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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.

Network36.232.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
36.232.0.0
Broadcast address
36.233.255.255
First usable
36.232.0.1
Last usable
36.233.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
A (default /8)
As numbers
Hex 24E80000 · Integer 619184128 to 619315199
Reverse DNS zones
232.36.in-addr.arpa
233.36.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00100100.11101000.00000000.0000000036.232.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network00100100.11101000.00000000.0000000036.232.0.0
Broadcast00100100.11101001.11111111.1111111136.233.255.255
Split into smaller subnets/25
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

36.232.0.0/15 makes 1,024 subnets of /25; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
136.232.0.0/2536.232.0.1 to 36.232.0.12636.232.0.127126
236.232.0.128/2536.232.0.129 to 36.232.0.25436.232.0.255126
336.232.1.0/2536.232.1.1 to 36.232.1.12636.232.1.127126
436.232.1.128/2536.232.1.129 to 36.232.1.25436.232.1.255126
536.232.2.0/2536.232.2.1 to 36.232.2.12636.232.2.127126
636.232.2.128/2536.232.2.129 to 36.232.2.25436.232.2.255126
736.232.3.0/2536.232.3.1 to 36.232.3.12636.232.3.127126
836.232.3.128/2536.232.3.129 to 36.232.3.25436.232.3.255126
936.232.4.0/2536.232.4.1 to 36.232.4.12636.232.4.127126
1036.232.4.128/2536.232.4.129 to 36.232.4.25436.232.4.255126
1136.232.5.0/2536.232.5.1 to 36.232.5.12636.232.5.127126
1236.232.5.128/2536.232.5.129 to 36.232.5.25436.232.5.255126
1336.232.6.0/2536.232.6.1 to 36.232.6.12636.232.6.127126
1436.232.6.128/2536.232.6.129 to 36.232.6.25436.232.6.255126
1536.232.7.0/2536.232.7.1 to 36.232.7.12636.232.7.127126
1636.232.7.128/2536.232.7.129 to 36.232.7.25436.232.7.255126
1736.232.8.0/2536.232.8.1 to 36.232.8.12636.232.8.127126
1836.232.8.128/2536.232.8.129 to 36.232.8.25436.232.8.255126
1936.232.9.0/2536.232.9.1 to 36.232.9.12636.232.9.127126
2036.232.9.128/2536.232.9.129 to 36.232.9.25436.232.9.255126
2136.232.10.0/2536.232.10.1 to 36.232.10.12636.232.10.127126
2236.232.10.128/2536.232.10.129 to 36.232.10.25436.232.10.255126
2336.232.11.0/2536.232.11.1 to 36.232.11.12636.232.11.127126
2436.232.11.128/2536.232.11.129 to 36.232.11.25436.232.11.255126
2536.232.12.0/2536.232.12.1 to 36.232.12.12636.232.12.127126
2636.232.12.128/2536.232.12.129 to 36.232.12.25436.232.12.255126
2736.232.13.0/2536.232.13.1 to 36.232.13.12636.232.13.127126
2836.232.13.128/2536.232.13.129 to 36.232.13.25436.232.13.255126
2936.232.14.0/2536.232.14.1 to 36.232.14.12636.232.14.127126
3036.232.14.128/2536.232.14.129 to 36.232.14.25436.232.14.255126
3136.232.15.0/2536.232.15.1 to 36.232.15.12636.232.15.127126
3236.232.15.128/2536.232.15.129 to 36.232.15.25436.232.15.255126
3336.232.16.0/2536.232.16.1 to 36.232.16.12636.232.16.127126
