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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.

Network77.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
77.0.0.0
Broadcast address
77.255.255.255
First usable
77.0.0.1
Last usable
77.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
A (default /8)
As numbers
Hex 4D000000 · Integer 1291845632 to 1308622847
Reverse DNS zone
77.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01001101..00000000.00000000.0000000077.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network01001101..00000000.00000000.0000000077.0.0.0
Broadcast01001101..11111111.11111111.1111111177.255.255.255
Split into smaller subnets/16
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

77.0.0.0/8 makes 256 subnets of /16.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
177.0.0.0/1677.0.0.1 to 77.0.255.25477.0.255.25565,534
277.1.0.0/1677.1.0.1 to 77.1.255.25477.1.255.25565,534
377.2.0.0/1677.2.0.1 to 77.2.255.25477.2.255.25565,534
477.3.0.0/1677.3.0.1 to 77.3.255.25477.3.255.25565,534
577.4.0.0/1677.4.0.1 to 77.4.255.25477.4.255.25565,534
677.5.0.0/1677.5.0.1 to 77.5.255.25477.5.255.25565,534
777.6.0.0/1677.6.0.1 to 77.6.255.25477.6.255.25565,534
877.7.0.0/1677.7.0.1 to 77.7.255.25477.7.255.25565,534
977.8.0.0/1677.8.0.1 to 77.8.255.25477.8.255.25565,534
1077.9.0.0/1677.9.0.1 to 77.9.255.25477.9.255.25565,534
1177.10.0.0/1677.10.0.1 to 77.10.255.25477.10.255.25565,534
1277.11.0.0/1677.11.0.1 to 77.11.255.25477.11.255.25565,534
1377.12.0.0/1677.12.0.1 to 77.12.255.25477.12.255.25565,534
1477.13.0.0/1677.13.0.1 to 77.13.255.25477.13.255.25565,534
1577.14.0.0/1677.14.0.1 to 77.14.255.25477.14.255.25565,534
1677.15.0.0/1677.15.0.1 to 77.15.255.25477.15.255.25565,534
1777.16.0.0/1677.16.0.1 to 77.16.255.25477.16.255.25565,534
1877.17.0.0/1677.17.0.1 to 77.17.255.25477.17.255.25565,534
1977.18.0.0/1677.18.0.1 to 77.18.255.25477.18.255.25565,534
2077.19.0.0/1677.19.0.1 to 77.19.255.25477.19.255.25565,534
2177.20.0.0/1677.20.0.1 to 77.20.255.25477.20.255.25565,534
2277.21.0.0/1677.21.0.1 to 77.21.255.25477.21.255.25565,534
2377.22.0.0/1677.22.0.1 to 77.22.255.25477.22.255.25565,534
2477.23.0.0/1677.23.0.1 to 77.23.255.25477.23.255.25565,534
2577.24.0.0/1677.24.0.1 to 77.24.255.25477.24.255.25565,534
2677.25.0.0/1677.25.0.1 to 77.25.255.25477.25.255.25565,534
2777.26.0.0/1677.26.0.1 to 77.26.255.25477.26.255.25565,534
2877.27.0.0/1677.27.0.1 to 77.27.255.25477.27.255.25565,534
2977.28.0.0/1677.28.0.1 to 77.28.255.25477.28.255.25565,534
3077.29.0.0/1677.29.0.1 to 77.29.255.25477.29.255.25565,534
3177.30.0.0/1677.30.0.1 to 77.30.255.25477.30.255.25565,534
