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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.

Network77.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
77.0.0.0
Broadcast address
77.127.255.255
First usable
77.0.0.1
Last usable
77.127.255.254
Usable hosts
8,388,606 (8,388,608 less the network and broadcast addresses)
Subnet mask
255.128.0.0
Wildcard mask
0.127.255.255 (Cisco ACLs, OSPF)
Prefix length
/9
Type
Public public
Old class
A (default /8)
As numbers
Hex 4D000000 · Integer 1291845632 to 1300234239
Reverse DNS zones
0.77.in-addr.arpa
1.77.in-addr.arpa
2.77.in-addr.arpa
3.77.in-addr.arpa
4.77.in-addr.arpa
5.77.in-addr.arpa
6.77.in-addr.arpa
7.77.in-addr.arpa
8.77.in-addr.arpa
9.77.in-addr.arpa
10.77.in-addr.arpa
11.77.in-addr.arpa
12.77.in-addr.arpa
13.77.in-addr.arpa
14.77.in-addr.arpa
15.77.in-addr.arpa
and 112 more
/9 is not on a 8-bit boundary, so it takes 128 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01001101.00000000.00000000.0000000077.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network01001101.00000000.00000000.0000000077.0.0.0
Broadcast01001101.01111111.11111111.1111111177.127.255.255
Split into smaller subnets/17
/10 (2)/11 (4)/12 (8)/13 (16)/14 (32)/15 (64)/16 (128)/17 (256)/18 (512)/19 (1,024)/20 (2,048)/21 (4,096)

77.0.0.0/9 makes 256 subnets of /17.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
177.0.0.0/1777.0.0.1 to 77.0.127.25477.0.127.25532,766
277.0.128.0/1777.0.128.1 to 77.0.255.25477.0.255.25532,766
377.1.0.0/1777.1.0.1 to 77.1.127.25477.1.127.25532,766
477.1.128.0/1777.1.128.1 to 77.1.255.25477.1.255.25532,766
577.2.0.0/1777.2.0.1 to 77.2.127.25477.2.127.25532,766
677.2.128.0/1777.2.128.1 to 77.2.255.25477.2.255.25532,766
777.3.0.0/1777.3.0.1 to 77.3.127.25477.3.127.25532,766
877.3.128.0/1777.3.128.1 to 77.3.255.25477.3.255.25532,766
977.4.0.0/1777.4.0.1 to 77.4.127.25477.4.127.25532,766
1077.4.128.0/1777.4.128.1 to 77.4.255.25477.4.255.25532,766
1177.5.0.0/1777.5.0.1 to 77.5.127.25477.5.127.25532,766
1277.5.128.0/1777.5.128.1 to 77.5.255.25477.5.255.25532,766
1377.6.0.0/1777.6.0.1 to 77.6.127.25477.6.127.25532,766
1477.6.128.0/1777.6.128.1 to 77.6.255.25477.6.255.25532,766
1577.7.0.0/1777.7.0.1 to 77.7.127.25477.7.127.25532,766
1677.7.128.0/1777.7.128.1 to 77.7.255.25477.7.255.25532,766
1777.8.0.0/1777.8.0.1 to 77.8.127.25477.8.127.25532,766
1877.8.128.0/1777.8.128.1 to 77.8.255.25477.8.255.25532,766
1977.9.0.0/1777.9.0.1 to 77.9.127.25477.9.127.25532,766
2077.9.128.0/1777.9.128.1 to 77.9.255.25477.9.255.25532,766
2177.10.0.0/1777.10.0.1 to 77.10.127.25477.10.127.25532,766
2277.10.128.0/1777.10.128.1 to 77.10.255.25477.10.255.25532,766
2377.11.0.0/1777.11.0.1 to 77.11.127.25477.11.127.25532,766
2477.11.128.0/1777.11.128.1 to 77.11.255.25477.11.255.25532,766
2577.12.0.0/1777.12.0.1 to 77.12.127.25477.12.127.25532,766
2677.12.128.0/1777.12.128.1 to 77.12.255.25477.12.255.25532,766
