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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.

Network46.25.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
46.25.0.0
Broadcast address
46.25.127.255
First usable
46.25.0.1
Last usable
46.25.127.254
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 2E190000 · Integer 773390336 to 773423103
Reverse DNS zones
0.25.46.in-addr.arpa
1.25.46.in-addr.arpa
2.25.46.in-addr.arpa
3.25.46.in-addr.arpa
4.25.46.in-addr.arpa
5.25.46.in-addr.arpa
6.25.46.in-addr.arpa
7.25.46.in-addr.arpa
8.25.46.in-addr.arpa
9.25.46.in-addr.arpa
10.25.46.in-addr.arpa
11.25.46.in-addr.arpa
12.25.46.in-addr.arpa
13.25.46.in-addr.arpa
14.25.46.in-addr.arpa
15.25.46.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
Address00101110.00011001.00000000.0000000046.25.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network00101110.00011001.00000000.0000000046.25.0.0
Broadcast00101110.00011001.01111111.1111111146.25.127.255
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)

46.25.0.0/17 makes 256 subnets of /25.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
146.25.0.0/2546.25.0.1 to 46.25.0.12646.25.0.127126
246.25.0.128/2546.25.0.129 to 46.25.0.25446.25.0.255126
346.25.1.0/2546.25.1.1 to 46.25.1.12646.25.1.127126
446.25.1.128/2546.25.1.129 to 46.25.1.25446.25.1.255126
546.25.2.0/2546.25.2.1 to 46.25.2.12646.25.2.127126
646.25.2.128/2546.25.2.129 to 46.25.2.25446.25.2.255126
746.25.3.0/2546.25.3.1 to 46.25.3.12646.25.3.127126
846.25.3.128/2546.25.3.129 to 46.25.3.25446.25.3.255126
946.25.4.0/2546.25.4.1 to 46.25.4.12646.25.4.127126
1046.25.4.128/2546.25.4.129 to 46.25.4.25446.25.4.255126
1146.25.5.0/2546.25.5.1 to 46.25.5.12646.25.5.127126
1246.25.5.128/2546.25.5.129 to 46.25.5.25446.25.5.255126
1346.25.6.0/2546.25.6.1 to 46.25.6.12646.25.6.127126
1446.25.6.128/2546.25.6.129 to 46.25.6.25446.25.6.255126
1546.25.7.0/2546.25.7.1 to 46.25.7.12646.25.7.127126
1646.25.7.128/2546.25.7.129 to 46.25.7.25446.25.7.255126
1746.25.8.0/2546.25.8.1 to 46.25.8.12646.25.8.127126
1846.25.8.128/2546.25.8.129 to 46.25.8.25446.25.8.255126
1946.25.9.0/2546.25.9.1 to 46.25.9.12646.25.9.127126
2046.25.9.128/2546.25.9.129 to 46.25.9.25446.25.9.255126
2146.25.10.0/2546.25.10.1 to 46.25.10.12646.25.10.127126
2246.25.10.128/2546.25.10.129 to 46.25.10.25446.25.10.255126
2346.25.11.0/2546.25.11.1 to 46.25.11.12646.25.11.127126
2446.25.11.128/2546.25.11.129 to 46.25.11.25446.25.11.255126
2546.25.12.0/2546.25.12.1 to 46.25.12.12646.25.12.127126
2646.25.12.128/2546.25.12.129 to 46.25.12.25446.25.12.255126
2746.25.13.0/2546.25.13.1 to 46.25.13.12646.25.13.127126
2846.25.13.128/2546.25.13.129 to 46.25.13.25446.25.13.255126
2946.25.14.0/2546.25.14.1 to 46.25.14.12646.25.14.127126
