48.63.65.22248.63.65.2232
12148.63.65.224/3048.63.65.225 to 48.63.65.22648.63.65.2272
12248.63.65.228/3048.63.65.229 to 48.63.65.23048.63.65.2312
12348.63.65.232/3048.63.65.233 to 48.63.65.23448.63.65.2352
12448.63.65.236/3048.63.65.237 to 48.63.65.23848.63.65.2392
12548.63.65.240/3048.63.65.241 to 48.63.65.24248.63.65.2432
12648.63.65.244/3048.63.65.245 to 48.63.65.24648.63.65.2472
12748.63.65.248/3048.63.65.249 to 48.63.65.25048.63.65.2512
12848.63.65.252/3048.63.65.253 to 48.63.65.25448.63.65.2552
12948.63.66.0/3048.63.66.1 to 48.63.66.248.63.66.32
13048.63.66.4/3048.63.66.5 to 48.63.66.648.63.66.72
13148.63.66.8/3048.63.66.9 to 48.63.66.1048.63.66.112
13248.63.66.12/3048.63.66.13 to 48.63.66.1448.63.66.152
13348.63.66.16/3048.63.66.17 to 48.63.66.1848.63.66.192
13448.63.66.20/3048.63.66.21 to 48.63.66.2248.63.66.232
13548.63.66.24/3048.63.66.25 to 48.63.66.2648.63.66.272
13648.63.66.28/3048.63.66.29 to 48.63.66.3048.63.66.312
13748.63.66.32/3048.63.66.33 to 48.63.66.3448.63.66.352
13848.63.66.36/3048.63.66.37 to 48.63.66.3848.63.66.392
13948.63.66.40/3048.63.66.41 to 48.63.66.4248.63.66.432
14048.63.66.44/3048.63.66.45 to 48.63.66.4648.63.66.472
14148.63.66.48/3048.63.66.49 to 48.63.66.5048.63.66.512
14248.63.66.52/3048.63.66.53 to 48.63.66.5448.63.66.552
14348.63.66.56/3048.63.66.57 to 48.63.66.5848.63.66.592
14448.63.66.60/3048.63.66.61 to 48.63.66.6248.63.66.632
14548.63.66.64/3048.63.66.65 to 48.63.66.6648.63.66.672
14648.63.66.68/3048.63.66.69 to 48.63.66.7048.63.66.712
14748.63.66.72/3048.63.66.73 to 48.63.66.7448.63.66.752
14848.63.66.76/3048.63.66.77 to 48.63.66.7848.63.66.792
14948.63.66.80/3048.63.66.81 to 48.63.66.8248.63.66.832
15048.63.66.84/3048.63.66.85 to 48.63.66.8648.63.66.872
15148.63.66.88/3048.63.66.89 to 48.63.66.9048.63.66.912
15248.63.66.92/3048.63.66.93 to 48.63.66.9448.63.66.952
15348.63.66.96/3048.63.66.97 to 48.63.66.9848.63.66.992
15448.63.66.100/3048.63.66.101 to 48.63.66.10248.63.66.1032
15548.63.66.104/3048.63.66.105 to 48.63.66.10648.63.66.1072
15648.63.66.108/3048.63.66.109 to 48.63.66.11048.63.66.1112
15748.63.66.112/3048.63.66.113 to 48.63.66.11448.63.66.1152
15848.63.66.116/3048.63.66.117 to 48.63.66.11848.63.66.1192
15948.63.66.120/3048.63.66.121 to 48.63.66.12248.63.66.1232
16048.63.66.124/3048.63.66.125 to 48.63.66.12648.63.66.1272
16148.63.66.128/3048.63.66.129 to 48.63.66.13048.63.66.1312
16248.63.66.132/3048.63.66.133 to 48.63.66.13448.63.66.1352
16348.63.66.136/3048.63.66.137 to 48.63.66.13848.63.66.1392
16448.63.66.140/3048.63.66.141 to 48.63.66.14248.63.66.1432
16548.63.66.144/3048.63.66.145 to 48.63.66.14648.63.66.1472
16648.63.66.148/3048.63.66.149 to 48.63.66.15048.63.66.1512
