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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.

Network86.7.48.0/20
Usable hosts4,094
Subnet mask255.255.240.0
Addresses4,096
Network address
86.7.48.0
Broadcast address
86.7.63.255
First usable
86.7.48.1
Last usable
86.7.63.254
Usable hosts
4,094 (4,096 less the network and broadcast addresses)
Subnet mask
255.255.240.0
Wildcard mask
0.0.15.255 (Cisco ACLs, OSPF)
Prefix length
/20
Type
Public public
Old class
A (default /8)
As numbers
Hex 56073000 · Integer 1443311616 to 1443315711
Reverse DNS zones
48.7.86.in-addr.arpa
49.7.86.in-addr.arpa
50.7.86.in-addr.arpa
51.7.86.in-addr.arpa
52.7.86.in-addr.arpa
53.7.86.in-addr.arpa
54.7.86.in-addr.arpa
55.7.86.in-addr.arpa
56.7.86.in-addr.arpa
57.7.86.in-addr.arpa
58.7.86.in-addr.arpa
59.7.86.in-addr.arpa
60.7.86.in-addr.arpa
61.7.86.in-addr.arpa
62.7.86.in-addr.arpa
63.7.86.in-addr.arpa
/20 is not on a 8-bit boundary, so it takes 16 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01010110.00000111.00110000.0000000086.7.48.0
Subnet mask11111111.11111111.11110000.00000000255.255.240.0
Network01010110.00000111.00110000.0000000086.7.48.0
Broadcast01010110.00000111.00111111.1111111186.7.63.255
Split into smaller subnets/32
/21 (2)/22 (4)/23 (8)/24 (16)/25 (32)/26 (64)/27 (128)/28 (256)/29 (512)/30 (1,024)/31 (2,048)/32 (4,096)

86.7.48.0/20 makes 4,096 subnets of /32; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
186.7.48.0/3286.7.48.0 to 86.7.48.0—1
286.7.48.1/3286.7.48.1 to 86.7.48.1—1
386.7.48.2/3286.7.48.2 to 86.7.48.2—1
486.7.48.3/3286.7.48.3 to 86.7.48.3—1
586.7.48.4/3286.7.48.4 to 86.7.48.4—1
686.7.48.5/3286.7.48.5 to 86.7.48.5—1
786.7.48.6/3286.7.48.6 to 86.7.48.6—1
886.7.48.7/3286.7.48.7 to 86.7.48.7—1
986.7.48.8/3286.7.48.8 to 86.7.48.8—1
1086.7.48.9/3286.7.48.9 to 86.7.48.9—1
1186.7.48.10/3286.7.48.10 to 86.7.48.10—1
1286.7.48.11/3286.7.48.11 to 86.7.48.11—1
1386.7.48.12/3286.7.48.12 to 86.7.48.12—1
1486.7.48.13/3286.7.48.13 to 86.7.48.13—1
1586.7.48.14/3286.7.48.14 to 86.7.48.14—1
1686.7.48.15/3286.7.48.15 to 86.7.48.15—1
1786.7.48.16/3286.7.48.16 to 86.7.48.16—1
1886.7.48.17/3286.7.48.17 to 86.7.48.17—1
1986.7.48.18/3286.7.48.18 to 86.7.48.18—1
2086.7.48.19/3286.7.48.19 to 86.7.48.19—1
2186.7.48.20/3286.7.48.20 to 86.7.48.20—1
2286.7.48.21/3286.7.48.21 to 86.7.48.21—1
2386.7.48.22/3286.7.48.22 to 86.7.48.22—1
2486.7.48.23/3286.7.48.23 to 86.7.48.23—1
2586.7.48.24/3286.7.48.24 to 86.7.48.24—1
2686.7.48.25/3286.7.48.25 to 86.7.48.25—1
2786.7.48.26/3286.7.48.26 to 86.7.48.26—1
2886.7.48.27/3286.7.48.27 to 86.7.48.27—1