3046.25.14.128/2546.25.14.129 to 46.25.14.25446.25.14.255126
3146.25.15.0/2546.25.15.1 to 46.25.15.12646.25.15.127126
3246.25.15.128/2546.25.15.129 to 46.25.15.25446.25.15.255126
3346.25.16.0/2546.25.16.1 to 46.25.16.12646.25.16.127126
3446.25.16.128/2546.25.16.129 to 46.25.16.25446.25.16.255126
3546.25.17.0/2546.25.17.1 to 46.25.17.12646.25.17.127126
3646.25.17.128/2546.25.17.129 to 46.25.17.25446.25.17.255126
3746.25.18.0/2546.25.18.1 to 46.25.18.12646.25.18.127126
3846.25.18.128/2546.25.18.129 to 46.25.18.25446.25.18.255126
3946.25.19.0/2546.25.19.1 to 46.25.19.12646.25.19.127126
4046.25.19.128/2546.25.19.129 to 46.25.19.25446.25.19.255126
4146.25.20.0/2546.25.20.1 to 46.25.20.12646.25.20.127126
4246.25.20.128/2546.25.20.129 to 46.25.20.25446.25.20.255126
4346.25.21.0/2546.25.21.1 to 46.25.21.12646.25.21.127126
4446.25.21.128/2546.25.21.129 to 46.25.21.25446.25.21.255126
4546.25.22.0/2546.25.22.1 to 46.25.22.12646.25.22.127126
4646.25.22.128/2546.25.22.129 to 46.25.22.25446.25.22.255126
4746.25.23.0/2546.25.23.1 to 46.25.23.12646.25.23.127126
4846.25.23.128/2546.25.23.129 to 46.25.23.25446.25.23.255126
4946.25.24.0/2546.25.24.1 to 46.25.24.12646.25.24.127126
5046.25.24.128/2546.25.24.129 to 46.25.24.25446.25.24.255126
5146.25.25.0/2546.25.25.1 to 46.25.25.12646.25.25.127126
5246.25.25.128/2546.25.25.129 to 46.25.25.25446.25.25.255126
5346.25.26.0/2546.25.26.1 to 46.25.26.12646.25.26.127126
5446.25.26.128/2546.25.26.129 to 46.25.26.25446.25.26.255126
5546.25.27.0/2546.25.27.1 to 46.25.27.12646.25.27.127126
5646.25.27.128/2546.25.27.129 to 46.25.27.25446.25.27.255126
5746.25.28.0/2546.25.28.1 to 46.25.28.12646.25.28.127126
5846.25.28.128/2546.25.28.129 to 46.25.28.25446.25.28.255126
5946.25.29.0/2546.25.29.1 to 46.25.29.12646.25.29.127126
6046.25.29.128/2546.25.29.129 to 46.25.29.25446.25.29.255126
6146.25.30.0/2546.25.30.1 to 46.25.30.12646.25.30.127126
6246.25.30.128/2546.25.30.129 to 46.25.30.25446.25.30.255126
6346.25.31.0/2546.25.31.1 to 46.25.31.12646.25.31.127126
6446.25.31.128/2546.25.31.129 to 46.25.31.25446.25.31.255126
6546.25.32.0/2546.25.32.1 to 46.25.32.12646.25.32.127126
6646.25.32.128/2546.25.32.129 to 46.25.32.25446.25.32.255126
6746.25.33.0/2546.25.33.1 to 46.25.33.12646.25.33.127126
6846.25.33.128/2546.25.33.129 to 46.25.33.25446.25.33.255126
6946.25.34.0/2546.25.34.1 to 46.25.34.12646.25.34.127126
7046.25.34.128/2546.25.34.129 to 46.25.34.25446.25.34.255126
7146.25.35.0/2546.25.35.1 to 46.25.35.12646.25.35.127126
7246.25.35.128/2546.25.35.129 to 46.25.35.25446.25.35.255126
7346.25.36.0/2546.25.36.1 to 46.25.36.12646.25.36.127126
7446.25.36.128/2546.25.36.129 to 46.25.36.25446.25.36.255126
7546.25.37.0/2546.25.37.1 to 46.25.37.12646.25.37.127126
7646.25.37.128/2546.25.37.129 to 46.25.37.25446.25.37.255126