16748.63.66.152/3048.63.66.153 to 48.63.66.15448.63.66.1552
16848.63.66.156/3048.63.66.157 to 48.63.66.15848.63.66.1592
16948.63.66.160/3048.63.66.161 to 48.63.66.16248.63.66.1632
17048.63.66.164/3048.63.66.165 to 48.63.66.16648.63.66.1672
17148.63.66.168/3048.63.66.169 to 48.63.66.17048.63.66.1712
17248.63.66.172/3048.63.66.173 to 48.63.66.17448.63.66.1752
17348.63.66.176/3048.63.66.177 to 48.63.66.17848.63.66.1792
17448.63.66.180/3048.63.66.181 to 48.63.66.18248.63.66.1832
17548.63.66.184/3048.63.66.185 to 48.63.66.18648.63.66.1872
17648.63.66.188/3048.63.66.189 to 48.63.66.19048.63.66.1912
17748.63.66.192/3048.63.66.193 to 48.63.66.19448.63.66.1952
17848.63.66.196/3048.63.66.197 to 48.63.66.19848.63.66.1992
17948.63.66.200/3048.63.66.201 to 48.63.66.20248.63.66.2032
18048.63.66.204/3048.63.66.205 to 48.63.66.20648.63.66.2072
18148.63.66.208/3048.63.66.209 to 48.63.66.21048.63.66.2112
18248.63.66.212/3048.63.66.213 to 48.63.66.21448.63.66.2152
18348.63.66.216/3048.63.66.217 to 48.63.66.21848.63.66.2192
18448.63.66.220/3048.63.66.221 to 48.63.66.22248.63.66.2232
18548.63.66.224/3048.63.66.225 to 48.63.66.22648.63.66.2272
18648.63.66.228/3048.63.66.229 to 48.63.66.23048.63.66.2312
18748.63.66.232/3048.63.66.233 to 48.63.66.23448.63.66.2352
18848.63.66.236/3048.63.66.237 to 48.63.66.23848.63.66.2392
18948.63.66.240/3048.63.66.241 to 48.63.66.24248.63.66.2432
19048.63.66.244/3048.63.66.245 to 48.63.66.24648.63.66.2472
19148.63.66.248/3048.63.66.249 to 48.63.66.25048.63.66.2512
19248.63.66.252/3048.63.66.253 to 48.63.66.25448.63.66.2552
19348.63.67.0/3048.63.67.1 to 48.63.67.248.63.67.32
19448.63.67.4/3048.63.67.5 to 48.63.67.648.63.67.72
19548.63.67.8/3048.63.67.9 to 48.63.67.1048.63.67.112
19648.63.67.12/3048.63.67.13 to 48.63.67.1448.63.67.152
19748.63.67.16/3048.63.67.17 to 48.63.67.1848.63.67.192
19848.63.67.20/3048.63.67.21 to 48.63.67.2248.63.67.232
19948.63.67.24/3048.63.67.25 to 48.63.67.2648.63.67.272
20048.63.67.28/3048.63.67.29 to 48.63.67.3048.63.67.312
20148.63.67.32/3048.63.67.33 to 48.63.67.3448.63.67.352
20248.63.67.36/3048.63.67.37 to 48.63.67.3848.63.67.392
20348.63.67.40/3048.63.67.41 to 48.63.67.4248.63.67.432
20448.63.67.44/3048.63.67.45 to 48.63.67.4648.63.67.472
20548.63.67.48/3048.63.67.49 to 48.63.67.5048.63.67.512
20648.63.67.52/3048.63.67.53 to 48.63.67.5448.63.67.552
20748.63.67.56/3048.63.67.57 to 48.63.67.5848.63.67.592
20848.63.67.60/3048.63.67.61 to 48.63.67.6248.63.67.632
20948.63.67.64/3048.63.67.65 to 48.63.67.6648.63.67.672
21048.63.67.68/3048.63.67.69 to 48.63.67.7048.63.67.712
21148.63.67.72/3048.63.67.73 to 48.63.67.7448.63.67.752
21248.63.67.76/3048.63.67.77 to 48.63.67.7848.63.67.792
