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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.

Network36.3.76.0/22
Usable hosts1,022
Subnet mask255.255.252.0
Addresses1,024
Network address
36.3.76.0
Broadcast address
36.3.79.255
First usable
36.3.76.1
Last usable
36.3.79.254
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 24034C00 · Integer 604195840 to 604196863
Reverse DNS zones
76.3.36.in-addr.arpa
77.3.36.in-addr.arpa
78.3.36.in-addr.arpa
79.3.36.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
Address00100100.00000011.01001100.0000000036.3.76.0
Subnet mask11111111.11111111.11111100.00000000255.255.252.0
Network00100100.00000011.01001100.0000000036.3.76.0
Broadcast00100100.00000011.01001111.1111111136.3.79.255
Split into smaller subnets/32
/23 (2)/24 (4)/25 (8)/26 (16)/27 (32)/28 (64)/29 (128)/30 (256)/31 (512)/32 (1,024)

36.3.76.0/22 makes 1,024 subnets of /32; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
136.3.76.0/3236.3.76.0 to 36.3.76.0—1
236.3.76.1/3236.3.76.1 to 36.3.76.1—1
336.3.76.2/3236.3.76.2 to 36.3.76.2—1
436.3.76.3/3236.3.76.3 to 36.3.76.3—1
536.3.76.4/3236.3.76.4 to 36.3.76.4—1
636.3.76.5/3236.3.76.5 to 36.3.76.5—1
736.3.76.6/3236.3.76.6 to 36.3.76.6—1
836.3.76.7/3236.3.76.7 to 36.3.76.7—1
936.3.76.8/3236.3.76.8 to 36.3.76.8—1
1036.3.76.9/3236.3.76.9 to 36.3.76.9—1
1136.3.76.10/3236.3.76.10 to 36.3.76.10—1
1236.3.76.11/3236.3.76.11 to 36.3.76.11—1
1336.3.76.12/3236.3.76.12 to 36.3.76.12—1
1436.3.76.13/3236.3.76.13 to 36.3.76.13—1
1536.3.76.14/3236.3.76.14 to 36.3.76.14—1
1636.3.76.15/3236.3.76.15 to 36.3.76.15—1
1736.3.76.16/3236.3.76.16 to 36.3.76.16—1
1836.3.76.17/3236.3.76.17 to 36.3.76.17—1
1936.3.76.18/3236.3.76.18 to 36.3.76.18—1
2036.3.76.19/3236.3.76.19 to 36.3.76.19—1
2136.3.76.20/3236.3.76.20 to 36.3.76.20—1
2236.3.76.21/3236.3.76.21 to 36.3.76.21—1
2336.3.76.22/3236.3.76.22 to 36.3.76.22—1
2436.3.76.23/3236.3.76.23 to 36.3.76.23—1
2536.3.76.24/3236.3.76.24 to 36.3.76.24—1
2636.3.76.25/3236.3.76.25 to 36.3.76.25—1
2736.3.76.26/3236.3.76.26 to 36.3.76.26—1
2836.3.76.27/3236.3.76.27 to 36.3.76.27—1
2936.3.76.28/3236.3.76.28 to 36.3.76.28—1
3036.3.76.29/3236.3.76.29 to 36.3.76.29—1
3136.3.76.30/3236.3.76.30 to 36.3.76.30—1
3236.3.76.31/3236.3.76.31 to 36.3.76.31—1
3336.3.76.32/3236.3.76.32 to 36.3.76.32—1
3436.3.76.33/3236.3.76.33 to 36.3.76.33—1
3536.3.76.34/3236.3.76.34 to 36.3.76.34—1
3636.3.76.35/3236.3.76.35 to 36.3.76.35—1
3736.3.76.36/3236.3.76.36 to 36.3.76.36—1