7746.25.38.0/2546.25.38.1 to 46.25.38.12646.25.38.127126
7846.25.38.128/2546.25.38.129 to 46.25.38.25446.25.38.255126
7946.25.39.0/2546.25.39.1 to 46.25.39.12646.25.39.127126
8046.25.39.128/2546.25.39.129 to 46.25.39.25446.25.39.255126
8146.25.40.0/2546.25.40.1 to 46.25.40.12646.25.40.127126
8246.25.40.128/2546.25.40.129 to 46.25.40.25446.25.40.255126
8346.25.41.0/2546.25.41.1 to 46.25.41.12646.25.41.127126
8446.25.41.128/2546.25.41.129 to 46.25.41.25446.25.41.255126
8546.25.42.0/2546.25.42.1 to 46.25.42.12646.25.42.127126
8646.25.42.128/2546.25.42.129 to 46.25.42.25446.25.42.255126
8746.25.43.0/2546.25.43.1 to 46.25.43.12646.25.43.127126
8846.25.43.128/2546.25.43.129 to 46.25.43.25446.25.43.255126
8946.25.44.0/2546.25.44.1 to 46.25.44.12646.25.44.127126
9046.25.44.128/2546.25.44.129 to 46.25.44.25446.25.44.255126
9146.25.45.0/2546.25.45.1 to 46.25.45.12646.25.45.127126
9246.25.45.128/2546.25.45.129 to 46.25.45.25446.25.45.255126
9346.25.46.0/2546.25.46.1 to 46.25.46.12646.25.46.127126
9446.25.46.128/2546.25.46.129 to 46.25.46.25446.25.46.255126
9546.25.47.0/2546.25.47.1 to 46.25.47.12646.25.47.127126
9646.25.47.128/2546.25.47.129 to 46.25.47.25446.25.47.255126
9746.25.48.0/2546.25.48.1 to 46.25.48.12646.25.48.127126
9846.25.48.128/2546.25.48.129 to 46.25.48.25446.25.48.255126
9946.25.49.0/2546.25.49.1 to 46.25.49.12646.25.49.127126
10046.25.49.128/2546.25.49.129 to 46.25.49.25446.25.49.255126
10146.25.50.0/2546.25.50.1 to 46.25.50.12646.25.50.127126
10246.25.50.128/2546.25.50.129 to 46.25.50.25446.25.50.255126
10346.25.51.0/2546.25.51.1 to 46.25.51.12646.25.51.127126
10446.25.51.128/2546.25.51.129 to 46.25.51.25446.25.51.255126
10546.25.52.0/2546.25.52.1 to 46.25.52.12646.25.52.127126
10646.25.52.128/2546.25.52.129 to 46.25.52.25446.25.52.255126
10746.25.53.0/2546.25.53.1 to 46.25.53.12646.25.53.127126
10846.25.53.128/2546.25.53.129 to 46.25.53.25446.25.53.255126
10946.25.54.0/2546.25.54.1 to 46.25.54.12646.25.54.127126
11046.25.54.128/2546.25.54.129 to 46.25.54.25446.25.54.255126
11146.25.55.0/2546.25.55.1 to 46.25.55.12646.25.55.127126
11246.25.55.128/2546.25.55.129 to 46.25.55.25446.25.55.255126
11346.25.56.0/2546.25.56.1 to 46.25.56.12646.25.56.127126
11446.25.56.128/2546.25.56.129 to 46.25.56.25446.25.56.255126
11546.25.57.0/2546.25.57.1 to 46.25.57.12646.25.57.127126
11646.25.57.128/2546.25.57.129 to 46.25.57.25446.25.57.255126
11746.25.58.0/2546.25.58.1 to 46.25.58.12646.25.58.127126
11846.25.58.128/2546.25.58.129 to 46.25.58.25446.25.58.255126
11946.25.59.0/2546.25.59.1 to 46.25.59.12646.25.59.127126
12046.25.59.128/2546.25.59.129 to 46.25.59.25446.25.59.255126
12146.25.60.0/2546.25.60.1 to 46.25.60.12646.25.60.127126
12246.25.60.128/2546.25.60.129 to 46.25.60.25446.25.60.255126
12346.25.61.0/2546.25.61.1 to 46.25.61.12646.25.61.127126
