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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.

Network76.2.78.0/24
Usable hosts254
Subnet mask255.255.255.0
Addresses256
Network address
76.2.78.0
Broadcast address
76.2.78.255
First usable
76.2.78.1
Last usable
76.2.78.254
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 4C024E00 · Integer 1275219456 to 1275219711
Reverse DNS zone
78.2.76.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01001100.00000010.01001110..0000000076.2.78.0
Subnet mask11111111.11111111.11111111..00000000255.255.255.0
Network01001100.00000010.01001110..0000000076.2.78.0
Broadcast01001100.00000010.01001110..1111111176.2.78.255
Split into smaller subnets/32
/25 (2)/26 (4)/27 (8)/28 (16)/29 (32)/30 (64)/31 (128)/32 (256)

76.2.78.0/24 makes 256 subnets of /32.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
176.2.78.0/3276.2.78.0 to 76.2.78.0—1
276.2.78.1/3276.2.78.1 to 76.2.78.1—1
376.2.78.2/3276.2.78.2 to 76.2.78.2—1
476.2.78.3/3276.2.78.3 to 76.2.78.3—1
576.2.78.4/3276.2.78.4 to 76.2.78.4—1
676.2.78.5/3276.2.78.5 to 76.2.78.5—1
776.2.78.6/3276.2.78.6 to 76.2.78.6—1
876.2.78.7/3276.2.78.7 to 76.2.78.7—1
976.2.78.8/3276.2.78.8 to 76.2.78.8—1
1076.2.78.9/3276.2.78.9 to 76.2.78.9—1
1176.2.78.10/3276.2.78.10 to 76.2.78.10—1
1276.2.78.11/3276.2.78.11 to 76.2.78.11—1
1376.2.78.12/3276.2.78.12 to 76.2.78.12—1
1476.2.78.13/3276.2.78.13 to 76.2.78.13—1
1576.2.78.14/3276.2.78.14 to 76.2.78.14—1
1676.2.78.15/3276.2.78.15 to 76.2.78.15—1
1776.2.78.16/3276.2.78.16 to 76.2.78.16—1
1876.2.78.17/3276.2.78.17 to 76.2.78.17—1
1976.2.78.18/3276.2.78.18 to 76.2.78.18—1
2076.2.78.19/3276.2.78.19 to 76.2.78.19—1
2176.2.78.20/3276.2.78.20 to 76.2.78.20—1
2276.2.78.21/3276.2.78.21 to 76.2.78.21—1
2376.2.78.22/3276.2.78.22 to 76.2.78.22—1
2476.2.78.23/3276.2.78.23 to 76.2.78.23—1
2576.2.78.24/3276.2.78.24 to 76.2.78.24—1
2676.2.78.25/3276.2.78.25 to 76.2.78.25—1
2776.2.78.26/3276.2.78.26 to 76.2.78.26—1
2876.2.78.27/3276.2.78.27 to 76.2.78.27—1
2976.2.78.28/3276.2.78.28 to 76.2.78.28—1
3076.2.78.29/3276.2.78.29 to 76.2.78.29—1
3176.2.78.30/3276.2.78.30 to 76.2.78.30—1
3276.2.78.31/3276.2.78.31 to 76.2.78.31—1
3376.2.78.32/3276.2.78.32 to 76.2.78.32—1
3476.2.78.33/3276.2.78.33 to 76.2.78.33—1
3576.2.78.34/3276.2.78.34 to 76.2.78.34—1
3676.2.78.35/3276.2.78.35 to 76.2.78.35—1
3776.2.78.36/3276.2.78.36 to 76.2.78.36—1
3876.2.78.37/3276.2.78.37 to 76.2.78.37—1
3976.2.78.38/3276.2.78.38 to 76.2.78.38—1