2986.7.48.28/3286.7.48.28 to 86.7.48.28—1
3086.7.48.29/3286.7.48.29 to 86.7.48.29—1
3186.7.48.30/3286.7.48.30 to 86.7.48.30—1
3286.7.48.31/3286.7.48.31 to 86.7.48.31—1
3386.7.48.32/3286.7.48.32 to 86.7.48.32—1
3486.7.48.33/3286.7.48.33 to 86.7.48.33—1
3586.7.48.34/3286.7.48.34 to 86.7.48.34—1
3686.7.48.35/3286.7.48.35 to 86.7.48.35—1
3786.7.48.36/3286.7.48.36 to 86.7.48.36—1
3886.7.48.37/3286.7.48.37 to 86.7.48.37—1
3986.7.48.38/3286.7.48.38 to 86.7.48.38—1
4086.7.48.39/3286.7.48.39 to 86.7.48.39—1
4186.7.48.40/3286.7.48.40 to 86.7.48.40—1
4286.7.48.41/3286.7.48.41 to 86.7.48.41—1
4386.7.48.42/3286.7.48.42 to 86.7.48.42—1
4486.7.48.43/3286.7.48.43 to 86.7.48.43—1
4586.7.48.44/3286.7.48.44 to 86.7.48.44—1
4686.7.48.45/3286.7.48.45 to 86.7.48.45—1
4786.7.48.46/3286.7.48.46 to 86.7.48.46—1
4886.7.48.47/3286.7.48.47 to 86.7.48.47—1
4986.7.48.48/3286.7.48.48 to 86.7.48.48—1
5086.7.48.49/3286.7.48.49 to 86.7.48.49—1
5186.7.48.50/3286.7.48.50 to 86.7.48.50—1
5286.7.48.51/3286.7.48.51 to 86.7.48.51—1
5386.7.48.52/3286.7.48.52 to 86.7.48.52—1
5486.7.48.53/3286.7.48.53 to 86.7.48.53—1
5586.7.48.54/3286.7.48.54 to 86.7.48.54—1
5686.7.48.55/3286.7.48.55 to 86.7.48.55—1
5786.7.48.56/3286.7.48.56 to 86.7.48.56—1
5886.7.48.57/3286.7.48.57 to 86.7.48.57—1
5986.7.48.58/3286.7.48.58 to 86.7.48.58—1
6086.7.48.59/3286.7.48.59 to 86.7.48.59—1
6186.7.48.60/3286.7.48.60 to 86.7.48.60—1
6286.7.48.61/3286.7.48.61 to 86.7.48.61—1
6386.7.48.62/3286.7.48.62 to 86.7.48.62—1
6486.7.48.63/3286.7.48.63 to 86.7.48.63—1
6586.7.48.64/3286.7.48.64 to 86.7.48.64—1
6686.7.48.65/3286.7.48.65 to 86.7.48.65—1
6786.7.48.66/3286.7.48.66 to 86.7.48.66—1
6886.7.48.67/3286.7.48.67 to 86.7.48.67—1
6986.7.48.68/3286.7.48.68 to 86.7.48.68—1
7086.7.48.69/3286.7.48.69 to 86.7.48.69—1
7186.7.48.70/3286.7.48.70 to 86.7.48.70—1
7286.7.48.71/3286.7.48.71 to 86.7.48.71—1
7386.7.48.72/3286.7.48.72 to 86.7.48.72—1
7486.7.48.73/3286.7.48.73 to 86.7.48.73—1
7586.7.48.74/3286.7.48.74 to 86.7.48.74—1
7686.7.48.75/3286.7.48.75 to 86.7.48.75—1
7786.7.48.76/3286.7.48.76 to 86.7.48.76—1
7886.7.48.77/3286.7.48.77 to 86.7.48.77—1
7986.7.48.78/3286.7.48.78 to 86.7.48.78—1
8086.7.48.79/3286.7.48.79 to 86.7.48.79—1
8186.7.48.80/3286.7.48.80 to 86.7.48.80—1
8286.7.48.81/3286.7.48.81 to 86.7.48.81—1
8386.7.48.82/3286.7.48.82 to 86.7.48.82—1
8486.7.48.83/3286.7.48.83 to 86.7.48.83—1
8586.7.48.84/3286.7.48.84 to 86.7.48.84—1
8686.7.48.85/3286.7.48.85 to 86.7.48.85—1
8786.7.48.86/3286.7.48.86 to 86.7.48.86—1
8886.7.48.87/3286.7.48.87 to 86.7.48.87—1
8986.7.48.88/3286.7.48.88 to 86.7.48.88—1
