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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.

Network33.192.0.0/14
Usable hosts262,142
Subnet mask255.252.0.0
Addresses262,144
Network address
33.192.0.0
Broadcast address
33.195.255.255
First usable
33.192.0.1
Last usable
33.195.255.254
Usable hosts
262,142 (262,144 less the network and broadcast addresses)
Subnet mask
255.252.0.0
Wildcard mask
0.3.255.255 (Cisco ACLs, OSPF)
Prefix length
/14
Type
Public public
Old class
A (default /8)
As numbers
Hex 21C00000 · Integer 566231040 to 566493183
Reverse DNS zones
192.33.in-addr.arpa
193.33.in-addr.arpa
194.33.in-addr.arpa
195.33.in-addr.arpa
/14 is not on a 8-bit boundary, so it takes 4 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00100001.11000000.00000000.0000000033.192.0.0
Subnet mask11111111.11111100.00000000.00000000255.252.0.0
Network00100001.11000000.00000000.0000000033.192.0.0
Broadcast00100001.11000011.11111111.1111111133.195.255.255
Split into smaller subnets/25
/15 (2)/16 (4)/17 (8)/18 (16)/19 (32)/20 (64)/21 (128)/22 (256)/23 (512)/24 (1,024)/25 (2,048)/26 (4,096)

33.192.0.0/14 makes 2,048 subnets of /25; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
133.192.0.0/2533.192.0.1 to 33.192.0.12633.192.0.127126
233.192.0.128/2533.192.0.129 to 33.192.0.25433.192.0.255126
333.192.1.0/2533.192.1.1 to 33.192.1.12633.192.1.127126
433.192.1.128/2533.192.1.129 to 33.192.1.25433.192.1.255126
533.192.2.0/2533.192.2.1 to 33.192.2.12633.192.2.127126
633.192.2.128/2533.192.2.129 to 33.192.2.25433.192.2.255126
733.192.3.0/2533.192.3.1 to 33.192.3.12633.192.3.127126
833.192.3.128/2533.192.3.129 to 33.192.3.25433.192.3.255126
933.192.4.0/2533.192.4.1 to 33.192.4.12633.192.4.127126
1033.192.4.128/2533.192.4.129 to 33.192.4.25433.192.4.255126
1133.192.5.0/2533.192.5.1 to 33.192.5.12633.192.5.127126
1233.192.5.128/2533.192.5.129 to 33.192.5.25433.192.5.255126
1333.192.6.0/2533.192.6.1 to 33.192.6.12633.192.6.127126
1433.192.6.128/2533.192.6.129 to 33.192.6.25433.192.6.255126
1533.192.7.0/2533.192.7.1 to 33.192.7.12633.192.7.127126
1633.192.7.128/2533.192.7.129 to 33.192.7.25433.192.7.255126
1733.192.8.0/2533.192.8.1 to 33.192.8.12633.192.8.127126
1833.192.8.128/2533.192.8.129 to 33.192.8.25433.192.8.255126
1933.192.9.0/2533.192.9.1 to 33.192.9.12633.192.9.127126
2033.192.9.128/2533.192.9.129 to 33.192.9.25433.192.9.255126
2133.192.10.0/2533.192.10.1 to 33.192.10.12633.192.10.127126
2233.192.10.128/2533.192.10.129 to 33.192.10.25433.192.10.255126
2333.192.11.0/2533.192.11.1 to 33.192.11.12633.192.11.127126
2433.192.11.128/2533.192.11.129 to 33.192.11.25433.192.11.255126
2533.192.12.0/2533.192.12.1 to 33.192.12.12633.192.12.127126
2633.192.12.128/2533.192.12.129 to 33.192.12.25433.192.12.255126
2733.192.13.0/2533.192.13.1 to 33.192.13.12633.192.13.127126
2833.192.13.128/2533.192.13.129 to 33.192.13.25433.192.13.255126
2933.192.14.0/2533.192.14.1 to 33.192.14.12633.192.14.127126