2777.13.0.0/1777.13.0.1 to 77.13.127.25477.13.127.25532,766
2877.13.128.0/1777.13.128.1 to 77.13.255.25477.13.255.25532,766
2977.14.0.0/1777.14.0.1 to 77.14.127.25477.14.127.25532,766
3077.14.128.0/1777.14.128.1 to 77.14.255.25477.14.255.25532,766
3177.15.0.0/1777.15.0.1 to 77.15.127.25477.15.127.25532,766
3277.15.128.0/1777.15.128.1 to 77.15.255.25477.15.255.25532,766
3377.16.0.0/1777.16.0.1 to 77.16.127.25477.16.127.25532,766
3477.16.128.0/1777.16.128.1 to 77.16.255.25477.16.255.25532,766
3577.17.0.0/1777.17.0.1 to 77.17.127.25477.17.127.25532,766
3677.17.128.0/1777.17.128.1 to 77.17.255.25477.17.255.25532,766
3777.18.0.0/1777.18.0.1 to 77.18.127.25477.18.127.25532,766
3877.18.128.0/1777.18.128.1 to 77.18.255.25477.18.255.25532,766
3977.19.0.0/1777.19.0.1 to 77.19.127.25477.19.127.25532,766
4077.19.128.0/1777.19.128.1 to 77.19.255.25477.19.255.25532,766
4177.20.0.0/1777.20.0.1 to 77.20.127.25477.20.127.25532,766
4277.20.128.0/1777.20.128.1 to 77.20.255.25477.20.255.25532,766
4377.21.0.0/1777.21.0.1 to 77.21.127.25477.21.127.25532,766
4477.21.128.0/1777.21.128.1 to 77.21.255.25477.21.255.25532,766
4577.22.0.0/1777.22.0.1 to 77.22.127.25477.22.127.25532,766
4677.22.128.0/1777.22.128.1 to 77.22.255.25477.22.255.25532,766
4777.23.0.0/1777.23.0.1 to 77.23.127.25477.23.127.25532,766
4877.23.128.0/1777.23.128.1 to 77.23.255.25477.23.255.25532,766
4977.24.0.0/1777.24.0.1 to 77.24.127.25477.24.127.25532,766
5077.24.128.0/1777.24.128.1 to 77.24.255.25477.24.255.25532,766
5177.25.0.0/1777.25.0.1 to 77.25.127.25477.25.127.25532,766
5277.25.128.0/1777.25.128.1 to 77.25.255.25477.25.255.25532,766
5377.26.0.0/1777.26.0.1 to 77.26.127.25477.26.127.25532,766
5477.26.128.0/1777.26.128.1 to 77.26.255.25477.26.255.25532,766
5577.27.0.0/1777.27.0.1 to 77.27.127.25477.27.127.25532,766
5677.27.128.0/1777.27.128.1 to 77.27.255.25477.27.255.25532,766
5777.28.0.0/1777.28.0.1 to 77.28.127.25477.28.127.25532,766
5877.28.128.0/1777.28.128.1 to 77.28.255.25477.28.255.25532,766
5977.29.0.0/1777.29.0.1 to 77.29.127.25477.29.127.25532,766
6077.29.128.0/1777.29.128.1 to 77.29.255.25477.29.255.25532,766
6177.30.0.0/1777.30.0.1 to 77.30.127.25477.30.127.25532,766
6277.30.128.0/1777.30.128.1 to 77.30.255.25477.30.255.25532,766
6377.31.0.0/1777.31.0.1 to 77.31.127.25477.31.127.25532,766
6477.31.128.0/1777.31.128.1 to 77.31.255.25477.31.255.25532,766
6577.32.0.0/1777.32.0.1 to 77.32.127.25477.32.127.25532,766
6677.32.128.0/1777.32.128.1 to 77.32.255.25477.32.255.25532,766
6777.33.0.0/1777.33.0.1 to 77.33.127.25477.33.127.25532,766
6877.33.128.0/1777.33.128.1 to 77.33.255.25477.33.255.25532,766
6977.34.0.0/1777.34.0.1 to 77.34.127.25477.34.127.25532,766
7077.34.128.0/1777.34.128.1 to 77.34.255.25477.34.255.25532,766
7177.35.0.0/1777.35.0.1 to 77.35.127.25477.35.127.25532,766
7277.35.128.0/1777.35.128.1 to 77.35.255.25477.35.255.25532,766
7377.36.0.0/1777.36.0.1 to 77.36.127.25477.36.127.25532,766
7477.36.128.0/1777.36.128.1 to 77.36.255.25477.36.255.25532,766
