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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.

Network78.89.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
78.89.0.0
Broadcast address
78.89.127.255
First usable
78.89.0.1
Last usable
78.89.127.254
Usable hosts
32,766 (32,768 less the network and broadcast addresses)
Subnet mask
255.255.128.0
Wildcard mask
0.0.127.255 (Cisco ACLs, OSPF)
Prefix length
/17
Type
Public public
Old class
A (default /8)
As numbers
Hex 4E590000 · Integer 1314455552 to 1314488319
Reverse DNS zones
0.89.78.in-addr.arpa
1.89.78.in-addr.arpa
2.89.78.in-addr.arpa
3.89.78.in-addr.arpa
4.89.78.in-addr.arpa
5.89.78.in-addr.arpa
6.89.78.in-addr.arpa
7.89.78.in-addr.arpa
8.89.78.in-addr.arpa
9.89.78.in-addr.arpa
10.89.78.in-addr.arpa
11.89.78.in-addr.arpa
12.89.78.in-addr.arpa
13.89.78.in-addr.arpa
14.89.78.in-addr.arpa
15.89.78.in-addr.arpa
and 112 more
/17 is not on a 8-bit boundary, so it takes 128 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01001110.01011001.00000000.0000000078.89.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network01001110.01011001.00000000.0000000078.89.0.0
Broadcast01001110.01011001.01111111.1111111178.89.127.255
Split into smaller subnets/25
/18 (2)/19 (4)/20 (8)/21 (16)/22 (32)/23 (64)/24 (128)/25 (256)/26 (512)/27 (1,024)/28 (2,048)/29 (4,096)

78.89.0.0/17 makes 256 subnets of /25.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
178.89.0.0/2578.89.0.1 to 78.89.0.12678.89.0.127126
278.89.0.128/2578.89.0.129 to 78.89.0.25478.89.0.255126
378.89.1.0/2578.89.1.1 to 78.89.1.12678.89.1.127126
478.89.1.128/2578.89.1.129 to 78.89.1.25478.89.1.255126
578.89.2.0/2578.89.2.1 to 78.89.2.12678.89.2.127126
678.89.2.128/2578.89.2.129 to 78.89.2.25478.89.2.255126
778.89.3.0/2578.89.3.1 to 78.89.3.12678.89.3.127126
878.89.3.128/2578.89.3.129 to 78.89.3.25478.89.3.255126
978.89.4.0/2578.89.4.1 to 78.89.4.12678.89.4.127126
1078.89.4.128/2578.89.4.129 to 78.89.4.25478.89.4.255126
1178.89.5.0/2578.89.5.1 to 78.89.5.12678.89.5.127126
1278.89.5.128/2578.89.5.129 to 78.89.5.25478.89.5.255126
1378.89.6.0/2578.89.6.1 to 78.89.6.12678.89.6.127126
1478.89.6.128/2578.89.6.129 to 78.89.6.25478.89.6.255126
1578.89.7.0/2578.89.7.1 to 78.89.7.12678.89.7.127126
1678.89.7.128/2578.89.7.129 to 78.89.7.25478.89.7.255126
1778.89.8.0/2578.89.8.1 to 78.89.8.12678.89.8.127126
1878.89.8.128/2578.89.8.129 to 78.89.8.25478.89.8.255126
1978.89.9.0/2578.89.9.1 to 78.89.9.12678.89.9.127126
2078.89.9.128/2578.89.9.129 to 78.89.9.25478.89.9.255126
2178.89.10.0/2578.89.10.1 to 78.89.10.12678.89.10.127126
2278.89.10.128/2578.89.10.129 to 78.89.10.25478.89.10.255126
2378.89.11.0/2578.89.11.1 to 78.89.11.12678.89.11.127126
2478.89.11.128/2578.89.11.129 to 78.89.11.25478.89.11.255126
2578.89.12.0/2578.89.12.1 to 78.89.12.12678.89.12.127126