3033.192.14.128/2533.192.14.129 to 33.192.14.25433.192.14.255126
3133.192.15.0/2533.192.15.1 to 33.192.15.12633.192.15.127126
3233.192.15.128/2533.192.15.129 to 33.192.15.25433.192.15.255126
3333.192.16.0/2533.192.16.1 to 33.192.16.12633.192.16.127126
3433.192.16.128/2533.192.16.129 to 33.192.16.25433.192.16.255126
3533.192.17.0/2533.192.17.1 to 33.192.17.12633.192.17.127126
3633.192.17.128/2533.192.17.129 to 33.192.17.25433.192.17.255126
3733.192.18.0/2533.192.18.1 to 33.192.18.12633.192.18.127126
3833.192.18.128/2533.192.18.129 to 33.192.18.25433.192.18.255126
3933.192.19.0/2533.192.19.1 to 33.192.19.12633.192.19.127126
4033.192.19.128/2533.192.19.129 to 33.192.19.25433.192.19.255126
4133.192.20.0/2533.192.20.1 to 33.192.20.12633.192.20.127126
4233.192.20.128/2533.192.20.129 to 33.192.20.25433.192.20.255126
4333.192.21.0/2533.192.21.1 to 33.192.21.12633.192.21.127126
4433.192.21.128/2533.192.21.129 to 33.192.21.25433.192.21.255126
4533.192.22.0/2533.192.22.1 to 33.192.22.12633.192.22.127126
4633.192.22.128/2533.192.22.129 to 33.192.22.25433.192.22.255126
4733.192.23.0/2533.192.23.1 to 33.192.23.12633.192.23.127126
4833.192.23.128/2533.192.23.129 to 33.192.23.25433.192.23.255126
4933.192.24.0/2533.192.24.1 to 33.192.24.12633.192.24.127126
5033.192.24.128/2533.192.24.129 to 33.192.24.25433.192.24.255126
5133.192.25.0/2533.192.25.1 to 33.192.25.12633.192.25.127126
5233.192.25.128/2533.192.25.129 to 33.192.25.25433.192.25.255126
5333.192.26.0/2533.192.26.1 to 33.192.26.12633.192.26.127126
5433.192.26.128/2533.192.26.129 to 33.192.26.25433.192.26.255126
5533.192.27.0/2533.192.27.1 to 33.192.27.12633.192.27.127126
5633.192.27.128/2533.192.27.129 to 33.192.27.25433.192.27.255126
5733.192.28.0/2533.192.28.1 to 33.192.28.12633.192.28.127126
5833.192.28.128/2533.192.28.129 to 33.192.28.25433.192.28.255126
5933.192.29.0/2533.192.29.1 to 33.192.29.12633.192.29.127126
6033.192.29.128/2533.192.29.129 to 33.192.29.25433.192.29.255126
6133.192.30.0/2533.192.30.1 to 33.192.30.12633.192.30.127126
6233.192.30.128/2533.192.30.129 to 33.192.30.25433.192.30.255126
6333.192.31.0/2533.192.31.1 to 33.192.31.12633.192.31.127126
6433.192.31.128/2533.192.31.129 to 33.192.31.25433.192.31.255126
6533.192.32.0/2533.192.32.1 to 33.192.32.12633.192.32.127126
6633.192.32.128/2533.192.32.129 to 33.192.32.25433.192.32.255126
6733.192.33.0/2533.192.33.1 to 33.192.33.12633.192.33.127126
6833.192.33.128/2533.192.33.129 to 33.192.33.25433.192.33.255126
6933.192.34.0/2533.192.34.1 to 33.192.34.12633.192.34.127126
7033.192.34.128/2533.192.34.129 to 33.192.34.25433.192.34.255126
7133.192.35.0/2533.192.35.1 to 33.192.35.12633.192.35.127126
7233.192.35.128/2533.192.35.129 to 33.192.35.25433.192.35.255126
7333.192.36.0/2533.192.36.1 to 33.192.36.12633.192.36.127126
7433.192.36.128/2533.192.36.129 to 33.192.36.25433.192.36.255126
7533.192.37.0/2533.192.37.1 to 33.192.37.12633.192.37.127126
7633.192.37.128/2533.192.37.129 to 33.192.37.25433.192.37.255126
