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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.

Network75.167.167.0/24
Usable hosts254
Subnet mask255.255.255.0
Addresses256
Network address
75.167.167.0
Broadcast address
75.167.167.255
First usable
75.167.167.1
Last usable
75.167.167.254
Usable hosts
254 (256 less the network and broadcast addresses)
Subnet mask
255.255.255.0
Wildcard mask
0.0.0.255 (Cisco ACLs, OSPF)
Prefix length
/24
Type
Public public
Old class
A (default /8)
As numbers
Hex 4BA7A700 · Integer 1269278464 to 1269278719
Reverse DNS zone
167.167.75.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01001011.10100111.10100111..0000000075.167.167.0
Subnet mask11111111.11111111.11111111..00000000255.255.255.0
Network01001011.10100111.10100111..0000000075.167.167.0
Broadcast01001011.10100111.10100111..1111111175.167.167.255
Split into smaller subnets/32
/25 (2)/26 (4)/27 (8)/28 (16)/29 (32)/30 (64)/31 (128)/32 (256)

75.167.167.0/24 makes 256 subnets of /32.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
175.167.167.0/3275.167.167.0 to 75.167.167.0—1
275.167.167.1/3275.167.167.1 to 75.167.167.1—1
375.167.167.2/3275.167.167.2 to 75.167.167.2—1
475.167.167.3/3275.167.167.3 to 75.167.167.3—1
575.167.167.4/3275.167.167.4 to 75.167.167.4—1
675.167.167.5/3275.167.167.5 to 75.167.167.5—1
775.167.167.6/3275.167.167.6 to 75.167.167.6—1
875.167.167.7/3275.167.167.7 to 75.167.167.7—1
975.167.167.8/3275.167.167.8 to 75.167.167.8—1
1075.167.167.9/3275.167.167.9 to 75.167.167.9—1
1175.167.167.10/3275.167.167.10 to 75.167.167.10—1
1275.167.167.11/3275.167.167.11 to 75.167.167.11—1
1375.167.167.12/3275.167.167.12 to 75.167.167.12—1
1475.167.167.13/3275.167.167.13 to 75.167.167.13—1
1575.167.167.14/3275.167.167.14 to 75.167.167.14—1
1675.167.167.15/3275.167.167.15 to 75.167.167.15—1
1775.167.167.16/3275.167.167.16 to 75.167.167.16—1
1875.167.167.17/3275.167.167.17 to 75.167.167.17—1
1975.167.167.18/3275.167.167.18 to 75.167.167.18—1
2075.167.167.19/3275.167.167.19 to 75.167.167.19—1
2175.167.167.20/3275.167.167.20 to 75.167.167.20—1
2275.167.167.21/3275.167.167.21 to 75.167.167.21—1
2375.167.167.22/3275.167.167.22 to 75.167.167.22—1
2475.167.167.23/3275.167.167.23 to 75.167.167.23—1
2575.167.167.24/3275.167.167.24 to 75.167.167.24—1
2675.167.167.25/3275.167.167.25 to 75.167.167.25—1
2775.167.167.26/3275.167.167.26 to 75.167.167.26—1
2875.167.167.27/3275.167.167.27 to 75.167.167.27—1
2975.167.167.28/3275.167.167.28 to 75.167.167.28—1
3075.167.167.29/3275.167.167.29 to 75.167.167.29—1
3175.167.167.30/3275.167.167.30 to 75.167.167.30—1
3275.167.167.31/3275.167.167.31 to 75.167.167.31—1
3375.167.167.32/3275.167.167.32 to 75.167.167.32—1
3475.167.167.33/3275.167.167.33 to 75.167.167.33—1
3575.167.167.34/3275.167.167.34 to 75.167.167.34—1
3675.167.167.35/3275.167.167.35 to 75.167.167.35—1
3775.167.167.36/3275.167.167.36 to 75.167.167.36—1
3875.167.167.37/3275.167.167.37 to 75.167.167.37—1