2678.89.12.128/2578.89.12.129 to 78.89.12.25478.89.12.255126
2778.89.13.0/2578.89.13.1 to 78.89.13.12678.89.13.127126
2878.89.13.128/2578.89.13.129 to 78.89.13.25478.89.13.255126
2978.89.14.0/2578.89.14.1 to 78.89.14.12678.89.14.127126
3078.89.14.128/2578.89.14.129 to 78.89.14.25478.89.14.255126
3178.89.15.0/2578.89.15.1 to 78.89.15.12678.89.15.127126
3278.89.15.128/2578.89.15.129 to 78.89.15.25478.89.15.255126
3378.89.16.0/2578.89.16.1 to 78.89.16.12678.89.16.127126
3478.89.16.128/2578.89.16.129 to 78.89.16.25478.89.16.255126
3578.89.17.0/2578.89.17.1 to 78.89.17.12678.89.17.127126
3678.89.17.128/2578.89.17.129 to 78.89.17.25478.89.17.255126
3778.89.18.0/2578.89.18.1 to 78.89.18.12678.89.18.127126
3878.89.18.128/2578.89.18.129 to 78.89.18.25478.89.18.255126
3978.89.19.0/2578.89.19.1 to 78.89.19.12678.89.19.127126
4078.89.19.128/2578.89.19.129 to 78.89.19.25478.89.19.255126
4178.89.20.0/2578.89.20.1 to 78.89.20.12678.89.20.127126
4278.89.20.128/2578.89.20.129 to 78.89.20.25478.89.20.255126
4378.89.21.0/2578.89.21.1 to 78.89.21.12678.89.21.127126
4478.89.21.128/2578.89.21.129 to 78.89.21.25478.89.21.255126
4578.89.22.0/2578.89.22.1 to 78.89.22.12678.89.22.127126
4678.89.22.128/2578.89.22.129 to 78.89.22.25478.89.22.255126
4778.89.23.0/2578.89.23.1 to 78.89.23.12678.89.23.127126
4878.89.23.128/2578.89.23.129 to 78.89.23.25478.89.23.255126
4978.89.24.0/2578.89.24.1 to 78.89.24.12678.89.24.127126
5078.89.24.128/2578.89.24.129 to 78.89.24.25478.89.24.255126
5178.89.25.0/2578.89.25.1 to 78.89.25.12678.89.25.127126
5278.89.25.128/2578.89.25.129 to 78.89.25.25478.89.25.255126
5378.89.26.0/2578.89.26.1 to 78.89.26.12678.89.26.127126
5478.89.26.128/2578.89.26.129 to 78.89.26.25478.89.26.255126
5578.89.27.0/2578.89.27.1 to 78.89.27.12678.89.27.127126
5678.89.27.128/2578.89.27.129 to 78.89.27.25478.89.27.255126
5778.89.28.0/2578.89.28.1 to 78.89.28.12678.89.28.127126
5878.89.28.128/2578.89.28.129 to 78.89.28.25478.89.28.255126
5978.89.29.0/2578.89.29.1 to 78.89.29.12678.89.29.127126
6078.89.29.128/2578.89.29.129 to 78.89.29.25478.89.29.255126
6178.89.30.0/2578.89.30.1 to 78.89.30.12678.89.30.127126
6278.89.30.128/2578.89.30.129 to 78.89.30.25478.89.30.255126
6378.89.31.0/2578.89.31.1 to 78.89.31.12678.89.31.127126
6478.89.31.128/2578.89.31.129 to 78.89.31.25478.89.31.255126
6578.89.32.0/2578.89.32.1 to 78.89.32.12678.89.32.127126
6678.89.32.128/2578.89.32.129 to 78.89.32.25478.89.32.255126
6778.89.33.0/2578.89.33.1 to 78.89.33.12678.89.33.127126
6878.89.33.128/2578.89.33.129 to 78.89.33.25478.89.33.255126
6978.89.34.0/2578.89.34.1 to 78.89.34.12678.89.34.127126
7078.89.34.128/2578.89.34.129 to 78.89.34.25478.89.34.255126
7178.89.35.0/2578.89.35.1 to 78.89.35.12678.89.35.127126
7278.89.35.128/2578.89.35.129 to 78.89.35.25478.89.35.255126
7378.89.36.0/2578.89.36.1 to 78.89.36.12678.89.36.127126