7733.192.38.0/2533.192.38.1 to 33.192.38.12633.192.38.127126
7833.192.38.128/2533.192.38.129 to 33.192.38.25433.192.38.255126
7933.192.39.0/2533.192.39.1 to 33.192.39.12633.192.39.127126
8033.192.39.128/2533.192.39.129 to 33.192.39.25433.192.39.255126
8133.192.40.0/2533.192.40.1 to 33.192.40.12633.192.40.127126
8233.192.40.128/2533.192.40.129 to 33.192.40.25433.192.40.255126
8333.192.41.0/2533.192.41.1 to 33.192.41.12633.192.41.127126
8433.192.41.128/2533.192.41.129 to 33.192.41.25433.192.41.255126
8533.192.42.0/2533.192.42.1 to 33.192.42.12633.192.42.127126
8633.192.42.128/2533.192.42.129 to 33.192.42.25433.192.42.255126
8733.192.43.0/2533.192.43.1 to 33.192.43.12633.192.43.127126
8833.192.43.128/2533.192.43.129 to 33.192.43.25433.192.43.255126
8933.192.44.0/2533.192.44.1 to 33.192.44.12633.192.44.127126
9033.192.44.128/2533.192.44.129 to 33.192.44.25433.192.44.255126
9133.192.45.0/2533.192.45.1 to 33.192.45.12633.192.45.127126
9233.192.45.128/2533.192.45.129 to 33.192.45.25433.192.45.255126
9333.192.46.0/2533.192.46.1 to 33.192.46.12633.192.46.127126
9433.192.46.128/2533.192.46.129 to 33.192.46.25433.192.46.255126
9533.192.47.0/2533.192.47.1 to 33.192.47.12633.192.47.127126
9633.192.47.128/2533.192.47.129 to 33.192.47.25433.192.47.255126
9733.192.48.0/2533.192.48.1 to 33.192.48.12633.192.48.127126
9833.192.48.128/2533.192.48.129 to 33.192.48.25433.192.48.255126
9933.192.49.0/2533.192.49.1 to 33.192.49.12633.192.49.127126
10033.192.49.128/2533.192.49.129 to 33.192.49.25433.192.49.255126
10133.192.50.0/2533.192.50.1 to 33.192.50.12633.192.50.127126
10233.192.50.128/2533.192.50.129 to 33.192.50.25433.192.50.255126
10333.192.51.0/2533.192.51.1 to 33.192.51.12633.192.51.127126
10433.192.51.128/2533.192.51.129 to 33.192.51.25433.192.51.255126
10533.192.52.0/2533.192.52.1 to 33.192.52.12633.192.52.127126
10633.192.52.128/2533.192.52.129 to 33.192.52.25433.192.52.255126
10733.192.53.0/2533.192.53.1 to 33.192.53.12633.192.53.127126
10833.192.53.128/2533.192.53.129 to 33.192.53.25433.192.53.255126
10933.192.54.0/2533.192.54.1 to 33.192.54.12633.192.54.127126
11033.192.54.128/2533.192.54.129 to 33.192.54.25433.192.54.255126
11133.192.55.0/2533.192.55.1 to 33.192.55.12633.192.55.127126
11233.192.55.128/2533.192.55.129 to 33.192.55.25433.192.55.255126
11333.192.56.0/2533.192.56.1 to 33.192.56.12633.192.56.127126
11433.192.56.128/2533.192.56.129 to 33.192.56.25433.192.56.255126
11533.192.57.0/2533.192.57.1 to 33.192.57.12633.192.57.127126
11633.192.57.128/2533.192.57.129 to 33.192.57.25433.192.57.255126
11733.192.58.0/2533.192.58.1 to 33.192.58.12633.192.58.127126
11833.192.58.128/2533.192.58.129 to 33.192.58.25433.192.58.255126
11933.192.59.0/2533.192.59.1 to 33.192.59.12633.192.59.127126
12033.192.59.128/2533.192.59.129 to 33.192.59.25433.192.59.255126
12133.192.60.0/2533.192.60.1 to 33.192.60.12633.192.60.127126
12233.192.60.128/2533.192.60.129 to 33.192.60.25433.192.60.255126