3436.232.16.128/2536.232.16.129 to 36.232.16.25436.232.16.255126
3536.232.17.0/2536.232.17.1 to 36.232.17.12636.232.17.127126
3636.232.17.128/2536.232.17.129 to 36.232.17.25436.232.17.255126
3736.232.18.0/2536.232.18.1 to 36.232.18.12636.232.18.127126
3836.232.18.128/2536.232.18.129 to 36.232.18.25436.232.18.255126
3936.232.19.0/2536.232.19.1 to 36.232.19.12636.232.19.127126
4036.232.19.128/2536.232.19.129 to 36.232.19.25436.232.19.255126
4136.232.20.0/2536.232.20.1 to 36.232.20.12636.232.20.127126
4236.232.20.128/2536.232.20.129 to 36.232.20.25436.232.20.255126
4336.232.21.0/2536.232.21.1 to 36.232.21.12636.232.21.127126
4436.232.21.128/2536.232.21.129 to 36.232.21.25436.232.21.255126
4536.232.22.0/2536.232.22.1 to 36.232.22.12636.232.22.127126
4636.232.22.128/2536.232.22.129 to 36.232.22.25436.232.22.255126
4736.232.23.0/2536.232.23.1 to 36.232.23.12636.232.23.127126
4836.232.23.128/2536.232.23.129 to 36.232.23.25436.232.23.255126
4936.232.24.0/2536.232.24.1 to 36.232.24.12636.232.24.127126
5036.232.24.128/2536.232.24.129 to 36.232.24.25436.232.24.255126
5136.232.25.0/2536.232.25.1 to 36.232.25.12636.232.25.127126
5236.232.25.128/2536.232.25.129 to 36.232.25.25436.232.25.255126
5336.232.26.0/2536.232.26.1 to 36.232.26.12636.232.26.127126
5436.232.26.128/2536.232.26.129 to 36.232.26.25436.232.26.255126
5536.232.27.0/2536.232.27.1 to 36.232.27.12636.232.27.127126
5636.232.27.128/2536.232.27.129 to 36.232.27.25436.232.27.255126
5736.232.28.0/2536.232.28.1 to 36.232.28.12636.232.28.127126
5836.232.28.128/2536.232.28.129 to 36.232.28.25436.232.28.255126
5936.232.29.0/2536.232.29.1 to 36.232.29.12636.232.29.127126
6036.232.29.128/2536.232.29.129 to 36.232.29.25436.232.29.255126
6136.232.30.0/2536.232.30.1 to 36.232.30.12636.232.30.127126
6236.232.30.128/2536.232.30.129 to 36.232.30.25436.232.30.255126
6336.232.31.0/2536.232.31.1 to 36.232.31.12636.232.31.127126
6436.232.31.128/2536.232.31.129 to 36.232.31.25436.232.31.255126
6536.232.32.0/2536.232.32.1 to 36.232.32.12636.232.32.127126
6636.232.32.128/2536.232.32.129 to 36.232.32.25436.232.32.255126
6736.232.33.0/2536.232.33.1 to 36.232.33.12636.232.33.127126
6836.232.33.128/2536.232.33.129 to 36.232.33.25436.232.33.255126
6936.232.34.0/2536.232.34.1 to 36.232.34.12636.232.34.127126
7036.232.34.128/2536.232.34.129 to 36.232.34.25436.232.34.255126
7136.232.35.0/2536.232.35.1 to 36.232.35.12636.232.35.127126
7236.232.35.128/2536.232.35.129 to 36.232.35.25436.232.35.255126
7336.232.36.0/2536.232.36.1 to 36.232.36.12636.232.36.127126
7436.232.36.128/2536.232.36.129 to 36.232.36.25436.232.36.255126
7536.232.37.0/2536.232.37.1 to 36.232.37.12636.232.37.127126
7636.232.37.128/2536.232.37.129 to 36.232.37.25436.232.37.255126
7736.232.38.0/2536.232.38.1 to 36.232.38.12636.232.38.127126
7836.232.38.128/2536.232.38.129 to 36.232.38.25436.232.38.255126
7936.232.39.0/2536.232.39.1 to 36.232.39.12636.232.39.127126