3836.3.76.37/3236.3.76.37 to 36.3.76.37—1
3936.3.76.38/3236.3.76.38 to 36.3.76.38—1
4036.3.76.39/3236.3.76.39 to 36.3.76.39—1
4136.3.76.40/3236.3.76.40 to 36.3.76.40—1
4236.3.76.41/3236.3.76.41 to 36.3.76.41—1
4336.3.76.42/3236.3.76.42 to 36.3.76.42—1
4436.3.76.43/3236.3.76.43 to 36.3.76.43—1
4536.3.76.44/3236.3.76.44 to 36.3.76.44—1
4636.3.76.45/3236.3.76.45 to 36.3.76.45—1
4736.3.76.46/3236.3.76.46 to 36.3.76.46—1
4836.3.76.47/3236.3.76.47 to 36.3.76.47—1
4936.3.76.48/3236.3.76.48 to 36.3.76.48—1
5036.3.76.49/3236.3.76.49 to 36.3.76.49—1
5136.3.76.50/3236.3.76.50 to 36.3.76.50—1
5236.3.76.51/3236.3.76.51 to 36.3.76.51—1
5336.3.76.52/3236.3.76.52 to 36.3.76.52—1
5436.3.76.53/3236.3.76.53 to 36.3.76.53—1
5536.3.76.54/3236.3.76.54 to 36.3.76.54—1
5636.3.76.55/3236.3.76.55 to 36.3.76.55—1
5736.3.76.56/3236.3.76.56 to 36.3.76.56—1
5836.3.76.57/3236.3.76.57 to 36.3.76.57—1
5936.3.76.58/3236.3.76.58 to 36.3.76.58—1
6036.3.76.59/3236.3.76.59 to 36.3.76.59—1
6136.3.76.60/3236.3.76.60 to 36.3.76.60—1
6236.3.76.61/3236.3.76.61 to 36.3.76.61—1
6336.3.76.62/3236.3.76.62 to 36.3.76.62—1
6436.3.76.63/3236.3.76.63 to 36.3.76.63—1
6536.3.76.64/3236.3.76.64 to 36.3.76.64—1
6636.3.76.65/3236.3.76.65 to 36.3.76.65—1
6736.3.76.66/3236.3.76.66 to 36.3.76.66—1
6836.3.76.67/3236.3.76.67 to 36.3.76.67—1
6936.3.76.68/3236.3.76.68 to 36.3.76.68—1
7036.3.76.69/3236.3.76.69 to 36.3.76.69—1
7136.3.76.70/3236.3.76.70 to 36.3.76.70—1
7236.3.76.71/3236.3.76.71 to 36.3.76.71—1
7336.3.76.72/3236.3.76.72 to 36.3.76.72—1
7436.3.76.73/3236.3.76.73 to 36.3.76.73—1
7536.3.76.74/3236.3.76.74 to 36.3.76.74—1
7636.3.76.75/3236.3.76.75 to 36.3.76.75—1
7736.3.76.76/3236.3.76.76 to 36.3.76.76—1
7836.3.76.77/3236.3.76.77 to 36.3.76.77—1
7936.3.76.78/3236.3.76.78 to 36.3.76.78—1
8036.3.76.79/3236.3.76.79 to 36.3.76.79—1
8136.3.76.80/3236.3.76.80 to 36.3.76.80—1
8236.3.76.81/3236.3.76.81 to 36.3.76.81—1
8336.3.76.82/3236.3.76.82 to 36.3.76.82—1
8436.3.76.83/3236.3.76.83 to 36.3.76.83—1
8536.3.76.84/3236.3.76.84 to 36.3.76.84—1
8636.3.76.85/3236.3.76.85 to 36.3.76.85—1
8736.3.76.86/3236.3.76.86 to 36.3.76.86—1
8836.3.76.87/3236.3.76.87 to 36.3.76.87—1
8936.3.76.88/3236.3.76.88 to 36.3.76.88—1
9036.3.76.89/3236.3.76.89 to 36.3.76.89—1
9136.3.76.90/3236.3.76.90 to 36.3.76.90—1
9236.3.76.91/3236.3.76.91 to 36.3.76.91—1
9336.3.76.92/3236.3.76.92 to 36.3.76.92—1
9436.3.76.93/3236.3.76.93 to 36.3.76.93—1
9536.3.76.94/3236.3.76.94 to 36.3.76.94—1
9636.3.76.95/3236.3.76.95 to 36.3.76.95—1