12446.25.61.128/2546.25.61.129 to 46.25.61.25446.25.61.255126
12546.25.62.0/2546.25.62.1 to 46.25.62.12646.25.62.127126
12646.25.62.128/2546.25.62.129 to 46.25.62.25446.25.62.255126
12746.25.63.0/2546.25.63.1 to 46.25.63.12646.25.63.127126
12846.25.63.128/2546.25.63.129 to 46.25.63.25446.25.63.255126
12946.25.64.0/2546.25.64.1 to 46.25.64.12646.25.64.127126
13046.25.64.128/2546.25.64.129 to 46.25.64.25446.25.64.255126
13146.25.65.0/2546.25.65.1 to 46.25.65.12646.25.65.127126
13246.25.65.128/2546.25.65.129 to 46.25.65.25446.25.65.255126
13346.25.66.0/2546.25.66.1 to 46.25.66.12646.25.66.127126
13446.25.66.128/2546.25.66.129 to 46.25.66.25446.25.66.255126
13546.25.67.0/2546.25.67.1 to 46.25.67.12646.25.67.127126
13646.25.67.128/2546.25.67.129 to 46.25.67.25446.25.67.255126
13746.25.68.0/2546.25.68.1 to 46.25.68.12646.25.68.127126
13846.25.68.128/2546.25.68.129 to 46.25.68.25446.25.68.255126
13946.25.69.0/2546.25.69.1 to 46.25.69.12646.25.69.127126
14046.25.69.128/2546.25.69.129 to 46.25.69.25446.25.69.255126
14146.25.70.0/2546.25.70.1 to 46.25.70.12646.25.70.127126
14246.25.70.128/2546.25.70.129 to 46.25.70.25446.25.70.255126
14346.25.71.0/2546.25.71.1 to 46.25.71.12646.25.71.127126
14446.25.71.128/2546.25.71.129 to 46.25.71.25446.25.71.255126
14546.25.72.0/2546.25.72.1 to 46.25.72.12646.25.72.127126
14646.25.72.128/2546.25.72.129 to 46.25.72.25446.25.72.255126
14746.25.73.0/2546.25.73.1 to 46.25.73.12646.25.73.127126
14846.25.73.128/2546.25.73.129 to 46.25.73.25446.25.73.255126
14946.25.74.0/2546.25.74.1 to 46.25.74.12646.25.74.127126
15046.25.74.128/2546.25.74.129 to 46.25.74.25446.25.74.255126
15146.25.75.0/2546.25.75.1 to 46.25.75.12646.25.75.127126
15246.25.75.128/2546.25.75.129 to 46.25.75.25446.25.75.255126
15346.25.76.0/2546.25.76.1 to 46.25.76.12646.25.76.127126
15446.25.76.128/2546.25.76.129 to 46.25.76.25446.25.76.255126
15546.25.77.0/2546.25.77.1 to 46.25.77.12646.25.77.127126
15646.25.77.128/2546.25.77.129 to 46.25.77.25446.25.77.255126
15746.25.78.0/2546.25.78.1 to 46.25.78.12646.25.78.127126
15846.25.78.128/2546.25.78.129 to 46.25.78.25446.25.78.255126
15946.25.79.0/2546.25.79.1 to 46.25.79.12646.25.79.127126
16046.25.79.128/2546.25.79.129 to 46.25.79.25446.25.79.255126
16146.25.80.0/2546.25.80.1 to 46.25.80.12646.25.80.127126
16246.25.80.128/2546.25.80.129 to 46.25.80.25446.25.80.255126
16346.25.81.0/2546.25.81.1 to 46.25.81.12646.25.81.127126
16446.25.81.128/2546.25.81.129 to 46.25.81.25446.25.81.255126
16546.25.82.0/2546.25.82.1 to 46.25.82.12646.25.82.127126
16646.25.82.128/2546.25.82.129 to 46.25.82.25446.25.82.255126
16746.25.83.0/2546.25.83.1 to 46.25.83.12646.25.83.127126
16846.25.83.128/2546.25.83.129 to 46.25.83.25446.25.83.255126
16946.25.84.0/2546.25.84.1 to 46.25.84.12646.25.84.127126