8036.232.39.128/2536.232.39.129 to 36.232.39.25436.232.39.255126
8136.232.40.0/2536.232.40.1 to 36.232.40.12636.232.40.127126
8236.232.40.128/2536.232.40.129 to 36.232.40.25436.232.40.255126
8336.232.41.0/2536.232.41.1 to 36.232.41.12636.232.41.127126
8436.232.41.128/2536.232.41.129 to 36.232.41.25436.232.41.255126
8536.232.42.0/2536.232.42.1 to 36.232.42.12636.232.42.127126
8636.232.42.128/2536.232.42.129 to 36.232.42.25436.232.42.255126
8736.232.43.0/2536.232.43.1 to 36.232.43.12636.232.43.127126
8836.232.43.128/2536.232.43.129 to 36.232.43.25436.232.43.255126
8936.232.44.0/2536.232.44.1 to 36.232.44.12636.232.44.127126
9036.232.44.128/2536.232.44.129 to 36.232.44.25436.232.44.255126
9136.232.45.0/2536.232.45.1 to 36.232.45.12636.232.45.127126
9236.232.45.128/2536.232.45.129 to 36.232.45.25436.232.45.255126
9336.232.46.0/2536.232.46.1 to 36.232.46.12636.232.46.127126
9436.232.46.128/2536.232.46.129 to 36.232.46.25436.232.46.255126
9536.232.47.0/2536.232.47.1 to 36.232.47.12636.232.47.127126
9636.232.47.128/2536.232.47.129 to 36.232.47.25436.232.47.255126
9736.232.48.0/2536.232.48.1 to 36.232.48.12636.232.48.127126
9836.232.48.128/2536.232.48.129 to 36.232.48.25436.232.48.255126
9936.232.49.0/2536.232.49.1 to 36.232.49.12636.232.49.127126
10036.232.49.128/2536.232.49.129 to 36.232.49.25436.232.49.255126
10136.232.50.0/2536.232.50.1 to 36.232.50.12636.232.50.127126
10236.232.50.128/2536.232.50.129 to 36.232.50.25436.232.50.255126
10336.232.51.0/2536.232.51.1 to 36.232.51.12636.232.51.127126
10436.232.51.128/2536.232.51.129 to 36.232.51.25436.232.51.255126
10536.232.52.0/2536.232.52.1 to 36.232.52.12636.232.52.127126
10636.232.52.128/2536.232.52.129 to 36.232.52.25436.232.52.255126
10736.232.53.0/2536.232.53.1 to 36.232.53.12636.232.53.127126
10836.232.53.128/2536.232.53.129 to 36.232.53.25436.232.53.255126
10936.232.54.0/2536.232.54.1 to 36.232.54.12636.232.54.127126
11036.232.54.128/2536.232.54.129 to 36.232.54.25436.232.54.255126
11136.232.55.0/2536.232.55.1 to 36.232.55.12636.232.55.127126
11236.232.55.128/2536.232.55.129 to 36.232.55.25436.232.55.255126
11336.232.56.0/2536.232.56.1 to 36.232.56.12636.232.56.127126
11436.232.56.128/2536.232.56.129 to 36.232.56.25436.232.56.255126
11536.232.57.0/2536.232.57.1 to 36.232.57.12636.232.57.127126
11636.232.57.128/2536.232.57.129 to 36.232.57.25436.232.57.255126
11736.232.58.0/2536.232.58.1 to 36.232.58.12636.232.58.127126
11836.232.58.128/2536.232.58.129 to 36.232.58.25436.232.58.255126
11936.232.59.0/2536.232.59.1 to 36.232.59.12636.232.59.127126
12036.232.59.128/2536.232.59.129 to 36.232.59.25436.232.59.255126
12136.232.60.0/2536.232.60.1 to 36.232.60.12636.232.60.127126
12236.232.60.128/2536.232.60.129 to 36.232.60.25436.232.60.255126
12336.232.61.0/2536.232.61.1 to 36.232.61.12636.232.61.127126
12436.232.61.128/2536.232.61.129 to 36.232.61.25436.232.61.255126
12536.232.62.0/2536.232.62.1 to 36.232.62.12636.232.62.127126
