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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.

Network60.2.80.0/20
Usable hosts4,094
Subnet mask255.255.240.0
Addresses4,096
Network address
60.2.80.0
Broadcast address
60.2.95.255
First usable
60.2.80.1
Last usable
60.2.95.254
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 3C025000 · Integer 1006784512 to 1006788607
Reverse DNS zones
80.2.60.in-addr.arpa
81.2.60.in-addr.arpa
82.2.60.in-addr.arpa
83.2.60.in-addr.arpa
84.2.60.in-addr.arpa
85.2.60.in-addr.arpa
86.2.60.in-addr.arpa
87.2.60.in-addr.arpa
88.2.60.in-addr.arpa
89.2.60.in-addr.arpa
90.2.60.in-addr.arpa
91.2.60.in-addr.arpa
92.2.60.in-addr.arpa
93.2.60.in-addr.arpa
94.2.60.in-addr.arpa
95.2.60.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
Address00111100.00000010.01010000.0000000060.2.80.0
Subnet mask11111111.11111111.11110000.00000000255.255.240.0
Network00111100.00000010.01010000.0000000060.2.80.0
Broadcast00111100.00000010.01011111.1111111160.2.95.255
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)

60.2.80.0/20 makes 4,096 subnets of /32; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
160.2.80.0/3260.2.80.0 to 60.2.80.0—1
260.2.80.1/3260.2.80.1 to 60.2.80.1—1
360.2.80.2/3260.2.80.2 to 60.2.80.2—1
460.2.80.3/3260.2.80.3 to 60.2.80.3—1
560.2.80.4/3260.2.80.4 to 60.2.80.4—1
660.2.80.5/3260.2.80.5 to 60.2.80.5—1
760.2.80.6/3260.2.80.6 to 60.2.80.6—1
860.2.80.7/3260.2.80.7 to 60.2.80.7—1
960.2.80.8/3260.2.80.8 to 60.2.80.8—1
1060.2.80.9/3260.2.80.9 to 60.2.80.9—1
1160.2.80.10/3260.2.80.10 to 60.2.80.10—1
1260.2.80.11/3260.2.80.11 to 60.2.80.11—1
1360.2.80.12/3260.2.80.12 to 60.2.80.12—1
1460.2.80.13/3260.2.80.13 to 60.2.80.13—1
1560.2.80.14/3260.2.80.14 to 60.2.80.14—1
1660.2.80.15/3260.2.80.15 to 60.2.80.15—1
1760.2.80.16/3260.2.80.16 to 60.2.80.16—1
1860.2.80.17/3260.2.80.17 to 60.2.80.17—1
1960.2.80.18/3260.2.80.18 to 60.2.80.18—1
2060.2.80.19/3260.2.80.19 to 60.2.80.19—1
2160.2.80.20/3260.2.80.20 to 60.2.80.20—1
2260.2.80.21/3260.2.80.21 to 60.2.80.21—1
2360.2.80.22/3260.2.80.22 to 60.2.80.22—1
2460.2.80.23/3260.2.80.23 to 60.2.80.23—1
2560.2.80.24/3260.2.80.24 to 60.2.80.24—1
2660.2.80.25/3260.2.80.25 to 60.2.80.25—1
2760.2.80.26/3260.2.80.26 to 60.2.80.26—1
2860.2.80.27/3260.2.80.27 to 60.2.80.27—1
2960.2.80.28/3260.2.80.28 to 60.2.80.28—1
3060.2.80.29/3260.2.80.29 to 60.2.80.29—1
3160.2.80.30/3260.2.80.30 to 60.2.80.30—1
3260.2.80.31/3260.2.80.31 to 60.2.80.31—1
3360.2.80.32/3260.2.80.32 to 60.2.80.32—1