7577.37.0.0/1777.37.0.1 to 77.37.127.25477.37.127.25532,766
7677.37.128.0/1777.37.128.1 to 77.37.255.25477.37.255.25532,766
7777.38.0.0/1777.38.0.1 to 77.38.127.25477.38.127.25532,766
7877.38.128.0/1777.38.128.1 to 77.38.255.25477.38.255.25532,766
7977.39.0.0/1777.39.0.1 to 77.39.127.25477.39.127.25532,766
8077.39.128.0/1777.39.128.1 to 77.39.255.25477.39.255.25532,766
8177.40.0.0/1777.40.0.1 to 77.40.127.25477.40.127.25532,766
8277.40.128.0/1777.40.128.1 to 77.40.255.25477.40.255.25532,766
8377.41.0.0/1777.41.0.1 to 77.41.127.25477.41.127.25532,766
8477.41.128.0/1777.41.128.1 to 77.41.255.25477.41.255.25532,766
8577.42.0.0/1777.42.0.1 to 77.42.127.25477.42.127.25532,766
8677.42.128.0/1777.42.128.1 to 77.42.255.25477.42.255.25532,766
8777.43.0.0/1777.43.0.1 to 77.43.127.25477.43.127.25532,766
8877.43.128.0/1777.43.128.1 to 77.43.255.25477.43.255.25532,766
8977.44.0.0/1777.44.0.1 to 77.44.127.25477.44.127.25532,766
9077.44.128.0/1777.44.128.1 to 77.44.255.25477.44.255.25532,766
9177.45.0.0/1777.45.0.1 to 77.45.127.25477.45.127.25532,766
9277.45.128.0/1777.45.128.1 to 77.45.255.25477.45.255.25532,766
9377.46.0.0/1777.46.0.1 to 77.46.127.25477.46.127.25532,766
9477.46.128.0/1777.46.128.1 to 77.46.255.25477.46.255.25532,766
9577.47.0.0/1777.47.0.1 to 77.47.127.25477.47.127.25532,766
9677.47.128.0/1777.47.128.1 to 77.47.255.25477.47.255.25532,766
9777.48.0.0/1777.48.0.1 to 77.48.127.25477.48.127.25532,766
9877.48.128.0/1777.48.128.1 to 77.48.255.25477.48.255.25532,766
9977.49.0.0/1777.49.0.1 to 77.49.127.25477.49.127.25532,766
10077.49.128.0/1777.49.128.1 to 77.49.255.25477.49.255.25532,766
10177.50.0.0/1777.50.0.1 to 77.50.127.25477.50.127.25532,766
10277.50.128.0/1777.50.128.1 to 77.50.255.25477.50.255.25532,766
10377.51.0.0/1777.51.0.1 to 77.51.127.25477.51.127.25532,766
10477.51.128.0/1777.51.128.1 to 77.51.255.25477.51.255.25532,766
10577.52.0.0/1777.52.0.1 to 77.52.127.25477.52.127.25532,766
10677.52.128.0/1777.52.128.1 to 77.52.255.25477.52.255.25532,766
10777.53.0.0/1777.53.0.1 to 77.53.127.25477.53.127.25532,766
10877.53.128.0/1777.53.128.1 to 77.53.255.25477.53.255.25532,766
10977.54.0.0/1777.54.0.1 to 77.54.127.25477.54.127.25532,766
11077.54.128.0/1777.54.128.1 to 77.54.255.25477.54.255.25532,766
11177.55.0.0/1777.55.0.1 to 77.55.127.25477.55.127.25532,766
11277.55.128.0/1777.55.128.1 to 77.55.255.25477.55.255.25532,766
11377.56.0.0/1777.56.0.1 to 77.56.127.25477.56.127.25532,766
11477.56.128.0/1777.56.128.1 to 77.56.255.25477.56.255.25532,766
11577.57.0.0/1777.57.0.1 to 77.57.127.25477.57.127.25532,766
11677.57.128.0/1777.57.128.1 to 77.57.255.25477.57.255.25532,766
11777.58.0.0/1777.58.0.1 to 77.58.127.25477.58.127.25532,766
11877.58.128.0/1777.58.128.1 to 77.58.255.25477.58.255.25532,766
11977.59.0.0/1777.59.0.1 to 77.59.127.25477.59.127.25532,766
12077.59.128.0/1777.59.128.1 to 77.59.255.25477.59.255.25532,766
12177.60.0.0/1777.60.0.1 to 77.60.127.25477.60.127.25532,766