9736.3.76.96/3236.3.76.96 to 36.3.76.96—1
9836.3.76.97/3236.3.76.97 to 36.3.76.97—1
9936.3.76.98/3236.3.76.98 to 36.3.76.98—1
10036.3.76.99/3236.3.76.99 to 36.3.76.99—1
10136.3.76.100/3236.3.76.100 to 36.3.76.100—1
10236.3.76.101/3236.3.76.101 to 36.3.76.101—1
10336.3.76.102/3236.3.76.102 to 36.3.76.102—1
10436.3.76.103/3236.3.76.103 to 36.3.76.103—1
10536.3.76.104/3236.3.76.104 to 36.3.76.104—1
10636.3.76.105/3236.3.76.105 to 36.3.76.105—1
10736.3.76.106/3236.3.76.106 to 36.3.76.106—1
10836.3.76.107/3236.3.76.107 to 36.3.76.107—1
10936.3.76.108/3236.3.76.108 to 36.3.76.108—1
11036.3.76.109/3236.3.76.109 to 36.3.76.109—1
11136.3.76.110/3236.3.76.110 to 36.3.76.110—1
11236.3.76.111/3236.3.76.111 to 36.3.76.111—1
11336.3.76.112/3236.3.76.112 to 36.3.76.112—1
11436.3.76.113/3236.3.76.113 to 36.3.76.113—1
11536.3.76.114/3236.3.76.114 to 36.3.76.114—1
11636.3.76.115/3236.3.76.115 to 36.3.76.115—1
11736.3.76.116/3236.3.76.116 to 36.3.76.116—1
11836.3.76.117/3236.3.76.117 to 36.3.76.117—1
11936.3.76.118/3236.3.76.118 to 36.3.76.118—1
12036.3.76.119/3236.3.76.119 to 36.3.76.119—1
12136.3.76.120/3236.3.76.120 to 36.3.76.120—1
12236.3.76.121/3236.3.76.121 to 36.3.76.121—1
12336.3.76.122/3236.3.76.122 to 36.3.76.122—1
12436.3.76.123/3236.3.76.123 to 36.3.76.123—1
12536.3.76.124/3236.3.76.124 to 36.3.76.124—1
12636.3.76.125/3236.3.76.125 to 36.3.76.125—1
12736.3.76.126/3236.3.76.126 to 36.3.76.126—1
12836.3.76.127/3236.3.76.127 to 36.3.76.127—1
12936.3.76.128/3236.3.76.128 to 36.3.76.128—1
13036.3.76.129/3236.3.76.129 to 36.3.76.129—1
13136.3.76.130/3236.3.76.130 to 36.3.76.130—1
13236.3.76.131/3236.3.76.131 to 36.3.76.131—1
13336.3.76.132/3236.3.76.132 to 36.3.76.132—1
13436.3.76.133/3236.3.76.133 to 36.3.76.133—1
13536.3.76.134/3236.3.76.134 to 36.3.76.134—1
13636.3.76.135/3236.3.76.135 to 36.3.76.135—1
13736.3.76.136/3236.3.76.136 to 36.3.76.136—1
13836.3.76.137/3236.3.76.137 to 36.3.76.137—1
13936.3.76.138/3236.3.76.138 to 36.3.76.138—1
14036.3.76.139/3236.3.76.139 to 36.3.76.139—1
14136.3.76.140/3236.3.76.140 to 36.3.76.140—1
14236.3.76.141/3236.3.76.141 to 36.3.76.141—1
14336.3.76.142/3236.3.76.142 to 36.3.76.142—1
14436.3.76.143/3236.3.76.143 to 36.3.76.143—1
14536.3.76.144/3236.3.76.144 to 36.3.76.144—1
14636.3.76.145/3236.3.76.145 to 36.3.76.145—1
14736.3.76.146/3236.3.76.146 to 36.3.76.146—1
14836.3.76.147/3236.3.76.147 to 36.3.76.147—1
14936.3.76.148/3236.3.76.148 to 36.3.76.148—1
15036.3.76.149/3236.3.76.149 to 36.3.76.149—1