3975.167.167.38/3275.167.167.38 to 75.167.167.38—1
4075.167.167.39/3275.167.167.39 to 75.167.167.39—1
4175.167.167.40/3275.167.167.40 to 75.167.167.40—1
4275.167.167.41/3275.167.167.41 to 75.167.167.41—1
4375.167.167.42/3275.167.167.42 to 75.167.167.42—1
4475.167.167.43/3275.167.167.43 to 75.167.167.43—1
4575.167.167.44/3275.167.167.44 to 75.167.167.44—1
4675.167.167.45/3275.167.167.45 to 75.167.167.45—1
4775.167.167.46/3275.167.167.46 to 75.167.167.46—1
4875.167.167.47/3275.167.167.47 to 75.167.167.47—1
4975.167.167.48/3275.167.167.48 to 75.167.167.48—1
5075.167.167.49/3275.167.167.49 to 75.167.167.49—1
5175.167.167.50/3275.167.167.50 to 75.167.167.50—1
5275.167.167.51/3275.167.167.51 to 75.167.167.51—1
5375.167.167.52/3275.167.167.52 to 75.167.167.52—1
5475.167.167.53/3275.167.167.53 to 75.167.167.53—1
5575.167.167.54/3275.167.167.54 to 75.167.167.54—1
5675.167.167.55/3275.167.167.55 to 75.167.167.55—1
5775.167.167.56/3275.167.167.56 to 75.167.167.56—1
5875.167.167.57/3275.167.167.57 to 75.167.167.57—1
5975.167.167.58/3275.167.167.58 to 75.167.167.58—1
6075.167.167.59/3275.167.167.59 to 75.167.167.59—1
6175.167.167.60/3275.167.167.60 to 75.167.167.60—1
6275.167.167.61/3275.167.167.61 to 75.167.167.61—1
6375.167.167.62/3275.167.167.62 to 75.167.167.62—1
6475.167.167.63/3275.167.167.63 to 75.167.167.63—1
6575.167.167.64/3275.167.167.64 to 75.167.167.64—1
6675.167.167.65/3275.167.167.65 to 75.167.167.65—1
6775.167.167.66/3275.167.167.66 to 75.167.167.66—1
6875.167.167.67/3275.167.167.67 to 75.167.167.67—1
6975.167.167.68/3275.167.167.68 to 75.167.167.68—1
7075.167.167.69/3275.167.167.69 to 75.167.167.69—1
7175.167.167.70/3275.167.167.70 to 75.167.167.70—1
7275.167.167.71/3275.167.167.71 to 75.167.167.71—1
7375.167.167.72/3275.167.167.72 to 75.167.167.72—1
7475.167.167.73/3275.167.167.73 to 75.167.167.73—1
7575.167.167.74/3275.167.167.74 to 75.167.167.74—1
7675.167.167.75/3275.167.167.75 to 75.167.167.75—1
7775.167.167.76/3275.167.167.76 to 75.167.167.76—1
7875.167.167.77/3275.167.167.77 to 75.167.167.77—1
7975.167.167.78/3275.167.167.78 to 75.167.167.78—1
8075.167.167.79/3275.167.167.79 to 75.167.167.79—1
8175.167.167.80/3275.167.167.80 to 75.167.167.80—1
8275.167.167.81/3275.167.167.81 to 75.167.167.81—1
8375.167.167.82/3275.167.167.82 to 75.167.167.82—1
8475.167.167.83/3275.167.167.83 to 75.167.167.83—1
8575.167.167.84/3275.167.167.84 to 75.167.167.84—1
8675.167.167.85/3275.167.167.85 to 75.167.167.85—1
8775.167.167.86/3275.167.167.86 to 75.167.167.86—1
8875.167.167.87/3275.167.167.87 to 75.167.167.87—1
8975.167.167.88/3275.167.167.88 to 75.167.167.88—1
9075.167.167.89/3275.167.167.89 to 75.167.167.89—1
9175.167.167.90/3275.167.167.90 to 75.167.167.90—1
9275.167.167.91/3275.167.167.91 to 75.167.167.91—1
9375.167.167.92/3275.167.167.92 to 75.167.167.92—1
9475.167.167.93/3275.167.167.93 to 75.167.167.93—1
9575.167.167.94/3275.167.167.94 to 75.167.167.94—1
9675.167.167.95/3275.167.167.95 to 75.167.167.95—1