4076.2.78.39/3276.2.78.39 to 76.2.78.39—1
4176.2.78.40/3276.2.78.40 to 76.2.78.40—1
4276.2.78.41/3276.2.78.41 to 76.2.78.41—1
4376.2.78.42/3276.2.78.42 to 76.2.78.42—1
4476.2.78.43/3276.2.78.43 to 76.2.78.43—1
4576.2.78.44/3276.2.78.44 to 76.2.78.44—1
4676.2.78.45/3276.2.78.45 to 76.2.78.45—1
4776.2.78.46/3276.2.78.46 to 76.2.78.46—1
4876.2.78.47/3276.2.78.47 to 76.2.78.47—1
4976.2.78.48/3276.2.78.48 to 76.2.78.48—1
5076.2.78.49/3276.2.78.49 to 76.2.78.49—1
5176.2.78.50/3276.2.78.50 to 76.2.78.50—1
5276.2.78.51/3276.2.78.51 to 76.2.78.51—1
5376.2.78.52/3276.2.78.52 to 76.2.78.52—1
5476.2.78.53/3276.2.78.53 to 76.2.78.53—1
5576.2.78.54/3276.2.78.54 to 76.2.78.54—1
5676.2.78.55/3276.2.78.55 to 76.2.78.55—1
5776.2.78.56/3276.2.78.56 to 76.2.78.56—1
5876.2.78.57/3276.2.78.57 to 76.2.78.57—1
5976.2.78.58/3276.2.78.58 to 76.2.78.58—1
6076.2.78.59/3276.2.78.59 to 76.2.78.59—1
6176.2.78.60/3276.2.78.60 to 76.2.78.60—1
6276.2.78.61/3276.2.78.61 to 76.2.78.61—1
6376.2.78.62/3276.2.78.62 to 76.2.78.62—1
6476.2.78.63/3276.2.78.63 to 76.2.78.63—1
6576.2.78.64/3276.2.78.64 to 76.2.78.64—1
6676.2.78.65/3276.2.78.65 to 76.2.78.65—1
6776.2.78.66/3276.2.78.66 to 76.2.78.66—1
6876.2.78.67/3276.2.78.67 to 76.2.78.67—1
6976.2.78.68/3276.2.78.68 to 76.2.78.68—1
7076.2.78.69/3276.2.78.69 to 76.2.78.69—1
7176.2.78.70/3276.2.78.70 to 76.2.78.70—1
7276.2.78.71/3276.2.78.71 to 76.2.78.71—1
7376.2.78.72/3276.2.78.72 to 76.2.78.72—1
7476.2.78.73/3276.2.78.73 to 76.2.78.73—1
7576.2.78.74/3276.2.78.74 to 76.2.78.74—1
7676.2.78.75/3276.2.78.75 to 76.2.78.75—1
7776.2.78.76/3276.2.78.76 to 76.2.78.76—1
7876.2.78.77/3276.2.78.77 to 76.2.78.77—1
7976.2.78.78/3276.2.78.78 to 76.2.78.78—1
8076.2.78.79/3276.2.78.79 to 76.2.78.79—1
8176.2.78.80/3276.2.78.80 to 76.2.78.80—1
8276.2.78.81/3276.2.78.81 to 76.2.78.81—1
8376.2.78.82/3276.2.78.82 to 76.2.78.82—1
8476.2.78.83/3276.2.78.83 to 76.2.78.83—1
8576.2.78.84/3276.2.78.84 to 76.2.78.84—1
8676.2.78.85/3276.2.78.85 to 76.2.78.85—1
8776.2.78.86/3276.2.78.86 to 76.2.78.86—1
8876.2.78.87/3276.2.78.87 to 76.2.78.87—1
8976.2.78.88/3276.2.78.88 to 76.2.78.88—1
9076.2.78.89/3276.2.78.89 to 76.2.78.89—1
9176.2.78.90/3276.2.78.90 to 76.2.78.90—1
9276.2.78.91/3276.2.78.91 to 76.2.78.91—1
9376.2.78.92/3276.2.78.92 to 76.2.78.92—1
9476.2.78.93/3276.2.78.93 to 76.2.78.93—1
9576.2.78.94/3276.2.78.94 to 76.2.78.94—1
9676.2.78.95/3276.2.78.95 to 76.2.78.95—1
9776.2.78.96/3276.2.78.96 to 76.2.78.96—1