17046.25.84.128/2546.25.84.129 to 46.25.84.25446.25.84.255126
17146.25.85.0/2546.25.85.1 to 46.25.85.12646.25.85.127126
17246.25.85.128/2546.25.85.129 to 46.25.85.25446.25.85.255126
17346.25.86.0/2546.25.86.1 to 46.25.86.12646.25.86.127126
17446.25.86.128/2546.25.86.129 to 46.25.86.25446.25.86.255126
17546.25.87.0/2546.25.87.1 to 46.25.87.12646.25.87.127126
17646.25.87.128/2546.25.87.129 to 46.25.87.25446.25.87.255126
17746.25.88.0/2546.25.88.1 to 46.25.88.12646.25.88.127126
17846.25.88.128/2546.25.88.129 to 46.25.88.25446.25.88.255126
17946.25.89.0/2546.25.89.1 to 46.25.89.12646.25.89.127126
18046.25.89.128/2546.25.89.129 to 46.25.89.25446.25.89.255126
18146.25.90.0/2546.25.90.1 to 46.25.90.12646.25.90.127126
18246.25.90.128/2546.25.90.129 to 46.25.90.25446.25.90.255126
18346.25.91.0/2546.25.91.1 to 46.25.91.12646.25.91.127126
18446.25.91.128/2546.25.91.129 to 46.25.91.25446.25.91.255126
18546.25.92.0/2546.25.92.1 to 46.25.92.12646.25.92.127126
18646.25.92.128/2546.25.92.129 to 46.25.92.25446.25.92.255126
18746.25.93.0/2546.25.93.1 to 46.25.93.12646.25.93.127126
18846.25.93.128/2546.25.93.129 to 46.25.93.25446.25.93.255126
18946.25.94.0/2546.25.94.1 to 46.25.94.12646.25.94.127126
19046.25.94.128/2546.25.94.129 to 46.25.94.25446.25.94.255126
19146.25.95.0/2546.25.95.1 to 46.25.95.12646.25.95.127126
19246.25.95.128/2546.25.95.129 to 46.25.95.25446.25.95.255126
19346.25.96.0/2546.25.96.1 to 46.25.96.12646.25.96.127126
19446.25.96.128/2546.25.96.129 to 46.25.96.25446.25.96.255126
19546.25.97.0/2546.25.97.1 to 46.25.97.12646.25.97.127126
19646.25.97.128/2546.25.97.129 to 46.25.97.25446.25.97.255126
19746.25.98.0/2546.25.98.1 to 46.25.98.12646.25.98.127126
19846.25.98.128/2546.25.98.129 to 46.25.98.25446.25.98.255126
19946.25.99.0/2546.25.99.1 to 46.25.99.12646.25.99.127126
20046.25.99.128/2546.25.99.129 to 46.25.99.25446.25.99.255126
20146.25.100.0/2546.25.100.1 to 46.25.100.12646.25.100.127126
20246.25.100.128/2546.25.100.129 to 46.25.100.25446.25.100.255126
20346.25.101.0/2546.25.101.1 to 46.25.101.12646.25.101.127126
20446.25.101.128/2546.25.101.129 to 46.25.101.25446.25.101.255126
20546.25.102.0/2546.25.102.1 to 46.25.102.12646.25.102.127126
20646.25.102.128/2546.25.102.129 to 46.25.102.25446.25.102.255126
20746.25.103.0/2546.25.103.1 to 46.25.103.12646.25.103.127126
20846.25.103.128/2546.25.103.129 to 46.25.103.25446.25.103.255126
20946.25.104.0/2546.25.104.1 to 46.25.104.12646.25.104.127126
21046.25.104.128/2546.25.104.129 to 46.25.104.25446.25.104.255126
21146.25.105.0/2546.25.105.1 to 46.25.105.12646.25.105.127126
21246.25.105.128/2546.25.105.129 to 46.25.105.25446.25.105.255126
21346.25.106.0/2546.25.106.1 to 46.25.106.12646.25.106.127126
21446.25.106.128/2546.25.106.129 to 46.25.106.25446.25.106.255126