12277.60.128.0/1777.60.128.1 to 77.60.255.25477.60.255.25532,766
12377.61.0.0/1777.61.0.1 to 77.61.127.25477.61.127.25532,766
12477.61.128.0/1777.61.128.1 to 77.61.255.25477.61.255.25532,766
12577.62.0.0/1777.62.0.1 to 77.62.127.25477.62.127.25532,766
12677.62.128.0/1777.62.128.1 to 77.62.255.25477.62.255.25532,766
12777.63.0.0/1777.63.0.1 to 77.63.127.25477.63.127.25532,766
12877.63.128.0/1777.63.128.1 to 77.63.255.25477.63.255.25532,766
12977.64.0.0/1777.64.0.1 to 77.64.127.25477.64.127.25532,766
13077.64.128.0/1777.64.128.1 to 77.64.255.25477.64.255.25532,766
13177.65.0.0/1777.65.0.1 to 77.65.127.25477.65.127.25532,766
13277.65.128.0/1777.65.128.1 to 77.65.255.25477.65.255.25532,766
13377.66.0.0/1777.66.0.1 to 77.66.127.25477.66.127.25532,766
13477.66.128.0/1777.66.128.1 to 77.66.255.25477.66.255.25532,766
13577.67.0.0/1777.67.0.1 to 77.67.127.25477.67.127.25532,766
13677.67.128.0/1777.67.128.1 to 77.67.255.25477.67.255.25532,766
13777.68.0.0/1777.68.0.1 to 77.68.127.25477.68.127.25532,766
13877.68.128.0/1777.68.128.1 to 77.68.255.25477.68.255.25532,766
13977.69.0.0/1777.69.0.1 to 77.69.127.25477.69.127.25532,766
14077.69.128.0/1777.69.128.1 to 77.69.255.25477.69.255.25532,766
14177.70.0.0/1777.70.0.1 to 77.70.127.25477.70.127.25532,766
14277.70.128.0/1777.70.128.1 to 77.70.255.25477.70.255.25532,766
14377.71.0.0/1777.71.0.1 to 77.71.127.25477.71.127.25532,766
14477.71.128.0/1777.71.128.1 to 77.71.255.25477.71.255.25532,766
14577.72.0.0/1777.72.0.1 to 77.72.127.25477.72.127.25532,766
14677.72.128.0/1777.72.128.1 to 77.72.255.25477.72.255.25532,766
14777.73.0.0/1777.73.0.1 to 77.73.127.25477.73.127.25532,766
14877.73.128.0/1777.73.128.1 to 77.73.255.25477.73.255.25532,766
14977.74.0.0/1777.74.0.1 to 77.74.127.25477.74.127.25532,766
15077.74.128.0/1777.74.128.1 to 77.74.255.25477.74.255.25532,766
15177.75.0.0/1777.75.0.1 to 77.75.127.25477.75.127.25532,766
15277.75.128.0/1777.75.128.1 to 77.75.255.25477.75.255.25532,766
15377.76.0.0/1777.76.0.1 to 77.76.127.25477.76.127.25532,766
15477.76.128.0/1777.76.128.1 to 77.76.255.25477.76.255.25532,766
15577.77.0.0/1777.77.0.1 to 77.77.127.25477.77.127.25532,766
15677.77.128.0/1777.77.128.1 to 77.77.255.25477.77.255.25532,766
15777.78.0.0/1777.78.0.1 to 77.78.127.25477.78.127.25532,766
15877.78.128.0/1777.78.128.1 to 77.78.255.25477.78.255.25532,766
15977.79.0.0/1777.79.0.1 to 77.79.127.25477.79.127.25532,766
16077.79.128.0/1777.79.128.1 to 77.79.255.25477.79.255.25532,766
16177.80.0.0/1777.80.0.1 to 77.80.127.25477.80.127.25532,766
16277.80.128.0/1777.80.128.1 to 77.80.255.25477.80.255.25532,766
16377.81.0.0/1777.81.0.1 to 77.81.127.25477.81.127.25532,766
16477.81.128.0/1777.81.128.1 to 77.81.255.25477.81.255.25532,766
16577.82.0.0/1777.82.0.1 to 77.82.127.25477.82.127.25532,766
16677.82.128.0/1777.82.128.1 to 77.82.255.25477.82.255.25532,766
16777.83.0.0/1777.83.0.1 to 77.83.127.25477.83.127.25532,766