7478.89.36.128/2578.89.36.129 to 78.89.36.25478.89.36.255126
7578.89.37.0/2578.89.37.1 to 78.89.37.12678.89.37.127126
7678.89.37.128/2578.89.37.129 to 78.89.37.25478.89.37.255126
7778.89.38.0/2578.89.38.1 to 78.89.38.12678.89.38.127126
7878.89.38.128/2578.89.38.129 to 78.89.38.25478.89.38.255126
7978.89.39.0/2578.89.39.1 to 78.89.39.12678.89.39.127126
8078.89.39.128/2578.89.39.129 to 78.89.39.25478.89.39.255126
8178.89.40.0/2578.89.40.1 to 78.89.40.12678.89.40.127126
8278.89.40.128/2578.89.40.129 to 78.89.40.25478.89.40.255126
8378.89.41.0/2578.89.41.1 to 78.89.41.12678.89.41.127126
8478.89.41.128/2578.89.41.129 to 78.89.41.25478.89.41.255126
8578.89.42.0/2578.89.42.1 to 78.89.42.12678.89.42.127126
8678.89.42.128/2578.89.42.129 to 78.89.42.25478.89.42.255126
8778.89.43.0/2578.89.43.1 to 78.89.43.12678.89.43.127126
8878.89.43.128/2578.89.43.129 to 78.89.43.25478.89.43.255126
8978.89.44.0/2578.89.44.1 to 78.89.44.12678.89.44.127126
9078.89.44.128/2578.89.44.129 to 78.89.44.25478.89.44.255126
9178.89.45.0/2578.89.45.1 to 78.89.45.12678.89.45.127126
9278.89.45.128/2578.89.45.129 to 78.89.45.25478.89.45.255126
9378.89.46.0/2578.89.46.1 to 78.89.46.12678.89.46.127126
9478.89.46.128/2578.89.46.129 to 78.89.46.25478.89.46.255126
9578.89.47.0/2578.89.47.1 to 78.89.47.12678.89.47.127126
9678.89.47.128/2578.89.47.129 to 78.89.47.25478.89.47.255126
9778.89.48.0/2578.89.48.1 to 78.89.48.12678.89.48.127126
9878.89.48.128/2578.89.48.129 to 78.89.48.25478.89.48.255126
9978.89.49.0/2578.89.49.1 to 78.89.49.12678.89.49.127126
10078.89.49.128/2578.89.49.129 to 78.89.49.25478.89.49.255126
10178.89.50.0/2578.89.50.1 to 78.89.50.12678.89.50.127126
10278.89.50.128/2578.89.50.129 to 78.89.50.25478.89.50.255126
10378.89.51.0/2578.89.51.1 to 78.89.51.12678.89.51.127126
10478.89.51.128/2578.89.51.129 to 78.89.51.25478.89.51.255126
10578.89.52.0/2578.89.52.1 to 78.89.52.12678.89.52.127126
10678.89.52.128/2578.89.52.129 to 78.89.52.25478.89.52.255126
10778.89.53.0/2578.89.53.1 to 78.89.53.12678.89.53.127126
10878.89.53.128/2578.89.53.129 to 78.89.53.25478.89.53.255126
10978.89.54.0/2578.89.54.1 to 78.89.54.12678.89.54.127126
11078.89.54.128/2578.89.54.129 to 78.89.54.25478.89.54.255126
11178.89.55.0/2578.89.55.1 to 78.89.55.12678.89.55.127126
11278.89.55.128/2578.89.55.129 to 78.89.55.25478.89.55.255126
11378.89.56.0/2578.89.56.1 to 78.89.56.12678.89.56.127126
11478.89.56.128/2578.89.56.129 to 78.89.56.25478.89.56.255126
11578.89.57.0/2578.89.57.1 to 78.89.57.12678.89.57.127126
11678.89.57.128/2578.89.57.129 to 78.89.57.25478.89.57.255126
11778.89.58.0/2578.89.58.1 to 78.89.58.12678.89.58.127126
11878.89.58.128/2578.89.58.129 to 78.89.58.25478.89.58.255126
11978.89.59.0/2578.89.59.1 to 78.89.59.12678.89.59.127126
12078.89.59.128/2578.89.59.129 to 78.89.59.25478.89.59.255126