12333.192.61.0/2533.192.61.1 to 33.192.61.12633.192.61.127126
12433.192.61.128/2533.192.61.129 to 33.192.61.25433.192.61.255126
12533.192.62.0/2533.192.62.1 to 33.192.62.12633.192.62.127126
12633.192.62.128/2533.192.62.129 to 33.192.62.25433.192.62.255126
12733.192.63.0/2533.192.63.1 to 33.192.63.12633.192.63.127126
12833.192.63.128/2533.192.63.129 to 33.192.63.25433.192.63.255126
12933.192.64.0/2533.192.64.1 to 33.192.64.12633.192.64.127126
13033.192.64.128/2533.192.64.129 to 33.192.64.25433.192.64.255126
13133.192.65.0/2533.192.65.1 to 33.192.65.12633.192.65.127126
13233.192.65.128/2533.192.65.129 to 33.192.65.25433.192.65.255126
13333.192.66.0/2533.192.66.1 to 33.192.66.12633.192.66.127126
13433.192.66.128/2533.192.66.129 to 33.192.66.25433.192.66.255126
13533.192.67.0/2533.192.67.1 to 33.192.67.12633.192.67.127126
13633.192.67.128/2533.192.67.129 to 33.192.67.25433.192.67.255126
13733.192.68.0/2533.192.68.1 to 33.192.68.12633.192.68.127126
13833.192.68.128/2533.192.68.129 to 33.192.68.25433.192.68.255126
13933.192.69.0/2533.192.69.1 to 33.192.69.12633.192.69.127126
14033.192.69.128/2533.192.69.129 to 33.192.69.25433.192.69.255126
14133.192.70.0/2533.192.70.1 to 33.192.70.12633.192.70.127126
14233.192.70.128/2533.192.70.129 to 33.192.70.25433.192.70.255126
14333.192.71.0/2533.192.71.1 to 33.192.71.12633.192.71.127126
14433.192.71.128/2533.192.71.129 to 33.192.71.25433.192.71.255126
14533.192.72.0/2533.192.72.1 to 33.192.72.12633.192.72.127126
14633.192.72.128/2533.192.72.129 to 33.192.72.25433.192.72.255126
14733.192.73.0/2533.192.73.1 to 33.192.73.12633.192.73.127126
14833.192.73.128/2533.192.73.129 to 33.192.73.25433.192.73.255126
14933.192.74.0/2533.192.74.1 to 33.192.74.12633.192.74.127126
15033.192.74.128/2533.192.74.129 to 33.192.74.25433.192.74.255126
15133.192.75.0/2533.192.75.1 to 33.192.75.12633.192.75.127126
15233.192.75.128/2533.192.75.129 to 33.192.75.25433.192.75.255126
15333.192.76.0/2533.192.76.1 to 33.192.76.12633.192.76.127126
15433.192.76.128/2533.192.76.129 to 33.192.76.25433.192.76.255126
15533.192.77.0/2533.192.77.1 to 33.192.77.12633.192.77.127126
15633.192.77.128/2533.192.77.129 to 33.192.77.25433.192.77.255126
15733.192.78.0/2533.192.78.1 to 33.192.78.12633.192.78.127126
15833.192.78.128/2533.192.78.129 to 33.192.78.25433.192.78.255126
15933.192.79.0/2533.192.79.1 to 33.192.79.12633.192.79.127126
16033.192.79.128/2533.192.79.129 to 33.192.79.25433.192.79.255126
16133.192.80.0/2533.192.80.1 to 33.192.80.12633.192.80.127126
16233.192.80.128/2533.192.80.129 to 33.192.80.25433.192.80.255126
16333.192.81.0/2533.192.81.1 to 33.192.81.12633.192.81.127126
16433.192.81.128/2533.192.81.129 to 33.192.81.25433.192.81.255126
16533.192.82.0/2533.192.82.1 to 33.192.82.12633.192.82.127126
16633.192.82.128/2533.192.82.129 to 33.192.82.25433.192.82.255126
16733.192.83.0/2533.192.83.1 to 33.192.83.12633.192.83.127126
16833.192.83.128/2533.192.83.129 to 33.192.83.25433.192.83.255126