3460.2.80.33/3260.2.80.33 to 60.2.80.33—1
3560.2.80.34/3260.2.80.34 to 60.2.80.34—1
3660.2.80.35/3260.2.80.35 to 60.2.80.35—1
3760.2.80.36/3260.2.80.36 to 60.2.80.36—1
3860.2.80.37/3260.2.80.37 to 60.2.80.37—1
3960.2.80.38/3260.2.80.38 to 60.2.80.38—1
4060.2.80.39/3260.2.80.39 to 60.2.80.39—1
4160.2.80.40/3260.2.80.40 to 60.2.80.40—1
4260.2.80.41/3260.2.80.41 to 60.2.80.41—1
4360.2.80.42/3260.2.80.42 to 60.2.80.42—1
4460.2.80.43/3260.2.80.43 to 60.2.80.43—1
4560.2.80.44/3260.2.80.44 to 60.2.80.44—1
4660.2.80.45/3260.2.80.45 to 60.2.80.45—1
4760.2.80.46/3260.2.80.46 to 60.2.80.46—1
4860.2.80.47/3260.2.80.47 to 60.2.80.47—1
4960.2.80.48/3260.2.80.48 to 60.2.80.48—1
5060.2.80.49/3260.2.80.49 to 60.2.80.49—1
5160.2.80.50/3260.2.80.50 to 60.2.80.50—1
5260.2.80.51/3260.2.80.51 to 60.2.80.51—1
5360.2.80.52/3260.2.80.52 to 60.2.80.52—1
5460.2.80.53/3260.2.80.53 to 60.2.80.53—1
5560.2.80.54/3260.2.80.54 to 60.2.80.54—1
5660.2.80.55/3260.2.80.55 to 60.2.80.55—1
5760.2.80.56/3260.2.80.56 to 60.2.80.56—1
5860.2.80.57/3260.2.80.57 to 60.2.80.57—1
5960.2.80.58/3260.2.80.58 to 60.2.80.58—1
6060.2.80.59/3260.2.80.59 to 60.2.80.59—1
6160.2.80.60/3260.2.80.60 to 60.2.80.60—1
6260.2.80.61/3260.2.80.61 to 60.2.80.61—1
6360.2.80.62/3260.2.80.62 to 60.2.80.62—1
6460.2.80.63/3260.2.80.63 to 60.2.80.63—1
6560.2.80.64/3260.2.80.64 to 60.2.80.64—1
6660.2.80.65/3260.2.80.65 to 60.2.80.65—1
6760.2.80.66/3260.2.80.66 to 60.2.80.66—1
6860.2.80.67/3260.2.80.67 to 60.2.80.67—1
6960.2.80.68/3260.2.80.68 to 60.2.80.68—1
7060.2.80.69/3260.2.80.69 to 60.2.80.69—1
7160.2.80.70/3260.2.80.70 to 60.2.80.70—1
7260.2.80.71/3260.2.80.71 to 60.2.80.71—1
7360.2.80.72/3260.2.80.72 to 60.2.80.72—1
7460.2.80.73/3260.2.80.73 to 60.2.80.73—1
7560.2.80.74/3260.2.80.74 to 60.2.80.74—1
7660.2.80.75/3260.2.80.75 to 60.2.80.75—1
7760.2.80.76/3260.2.80.76 to 60.2.80.76—1
7860.2.80.77/3260.2.80.77 to 60.2.80.77—1
7960.2.80.78/3260.2.80.78 to 60.2.80.78—1
8060.2.80.79/3260.2.80.79 to 60.2.80.79—1
8160.2.80.80/3260.2.80.80 to 60.2.80.80—1
8260.2.80.81/3260.2.80.81 to 60.2.80.81—1
8360.2.80.82/3260.2.80.82 to 60.2.80.82—1
8460.2.80.83/3260.2.80.83 to 60.2.80.83—1
8560.2.80.84/3260.2.80.84 to 60.2.80.84—1
8660.2.80.85/3260.2.80.85 to 60.2.80.85—1
8760.2.80.86/3260.2.80.86 to 60.2.80.86—1
8860.2.80.87/3260.2.80.87 to 60.2.80.87—1
8960.2.80.88/3260.2.80.88 to 60.2.80.88—1
9060.2.80.89/3260.2.80.89 to 60.2.80.89—1
9160.2.80.90/3260.2.80.90 to 60.2.80.90—1
9260.2.80.91/3260.2.80.91 to 60.2.80.91—1
9360.2.80.92/3260.2.80.92 to 60.2.80.92—1