15136.3.76.150/3236.3.76.150 to 36.3.76.150—1
15236.3.76.151/3236.3.76.151 to 36.3.76.151—1
15336.3.76.152/3236.3.76.152 to 36.3.76.152—1
15436.3.76.153/3236.3.76.153 to 36.3.76.153—1
15536.3.76.154/3236.3.76.154 to 36.3.76.154—1
15636.3.76.155/3236.3.76.155 to 36.3.76.155—1
15736.3.76.156/3236.3.76.156 to 36.3.76.156—1
15836.3.76.157/3236.3.76.157 to 36.3.76.157—1
15936.3.76.158/3236.3.76.158 to 36.3.76.158—1
16036.3.76.159/3236.3.76.159 to 36.3.76.159—1
16136.3.76.160/3236.3.76.160 to 36.3.76.160—1
16236.3.76.161/3236.3.76.161 to 36.3.76.161—1
16336.3.76.162/3236.3.76.162 to 36.3.76.162—1
16436.3.76.163/3236.3.76.163 to 36.3.76.163—1
16536.3.76.164/3236.3.76.164 to 36.3.76.164—1
16636.3.76.165/3236.3.76.165 to 36.3.76.165—1
16736.3.76.166/3236.3.76.166 to 36.3.76.166—1
16836.3.76.167/3236.3.76.167 to 36.3.76.167—1
16936.3.76.168/3236.3.76.168 to 36.3.76.168—1
17036.3.76.169/3236.3.76.169 to 36.3.76.169—1
17136.3.76.170/3236.3.76.170 to 36.3.76.170—1
17236.3.76.171/3236.3.76.171 to 36.3.76.171—1
17336.3.76.172/3236.3.76.172 to 36.3.76.172—1
17436.3.76.173/3236.3.76.173 to 36.3.76.173—1
17536.3.76.174/3236.3.76.174 to 36.3.76.174—1
17636.3.76.175/3236.3.76.175 to 36.3.76.175—1
17736.3.76.176/3236.3.76.176 to 36.3.76.176—1
17836.3.76.177/3236.3.76.177 to 36.3.76.177—1
17936.3.76.178/3236.3.76.178 to 36.3.76.178—1
18036.3.76.179/3236.3.76.179 to 36.3.76.179—1
18136.3.76.180/3236.3.76.180 to 36.3.76.180—1
18236.3.76.181/3236.3.76.181 to 36.3.76.181—1
18336.3.76.182/3236.3.76.182 to 36.3.76.182—1
18436.3.76.183/3236.3.76.183 to 36.3.76.183—1
18536.3.76.184/3236.3.76.184 to 36.3.76.184—1
18636.3.76.185/3236.3.76.185 to 36.3.76.185—1
18736.3.76.186/3236.3.76.186 to 36.3.76.186—1
18836.3.76.187/3236.3.76.187 to 36.3.76.187—1
18936.3.76.188/3236.3.76.188 to 36.3.76.188—1
19036.3.76.189/3236.3.76.189 to 36.3.76.189—1
19136.3.76.190/3236.3.76.190 to 36.3.76.190—1
19236.3.76.191/3236.3.76.191 to 36.3.76.191—1
19336.3.76.192/3236.3.76.192 to 36.3.76.192—1
19436.3.76.193/3236.3.76.193 to 36.3.76.193—1
19536.3.76.194/3236.3.76.194 to 36.3.76.194—1
19636.3.76.195/3236.3.76.195 to 36.3.76.195—1
19736.3.76.196/3236.3.76.196 to 36.3.76.196—1
19836.3.76.197/3236.3.76.197 to 36.3.76.197—1
19936.3.76.198/3236.3.76.198 to 36.3.76.198—1
20036.3.76.199/3236.3.76.199 to 36.3.76.199—1
20136.3.76.200/3236.3.76.200 to 36.3.76.200—1
20236.3.76.201/3236.3.76.201 to 36.3.76.201—1
20336.3.76.202/3236.3.76.202 to 36.3.76.202—1
