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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.

Network30.3.76.0/22
Usable hosts1,022
Subnet mask255.255.252.0
Addresses1,024
Network address
30.3.76.0
Broadcast address
30.3.79.255
First usable
30.3.76.1
Last usable
30.3.79.254
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 1E034C00 · Integer 503532544 to 503533567
Reverse DNS zones
76.3.30.in-addr.arpa
77.3.30.in-addr.arpa
78.3.30.in-addr.arpa
79.3.30.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
Address00011110.00000011.01001100.0000000030.3.76.0
Subnet mask11111111.11111111.11111100.00000000255.255.252.0
Network00011110.00000011.01001100.0000000030.3.76.0
Broadcast00011110.00000011.01001111.1111111130.3.79.255
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)

30.3.76.0/22 makes 1,024 subnets of /32; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
130.3.76.0/3230.3.76.0 to 30.3.76.0—1
230.3.76.1/3230.3.76.1 to 30.3.76.1—1
330.3.76.2/3230.3.76.2 to 30.3.76.2—1
430.3.76.3/3230.3.76.3 to 30.3.76.3—1
530.3.76.4/3230.3.76.4 to 30.3.76.4—1
630.3.76.5/3230.3.76.5 to 30.3.76.5—1
730.3.76.6/3230.3.76.6 to 30.3.76.6—1
830.3.76.7/3230.3.76.7 to 30.3.76.7—1
930.3.76.8/3230.3.76.8 to 30.3.76.8—1
1030.3.76.9/3230.3.76.9 to 30.3.76.9—1
1130.3.76.10/3230.3.76.10 to 30.3.76.10—1
1230.3.76.11/3230.3.76.11 to 30.3.76.11—1
1330.3.76.12/3230.3.76.12 to 30.3.76.12—1
1430.3.76.13/3230.3.76.13 to 30.3.76.13—1
1530.3.76.14/3230.3.76.14 to 30.3.76.14—1
1630.3.76.15/3230.3.76.15 to 30.3.76.15—1
1730.3.76.16/3230.3.76.16 to 30.3.76.16—1
1830.3.76.17/3230.3.76.17 to 30.3.76.17—1
1930.3.76.18/3230.3.76.18 to 30.3.76.18—1
2030.3.76.19/3230.3.76.19 to 30.3.76.19—1
2130.3.76.20/3230.3.76.20 to 30.3.76.20—1
2230.3.76.21/3230.3.76.21 to 30.3.76.21—1
2330.3.76.22/3230.3.76.22 to 30.3.76.22—1
2430.3.76.23/3230.3.76.23 to 30.3.76.23—1
2530.3.76.24/3230.3.76.24 to 30.3.76.24—1
2630.3.76.25/3230.3.76.25 to 30.3.76.25—1
2730.3.76.26/3230.3.76.26 to 30.3.76.26—1
2830.3.76.27/3230.3.76.27 to 30.3.76.27—1
2930.3.76.28/3230.3.76.28 to 30.3.76.28—1
3030.3.76.29/3230.3.76.29 to 30.3.76.29—1
3130.3.76.30/3230.3.76.30 to 30.3.76.30—1
3230.3.76.31/3230.3.76.31 to 30.3.76.31—1
3330.3.76.32/3230.3.76.32 to 30.3.76.32—1
3430.3.76.33/3230.3.76.33 to 30.3.76.33—1
3530.3.76.34/3230.3.76.34 to 30.3.76.34—1
3630.3.76.35/3230.3.76.35 to 30.3.76.35—1
3730.3.76.36/3230.3.76.36 to 30.3.76.36—1
3830.3.76.37/3230.3.76.37 to 30.3.76.37—1