9086.7.48.89/3286.7.48.89 to 86.7.48.89—1
9186.7.48.90/3286.7.48.90 to 86.7.48.90—1
9286.7.48.91/3286.7.48.91 to 86.7.48.91—1
9386.7.48.92/3286.7.48.92 to 86.7.48.92—1
9486.7.48.93/3286.7.48.93 to 86.7.48.93—1
9586.7.48.94/3286.7.48.94 to 86.7.48.94—1
9686.7.48.95/3286.7.48.95 to 86.7.48.95—1
9786.7.48.96/3286.7.48.96 to 86.7.48.96—1
9886.7.48.97/3286.7.48.97 to 86.7.48.97—1
9986.7.48.98/3286.7.48.98 to 86.7.48.98—1
10086.7.48.99/3286.7.48.99 to 86.7.48.99—1
10186.7.48.100/3286.7.48.100 to 86.7.48.100—1
10286.7.48.101/3286.7.48.101 to 86.7.48.101—1
10386.7.48.102/3286.7.48.102 to 86.7.48.102—1
10486.7.48.103/3286.7.48.103 to 86.7.48.103—1
10586.7.48.104/3286.7.48.104 to 86.7.48.104—1
10686.7.48.105/3286.7.48.105 to 86.7.48.105—1
10786.7.48.106/3286.7.48.106 to 86.7.48.106—1
10886.7.48.107/3286.7.48.107 to 86.7.48.107—1
10986.7.48.108/3286.7.48.108 to 86.7.48.108—1
11086.7.48.109/3286.7.48.109 to 86.7.48.109—1
11186.7.48.110/3286.7.48.110 to 86.7.48.110—1
11286.7.48.111/3286.7.48.111 to 86.7.48.111—1
11386.7.48.112/3286.7.48.112 to 86.7.48.112—1
11486.7.48.113/3286.7.48.113 to 86.7.48.113—1
11586.7.48.114/3286.7.48.114 to 86.7.48.114—1
11686.7.48.115/3286.7.48.115 to 86.7.48.115—1
11786.7.48.116/3286.7.48.116 to 86.7.48.116—1
11886.7.48.117/3286.7.48.117 to 86.7.48.117—1
11986.7.48.118/3286.7.48.118 to 86.7.48.118—1
12086.7.48.119/3286.7.48.119 to 86.7.48.119—1
12186.7.48.120/3286.7.48.120 to 86.7.48.120—1
12286.7.48.121/3286.7.48.121 to 86.7.48.121—1
12386.7.48.122/3286.7.48.122 to 86.7.48.122—1
12486.7.48.123/3286.7.48.123 to 86.7.48.123—1
12586.7.48.124/3286.7.48.124 to 86.7.48.124—1
12686.7.48.125/3286.7.48.125 to 86.7.48.125—1
12786.7.48.126/3286.7.48.126 to 86.7.48.126—1
12886.7.48.127/3286.7.48.127 to 86.7.48.127—1
12986.7.48.128/3286.7.48.128 to 86.7.48.128—1
13086.7.48.129/3286.7.48.129 to 86.7.48.129—1
13186.7.48.130/3286.7.48.130 to 86.7.48.130—1
13286.7.48.131/3286.7.48.131 to 86.7.48.131—1
13386.7.48.132/3286.7.48.132 to 86.7.48.132—1
13486.7.48.133/3286.7.48.133 to 86.7.48.133—1
13586.7.48.134/3286.7.48.134 to 86.7.48.134—1
13686.7.48.135/3286.7.48.135 to 86.7.48.135—1
13786.7.48.136/3286.7.48.136 to 86.7.48.136—1
13886.7.48.137/3286.7.48.137 to 86.7.48.137—1
13986.7.48.138/3286.7.48.138 to 86.7.48.138—1
14086.7.48.139/3286.7.48.139 to 86.7.48.139—1
14186.7.48.140/3286.7.48.140 to 86.7.48.140—1
14286.7.48.141/3286.7.48.141 to 86.7.48.141—1
14386.7.48.142/3286.7.48.142 to 86.7.48.142—1
14486.7.48.143/3286.7.48.143 to 86.7.48.143—1
14586.7.48.144/3286.7.48.144 to 86.7.48.144—1
14686.7.48.145/3286.7.48.145 to 86.7.48.145—1