9460.2.80.93/3260.2.80.93 to 60.2.80.93—1
9560.2.80.94/3260.2.80.94 to 60.2.80.94—1
9660.2.80.95/3260.2.80.95 to 60.2.80.95—1
9760.2.80.96/3260.2.80.96 to 60.2.80.96—1
9860.2.80.97/3260.2.80.97 to 60.2.80.97—1
9960.2.80.98/3260.2.80.98 to 60.2.80.98—1
10060.2.80.99/3260.2.80.99 to 60.2.80.99—1
10160.2.80.100/3260.2.80.100 to 60.2.80.100—1
10260.2.80.101/3260.2.80.101 to 60.2.80.101—1
10360.2.80.102/3260.2.80.102 to 60.2.80.102—1
10460.2.80.103/3260.2.80.103 to 60.2.80.103—1
10560.2.80.104/3260.2.80.104 to 60.2.80.104—1
10660.2.80.105/3260.2.80.105 to 60.2.80.105—1
10760.2.80.106/3260.2.80.106 to 60.2.80.106—1
10860.2.80.107/3260.2.80.107 to 60.2.80.107—1
10960.2.80.108/3260.2.80.108 to 60.2.80.108—1
11060.2.80.109/3260.2.80.109 to 60.2.80.109—1
11160.2.80.110/3260.2.80.110 to 60.2.80.110—1
11260.2.80.111/3260.2.80.111 to 60.2.80.111—1
11360.2.80.112/3260.2.80.112 to 60.2.80.112—1
11460.2.80.113/3260.2.80.113 to 60.2.80.113—1
11560.2.80.114/3260.2.80.114 to 60.2.80.114—1
11660.2.80.115/3260.2.80.115 to 60.2.80.115—1
11760.2.80.116/3260.2.80.116 to 60.2.80.116—1
11860.2.80.117/3260.2.80.117 to 60.2.80.117—1
11960.2.80.118/3260.2.80.118 to 60.2.80.118—1
12060.2.80.119/3260.2.80.119 to 60.2.80.119—1
12160.2.80.120/3260.2.80.120 to 60.2.80.120—1
12260.2.80.121/3260.2.80.121 to 60.2.80.121—1
12360.2.80.122/3260.2.80.122 to 60.2.80.122—1
12460.2.80.123/3260.2.80.123 to 60.2.80.123—1
12560.2.80.124/3260.2.80.124 to 60.2.80.124—1
12660.2.80.125/3260.2.80.125 to 60.2.80.125—1
12760.2.80.126/3260.2.80.126 to 60.2.80.126—1
12860.2.80.127/3260.2.80.127 to 60.2.80.127—1
12960.2.80.128/3260.2.80.128 to 60.2.80.128—1
13060.2.80.129/3260.2.80.129 to 60.2.80.129—1
13160.2.80.130/3260.2.80.130 to 60.2.80.130—1
13260.2.80.131/3260.2.80.131 to 60.2.80.131—1
13360.2.80.132/3260.2.80.132 to 60.2.80.132—1
13460.2.80.133/3260.2.80.133 to 60.2.80.133—1
13560.2.80.134/3260.2.80.134 to 60.2.80.134—1
13660.2.80.135/3260.2.80.135 to 60.2.80.135—1
13760.2.80.136/3260.2.80.136 to 60.2.80.136—1
13860.2.80.137/3260.2.80.137 to 60.2.80.137—1
13960.2.80.138/3260.2.80.138 to 60.2.80.138—1
14060.2.80.139/3260.2.80.139 to 60.2.80.139—1
14160.2.80.140/3260.2.80.140 to 60.2.80.140—1
14260.2.80.141/3260.2.80.141 to 60.2.80.141—1
14360.2.80.142/3260.2.80.142 to 60.2.80.142—1
14460.2.80.143/3260.2.80.143 to 60.2.80.143—1
14560.2.80.144/3260.2.80.144 to 60.2.80.144—1
14660.2.80.145/3260.2.80.145 to 60.2.80.145—1
14760.2.80.146/3260.2.80.146 to 60.2.80.146—1
14860.2.80.147/3260.2.80.147 to 60.2.80.147—1