3930.3.76.38/3230.3.76.38 to 30.3.76.38—1
4030.3.76.39/3230.3.76.39 to 30.3.76.39—1
4130.3.76.40/3230.3.76.40 to 30.3.76.40—1
4230.3.76.41/3230.3.76.41 to 30.3.76.41—1
4330.3.76.42/3230.3.76.42 to 30.3.76.42—1
4430.3.76.43/3230.3.76.43 to 30.3.76.43—1
4530.3.76.44/3230.3.76.44 to 30.3.76.44—1
4630.3.76.45/3230.3.76.45 to 30.3.76.45—1
4730.3.76.46/3230.3.76.46 to 30.3.76.46—1
4830.3.76.47/3230.3.76.47 to 30.3.76.47—1
4930.3.76.48/3230.3.76.48 to 30.3.76.48—1
5030.3.76.49/3230.3.76.49 to 30.3.76.49—1
5130.3.76.50/3230.3.76.50 to 30.3.76.50—1
5230.3.76.51/3230.3.76.51 to 30.3.76.51—1
5330.3.76.52/3230.3.76.52 to 30.3.76.52—1
5430.3.76.53/3230.3.76.53 to 30.3.76.53—1
5530.3.76.54/3230.3.76.54 to 30.3.76.54—1
5630.3.76.55/3230.3.76.55 to 30.3.76.55—1
5730.3.76.56/3230.3.76.56 to 30.3.76.56—1
5830.3.76.57/3230.3.76.57 to 30.3.76.57—1
5930.3.76.58/3230.3.76.58 to 30.3.76.58—1
6030.3.76.59/3230.3.76.59 to 30.3.76.59—1
6130.3.76.60/3230.3.76.60 to 30.3.76.60—1
6230.3.76.61/3230.3.76.61 to 30.3.76.61—1
6330.3.76.62/3230.3.76.62 to 30.3.76.62—1
6430.3.76.63/3230.3.76.63 to 30.3.76.63—1
6530.3.76.64/3230.3.76.64 to 30.3.76.64—1
6630.3.76.65/3230.3.76.65 to 30.3.76.65—1
6730.3.76.66/3230.3.76.66 to 30.3.76.66—1
6830.3.76.67/3230.3.76.67 to 30.3.76.67—1
6930.3.76.68/3230.3.76.68 to 30.3.76.68—1
7030.3.76.69/3230.3.76.69 to 30.3.76.69—1
7130.3.76.70/3230.3.76.70 to 30.3.76.70—1
7230.3.76.71/3230.3.76.71 to 30.3.76.71—1
7330.3.76.72/3230.3.76.72 to 30.3.76.72—1
7430.3.76.73/3230.3.76.73 to 30.3.76.73—1
7530.3.76.74/3230.3.76.74 to 30.3.76.74—1
7630.3.76.75/3230.3.76.75 to 30.3.76.75—1
7730.3.76.76/3230.3.76.76 to 30.3.76.76—1
7830.3.76.77/3230.3.76.77 to 30.3.76.77—1
7930.3.76.78/3230.3.76.78 to 30.3.76.78—1
8030.3.76.79/3230.3.76.79 to 30.3.76.79—1
8130.3.76.80/3230.3.76.80 to 30.3.76.80—1
8230.3.76.81/3230.3.76.81 to 30.3.76.81—1
8330.3.76.82/3230.3.76.82 to 30.3.76.82—1
8430.3.76.83/3230.3.76.83 to 30.3.76.83—1
8530.3.76.84/3230.3.76.84 to 30.3.76.84—1
8630.3.76.85/3230.3.76.85 to 30.3.76.85—1
8730.3.76.86/3230.3.76.86 to 30.3.76.86—1
8830.3.76.87/3230.3.76.87 to 30.3.76.87—1
8930.3.76.88/3230.3.76.88 to 30.3.76.88—1
9030.3.76.89/3230.3.76.89 to 30.3.76.89—1
9130.3.76.90/3230.3.76.90 to 30.3.76.90—1
9230.3.76.91/3230.3.76.91 to 30.3.76.91—1
9330.3.76.92/3230.3.76.92 to 30.3.76.92—1
9430.3.76.93/3230.3.76.93 to 30.3.76.93—1
9530.3.76.94/3230.3.76.94 to 30.3.76.94—1
9630.3.76.95/3230.3.76.95 to 30.3.76.95—1
9730.3.76.96/3230.3.76.96 to 30.3.76.96—1