14786.7.48.146/3286.7.48.146 to 86.7.48.146—1
14886.7.48.147/3286.7.48.147 to 86.7.48.147—1
14986.7.48.148/3286.7.48.148 to 86.7.48.148—1
15086.7.48.149/3286.7.48.149 to 86.7.48.149—1
15186.7.48.150/3286.7.48.150 to 86.7.48.150—1
15286.7.48.151/3286.7.48.151 to 86.7.48.151—1
15386.7.48.152/3286.7.48.152 to 86.7.48.152—1
15486.7.48.153/3286.7.48.153 to 86.7.48.153—1
15586.7.48.154/3286.7.48.154 to 86.7.48.154—1
15686.7.48.155/3286.7.48.155 to 86.7.48.155—1
15786.7.48.156/3286.7.48.156 to 86.7.48.156—1
15886.7.48.157/3286.7.48.157 to 86.7.48.157—1
15986.7.48.158/3286.7.48.158 to 86.7.48.158—1
16086.7.48.159/3286.7.48.159 to 86.7.48.159—1
16186.7.48.160/3286.7.48.160 to 86.7.48.160—1
16286.7.48.161/3286.7.48.161 to 86.7.48.161—1
16386.7.48.162/3286.7.48.162 to 86.7.48.162—1
16486.7.48.163/3286.7.48.163 to 86.7.48.163—1
16586.7.48.164/3286.7.48.164 to 86.7.48.164—1
16686.7.48.165/3286.7.48.165 to 86.7.48.165—1
16786.7.48.166/3286.7.48.166 to 86.7.48.166—1
16886.7.48.167/3286.7.48.167 to 86.7.48.167—1
16986.7.48.168/3286.7.48.168 to 86.7.48.168—1
17086.7.48.169/3286.7.48.169 to 86.7.48.169—1
17186.7.48.170/3286.7.48.170 to 86.7.48.170—1
17286.7.48.171/3286.7.48.171 to 86.7.48.171—1
17386.7.48.172/3286.7.48.172 to 86.7.48.172—1
17486.7.48.173/3286.7.48.173 to 86.7.48.173—1
17586.7.48.174/3286.7.48.174 to 86.7.48.174—1
17686.7.48.175/3286.7.48.175 to 86.7.48.175—1
17786.7.48.176/3286.7.48.176 to 86.7.48.176—1
17886.7.48.177/3286.7.48.177 to 86.7.48.177—1
17986.7.48.178/3286.7.48.178 to 86.7.48.178—1
18086.7.48.179/3286.7.48.179 to 86.7.48.179—1
18186.7.48.180/3286.7.48.180 to 86.7.48.180—1
18286.7.48.181/3286.7.48.181 to 86.7.48.181—1
18386.7.48.182/3286.7.48.182 to 86.7.48.182—1
18486.7.48.183/3286.7.48.183 to 86.7.48.183—1
18586.7.48.184/3286.7.48.184 to 86.7.48.184—1
18686.7.48.185/3286.7.48.185 to 86.7.48.185—1
18786.7.48.186/3286.7.48.186 to 86.7.48.186—1
18886.7.48.187/3286.7.48.187 to 86.7.48.187—1
18986.7.48.188/3286.7.48.188 to 86.7.48.188—1
19086.7.48.189/3286.7.48.189 to 86.7.48.189—1
19186.7.48.190/3286.7.48.190 to 86.7.48.190—1
19286.7.48.191/3286.7.48.191 to 86.7.48.191—1
19386.7.48.192/3286.7.48.192 to 86.7.48.192—1
19486.7.48.193/3286.7.48.193 to 86.7.48.193—1
19586.7.48.194/3286.7.48.194 to 86.7.48.194—1
19686.7.48.195/3286.7.48.195 to 86.7.48.195—1
19786.7.48.196/3286.7.48.196 to 86.7.48.196—1
19886.7.48.197/3286.7.48.197 to 86.7.48.197—1
19986.7.48.198/3286.7.48.198 to 86.7.48.198—1
20086.7.48.199/3286.7.48.199 to 86.7.48.199—1
20186.7.48.200/3286.7.48.200 to 86.7.48.200—1