9775.167.167.96/3275.167.167.96 to 75.167.167.96—1
9875.167.167.97/3275.167.167.97 to 75.167.167.97—1
9975.167.167.98/3275.167.167.98 to 75.167.167.98—1
10075.167.167.99/3275.167.167.99 to 75.167.167.99—1
10175.167.167.100/3275.167.167.100 to 75.167.167.100—1
10275.167.167.101/3275.167.167.101 to 75.167.167.101—1
10375.167.167.102/3275.167.167.102 to 75.167.167.102—1
10475.167.167.103/3275.167.167.103 to 75.167.167.103—1
10575.167.167.104/3275.167.167.104 to 75.167.167.104—1
10675.167.167.105/3275.167.167.105 to 75.167.167.105—1
10775.167.167.106/3275.167.167.106 to 75.167.167.106—1
10875.167.167.107/3275.167.167.107 to 75.167.167.107—1
10975.167.167.108/3275.167.167.108 to 75.167.167.108—1
11075.167.167.109/3275.167.167.109 to 75.167.167.109—1
11175.167.167.110/3275.167.167.110 to 75.167.167.110—1
11275.167.167.111/3275.167.167.111 to 75.167.167.111—1
11375.167.167.112/3275.167.167.112 to 75.167.167.112—1
11475.167.167.113/3275.167.167.113 to 75.167.167.113—1
11575.167.167.114/3275.167.167.114 to 75.167.167.114—1
11675.167.167.115/3275.167.167.115 to 75.167.167.115—1
11775.167.167.116/3275.167.167.116 to 75.167.167.116—1
11875.167.167.117/3275.167.167.117 to 75.167.167.117—1
11975.167.167.118/3275.167.167.118 to 75.167.167.118—1
12075.167.167.119/3275.167.167.119 to 75.167.167.119—1
12175.167.167.120/3275.167.167.120 to 75.167.167.120—1
12275.167.167.121/3275.167.167.121 to 75.167.167.121—1
12375.167.167.122/3275.167.167.122 to 75.167.167.122—1
12475.167.167.123/3275.167.167.123 to 75.167.167.123—1
12575.167.167.124/3275.167.167.124 to 75.167.167.124—1
12675.167.167.125/3275.167.167.125 to 75.167.167.125—1
12775.167.167.126/3275.167.167.126 to 75.167.167.126—1
12875.167.167.127/3275.167.167.127 to 75.167.167.127—1
12975.167.167.128/3275.167.167.128 to 75.167.167.128—1
13075.167.167.129/3275.167.167.129 to 75.167.167.129—1
13175.167.167.130/3275.167.167.130 to 75.167.167.130—1
13275.167.167.131/3275.167.167.131 to 75.167.167.131—1
13375.167.167.132/3275.167.167.132 to 75.167.167.132—1
13475.167.167.133/3275.167.167.133 to 75.167.167.133—1
13575.167.167.134/3275.167.167.134 to 75.167.167.134—1
13675.167.167.135/3275.167.167.135 to 75.167.167.135—1
13775.167.167.136/3275.167.167.136 to 75.167.167.136—1
13875.167.167.137/3275.167.167.137 to 75.167.167.137—1
13975.167.167.138/3275.167.167.138 to 75.167.167.138—1
14075.167.167.139/3275.167.167.139 to 75.167.167.139—1
14175.167.167.140/3275.167.167.140 to 75.167.167.140—1
14275.167.167.141/3275.167.167.141 to 75.167.167.141—1
14375.167.167.142/3275.167.167.142 to 75.167.167.142—1
14475.167.167.143/3275.167.167.143 to 75.167.167.143—1
14575.167.167.144/3275.167.167.144 to 75.167.167.144—1
14675.167.167.145/3275.167.167.145 to 75.167.167.145—1
14775.167.167.146/3275.167.167.146 to 75.167.167.146—1
14875.167.167.147/3275.167.167.147 to 75.167.167.147—1
14975.167.167.148/3275.167.167.148 to 75.167.167.148—1
15075.167.167.149/3275.167.167.149 to 75.167.167.149—1