9830.3.76.97/3230.3.76.97 to 30.3.76.97—1
9930.3.76.98/3230.3.76.98 to 30.3.76.98—1
10030.3.76.99/3230.3.76.99 to 30.3.76.99—1
10130.3.76.100/3230.3.76.100 to 30.3.76.100—1
10230.3.76.101/3230.3.76.101 to 30.3.76.101—1
10330.3.76.102/3230.3.76.102 to 30.3.76.102—1
10430.3.76.103/3230.3.76.103 to 30.3.76.103—1
10530.3.76.104/3230.3.76.104 to 30.3.76.104—1
10630.3.76.105/3230.3.76.105 to 30.3.76.105—1
10730.3.76.106/3230.3.76.106 to 30.3.76.106—1
10830.3.76.107/3230.3.76.107 to 30.3.76.107—1
10930.3.76.108/3230.3.76.108 to 30.3.76.108—1
11030.3.76.109/3230.3.76.109 to 30.3.76.109—1
11130.3.76.110/3230.3.76.110 to 30.3.76.110—1
11230.3.76.111/3230.3.76.111 to 30.3.76.111—1
11330.3.76.112/3230.3.76.112 to 30.3.76.112—1
11430.3.76.113/3230.3.76.113 to 30.3.76.113—1
11530.3.76.114/3230.3.76.114 to 30.3.76.114—1
11630.3.76.115/3230.3.76.115 to 30.3.76.115—1
11730.3.76.116/3230.3.76.116 to 30.3.76.116—1
11830.3.76.117/3230.3.76.117 to 30.3.76.117—1
11930.3.76.118/3230.3.76.118 to 30.3.76.118—1
12030.3.76.119/3230.3.76.119 to 30.3.76.119—1
12130.3.76.120/3230.3.76.120 to 30.3.76.120—1
12230.3.76.121/3230.3.76.121 to 30.3.76.121—1
12330.3.76.122/3230.3.76.122 to 30.3.76.122—1
12430.3.76.123/3230.3.76.123 to 30.3.76.123—1
12530.3.76.124/3230.3.76.124 to 30.3.76.124—1
12630.3.76.125/3230.3.76.125 to 30.3.76.125—1
12730.3.76.126/3230.3.76.126 to 30.3.76.126—1
12830.3.76.127/3230.3.76.127 to 30.3.76.127—1
12930.3.76.128/3230.3.76.128 to 30.3.76.128—1
13030.3.76.129/3230.3.76.129 to 30.3.76.129—1
13130.3.76.130/3230.3.76.130 to 30.3.76.130—1
13230.3.76.131/3230.3.76.131 to 30.3.76.131—1
13330.3.76.132/3230.3.76.132 to 30.3.76.132—1
13430.3.76.133/3230.3.76.133 to 30.3.76.133—1
13530.3.76.134/3230.3.76.134 to 30.3.76.134—1
13630.3.76.135/3230.3.76.135 to 30.3.76.135—1
13730.3.76.136/3230.3.76.136 to 30.3.76.136—1
13830.3.76.137/3230.3.76.137 to 30.3.76.137—1
13930.3.76.138/3230.3.76.138 to 30.3.76.138—1
14030.3.76.139/3230.3.76.139 to 30.3.76.139—1
14130.3.76.140/3230.3.76.140 to 30.3.76.140—1
14230.3.76.141/3230.3.76.141 to 30.3.76.141—1
14330.3.76.142/3230.3.76.142 to 30.3.76.142—1
14430.3.76.143/3230.3.76.143 to 30.3.76.143—1
14530.3.76.144/3230.3.76.144 to 30.3.76.144—1
14630.3.76.145/3230.3.76.145 to 30.3.76.145—1
14730.3.76.146/3230.3.76.146 to 30.3.76.146—1
14830.3.76.147/3230.3.76.147 to 30.3.76.147—1
14930.3.76.148/3230.3.76.148 to 30.3.76.148—1
15030.3.76.149/3230.3.76.149 to 30.3.76.149—1