16877.83.128.0/1777.83.128.1 to 77.83.255.25477.83.255.25532,766
16977.84.0.0/1777.84.0.1 to 77.84.127.25477.84.127.25532,766
17077.84.128.0/1777.84.128.1 to 77.84.255.25477.84.255.25532,766
17177.85.0.0/1777.85.0.1 to 77.85.127.25477.85.127.25532,766
17277.85.128.0/1777.85.128.1 to 77.85.255.25477.85.255.25532,766
17377.86.0.0/1777.86.0.1 to 77.86.127.25477.86.127.25532,766
17477.86.128.0/1777.86.128.1 to 77.86.255.25477.86.255.25532,766
17577.87.0.0/1777.87.0.1 to 77.87.127.25477.87.127.25532,766
17677.87.128.0/1777.87.128.1 to 77.87.255.25477.87.255.25532,766
17777.88.0.0/1777.88.0.1 to 77.88.127.25477.88.127.25532,766
17877.88.128.0/1777.88.128.1 to 77.88.255.25477.88.255.25532,766
17977.89.0.0/1777.89.0.1 to 77.89.127.25477.89.127.25532,766
18077.89.128.0/1777.89.128.1 to 77.89.255.25477.89.255.25532,766
18177.90.0.0/1777.90.0.1 to 77.90.127.25477.90.127.25532,766
18277.90.128.0/1777.90.128.1 to 77.90.255.25477.90.255.25532,766
18377.91.0.0/1777.91.0.1 to 77.91.127.25477.91.127.25532,766
18477.91.128.0/1777.91.128.1 to 77.91.255.25477.91.255.25532,766
18577.92.0.0/1777.92.0.1 to 77.92.127.25477.92.127.25532,766
18677.92.128.0/1777.92.128.1 to 77.92.255.25477.92.255.25532,766
18777.93.0.0/1777.93.0.1 to 77.93.127.25477.93.127.25532,766
18877.93.128.0/1777.93.128.1 to 77.93.255.25477.93.255.25532,766
18977.94.0.0/1777.94.0.1 to 77.94.127.25477.94.127.25532,766
19077.94.128.0/1777.94.128.1 to 77.94.255.25477.94.255.25532,766
19177.95.0.0/1777.95.0.1 to 77.95.127.25477.95.127.25532,766
19277.95.128.0/1777.95.128.1 to 77.95.255.25477.95.255.25532,766
19377.96.0.0/1777.96.0.1 to 77.96.127.25477.96.127.25532,766
19477.96.128.0/1777.96.128.1 to 77.96.255.25477.96.255.25532,766
19577.97.0.0/1777.97.0.1 to 77.97.127.25477.97.127.25532,766
19677.97.128.0/1777.97.128.1 to 77.97.255.25477.97.255.25532,766
19777.98.0.0/1777.98.0.1 to 77.98.127.25477.98.127.25532,766
19877.98.128.0/1777.98.128.1 to 77.98.255.25477.98.255.25532,766
19977.99.0.0/1777.99.0.1 to 77.99.127.25477.99.127.25532,766
20077.99.128.0/1777.99.128.1 to 77.99.255.25477.99.255.25532,766
20177.100.0.0/1777.100.0.1 to 77.100.127.25477.100.127.25532,766
20277.100.128.0/1777.100.128.1 to 77.100.255.25477.100.255.25532,766
20377.101.0.0/1777.101.0.1 to 77.101.127.25477.101.127.25532,766
20477.101.128.0/1777.101.128.1 to 77.101.255.25477.101.255.25532,766
20577.102.0.0/1777.102.0.1 to 77.102.127.25477.102.127.25532,766
20677.102.128.0/1777.102.128.1 to 77.102.255.25477.102.255.25532,766
20777.103.0.0/1777.103.0.1 to 77.103.127.25477.103.127.25532,766
20877.103.128.0/1777.103.128.1 to 77.103.255.25477.103.255.25532,766
20977.104.0.0/1777.104.0.1 to 77.104.127.25477.104.127.25532,766
21077.104.128.0/1777.104.128.1 to 77.104.255.25477.104.255.25532,766
21177.105.0.0/1777.105.0.1 to 77.105.127.25477.105.127.25532,766
21277.105.128.0/1777.105.128.1 to 77.105.255.25477.105.255.25532,766
21377.106.0.0/1777.106.0.1 to 77.106.127.25477.106.127.25532,766