12178.89.60.0/2578.89.60.1 to 78.89.60.12678.89.60.127126
12278.89.60.128/2578.89.60.129 to 78.89.60.25478.89.60.255126
12378.89.61.0/2578.89.61.1 to 78.89.61.12678.89.61.127126
12478.89.61.128/2578.89.61.129 to 78.89.61.25478.89.61.255126
12578.89.62.0/2578.89.62.1 to 78.89.62.12678.89.62.127126
12678.89.62.128/2578.89.62.129 to 78.89.62.25478.89.62.255126
12778.89.63.0/2578.89.63.1 to 78.89.63.12678.89.63.127126
12878.89.63.128/2578.89.63.129 to 78.89.63.25478.89.63.255126
12978.89.64.0/2578.89.64.1 to 78.89.64.12678.89.64.127126
13078.89.64.128/2578.89.64.129 to 78.89.64.25478.89.64.255126
13178.89.65.0/2578.89.65.1 to 78.89.65.12678.89.65.127126
13278.89.65.128/2578.89.65.129 to 78.89.65.25478.89.65.255126
13378.89.66.0/2578.89.66.1 to 78.89.66.12678.89.66.127126
13478.89.66.128/2578.89.66.129 to 78.89.66.25478.89.66.255126
13578.89.67.0/2578.89.67.1 to 78.89.67.12678.89.67.127126
13678.89.67.128/2578.89.67.129 to 78.89.67.25478.89.67.255126
13778.89.68.0/2578.89.68.1 to 78.89.68.12678.89.68.127126
13878.89.68.128/2578.89.68.129 to 78.89.68.25478.89.68.255126
13978.89.69.0/2578.89.69.1 to 78.89.69.12678.89.69.127126
14078.89.69.128/2578.89.69.129 to 78.89.69.25478.89.69.255126
14178.89.70.0/2578.89.70.1 to 78.89.70.12678.89.70.127126
14278.89.70.128/2578.89.70.129 to 78.89.70.25478.89.70.255126
14378.89.71.0/2578.89.71.1 to 78.89.71.12678.89.71.127126
14478.89.71.128/2578.89.71.129 to 78.89.71.25478.89.71.255126
14578.89.72.0/2578.89.72.1 to 78.89.72.12678.89.72.127126
14678.89.72.128/2578.89.72.129 to 78.89.72.25478.89.72.255126
14778.89.73.0/2578.89.73.1 to 78.89.73.12678.89.73.127126
14878.89.73.128/2578.89.73.129 to 78.89.73.25478.89.73.255126
14978.89.74.0/2578.89.74.1 to 78.89.74.12678.89.74.127126
15078.89.74.128/2578.89.74.129 to 78.89.74.25478.89.74.255126
15178.89.75.0/2578.89.75.1 to 78.89.75.12678.89.75.127126
15278.89.75.128/2578.89.75.129 to 78.89.75.25478.89.75.255126
15378.89.76.0/2578.89.76.1 to 78.89.76.12678.89.76.127126
15478.89.76.128/2578.89.76.129 to 78.89.76.25478.89.76.255126
15578.89.77.0/2578.89.77.1 to 78.89.77.12678.89.77.127126
15678.89.77.128/2578.89.77.129 to 78.89.77.25478.89.77.255126
15778.89.78.0/2578.89.78.1 to 78.89.78.12678.89.78.127126
15878.89.78.128/2578.89.78.129 to 78.89.78.25478.89.78.255126
15978.89.79.0/2578.89.79.1 to 78.89.79.12678.89.79.127126
16078.89.79.128/2578.89.79.129 to 78.89.79.25478.89.79.255126
16178.89.80.0/2578.89.80.1 to 78.89.80.12678.89.80.127126
16278.89.80.128/2578.89.80.129 to 78.89.80.25478.89.80.255126
16378.89.81.0/2578.89.81.1 to 78.89.81.12678.89.81.127126
16478.89.81.128/2578.89.81.129 to 78.89.81.25478.89.81.255126
16578.89.82.0/2578.89.82.1 to 78.89.82.12678.89.82.127126
16678.89.82.128/2578.89.82.129 to 78.89.82.25478.89.82.255126
16778.89.83.0/2578.89.83.1 to 78.89.83.12678.89.83.127126