15130.3.76.150/3230.3.76.150 to 30.3.76.150—1
15230.3.76.151/3230.3.76.151 to 30.3.76.151—1
15330.3.76.152/3230.3.76.152 to 30.3.76.152—1
15430.3.76.153/3230.3.76.153 to 30.3.76.153—1
15530.3.76.154/3230.3.76.154 to 30.3.76.154—1
15630.3.76.155/3230.3.76.155 to 30.3.76.155—1
15730.3.76.156/3230.3.76.156 to 30.3.76.156—1
15830.3.76.157/3230.3.76.157 to 30.3.76.157—1
15930.3.76.158/3230.3.76.158 to 30.3.76.158—1
16030.3.76.159/3230.3.76.159 to 30.3.76.159—1
16130.3.76.160/3230.3.76.160 to 30.3.76.160—1
16230.3.76.161/3230.3.76.161 to 30.3.76.161—1
16330.3.76.162/3230.3.76.162 to 30.3.76.162—1
16430.3.76.163/3230.3.76.163 to 30.3.76.163—1
16530.3.76.164/3230.3.76.164 to 30.3.76.164—1
16630.3.76.165/3230.3.76.165 to 30.3.76.165—1
16730.3.76.166/3230.3.76.166 to 30.3.76.166—1
16830.3.76.167/3230.3.76.167 to 30.3.76.167—1
16930.3.76.168/3230.3.76.168 to 30.3.76.168—1
17030.3.76.169/3230.3.76.169 to 30.3.76.169—1
17130.3.76.170/3230.3.76.170 to 30.3.76.170—1
17230.3.76.171/3230.3.76.171 to 30.3.76.171—1
17330.3.76.172/3230.3.76.172 to 30.3.76.172—1
17430.3.76.173/3230.3.76.173 to 30.3.76.173—1
17530.3.76.174/3230.3.76.174 to 30.3.76.174—1
17630.3.76.175/3230.3.76.175 to 30.3.76.175—1
17730.3.76.176/3230.3.76.176 to 30.3.76.176—1
17830.3.76.177/3230.3.76.177 to 30.3.76.177—1
17930.3.76.178/3230.3.76.178 to 30.3.76.178—1
18030.3.76.179/3230.3.76.179 to 30.3.76.179—1
18130.3.76.180/3230.3.76.180 to 30.3.76.180—1
18230.3.76.181/3230.3.76.181 to 30.3.76.181—1
18330.3.76.182/3230.3.76.182 to 30.3.76.182—1
18430.3.76.183/3230.3.76.183 to 30.3.76.183—1
18530.3.76.184/3230.3.76.184 to 30.3.76.184—1
18630.3.76.185/3230.3.76.185 to 30.3.76.185—1
18730.3.76.186/3230.3.76.186 to 30.3.76.186—1
18830.3.76.187/3230.3.76.187 to 30.3.76.187—1
18930.3.76.188/3230.3.76.188 to 30.3.76.188—1
19030.3.76.189/3230.3.76.189 to 30.3.76.189—1
19130.3.76.190/3230.3.76.190 to 30.3.76.190—1
19230.3.76.191/3230.3.76.191 to 30.3.76.191—1
19330.3.76.192/3230.3.76.192 to 30.3.76.192—1
19430.3.76.193/3230.3.76.193 to 30.3.76.193—1
19530.3.76.194/3230.3.76.194 to 30.3.76.194—1
19630.3.76.195/3230.3.76.195 to 30.3.76.195—1
19730.3.76.196/3230.3.76.196 to 30.3.76.196—1
19830.3.76.197/3230.3.76.197 to 30.3.76.197—1
19930.3.76.198/3230.3.76.198 to 30.3.76.198—1
20030.3.76.199/3230.3.76.199 to 30.3.76.199—1
20130.3.76.200/3230.3.76.200 to 30.3.76.200—1
20230.3.76.201/3230.3.76.201 to 30.3.76.201—1
20330.3.76.202/3230.3.76.202 to 30.3.76.202—1
20430.3.76.203/3230.3.76.203 to 30.3.76.203—1