20436.3.76.203/3236.3.76.203 to 36.3.76.203—1
20536.3.76.204/3236.3.76.204 to 36.3.76.204—1
20636.3.76.205/3236.3.76.205 to 36.3.76.205—1
20736.3.76.206/3236.3.76.206 to 36.3.76.206—1
20836.3.76.207/3236.3.76.207 to 36.3.76.207—1
20936.3.76.208/3236.3.76.208 to 36.3.76.208—1
21036.3.76.209/3236.3.76.209 to 36.3.76.209—1
21136.3.76.210/3236.3.76.210 to 36.3.76.210—1
21236.3.76.211/3236.3.76.211 to 36.3.76.211—1
21336.3.76.212/3236.3.76.212 to 36.3.76.212—1
21436.3.76.213/3236.3.76.213 to 36.3.76.213—1
21536.3.76.214/3236.3.76.214 to 36.3.76.214—1
21636.3.76.215/3236.3.76.215 to 36.3.76.215—1
21736.3.76.216/3236.3.76.216 to 36.3.76.216—1
21836.3.76.217/3236.3.76.217 to 36.3.76.217—1
21936.3.76.218/3236.3.76.218 to 36.3.76.218—1
22036.3.76.219/3236.3.76.219 to 36.3.76.219—1
22136.3.76.220/3236.3.76.220 to 36.3.76.220—1
22236.3.76.221/3236.3.76.221 to 36.3.76.221—1
22336.3.76.222/3236.3.76.222 to 36.3.76.222—1
22436.3.76.223/3236.3.76.223 to 36.3.76.223—1
22536.3.76.224/3236.3.76.224 to 36.3.76.224—1
22636.3.76.225/3236.3.76.225 to 36.3.76.225—1
22736.3.76.226/3236.3.76.226 to 36.3.76.226—1
22836.3.76.227/3236.3.76.227 to 36.3.76.227—1
22936.3.76.228/3236.3.76.228 to 36.3.76.228—1
23036.3.76.229/3236.3.76.229 to 36.3.76.229—1
23136.3.76.230/3236.3.76.230 to 36.3.76.230—1
23236.3.76.231/3236.3.76.231 to 36.3.76.231—1
23336.3.76.232/3236.3.76.232 to 36.3.76.232—1
23436.3.76.233/3236.3.76.233 to 36.3.76.233—1
23536.3.76.234/3236.3.76.234 to 36.3.76.234—1
23636.3.76.235/3236.3.76.235 to 36.3.76.235—1
23736.3.76.236/3236.3.76.236 to 36.3.76.236—1
23836.3.76.237/3236.3.76.237 to 36.3.76.237—1
23936.3.76.238/3236.3.76.238 to 36.3.76.238—1
24036.3.76.239/3236.3.76.239 to 36.3.76.239—1
24136.3.76.240/3236.3.76.240 to 36.3.76.240—1
24236.3.76.241/3236.3.76.241 to 36.3.76.241—1
24336.3.76.242/3236.3.76.242 to 36.3.76.242—1
24436.3.76.243/3236.3.76.243 to 36.3.76.243—1
24536.3.76.244/3236.3.76.244 to 36.3.76.244—1
24636.3.76.245/3236.3.76.245 to 36.3.76.245—1
24736.3.76.246/3236.3.76.246 to 36.3.76.246—1
24836.3.76.247/3236.3.76.247 to 36.3.76.247—1
24936.3.76.248/3236.3.76.248 to 36.3.76.248—1
25036.3.76.249/3236.3.76.249 to 36.3.76.249—1
25136.3.76.250/3236.3.76.250 to 36.3.76.250—1
25236.3.76.251/3236.3.76.251 to 36.3.76.251—1
25336.3.76.252/3236.3.76.252 to 36.3.76.252—1
25436.3.76.253/3236.3.76.253 to 36.3.76.253—1
25536.3.76.254/3236.3.76.254 to 36.3.76.254—1
25636.3.76.255/3236.3.76.255 to 36.3.76.255—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.