12636.232.62.128/2536.232.62.129 to 36.232.62.25436.232.62.255126
12736.232.63.0/2536.232.63.1 to 36.232.63.12636.232.63.127126
12836.232.63.128/2536.232.63.129 to 36.232.63.25436.232.63.255126
12936.232.64.0/2536.232.64.1 to 36.232.64.12636.232.64.127126
13036.232.64.128/2536.232.64.129 to 36.232.64.25436.232.64.255126
13136.232.65.0/2536.232.65.1 to 36.232.65.12636.232.65.127126
13236.232.65.128/2536.232.65.129 to 36.232.65.25436.232.65.255126
13336.232.66.0/2536.232.66.1 to 36.232.66.12636.232.66.127126
13436.232.66.128/2536.232.66.129 to 36.232.66.25436.232.66.255126
13536.232.67.0/2536.232.67.1 to 36.232.67.12636.232.67.127126
13636.232.67.128/2536.232.67.129 to 36.232.67.25436.232.67.255126
13736.232.68.0/2536.232.68.1 to 36.232.68.12636.232.68.127126
13836.232.68.128/2536.232.68.129 to 36.232.68.25436.232.68.255126
13936.232.69.0/2536.232.69.1 to 36.232.69.12636.232.69.127126
14036.232.69.128/2536.232.69.129 to 36.232.69.25436.232.69.255126
14136.232.70.0/2536.232.70.1 to 36.232.70.12636.232.70.127126
14236.232.70.128/2536.232.70.129 to 36.232.70.25436.232.70.255126
14336.232.71.0/2536.232.71.1 to 36.232.71.12636.232.71.127126
14436.232.71.128/2536.232.71.129 to 36.232.71.25436.232.71.255126
14536.232.72.0/2536.232.72.1 to 36.232.72.12636.232.72.127126
14636.232.72.128/2536.232.72.129 to 36.232.72.25436.232.72.255126
14736.232.73.0/2536.232.73.1 to 36.232.73.12636.232.73.127126
14836.232.73.128/2536.232.73.129 to 36.232.73.25436.232.73.255126
14936.232.74.0/2536.232.74.1 to 36.232.74.12636.232.74.127126
15036.232.74.128/2536.232.74.129 to 36.232.74.25436.232.74.255126
15136.232.75.0/2536.232.75.1 to 36.232.75.12636.232.75.127126
15236.232.75.128/2536.232.75.129 to 36.232.75.25436.232.75.255126
15336.232.76.0/2536.232.76.1 to 36.232.76.12636.232.76.127126
15436.232.76.128/2536.232.76.129 to 36.232.76.25436.232.76.255126
15536.232.77.0/2536.232.77.1 to 36.232.77.12636.232.77.127126
15636.232.77.128/2536.232.77.129 to 36.232.77.25436.232.77.255126
15736.232.78.0/2536.232.78.1 to 36.232.78.12636.232.78.127126
15836.232.78.128/2536.232.78.129 to 36.232.78.25436.232.78.255126
15936.232.79.0/2536.232.79.1 to 36.232.79.12636.232.79.127126
16036.232.79.128/2536.232.79.129 to 36.232.79.25436.232.79.255126
16136.232.80.0/2536.232.80.1 to 36.232.80.12636.232.80.127126
16236.232.80.128/2536.232.80.129 to 36.232.80.25436.232.80.255126
16336.232.81.0/2536.232.81.1 to 36.232.81.12636.232.81.127126
16436.232.81.128/2536.232.81.129 to 36.232.81.25436.232.81.255126
16536.232.82.0/2536.232.82.1 to 36.232.82.12636.232.82.127126
16636.232.82.128/2536.232.82.129 to 36.232.82.25436.232.82.255126
16736.232.83.0/2536.232.83.1 to 36.232.83.12636.232.83.127126
16836.232.83.128/2536.232.83.129 to 36.232.83.25436.232.83.255126
16936.232.84.0/2536.232.84.1 to 36.232.84.12636.232.84.127126
17036.232.84.128/2536.232.84.129 to 36.232.84.25436.232.84.255126