15175.167.167.150/3275.167.167.150 to 75.167.167.150—1
15275.167.167.151/3275.167.167.151 to 75.167.167.151—1
15375.167.167.152/3275.167.167.152 to 75.167.167.152—1
15475.167.167.153/3275.167.167.153 to 75.167.167.153—1
15575.167.167.154/3275.167.167.154 to 75.167.167.154—1
15675.167.167.155/3275.167.167.155 to 75.167.167.155—1
15775.167.167.156/3275.167.167.156 to 75.167.167.156—1
15875.167.167.157/3275.167.167.157 to 75.167.167.157—1
15975.167.167.158/3275.167.167.158 to 75.167.167.158—1
16075.167.167.159/3275.167.167.159 to 75.167.167.159—1
16175.167.167.160/3275.167.167.160 to 75.167.167.160—1
16275.167.167.161/3275.167.167.161 to 75.167.167.161—1
16375.167.167.162/3275.167.167.162 to 75.167.167.162—1
16475.167.167.163/3275.167.167.163 to 75.167.167.163—1
16575.167.167.164/3275.167.167.164 to 75.167.167.164—1
16675.167.167.165/3275.167.167.165 to 75.167.167.165—1
16775.167.167.166/3275.167.167.166 to 75.167.167.166—1
16875.167.167.167/3275.167.167.167 to 75.167.167.167—1
16975.167.167.168/3275.167.167.168 to 75.167.167.168—1
17075.167.167.169/3275.167.167.169 to 75.167.167.169—1
17175.167.167.170/3275.167.167.170 to 75.167.167.170—1
17275.167.167.171/3275.167.167.171 to 75.167.167.171—1
17375.167.167.172/3275.167.167.172 to 75.167.167.172—1
17475.167.167.173/3275.167.167.173 to 75.167.167.173—1
17575.167.167.174/3275.167.167.174 to 75.167.167.174—1
17675.167.167.175/3275.167.167.175 to 75.167.167.175—1
17775.167.167.176/3275.167.167.176 to 75.167.167.176—1
17875.167.167.177/3275.167.167.177 to 75.167.167.177—1
17975.167.167.178/3275.167.167.178 to 75.167.167.178—1
18075.167.167.179/3275.167.167.179 to 75.167.167.179—1
18175.167.167.180/3275.167.167.180 to 75.167.167.180—1
18275.167.167.181/3275.167.167.181 to 75.167.167.181—1
18375.167.167.182/3275.167.167.182 to 75.167.167.182—1
18475.167.167.183/3275.167.167.183 to 75.167.167.183—1
18575.167.167.184/3275.167.167.184 to 75.167.167.184—1
18675.167.167.185/3275.167.167.185 to 75.167.167.185—1
18775.167.167.186/3275.167.167.186 to 75.167.167.186—1
18875.167.167.187/3275.167.167.187 to 75.167.167.187—1
18975.167.167.188/3275.167.167.188 to 75.167.167.188—1
19075.167.167.189/3275.167.167.189 to 75.167.167.189—1
19175.167.167.190/3275.167.167.190 to 75.167.167.190—1
19275.167.167.191/3275.167.167.191 to 75.167.167.191—1
19375.167.167.192/3275.167.167.192 to 75.167.167.192—1
19475.167.167.193/3275.167.167.193 to 75.167.167.193—1
19575.167.167.194/3275.167.167.194 to 75.167.167.194—1
19675.167.167.195/3275.167.167.195 to 75.167.167.195—1
19775.167.167.196/3275.167.167.196 to 75.167.167.196—1
19875.167.167.197/3275.167.167.197 to 75.167.167.197—1
19975.167.167.198/3275.167.167.198 to 75.167.167.198—1
20075.167.167.199/3275.167.167.199 to 75.167.167.199—1
20175.167.167.200/3275.167.167.200 to 75.167.167.200—1
20275.167.167.201/3275.167.167.201 to 75.167.167.201—1
20375.167.167.202/3275.167.167.202 to 75.167.167.202—1