9876.2.78.97/3276.2.78.97 to 76.2.78.97—1
9976.2.78.98/3276.2.78.98 to 76.2.78.98—1
10076.2.78.99/3276.2.78.99 to 76.2.78.99—1
10176.2.78.100/3276.2.78.100 to 76.2.78.100—1
10276.2.78.101/3276.2.78.101 to 76.2.78.101—1
10376.2.78.102/3276.2.78.102 to 76.2.78.102—1
10476.2.78.103/3276.2.78.103 to 76.2.78.103—1
10576.2.78.104/3276.2.78.104 to 76.2.78.104—1
10676.2.78.105/3276.2.78.105 to 76.2.78.105—1
10776.2.78.106/3276.2.78.106 to 76.2.78.106—1
10876.2.78.107/3276.2.78.107 to 76.2.78.107—1
10976.2.78.108/3276.2.78.108 to 76.2.78.108—1
11076.2.78.109/3276.2.78.109 to 76.2.78.109—1
11176.2.78.110/3276.2.78.110 to 76.2.78.110—1
11276.2.78.111/3276.2.78.111 to 76.2.78.111—1
11376.2.78.112/3276.2.78.112 to 76.2.78.112—1
11476.2.78.113/3276.2.78.113 to 76.2.78.113—1
11576.2.78.114/3276.2.78.114 to 76.2.78.114—1
11676.2.78.115/3276.2.78.115 to 76.2.78.115—1
11776.2.78.116/3276.2.78.116 to 76.2.78.116—1
11876.2.78.117/3276.2.78.117 to 76.2.78.117—1
11976.2.78.118/3276.2.78.118 to 76.2.78.118—1
12076.2.78.119/3276.2.78.119 to 76.2.78.119—1
12176.2.78.120/3276.2.78.120 to 76.2.78.120—1
12276.2.78.121/3276.2.78.121 to 76.2.78.121—1
12376.2.78.122/3276.2.78.122 to 76.2.78.122—1
12476.2.78.123/3276.2.78.123 to 76.2.78.123—1
12576.2.78.124/3276.2.78.124 to 76.2.78.124—1
12676.2.78.125/3276.2.78.125 to 76.2.78.125—1
12776.2.78.126/3276.2.78.126 to 76.2.78.126—1
12876.2.78.127/3276.2.78.127 to 76.2.78.127—1
12976.2.78.128/3276.2.78.128 to 76.2.78.128—1
13076.2.78.129/3276.2.78.129 to 76.2.78.129—1
13176.2.78.130/3276.2.78.130 to 76.2.78.130—1
13276.2.78.131/3276.2.78.131 to 76.2.78.131—1
13376.2.78.132/3276.2.78.132 to 76.2.78.132—1
13476.2.78.133/3276.2.78.133 to 76.2.78.133—1
13576.2.78.134/3276.2.78.134 to 76.2.78.134—1
13676.2.78.135/3276.2.78.135 to 76.2.78.135—1
13776.2.78.136/3276.2.78.136 to 76.2.78.136—1
13876.2.78.137/3276.2.78.137 to 76.2.78.137—1
13976.2.78.138/3276.2.78.138 to 76.2.78.138—1
14076.2.78.139/3276.2.78.139 to 76.2.78.139—1
14176.2.78.140/3276.2.78.140 to 76.2.78.140—1
14276.2.78.141/3276.2.78.141 to 76.2.78.141—1
14376.2.78.142/3276.2.78.142 to 76.2.78.142—1
14476.2.78.143/3276.2.78.143 to 76.2.78.143—1
14576.2.78.144/3276.2.78.144 to 76.2.78.144—1
14676.2.78.145/3276.2.78.145 to 76.2.78.145—1
14776.2.78.146/3276.2.78.146 to 76.2.78.146—1
14876.2.78.147/3276.2.78.147 to 76.2.78.147—1
14976.2.78.148/3276.2.78.148 to 76.2.78.148—1
15076.2.78.149/3276.2.78.149 to 76.2.78.149—1
15176.2.78.150/3276.2.78.150 to 76.2.78.150—1