17136.232.85.0/2536.232.85.1 to 36.232.85.12636.232.85.127126
17236.232.85.128/2536.232.85.129 to 36.232.85.25436.232.85.255126
17336.232.86.0/2536.232.86.1 to 36.232.86.12636.232.86.127126
17436.232.86.128/2536.232.86.129 to 36.232.86.25436.232.86.255126
17536.232.87.0/2536.232.87.1 to 36.232.87.12636.232.87.127126
17636.232.87.128/2536.232.87.129 to 36.232.87.25436.232.87.255126
17736.232.88.0/2536.232.88.1 to 36.232.88.12636.232.88.127126
17836.232.88.128/2536.232.88.129 to 36.232.88.25436.232.88.255126
17936.232.89.0/2536.232.89.1 to 36.232.89.12636.232.89.127126
18036.232.89.128/2536.232.89.129 to 36.232.89.25436.232.89.255126
18136.232.90.0/2536.232.90.1 to 36.232.90.12636.232.90.127126
18236.232.90.128/2536.232.90.129 to 36.232.90.25436.232.90.255126
18336.232.91.0/2536.232.91.1 to 36.232.91.12636.232.91.127126
18436.232.91.128/2536.232.91.129 to 36.232.91.25436.232.91.255126
18536.232.92.0/2536.232.92.1 to 36.232.92.12636.232.92.127126
18636.232.92.128/2536.232.92.129 to 36.232.92.25436.232.92.255126
18736.232.93.0/2536.232.93.1 to 36.232.93.12636.232.93.127126
18836.232.93.128/2536.232.93.129 to 36.232.93.25436.232.93.255126
18936.232.94.0/2536.232.94.1 to 36.232.94.12636.232.94.127126
19036.232.94.128/2536.232.94.129 to 36.232.94.25436.232.94.255126
19136.232.95.0/2536.232.95.1 to 36.232.95.12636.232.95.127126
19236.232.95.128/2536.232.95.129 to 36.232.95.25436.232.95.255126
19336.232.96.0/2536.232.96.1 to 36.232.96.12636.232.96.127126
19436.232.96.128/2536.232.96.129 to 36.232.96.25436.232.96.255126
19536.232.97.0/2536.232.97.1 to 36.232.97.12636.232.97.127126
19636.232.97.128/2536.232.97.129 to 36.232.97.25436.232.97.255126
19736.232.98.0/2536.232.98.1 to 36.232.98.12636.232.98.127126
19836.232.98.128/2536.232.98.129 to 36.232.98.25436.232.98.255126
19936.232.99.0/2536.232.99.1 to 36.232.99.12636.232.99.127126
20036.232.99.128/2536.232.99.129 to 36.232.99.25436.232.99.255126
20136.232.100.0/2536.232.100.1 to 36.232.100.12636.232.100.127126
20236.232.100.128/2536.232.100.129 to 36.232.100.25436.232.100.255126
20336.232.101.0/2536.232.101.1 to 36.232.101.12636.232.101.127126
20436.232.101.128/2536.232.101.129 to 36.232.101.25436.232.101.255126
20536.232.102.0/2536.232.102.1 to 36.232.102.12636.232.102.127126
20636.232.102.128/2536.232.102.129 to 36.232.102.25436.232.102.255126
20736.232.103.0/2536.232.103.1 to 36.232.103.12636.232.103.127126
20836.232.103.128/2536.232.103.129 to 36.232.103.25436.232.103.255126
20936.232.104.0/2536.232.104.1 to 36.232.104.12636.232.104.127126
21036.232.104.128/2536.232.104.129 to 36.232.104.25436.232.104.255126
21136.232.105.0/2536.232.105.1 to 36.232.105.12636.232.105.127126
21236.232.105.128/2536.232.105.129 to 36.232.105.25436.232.105.255126
21336.232.106.0/2536.232.106.1 to 36.232.106.12636.232.106.127126
21436.232.106.128/2536.232.106.129 to 36.232.106.25436.232.106.255126