14960.2.80.148/3260.2.80.148 to 60.2.80.148—1
15060.2.80.149/3260.2.80.149 to 60.2.80.149—1
15160.2.80.150/3260.2.80.150 to 60.2.80.150—1
15260.2.80.151/3260.2.80.151 to 60.2.80.151—1
15360.2.80.152/3260.2.80.152 to 60.2.80.152—1
15460.2.80.153/3260.2.80.153 to 60.2.80.153—1
15560.2.80.154/3260.2.80.154 to 60.2.80.154—1
15660.2.80.155/3260.2.80.155 to 60.2.80.155—1
15760.2.80.156/3260.2.80.156 to 60.2.80.156—1
15860.2.80.157/3260.2.80.157 to 60.2.80.157—1
15960.2.80.158/3260.2.80.158 to 60.2.80.158—1
16060.2.80.159/3260.2.80.159 to 60.2.80.159—1
16160.2.80.160/3260.2.80.160 to 60.2.80.160—1
16260.2.80.161/3260.2.80.161 to 60.2.80.161—1
16360.2.80.162/3260.2.80.162 to 60.2.80.162—1
16460.2.80.163/3260.2.80.163 to 60.2.80.163—1
16560.2.80.164/3260.2.80.164 to 60.2.80.164—1
16660.2.80.165/3260.2.80.165 to 60.2.80.165—1
16760.2.80.166/3260.2.80.166 to 60.2.80.166—1
16860.2.80.167/3260.2.80.167 to 60.2.80.167—1
16960.2.80.168/3260.2.80.168 to 60.2.80.168—1
17060.2.80.169/3260.2.80.169 to 60.2.80.169—1
17160.2.80.170/3260.2.80.170 to 60.2.80.170—1
17260.2.80.171/3260.2.80.171 to 60.2.80.171—1
17360.2.80.172/3260.2.80.172 to 60.2.80.172—1
17460.2.80.173/3260.2.80.173 to 60.2.80.173—1
17560.2.80.174/3260.2.80.174 to 60.2.80.174—1
17660.2.80.175/3260.2.80.175 to 60.2.80.175—1
17760.2.80.176/3260.2.80.176 to 60.2.80.176—1
17860.2.80.177/3260.2.80.177 to 60.2.80.177—1
17960.2.80.178/3260.2.80.178 to 60.2.80.178—1
18060.2.80.179/3260.2.80.179 to 60.2.80.179—1
18160.2.80.180/3260.2.80.180 to 60.2.80.180—1
18260.2.80.181/3260.2.80.181 to 60.2.80.181—1
18360.2.80.182/3260.2.80.182 to 60.2.80.182—1
18460.2.80.183/3260.2.80.183 to 60.2.80.183—1
18560.2.80.184/3260.2.80.184 to 60.2.80.184—1
18660.2.80.185/3260.2.80.185 to 60.2.80.185—1
18760.2.80.186/3260.2.80.186 to 60.2.80.186—1
18860.2.80.187/3260.2.80.187 to 60.2.80.187—1
18960.2.80.188/3260.2.80.188 to 60.2.80.188—1
19060.2.80.189/3260.2.80.189 to 60.2.80.189—1
19160.2.80.190/3260.2.80.190 to 60.2.80.190—1
19260.2.80.191/3260.2.80.191 to 60.2.80.191—1
19360.2.80.192/3260.2.80.192 to 60.2.80.192—1
19460.2.80.193/3260.2.80.193 to 60.2.80.193—1
19560.2.80.194/3260.2.80.194 to 60.2.80.194—1
19660.2.80.195/3260.2.80.195 to 60.2.80.195—1
19760.2.80.196/3260.2.80.196 to 60.2.80.196—1
19860.2.80.197/3260.2.80.197 to 60.2.80.197—1
19960.2.80.198/3260.2.80.198 to 60.2.80.198—1
20060.2.80.199/3260.2.80.199 to 60.2.80.199—1
20160.2.80.200/3260.2.80.200 to 60.2.80.200—1
20260.2.80.201/3260.2.80.201 to 60.2.80.201—1
20360.2.80.202/3260.2.80.202 to 60.2.80.202—1