15276.2.78.151/3276.2.78.151 to 76.2.78.151—1
15376.2.78.152/3276.2.78.152 to 76.2.78.152—1
15476.2.78.153/3276.2.78.153 to 76.2.78.153—1
15576.2.78.154/3276.2.78.154 to 76.2.78.154—1
15676.2.78.155/3276.2.78.155 to 76.2.78.155—1
15776.2.78.156/3276.2.78.156 to 76.2.78.156—1
15876.2.78.157/3276.2.78.157 to 76.2.78.157—1
15976.2.78.158/3276.2.78.158 to 76.2.78.158—1
16076.2.78.159/3276.2.78.159 to 76.2.78.159—1
16176.2.78.160/3276.2.78.160 to 76.2.78.160—1
16276.2.78.161/3276.2.78.161 to 76.2.78.161—1
16376.2.78.162/3276.2.78.162 to 76.2.78.162—1
16476.2.78.163/3276.2.78.163 to 76.2.78.163—1
16576.2.78.164/3276.2.78.164 to 76.2.78.164—1
16676.2.78.165/3276.2.78.165 to 76.2.78.165—1
16776.2.78.166/3276.2.78.166 to 76.2.78.166—1
16876.2.78.167/3276.2.78.167 to 76.2.78.167—1
16976.2.78.168/3276.2.78.168 to 76.2.78.168—1
17076.2.78.169/3276.2.78.169 to 76.2.78.169—1
17176.2.78.170/3276.2.78.170 to 76.2.78.170—1
17276.2.78.171/3276.2.78.171 to 76.2.78.171—1
17376.2.78.172/3276.2.78.172 to 76.2.78.172—1
17476.2.78.173/3276.2.78.173 to 76.2.78.173—1
17576.2.78.174/3276.2.78.174 to 76.2.78.174—1
17676.2.78.175/3276.2.78.175 to 76.2.78.175—1
17776.2.78.176/3276.2.78.176 to 76.2.78.176—1
17876.2.78.177/3276.2.78.177 to 76.2.78.177—1
17976.2.78.178/3276.2.78.178 to 76.2.78.178—1
18076.2.78.179/3276.2.78.179 to 76.2.78.179—1
18176.2.78.180/3276.2.78.180 to 76.2.78.180—1
18276.2.78.181/3276.2.78.181 to 76.2.78.181—1
18376.2.78.182/3276.2.78.182 to 76.2.78.182—1
18476.2.78.183/3276.2.78.183 to 76.2.78.183—1
18576.2.78.184/3276.2.78.184 to 76.2.78.184—1
18676.2.78.185/3276.2.78.185 to 76.2.78.185—1
18776.2.78.186/3276.2.78.186 to 76.2.78.186—1
18876.2.78.187/3276.2.78.187 to 76.2.78.187—1
18976.2.78.188/3276.2.78.188 to 76.2.78.188—1
19076.2.78.189/3276.2.78.189 to 76.2.78.189—1
19176.2.78.190/3276.2.78.190 to 76.2.78.190—1
19276.2.78.191/3276.2.78.191 to 76.2.78.191—1
19376.2.78.192/3276.2.78.192 to 76.2.78.192—1
19476.2.78.193/3276.2.78.193 to 76.2.78.193—1
19576.2.78.194/3276.2.78.194 to 76.2.78.194—1
19676.2.78.195/3276.2.78.195 to 76.2.78.195—1
19776.2.78.196/3276.2.78.196 to 76.2.78.196—1
19876.2.78.197/3276.2.78.197 to 76.2.78.197—1
19976.2.78.198/3276.2.78.198 to 76.2.78.198—1
20076.2.78.199/3276.2.78.199 to 76.2.78.199—1
20176.2.78.200/3276.2.78.200 to 76.2.78.200—1
20276.2.78.201/3276.2.78.201 to 76.2.78.201—1
20376.2.78.202/3276.2.78.202 to 76.2.78.202—1
20476.2.78.203/3276.2.78.203 to 76.2.78.203—1