21477.106.128.0/1777.106.128.1 to 77.106.255.25477.106.255.25532,766
21577.107.0.0/1777.107.0.1 to 77.107.127.25477.107.127.25532,766
21677.107.128.0/1777.107.128.1 to 77.107.255.25477.107.255.25532,766
21777.108.0.0/1777.108.0.1 to 77.108.127.25477.108.127.25532,766
21877.108.128.0/1777.108.128.1 to 77.108.255.25477.108.255.25532,766
21977.109.0.0/1777.109.0.1 to 77.109.127.25477.109.127.25532,766
22077.109.128.0/1777.109.128.1 to 77.109.255.25477.109.255.25532,766
22177.110.0.0/1777.110.0.1 to 77.110.127.25477.110.127.25532,766
22277.110.128.0/1777.110.128.1 to 77.110.255.25477.110.255.25532,766
22377.111.0.0/1777.111.0.1 to 77.111.127.25477.111.127.25532,766
22477.111.128.0/1777.111.128.1 to 77.111.255.25477.111.255.25532,766
22577.112.0.0/1777.112.0.1 to 77.112.127.25477.112.127.25532,766
22677.112.128.0/1777.112.128.1 to 77.112.255.25477.112.255.25532,766
22777.113.0.0/1777.113.0.1 to 77.113.127.25477.113.127.25532,766
22877.113.128.0/1777.113.128.1 to 77.113.255.25477.113.255.25532,766
22977.114.0.0/1777.114.0.1 to 77.114.127.25477.114.127.25532,766
23077.114.128.0/1777.114.128.1 to 77.114.255.25477.114.255.25532,766
23177.115.0.0/1777.115.0.1 to 77.115.127.25477.115.127.25532,766
23277.115.128.0/1777.115.128.1 to 77.115.255.25477.115.255.25532,766
23377.116.0.0/1777.116.0.1 to 77.116.127.25477.116.127.25532,766
23477.116.128.0/1777.116.128.1 to 77.116.255.25477.116.255.25532,766
23577.117.0.0/1777.117.0.1 to 77.117.127.25477.117.127.25532,766
23677.117.128.0/1777.117.128.1 to 77.117.255.25477.117.255.25532,766
23777.118.0.0/1777.118.0.1 to 77.118.127.25477.118.127.25532,766
23877.118.128.0/1777.118.128.1 to 77.118.255.25477.118.255.25532,766
23977.119.0.0/1777.119.0.1 to 77.119.127.25477.119.127.25532,766
24077.119.128.0/1777.119.128.1 to 77.119.255.25477.119.255.25532,766
24177.120.0.0/1777.120.0.1 to 77.120.127.25477.120.127.25532,766
24277.120.128.0/1777.120.128.1 to 77.120.255.25477.120.255.25532,766
24377.121.0.0/1777.121.0.1 to 77.121.127.25477.121.127.25532,766
24477.121.128.0/1777.121.128.1 to 77.121.255.25477.121.255.25532,766
24577.122.0.0/1777.122.0.1 to 77.122.127.25477.122.127.25532,766
24677.122.128.0/1777.122.128.1 to 77.122.255.25477.122.255.25532,766
24777.123.0.0/1777.123.0.1 to 77.123.127.25477.123.127.25532,766
24877.123.128.0/1777.123.128.1 to 77.123.255.25477.123.255.25532,766
24977.124.0.0/1777.124.0.1 to 77.124.127.25477.124.127.25532,766
25077.124.128.0/1777.124.128.1 to 77.124.255.25477.124.255.25532,766
25177.125.0.0/1777.125.0.1 to 77.125.127.25477.125.127.25532,766
25277.125.128.0/1777.125.128.1 to 77.125.255.25477.125.255.25532,766
25377.126.0.0/1777.126.0.1 to 77.126.127.25477.126.127.25532,766
25477.126.128.0/1777.126.128.1 to 77.126.255.25477.126.255.25532,766
25577.127.0.0/1777.127.0.1 to 77.127.127.25477.127.127.25532,766
25677.127.128.0/1777.127.128.1 to 77.127.255.25477.127.255.25532,766

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.