21348.63.67.80/3048.63.67.81 to 48.63.67.8248.63.67.832
21448.63.67.84/3048.63.67.85 to 48.63.67.8648.63.67.872
21548.63.67.88/3048.63.67.89 to 48.63.67.9048.63.67.912
21648.63.67.92/3048.63.67.93 to 48.63.67.9448.63.67.952
21748.63.67.96/3048.63.67.97 to 48.63.67.9848.63.67.992
21848.63.67.100/3048.63.67.101 to 48.63.67.10248.63.67.1032
21948.63.67.104/3048.63.67.105 to 48.63.67.10648.63.67.1072
22048.63.67.108/3048.63.67.109 to 48.63.67.11048.63.67.1112
22148.63.67.112/3048.63.67.113 to 48.63.67.11448.63.67.1152
22248.63.67.116/3048.63.67.117 to 48.63.67.11848.63.67.1192
22348.63.67.120/3048.63.67.121 to 48.63.67.12248.63.67.1232
22448.63.67.124/3048.63.67.125 to 48.63.67.12648.63.67.1272
22548.63.67.128/3048.63.67.129 to 48.63.67.13048.63.67.1312
22648.63.67.132/3048.63.67.133 to 48.63.67.13448.63.67.1352
22748.63.67.136/3048.63.67.137 to 48.63.67.13848.63.67.1392
22848.63.67.140/3048.63.67.141 to 48.63.67.14248.63.67.1432
22948.63.67.144/3048.63.67.145 to 48.63.67.14648.63.67.1472
23048.63.67.148/3048.63.67.149 to 48.63.67.15048.63.67.1512
23148.63.67.152/3048.63.67.153 to 48.63.67.15448.63.67.1552
23248.63.67.156/3048.63.67.157 to 48.63.67.15848.63.67.1592
23348.63.67.160/3048.63.67.161 to 48.63.67.16248.63.67.1632
23448.63.67.164/3048.63.67.165 to 48.63.67.16648.63.67.1672
23548.63.67.168/3048.63.67.169 to 48.63.67.17048.63.67.1712
23648.63.67.172/3048.63.67.173 to 48.63.67.17448.63.67.1752
23748.63.67.176/3048.63.67.177 to 48.63.67.17848.63.67.1792
23848.63.67.180/3048.63.67.181 to 48.63.67.18248.63.67.1832
23948.63.67.184/3048.63.67.185 to 48.63.67.18648.63.67.1872
24048.63.67.188/3048.63.67.189 to 48.63.67.19048.63.67.1912
24148.63.67.192/3048.63.67.193 to 48.63.67.19448.63.67.1952
24248.63.67.196/3048.63.67.197 to 48.63.67.19848.63.67.1992
24348.63.67.200/3048.63.67.201 to 48.63.67.20248.63.67.2032
24448.63.67.204/3048.63.67.205 to 48.63.67.20648.63.67.2072
24548.63.67.208/3048.63.67.209 to 48.63.67.21048.63.67.2112
24648.63.67.212/3048.63.67.213 to 48.63.67.21448.63.67.2152
24748.63.67.216/3048.63.67.217 to 48.63.67.21848.63.67.2192
24848.63.67.220/3048.63.67.221 to 48.63.67.22248.63.67.2232
24948.63.67.224/3048.63.67.225 to 48.63.67.22648.63.67.2272
25048.63.67.228/3048.63.67.229 to 48.63.67.23048.63.67.2312
25148.63.67.232/3048.63.67.233 to 48.63.67.23448.63.67.2352
25248.63.67.236/3048.63.67.237 to 48.63.67.23848.63.67.2392
25348.63.67.240/3048.63.67.241 to 48.63.67.24248.63.67.2432
25448.63.67.244/3048.63.67.245 to 48.63.67.24648.63.67.2472
25548.63.67.248/3048.63.67.249 to 48.63.67.25048.63.67.2512
25648.63.67.252/3048.63.67.253 to 48.63.67.25448.63.67.2552

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.