20530.3.76.204/3230.3.76.204 to 30.3.76.204—1
20630.3.76.205/3230.3.76.205 to 30.3.76.205—1
20730.3.76.206/3230.3.76.206 to 30.3.76.206—1
20830.3.76.207/3230.3.76.207 to 30.3.76.207—1
20930.3.76.208/3230.3.76.208 to 30.3.76.208—1
21030.3.76.209/3230.3.76.209 to 30.3.76.209—1
21130.3.76.210/3230.3.76.210 to 30.3.76.210—1
21230.3.76.211/3230.3.76.211 to 30.3.76.211—1
21330.3.76.212/3230.3.76.212 to 30.3.76.212—1
21430.3.76.213/3230.3.76.213 to 30.3.76.213—1
21530.3.76.214/3230.3.76.214 to 30.3.76.214—1
21630.3.76.215/3230.3.76.215 to 30.3.76.215—1
21730.3.76.216/3230.3.76.216 to 30.3.76.216—1
21830.3.76.217/3230.3.76.217 to 30.3.76.217—1
21930.3.76.218/3230.3.76.218 to 30.3.76.218—1
22030.3.76.219/3230.3.76.219 to 30.3.76.219—1
22130.3.76.220/3230.3.76.220 to 30.3.76.220—1
22230.3.76.221/3230.3.76.221 to 30.3.76.221—1
22330.3.76.222/3230.3.76.222 to 30.3.76.222—1
22430.3.76.223/3230.3.76.223 to 30.3.76.223—1
22530.3.76.224/3230.3.76.224 to 30.3.76.224—1
22630.3.76.225/3230.3.76.225 to 30.3.76.225—1
22730.3.76.226/3230.3.76.226 to 30.3.76.226—1
22830.3.76.227/3230.3.76.227 to 30.3.76.227—1
22930.3.76.228/3230.3.76.228 to 30.3.76.228—1
23030.3.76.229/3230.3.76.229 to 30.3.76.229—1
23130.3.76.230/3230.3.76.230 to 30.3.76.230—1
23230.3.76.231/3230.3.76.231 to 30.3.76.231—1
23330.3.76.232/3230.3.76.232 to 30.3.76.232—1
23430.3.76.233/3230.3.76.233 to 30.3.76.233—1
23530.3.76.234/3230.3.76.234 to 30.3.76.234—1
23630.3.76.235/3230.3.76.235 to 30.3.76.235—1
23730.3.76.236/3230.3.76.236 to 30.3.76.236—1
23830.3.76.237/3230.3.76.237 to 30.3.76.237—1
23930.3.76.238/3230.3.76.238 to 30.3.76.238—1
24030.3.76.239/3230.3.76.239 to 30.3.76.239—1
24130.3.76.240/3230.3.76.240 to 30.3.76.240—1
24230.3.76.241/3230.3.76.241 to 30.3.76.241—1
24330.3.76.242/3230.3.76.242 to 30.3.76.242—1
24430.3.76.243/3230.3.76.243 to 30.3.76.243—1
24530.3.76.244/3230.3.76.244 to 30.3.76.244—1
24630.3.76.245/3230.3.76.245 to 30.3.76.245—1
24730.3.76.246/3230.3.76.246 to 30.3.76.246—1
24830.3.76.247/3230.3.76.247 to 30.3.76.247—1
24930.3.76.248/3230.3.76.248 to 30.3.76.248—1
25030.3.76.249/3230.3.76.249 to 30.3.76.249—1
25130.3.76.250/3230.3.76.250 to 30.3.76.250—1
25230.3.76.251/3230.3.76.251 to 30.3.76.251—1
25330.3.76.252/3230.3.76.252 to 30.3.76.252—1
25430.3.76.253/3230.3.76.253 to 30.3.76.253—1
25530.3.76.254/3230.3.76.254 to 30.3.76.254—1
25630.3.76.255/3230.3.76.255 to 30.3.76.255—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.