20460.2.80.203/3260.2.80.203 to 60.2.80.203—1
20560.2.80.204/3260.2.80.204 to 60.2.80.204—1
20660.2.80.205/3260.2.80.205 to 60.2.80.205—1
20760.2.80.206/3260.2.80.206 to 60.2.80.206—1
20860.2.80.207/3260.2.80.207 to 60.2.80.207—1
20960.2.80.208/3260.2.80.208 to 60.2.80.208—1
21060.2.80.209/3260.2.80.209 to 60.2.80.209—1
21160.2.80.210/3260.2.80.210 to 60.2.80.210—1
21260.2.80.211/3260.2.80.211 to 60.2.80.211—1
21360.2.80.212/3260.2.80.212 to 60.2.80.212—1
21460.2.80.213/3260.2.80.213 to 60.2.80.213—1
21560.2.80.214/3260.2.80.214 to 60.2.80.214—1
21660.2.80.215/3260.2.80.215 to 60.2.80.215—1
21760.2.80.216/3260.2.80.216 to 60.2.80.216—1
21860.2.80.217/3260.2.80.217 to 60.2.80.217—1
21960.2.80.218/3260.2.80.218 to 60.2.80.218—1
22060.2.80.219/3260.2.80.219 to 60.2.80.219—1
22160.2.80.220/3260.2.80.220 to 60.2.80.220—1
22260.2.80.221/3260.2.80.221 to 60.2.80.221—1
22360.2.80.222/3260.2.80.222 to 60.2.80.222—1
22460.2.80.223/3260.2.80.223 to 60.2.80.223—1
22560.2.80.224/3260.2.80.224 to 60.2.80.224—1
22660.2.80.225/3260.2.80.225 to 60.2.80.225—1
22760.2.80.226/3260.2.80.226 to 60.2.80.226—1
22860.2.80.227/3260.2.80.227 to 60.2.80.227—1
22960.2.80.228/3260.2.80.228 to 60.2.80.228—1
23060.2.80.229/3260.2.80.229 to 60.2.80.229—1
23160.2.80.230/3260.2.80.230 to 60.2.80.230—1
23260.2.80.231/3260.2.80.231 to 60.2.80.231—1
23360.2.80.232/3260.2.80.232 to 60.2.80.232—1
23460.2.80.233/3260.2.80.233 to 60.2.80.233—1
23560.2.80.234/3260.2.80.234 to 60.2.80.234—1
23660.2.80.235/3260.2.80.235 to 60.2.80.235—1
23760.2.80.236/3260.2.80.236 to 60.2.80.236—1
23860.2.80.237/3260.2.80.237 to 60.2.80.237—1
23960.2.80.238/3260.2.80.238 to 60.2.80.238—1
24060.2.80.239/3260.2.80.239 to 60.2.80.239—1
24160.2.80.240/3260.2.80.240 to 60.2.80.240—1
24260.2.80.241/3260.2.80.241 to 60.2.80.241—1
24360.2.80.242/3260.2.80.242 to 60.2.80.242—1
24460.2.80.243/3260.2.80.243 to 60.2.80.243—1
24560.2.80.244/3260.2.80.244 to 60.2.80.244—1
24660.2.80.245/3260.2.80.245 to 60.2.80.245—1
24760.2.80.246/3260.2.80.246 to 60.2.80.246—1
24860.2.80.247/3260.2.80.247 to 60.2.80.247—1
24960.2.80.248/3260.2.80.248 to 60.2.80.248—1
25060.2.80.249/3260.2.80.249 to 60.2.80.249—1
25160.2.80.250/3260.2.80.250 to 60.2.80.250—1
25260.2.80.251/3260.2.80.251 to 60.2.80.251—1
25360.2.80.252/3260.2.80.252 to 60.2.80.252—1
25460.2.80.253/3260.2.80.253 to 60.2.80.253—1
25560.2.80.254/3260.2.80.254 to 60.2.80.254—1
25660.2.80.255/3260.2.80.255 to 60.2.80.255—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.