16933.192.84.0/2533.192.84.1 to 33.192.84.12633.192.84.127126
17033.192.84.128/2533.192.84.129 to 33.192.84.25433.192.84.255126
17133.192.85.0/2533.192.85.1 to 33.192.85.12633.192.85.127126
17233.192.85.128/2533.192.85.129 to 33.192.85.25433.192.85.255126
17333.192.86.0/2533.192.86.1 to 33.192.86.12633.192.86.127126
17433.192.86.128/2533.192.86.129 to 33.192.86.25433.192.86.255126
17533.192.87.0/2533.192.87.1 to 33.192.87.12633.192.87.127126
17633.192.87.128/2533.192.87.129 to 33.192.87.25433.192.87.255126
17733.192.88.0/2533.192.88.1 to 33.192.88.12633.192.88.127126
17833.192.88.128/2533.192.88.129 to 33.192.88.25433.192.88.255126
17933.192.89.0/2533.192.89.1 to 33.192.89.12633.192.89.127126
18033.192.89.128/2533.192.89.129 to 33.192.89.25433.192.89.255126
18133.192.90.0/2533.192.90.1 to 33.192.90.12633.192.90.127126
18233.192.90.128/2533.192.90.129 to 33.192.90.25433.192.90.255126
18333.192.91.0/2533.192.91.1 to 33.192.91.12633.192.91.127126
18433.192.91.128/2533.192.91.129 to 33.192.91.25433.192.91.255126
18533.192.92.0/2533.192.92.1 to 33.192.92.12633.192.92.127126
18633.192.92.128/2533.192.92.129 to 33.192.92.25433.192.92.255126
18733.192.93.0/2533.192.93.1 to 33.192.93.12633.192.93.127126
18833.192.93.128/2533.192.93.129 to 33.192.93.25433.192.93.255126
18933.192.94.0/2533.192.94.1 to 33.192.94.12633.192.94.127126
19033.192.94.128/2533.192.94.129 to 33.192.94.25433.192.94.255126
19133.192.95.0/2533.192.95.1 to 33.192.95.12633.192.95.127126
19233.192.95.128/2533.192.95.129 to 33.192.95.25433.192.95.255126
19333.192.96.0/2533.192.96.1 to 33.192.96.12633.192.96.127126
19433.192.96.128/2533.192.96.129 to 33.192.96.25433.192.96.255126
19533.192.97.0/2533.192.97.1 to 33.192.97.12633.192.97.127126
19633.192.97.128/2533.192.97.129 to 33.192.97.25433.192.97.255126
19733.192.98.0/2533.192.98.1 to 33.192.98.12633.192.98.127126
19833.192.98.128/2533.192.98.129 to 33.192.98.25433.192.98.255126
19933.192.99.0/2533.192.99.1 to 33.192.99.12633.192.99.127126
20033.192.99.128/2533.192.99.129 to 33.192.99.25433.192.99.255126
20133.192.100.0/2533.192.100.1 to 33.192.100.12633.192.100.127126
20233.192.100.128/2533.192.100.129 to 33.192.100.25433.192.100.255126
20333.192.101.0/2533.192.101.1 to 33.192.101.12633.192.101.127126
20433.192.101.128/2533.192.101.129 to 33.192.101.25433.192.101.255126
20533.192.102.0/2533.192.102.1 to 33.192.102.12633.192.102.127126
20633.192.102.128/2533.192.102.129 to 33.192.102.25433.192.102.255126
20733.192.103.0/2533.192.103.1 to 33.192.103.12633.192.103.127126
20833.192.103.128/2533.192.103.129 to 33.192.103.25433.192.103.255126
20933.192.104.0/2533.192.104.1 to 33.192.104.12633.192.104.127126
21033.192.104.128/2533.192.104.129 to 33.192.104.25433.192.104.255126
21133.192.105.0/2533.192.105.1 to 33.192.105.12633.192.105.127126
21233.192.105.128/2533.192.105.129 to 33.192.105.25433.192.105.255126
21333.192.106.0/2533.192.106.1 to 33.192.106.12633.192.106.127126