20576.2.78.204/3276.2.78.204 to 76.2.78.204—1
20676.2.78.205/3276.2.78.205 to 76.2.78.205—1
20776.2.78.206/3276.2.78.206 to 76.2.78.206—1
20876.2.78.207/3276.2.78.207 to 76.2.78.207—1
20976.2.78.208/3276.2.78.208 to 76.2.78.208—1
21076.2.78.209/3276.2.78.209 to 76.2.78.209—1
21176.2.78.210/3276.2.78.210 to 76.2.78.210—1
21276.2.78.211/3276.2.78.211 to 76.2.78.211—1
21376.2.78.212/3276.2.78.212 to 76.2.78.212—1
21476.2.78.213/3276.2.78.213 to 76.2.78.213—1
21576.2.78.214/3276.2.78.214 to 76.2.78.214—1
21676.2.78.215/3276.2.78.215 to 76.2.78.215—1
21776.2.78.216/3276.2.78.216 to 76.2.78.216—1
21876.2.78.217/3276.2.78.217 to 76.2.78.217—1
21976.2.78.218/3276.2.78.218 to 76.2.78.218—1
22076.2.78.219/3276.2.78.219 to 76.2.78.219—1
22176.2.78.220/3276.2.78.220 to 76.2.78.220—1
22276.2.78.221/3276.2.78.221 to 76.2.78.221—1
22376.2.78.222/3276.2.78.222 to 76.2.78.222—1
22476.2.78.223/3276.2.78.223 to 76.2.78.223—1
22576.2.78.224/3276.2.78.224 to 76.2.78.224—1
22676.2.78.225/3276.2.78.225 to 76.2.78.225—1
22776.2.78.226/3276.2.78.226 to 76.2.78.226—1
22876.2.78.227/3276.2.78.227 to 76.2.78.227—1
22976.2.78.228/3276.2.78.228 to 76.2.78.228—1
23076.2.78.229/3276.2.78.229 to 76.2.78.229—1
23176.2.78.230/3276.2.78.230 to 76.2.78.230—1
23276.2.78.231/3276.2.78.231 to 76.2.78.231—1
23376.2.78.232/3276.2.78.232 to 76.2.78.232—1
23476.2.78.233/3276.2.78.233 to 76.2.78.233—1
23576.2.78.234/3276.2.78.234 to 76.2.78.234—1
23676.2.78.235/3276.2.78.235 to 76.2.78.235—1
23776.2.78.236/3276.2.78.236 to 76.2.78.236—1
23876.2.78.237/3276.2.78.237 to 76.2.78.237—1
23976.2.78.238/3276.2.78.238 to 76.2.78.238—1
24076.2.78.239/3276.2.78.239 to 76.2.78.239—1
24176.2.78.240/3276.2.78.240 to 76.2.78.240—1
24276.2.78.241/3276.2.78.241 to 76.2.78.241—1
24376.2.78.242/3276.2.78.242 to 76.2.78.242—1
24476.2.78.243/3276.2.78.243 to 76.2.78.243—1
24576.2.78.244/3276.2.78.244 to 76.2.78.244—1
24676.2.78.245/3276.2.78.245 to 76.2.78.245—1
24776.2.78.246/3276.2.78.246 to 76.2.78.246—1
24876.2.78.247/3276.2.78.247 to 76.2.78.247—1
24976.2.78.248/3276.2.78.248 to 76.2.78.248—1
25076.2.78.249/3276.2.78.249 to 76.2.78.249—1
25176.2.78.250/3276.2.78.250 to 76.2.78.250—1
25276.2.78.251/3276.2.78.251 to 76.2.78.251—1
25376.2.78.252/3276.2.78.252 to 76.2.78.252—1
25476.2.78.253/3276.2.78.253 to 76.2.78.253—1
25576.2.78.254/3276.2.78.254 to 76.2.78.254—1
25676.2.78.255/3276.2.78.255 to 76.2.78.255—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.