20286.7.48.201/3286.7.48.201 to 86.7.48.201—1
20386.7.48.202/3286.7.48.202 to 86.7.48.202—1
20486.7.48.203/3286.7.48.203 to 86.7.48.203—1
20586.7.48.204/3286.7.48.204 to 86.7.48.204—1
20686.7.48.205/3286.7.48.205 to 86.7.48.205—1
20786.7.48.206/3286.7.48.206 to 86.7.48.206—1
20886.7.48.207/3286.7.48.207 to 86.7.48.207—1
20986.7.48.208/3286.7.48.208 to 86.7.48.208—1
21086.7.48.209/3286.7.48.209 to 86.7.48.209—1
21186.7.48.210/3286.7.48.210 to 86.7.48.210—1
21286.7.48.211/3286.7.48.211 to 86.7.48.211—1
21386.7.48.212/3286.7.48.212 to 86.7.48.212—1
21486.7.48.213/3286.7.48.213 to 86.7.48.213—1
21586.7.48.214/3286.7.48.214 to 86.7.48.214—1
21686.7.48.215/3286.7.48.215 to 86.7.48.215—1
21786.7.48.216/3286.7.48.216 to 86.7.48.216—1
21886.7.48.217/3286.7.48.217 to 86.7.48.217—1
21986.7.48.218/3286.7.48.218 to 86.7.48.218—1
22086.7.48.219/3286.7.48.219 to 86.7.48.219—1
22186.7.48.220/3286.7.48.220 to 86.7.48.220—1
22286.7.48.221/3286.7.48.221 to 86.7.48.221—1
22386.7.48.222/3286.7.48.222 to 86.7.48.222—1
22486.7.48.223/3286.7.48.223 to 86.7.48.223—1
22586.7.48.224/3286.7.48.224 to 86.7.48.224—1
22686.7.48.225/3286.7.48.225 to 86.7.48.225—1
22786.7.48.226/3286.7.48.226 to 86.7.48.226—1
22886.7.48.227/3286.7.48.227 to 86.7.48.227—1
22986.7.48.228/3286.7.48.228 to 86.7.48.228—1
23086.7.48.229/3286.7.48.229 to 86.7.48.229—1
23186.7.48.230/3286.7.48.230 to 86.7.48.230—1
23286.7.48.231/3286.7.48.231 to 86.7.48.231—1
23386.7.48.232/3286.7.48.232 to 86.7.48.232—1
23486.7.48.233/3286.7.48.233 to 86.7.48.233—1
23586.7.48.234/3286.7.48.234 to 86.7.48.234—1
23686.7.48.235/3286.7.48.235 to 86.7.48.235—1
23786.7.48.236/3286.7.48.236 to 86.7.48.236—1
23886.7.48.237/3286.7.48.237 to 86.7.48.237—1
23986.7.48.238/3286.7.48.238 to 86.7.48.238—1
24086.7.48.239/3286.7.48.239 to 86.7.48.239—1
24186.7.48.240/3286.7.48.240 to 86.7.48.240—1
24286.7.48.241/3286.7.48.241 to 86.7.48.241—1
24386.7.48.242/3286.7.48.242 to 86.7.48.242—1
24486.7.48.243/3286.7.48.243 to 86.7.48.243—1
24586.7.48.244/3286.7.48.244 to 86.7.48.244—1
24686.7.48.245/3286.7.48.245 to 86.7.48.245—1
24786.7.48.246/3286.7.48.246 to 86.7.48.246—1
24886.7.48.247/3286.7.48.247 to 86.7.48.247—1
24986.7.48.248/3286.7.48.248 to 86.7.48.248—1
25086.7.48.249/3286.7.48.249 to 86.7.48.249—1
25186.7.48.250/3286.7.48.250 to 86.7.48.250—1
25286.7.48.251/3286.7.48.251 to 86.7.48.251—1
25386.7.48.252/3286.7.48.252 to 86.7.48.252—1
25486.7.48.253/3286.7.48.253 to 86.7.48.253—1
25586.7.48.254/3286.7.48.254 to 86.7.48.254—1
25686.7.48.255/3286.7.48.255 to 86.7.48.255—1

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.