21536.232.107.0/2536.232.107.1 to 36.232.107.12636.232.107.127126
21636.232.107.128/2536.232.107.129 to 36.232.107.25436.232.107.255126
21736.232.108.0/2536.232.108.1 to 36.232.108.12636.232.108.127126
21836.232.108.128/2536.232.108.129 to 36.232.108.25436.232.108.255126
21936.232.109.0/2536.232.109.1 to 36.232.109.12636.232.109.127126
22036.232.109.128/2536.232.109.129 to 36.232.109.25436.232.109.255126
22136.232.110.0/2536.232.110.1 to 36.232.110.12636.232.110.127126
22236.232.110.128/2536.232.110.129 to 36.232.110.25436.232.110.255126
22336.232.111.0/2536.232.111.1 to 36.232.111.12636.232.111.127126
22436.232.111.128/2536.232.111.129 to 36.232.111.25436.232.111.255126
22536.232.112.0/2536.232.112.1 to 36.232.112.12636.232.112.127126
22636.232.112.128/2536.232.112.129 to 36.232.112.25436.232.112.255126
22736.232.113.0/2536.232.113.1 to 36.232.113.12636.232.113.127126
22836.232.113.128/2536.232.113.129 to 36.232.113.25436.232.113.255126
22936.232.114.0/2536.232.114.1 to 36.232.114.12636.232.114.127126
23036.232.114.128/2536.232.114.129 to 36.232.114.25436.232.114.255126
23136.232.115.0/2536.232.115.1 to 36.232.115.12636.232.115.127126
23236.232.115.128/2536.232.115.129 to 36.232.115.25436.232.115.255126
23336.232.116.0/2536.232.116.1 to 36.232.116.12636.232.116.127126
23436.232.116.128/2536.232.116.129 to 36.232.116.25436.232.116.255126
23536.232.117.0/2536.232.117.1 to 36.232.117.12636.232.117.127126
23636.232.117.128/2536.232.117.129 to 36.232.117.25436.232.117.255126
23736.232.118.0/2536.232.118.1 to 36.232.118.12636.232.118.127126
23836.232.118.128/2536.232.118.129 to 36.232.118.25436.232.118.255126
23936.232.119.0/2536.232.119.1 to 36.232.119.12636.232.119.127126
24036.232.119.128/2536.232.119.129 to 36.232.119.25436.232.119.255126
24136.232.120.0/2536.232.120.1 to 36.232.120.12636.232.120.127126
24236.232.120.128/2536.232.120.129 to 36.232.120.25436.232.120.255126
24336.232.121.0/2536.232.121.1 to 36.232.121.12636.232.121.127126
24436.232.121.128/2536.232.121.129 to 36.232.121.25436.232.121.255126
24536.232.122.0/2536.232.122.1 to 36.232.122.12636.232.122.127126
24636.232.122.128/2536.232.122.129 to 36.232.122.25436.232.122.255126
24736.232.123.0/2536.232.123.1 to 36.232.123.12636.232.123.127126
24836.232.123.128/2536.232.123.129 to 36.232.123.25436.232.123.255126
24936.232.124.0/2536.232.124.1 to 36.232.124.12636.232.124.127126
25036.232.124.128/2536.232.124.129 to 36.232.124.25436.232.124.255126
25136.232.125.0/2536.232.125.1 to 36.232.125.12636.232.125.127126
25236.232.125.128/2536.232.125.129 to 36.232.125.25436.232.125.255126
25336.232.126.0/2536.232.126.1 to 36.232.126.12636.232.126.127126
25436.232.126.128/2536.232.126.129 to 36.232.126.25436.232.126.255126
25536.232.127.0/2536.232.127.1 to 36.232.127.12636.232.127.127126
25636.232.127.128/2536.232.127.129 to 36.232.127.25436.232.127.255126

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.