21433.192.106.128/2533.192.106.129 to 33.192.106.25433.192.106.255126
21533.192.107.0/2533.192.107.1 to 33.192.107.12633.192.107.127126
21633.192.107.128/2533.192.107.129 to 33.192.107.25433.192.107.255126
21733.192.108.0/2533.192.108.1 to 33.192.108.12633.192.108.127126
21833.192.108.128/2533.192.108.129 to 33.192.108.25433.192.108.255126
21933.192.109.0/2533.192.109.1 to 33.192.109.12633.192.109.127126
22033.192.109.128/2533.192.109.129 to 33.192.109.25433.192.109.255126
22133.192.110.0/2533.192.110.1 to 33.192.110.12633.192.110.127126
22233.192.110.128/2533.192.110.129 to 33.192.110.25433.192.110.255126
22333.192.111.0/2533.192.111.1 to 33.192.111.12633.192.111.127126
22433.192.111.128/2533.192.111.129 to 33.192.111.25433.192.111.255126
22533.192.112.0/2533.192.112.1 to 33.192.112.12633.192.112.127126
22633.192.112.128/2533.192.112.129 to 33.192.112.25433.192.112.255126
22733.192.113.0/2533.192.113.1 to 33.192.113.12633.192.113.127126
22833.192.113.128/2533.192.113.129 to 33.192.113.25433.192.113.255126
22933.192.114.0/2533.192.114.1 to 33.192.114.12633.192.114.127126
23033.192.114.128/2533.192.114.129 to 33.192.114.25433.192.114.255126
23133.192.115.0/2533.192.115.1 to 33.192.115.12633.192.115.127126
23233.192.115.128/2533.192.115.129 to 33.192.115.25433.192.115.255126
23333.192.116.0/2533.192.116.1 to 33.192.116.12633.192.116.127126
23433.192.116.128/2533.192.116.129 to 33.192.116.25433.192.116.255126
23533.192.117.0/2533.192.117.1 to 33.192.117.12633.192.117.127126
23633.192.117.128/2533.192.117.129 to 33.192.117.25433.192.117.255126
23733.192.118.0/2533.192.118.1 to 33.192.118.12633.192.118.127126
23833.192.118.128/2533.192.118.129 to 33.192.118.25433.192.118.255126
23933.192.119.0/2533.192.119.1 to 33.192.119.12633.192.119.127126
24033.192.119.128/2533.192.119.129 to 33.192.119.25433.192.119.255126
24133.192.120.0/2533.192.120.1 to 33.192.120.12633.192.120.127126
24233.192.120.128/2533.192.120.129 to 33.192.120.25433.192.120.255126
24333.192.121.0/2533.192.121.1 to 33.192.121.12633.192.121.127126
24433.192.121.128/2533.192.121.129 to 33.192.121.25433.192.121.255126
24533.192.122.0/2533.192.122.1 to 33.192.122.12633.192.122.127126
24633.192.122.128/2533.192.122.129 to 33.192.122.25433.192.122.255126
24733.192.123.0/2533.192.123.1 to 33.192.123.12633.192.123.127126
24833.192.123.128/2533.192.123.129 to 33.192.123.25433.192.123.255126
24933.192.124.0/2533.192.124.1 to 33.192.124.12633.192.124.127126
25033.192.124.128/2533.192.124.129 to 33.192.124.25433.192.124.255126
25133.192.125.0/2533.192.125.1 to 33.192.125.12633.192.125.127126
25233.192.125.128/2533.192.125.129 to 33.192.125.25433.192.125.255126
25333.192.126.0/2533.192.126.1 to 33.192.126.12633.192.126.127126
25433.192.126.128/2533.192.126.129 to 33.192.126.25433.192.126.255126
25533.192.127.0/2533.192.127.1 to 33.192.127.12633.192.127.127126
25633.192.127.128/2533.192.127.129 to 33.192.127.25433.192.127.255126

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.