16878.89.83.128/2578.89.83.129 to 78.89.83.25478.89.83.255126
16978.89.84.0/2578.89.84.1 to 78.89.84.12678.89.84.127126
17078.89.84.128/2578.89.84.129 to 78.89.84.25478.89.84.255126
17178.89.85.0/2578.89.85.1 to 78.89.85.12678.89.85.127126
17278.89.85.128/2578.89.85.129 to 78.89.85.25478.89.85.255126
17378.89.86.0/2578.89.86.1 to 78.89.86.12678.89.86.127126
17478.89.86.128/2578.89.86.129 to 78.89.86.25478.89.86.255126
17578.89.87.0/2578.89.87.1 to 78.89.87.12678.89.87.127126
17678.89.87.128/2578.89.87.129 to 78.89.87.25478.89.87.255126
17778.89.88.0/2578.89.88.1 to 78.89.88.12678.89.88.127126
17878.89.88.128/2578.89.88.129 to 78.89.88.25478.89.88.255126
17978.89.89.0/2578.89.89.1 to 78.89.89.12678.89.89.127126
18078.89.89.128/2578.89.89.129 to 78.89.89.25478.89.89.255126
18178.89.90.0/2578.89.90.1 to 78.89.90.12678.89.90.127126
18278.89.90.128/2578.89.90.129 to 78.89.90.25478.89.90.255126
18378.89.91.0/2578.89.91.1 to 78.89.91.12678.89.91.127126
18478.89.91.128/2578.89.91.129 to 78.89.91.25478.89.91.255126
18578.89.92.0/2578.89.92.1 to 78.89.92.12678.89.92.127126
18678.89.92.128/2578.89.92.129 to 78.89.92.25478.89.92.255126
18778.89.93.0/2578.89.93.1 to 78.89.93.12678.89.93.127126
18878.89.93.128/2578.89.93.129 to 78.89.93.25478.89.93.255126
18978.89.94.0/2578.89.94.1 to 78.89.94.12678.89.94.127126
19078.89.94.128/2578.89.94.129 to 78.89.94.25478.89.94.255126
19178.89.95.0/2578.89.95.1 to 78.89.95.12678.89.95.127126
19278.89.95.128/2578.89.95.129 to 78.89.95.25478.89.95.255126
19378.89.96.0/2578.89.96.1 to 78.89.96.12678.89.96.127126
19478.89.96.128/2578.89.96.129 to 78.89.96.25478.89.96.255126
19578.89.97.0/2578.89.97.1 to 78.89.97.12678.89.97.127126
19678.89.97.128/2578.89.97.129 to 78.89.97.25478.89.97.255126
19778.89.98.0/2578.89.98.1 to 78.89.98.12678.89.98.127126
19878.89.98.128/2578.89.98.129 to 78.89.98.25478.89.98.255126
19978.89.99.0/2578.89.99.1 to 78.89.99.12678.89.99.127126
20078.89.99.128/2578.89.99.129 to 78.89.99.25478.89.99.255126
20178.89.100.0/2578.89.100.1 to 78.89.100.12678.89.100.127126
20278.89.100.128/2578.89.100.129 to 78.89.100.25478.89.100.255126
20378.89.101.0/2578.89.101.1 to 78.89.101.12678.89.101.127126
20478.89.101.128/2578.89.101.129 to 78.89.101.25478.89.101.255126
20578.89.102.0/2578.89.102.1 to 78.89.102.12678.89.102.127126
20678.89.102.128/2578.89.102.129 to 78.89.102.25478.89.102.255126
20778.89.103.0/2578.89.103.1 to 78.89.103.12678.89.103.127126
20878.89.103.128/2578.89.103.129 to 78.89.103.25478.89.103.255126
20978.89.104.0/2578.89.104.1 to 78.89.104.12678.89.104.127126
21078.89.104.128/2578.89.104.129 to 78.89.104.25478.89.104.255126
21178.89.105.0/2578.89.105.1 to 78.89.105.12678.89.105.127126
21278.89.105.128/2578.89.105.129 to 78.89.105.25478.89.105.255126
21378.89.106.0/2578.89.106.1 to 78.89.106.12678.89.106.127126