21546.25.107.0/2546.25.107.1 to 46.25.107.12646.25.107.127126
21646.25.107.128/2546.25.107.129 to 46.25.107.25446.25.107.255126
21746.25.108.0/2546.25.108.1 to 46.25.108.12646.25.108.127126
21846.25.108.128/2546.25.108.129 to 46.25.108.25446.25.108.255126
21946.25.109.0/2546.25.109.1 to 46.25.109.12646.25.109.127126
22046.25.109.128/2546.25.109.129 to 46.25.109.25446.25.109.255126
22146.25.110.0/2546.25.110.1 to 46.25.110.12646.25.110.127126
22246.25.110.128/2546.25.110.129 to 46.25.110.25446.25.110.255126
22346.25.111.0/2546.25.111.1 to 46.25.111.12646.25.111.127126
22446.25.111.128/2546.25.111.129 to 46.25.111.25446.25.111.255126
22546.25.112.0/2546.25.112.1 to 46.25.112.12646.25.112.127126
22646.25.112.128/2546.25.112.129 to 46.25.112.25446.25.112.255126
22746.25.113.0/2546.25.113.1 to 46.25.113.12646.25.113.127126
22846.25.113.128/2546.25.113.129 to 46.25.113.25446.25.113.255126
22946.25.114.0/2546.25.114.1 to 46.25.114.12646.25.114.127126
23046.25.114.128/2546.25.114.129 to 46.25.114.25446.25.114.255126
23146.25.115.0/2546.25.115.1 to 46.25.115.12646.25.115.127126
23246.25.115.128/2546.25.115.129 to 46.25.115.25446.25.115.255126
23346.25.116.0/2546.25.116.1 to 46.25.116.12646.25.116.127126
23446.25.116.128/2546.25.116.129 to 46.25.116.25446.25.116.255126
23546.25.117.0/2546.25.117.1 to 46.25.117.12646.25.117.127126
23646.25.117.128/2546.25.117.129 to 46.25.117.25446.25.117.255126
23746.25.118.0/2546.25.118.1 to 46.25.118.12646.25.118.127126
23846.25.118.128/2546.25.118.129 to 46.25.118.25446.25.118.255126
23946.25.119.0/2546.25.119.1 to 46.25.119.12646.25.119.127126
24046.25.119.128/2546.25.119.129 to 46.25.119.25446.25.119.255126
24146.25.120.0/2546.25.120.1 to 46.25.120.12646.25.120.127126
24246.25.120.128/2546.25.120.129 to 46.25.120.25446.25.120.255126
24346.25.121.0/2546.25.121.1 to 46.25.121.12646.25.121.127126
24446.25.121.128/2546.25.121.129 to 46.25.121.25446.25.121.255126
24546.25.122.0/2546.25.122.1 to 46.25.122.12646.25.122.127126
24646.25.122.128/2546.25.122.129 to 46.25.122.25446.25.122.255126
24746.25.123.0/2546.25.123.1 to 46.25.123.12646.25.123.127126
24846.25.123.128/2546.25.123.129 to 46.25.123.25446.25.123.255126
24946.25.124.0/2546.25.124.1 to 46.25.124.12646.25.124.127126
25046.25.124.128/2546.25.124.129 to 46.25.124.25446.25.124.255126
25146.25.125.0/2546.25.125.1 to 46.25.125.12646.25.125.127126
25246.25.125.128/2546.25.125.129 to 46.25.125.25446.25.125.255126
25346.25.126.0/2546.25.126.1 to 46.25.126.12646.25.126.127126
25446.25.126.128/2546.25.126.129 to 46.25.126.25446.25.126.255126
25546.25.127.0/2546.25.127.1 to 46.25.127.12646.25.127.127126
25646.25.127.128/2546.25.127.129 to 46.25.127.25446.25.127.255126

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.