20475.167.167.203/3275.167.167.203 to 75.167.167.203—1
20575.167.167.204/3275.167.167.204 to 75.167.167.204—1
20675.167.167.205/3275.167.167.205 to 75.167.167.205—1
20775.167.167.206/3275.167.167.206 to 75.167.167.206—1
20875.167.167.207/3275.167.167.207 to 75.167.167.207—1
20975.167.167.208/3275.167.167.208 to 75.167.167.208—1
21075.167.167.209/3275.167.167.209 to 75.167.167.209—1
21175.167.167.210/3275.167.167.210 to 75.167.167.210—1
21275.167.167.211/3275.167.167.211 to 75.167.167.211—1
21375.167.167.212/3275.167.167.212 to 75.167.167.212—1
21475.167.167.213/3275.167.167.213 to 75.167.167.213—1
21575.167.167.214/3275.167.167.214 to 75.167.167.214—1
21675.167.167.215/3275.167.167.215 to 75.167.167.215—1
21775.167.167.216/3275.167.167.216 to 75.167.167.216—1
21875.167.167.217/3275.167.167.217 to 75.167.167.217—1
21975.167.167.218/3275.167.167.218 to 75.167.167.218—1
22075.167.167.219/3275.167.167.219 to 75.167.167.219—1
22175.167.167.220/3275.167.167.220 to 75.167.167.220—1
22275.167.167.221/3275.167.167.221 to 75.167.167.221—1
22375.167.167.222/3275.167.167.222 to 75.167.167.222—1
22475.167.167.223/3275.167.167.223 to 75.167.167.223—1
22575.167.167.224/3275.167.167.224 to 75.167.167.224—1
22675.167.167.225/3275.167.167.225 to 75.167.167.225—1
22775.167.167.226/3275.167.167.226 to 75.167.167.226—1
22875.167.167.227/3275.167.167.227 to 75.167.167.227—1
22975.167.167.228/3275.167.167.228 to 75.167.167.228—1
23075.167.167.229/3275.167.167.229 to 75.167.167.229—1
23175.167.167.230/3275.167.167.230 to 75.167.167.230—1
23275.167.167.231/3275.167.167.231 to 75.167.167.231—1
23375.167.167.232/3275.167.167.232 to 75.167.167.232—1
23475.167.167.233/3275.167.167.233 to 75.167.167.233—1
23575.167.167.234/3275.167.167.234 to 75.167.167.234—1
23675.167.167.235/3275.167.167.235 to 75.167.167.235—1
23775.167.167.236/3275.167.167.236 to 75.167.167.236—1
23875.167.167.237/3275.167.167.237 to 75.167.167.237—1
23975.167.167.238/3275.167.167.238 to 75.167.167.238—1
24075.167.167.239/3275.167.167.239 to 75.167.167.239—1
24175.167.167.240/3275.167.167.240 to 75.167.167.240—1
24275.167.167.241/3275.167.167.241 to 75.167.167.241—1
24375.167.167.242/3275.167.167.242 to 75.167.167.242—1
24475.167.167.243/3275.167.167.243 to 75.167.167.243—1
24575.167.167.244/3275.167.167.244 to 75.167.167.244—1
24675.167.167.245/3275.167.167.245 to 75.167.167.245—1
24775.167.167.246/3275.167.167.246 to 75.167.167.246—1
24875.167.167.247/3275.167.167.247 to 75.167.167.247—1
24975.167.167.248/3275.167.167.248 to 75.167.167.248—1
25075.167.167.249/3275.167.167.249 to 75.167.167.249—1
25175.167.167.250/3275.167.167.250 to 75.167.167.250—1
25275.167.167.251/3275.167.167.251 to 75.167.167.251—1
25375.167.167.252/3275.167.167.252 to 75.167.167.252—1
25475.167.167.253/3275.167.167.253 to 75.167.167.253—1
25575.167.167.254/3275.167.167.254 to 75.167.167.254—1
25675.167.167.255/3275.167.167.255 to 75.167.167.255—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.