21478.89.106.128/2578.89.106.129 to 78.89.106.25478.89.106.255126
21578.89.107.0/2578.89.107.1 to 78.89.107.12678.89.107.127126
21678.89.107.128/2578.89.107.129 to 78.89.107.25478.89.107.255126
21778.89.108.0/2578.89.108.1 to 78.89.108.12678.89.108.127126
21878.89.108.128/2578.89.108.129 to 78.89.108.25478.89.108.255126
21978.89.109.0/2578.89.109.1 to 78.89.109.12678.89.109.127126
22078.89.109.128/2578.89.109.129 to 78.89.109.25478.89.109.255126
22178.89.110.0/2578.89.110.1 to 78.89.110.12678.89.110.127126
22278.89.110.128/2578.89.110.129 to 78.89.110.25478.89.110.255126
22378.89.111.0/2578.89.111.1 to 78.89.111.12678.89.111.127126
22478.89.111.128/2578.89.111.129 to 78.89.111.25478.89.111.255126
22578.89.112.0/2578.89.112.1 to 78.89.112.12678.89.112.127126
22678.89.112.128/2578.89.112.129 to 78.89.112.25478.89.112.255126
22778.89.113.0/2578.89.113.1 to 78.89.113.12678.89.113.127126
22878.89.113.128/2578.89.113.129 to 78.89.113.25478.89.113.255126
22978.89.114.0/2578.89.114.1 to 78.89.114.12678.89.114.127126
23078.89.114.128/2578.89.114.129 to 78.89.114.25478.89.114.255126
23178.89.115.0/2578.89.115.1 to 78.89.115.12678.89.115.127126
23278.89.115.128/2578.89.115.129 to 78.89.115.25478.89.115.255126
23378.89.116.0/2578.89.116.1 to 78.89.116.12678.89.116.127126
23478.89.116.128/2578.89.116.129 to 78.89.116.25478.89.116.255126
23578.89.117.0/2578.89.117.1 to 78.89.117.12678.89.117.127126
23678.89.117.128/2578.89.117.129 to 78.89.117.25478.89.117.255126
23778.89.118.0/2578.89.118.1 to 78.89.118.12678.89.118.127126
23878.89.118.128/2578.89.118.129 to 78.89.118.25478.89.118.255126
23978.89.119.0/2578.89.119.1 to 78.89.119.12678.89.119.127126
24078.89.119.128/2578.89.119.129 to 78.89.119.25478.89.119.255126
24178.89.120.0/2578.89.120.1 to 78.89.120.12678.89.120.127126
24278.89.120.128/2578.89.120.129 to 78.89.120.25478.89.120.255126
24378.89.121.0/2578.89.121.1 to 78.89.121.12678.89.121.127126
24478.89.121.128/2578.89.121.129 to 78.89.121.25478.89.121.255126
24578.89.122.0/2578.89.122.1 to 78.89.122.12678.89.122.127126
24678.89.122.128/2578.89.122.129 to 78.89.122.25478.89.122.255126
24778.89.123.0/2578.89.123.1 to 78.89.123.12678.89.123.127126
24878.89.123.128/2578.89.123.129 to 78.89.123.25478.89.123.255126
24978.89.124.0/2578.89.124.1 to 78.89.124.12678.89.124.127126
25078.89.124.128/2578.89.124.129 to 78.89.124.25478.89.124.255126
25178.89.125.0/2578.89.125.1 to 78.89.125.12678.89.125.127126
25278.89.125.128/2578.89.125.129 to 78.89.125.25478.89.125.255126
25378.89.126.0/2578.89.126.1 to 78.89.126.12678.89.126.127126
25478.89.126.128/2578.89.126.129 to 78.89.126.25478.89.126.255126
25578.89.127.0/2578.89.127.1 to 78.89.127.12678.89.127.127126
25678.89.127.128/2578.89.127.129 to 78.89.127.25478.89.127.255126

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.