3277.31.0.0/1677.31.0.1 to 77.31.255.25477.31.255.25565,534
3377.32.0.0/1677.32.0.1 to 77.32.255.25477.32.255.25565,534
3477.33.0.0/1677.33.0.1 to 77.33.255.25477.33.255.25565,534
3577.34.0.0/1677.34.0.1 to 77.34.255.25477.34.255.25565,534
3677.35.0.0/1677.35.0.1 to 77.35.255.25477.35.255.25565,534
3777.36.0.0/1677.36.0.1 to 77.36.255.25477.36.255.25565,534
3877.37.0.0/1677.37.0.1 to 77.37.255.25477.37.255.25565,534
3977.38.0.0/1677.38.0.1 to 77.38.255.25477.38.255.25565,534
4077.39.0.0/1677.39.0.1 to 77.39.255.25477.39.255.25565,534
4177.40.0.0/1677.40.0.1 to 77.40.255.25477.40.255.25565,534
4277.41.0.0/1677.41.0.1 to 77.41.255.25477.41.255.25565,534
4377.42.0.0/1677.42.0.1 to 77.42.255.25477.42.255.25565,534
4477.43.0.0/1677.43.0.1 to 77.43.255.25477.43.255.25565,534
4577.44.0.0/1677.44.0.1 to 77.44.255.25477.44.255.25565,534
4677.45.0.0/1677.45.0.1 to 77.45.255.25477.45.255.25565,534
4777.46.0.0/1677.46.0.1 to 77.46.255.25477.46.255.25565,534
4877.47.0.0/1677.47.0.1 to 77.47.255.25477.47.255.25565,534
4977.48.0.0/1677.48.0.1 to 77.48.255.25477.48.255.25565,534
5077.49.0.0/1677.49.0.1 to 77.49.255.25477.49.255.25565,534
5177.50.0.0/1677.50.0.1 to 77.50.255.25477.50.255.25565,534
5277.51.0.0/1677.51.0.1 to 77.51.255.25477.51.255.25565,534
5377.52.0.0/1677.52.0.1 to 77.52.255.25477.52.255.25565,534
5477.53.0.0/1677.53.0.1 to 77.53.255.25477.53.255.25565,534
5577.54.0.0/1677.54.0.1 to 77.54.255.25477.54.255.25565,534
5677.55.0.0/1677.55.0.1 to 77.55.255.25477.55.255.25565,534
5777.56.0.0/1677.56.0.1 to 77.56.255.25477.56.255.25565,534
5877.57.0.0/1677.57.0.1 to 77.57.255.25477.57.255.25565,534
5977.58.0.0/1677.58.0.1 to 77.58.255.25477.58.255.25565,534
6077.59.0.0/1677.59.0.1 to 77.59.255.25477.59.255.25565,534
6177.60.0.0/1677.60.0.1 to 77.60.255.25477.60.255.25565,534
6277.61.0.0/1677.61.0.1 to 77.61.255.25477.61.255.25565,534
6377.62.0.0/1677.62.0.1 to 77.62.255.25477.62.255.25565,534
6477.63.0.0/1677.63.0.1 to 77.63.255.25477.63.255.25565,534
6577.64.0.0/1677.64.0.1 to 77.64.255.25477.64.255.25565,534
6677.65.0.0/1677.65.0.1 to 77.65.255.25477.65.255.25565,534
6777.66.0.0/1677.66.0.1 to 77.66.255.25477.66.255.25565,534
6877.67.0.0/1677.67.0.1 to 77.67.255.25477.67.255.25565,534
6977.68.0.0/1677.68.0.1 to 77.68.255.25477.68.255.25565,534
7077.69.0.0/1677.69.0.1 to 77.69.255.25477.69.255.25565,534
7177.70.0.0/1677.70.0.1 to 77.70.255.25477.70.255.25565,534
7277.71.0.0/1677.71.0.1 to 77.71.255.25477.71.255.25565,534
7377.72.0.0/1677.72.0.1 to 77.72.255.25477.72.255.25565,534
7477.73.0.0/1677.73.0.1 to 77.73.255.25477.73.255.25565,534
7577.74.0.0/1677.74.0.1 to 77.74.255.25477.74.255.25565,534
7677.75.0.0/1677.75.0.1 to 77.75.255.25477.75.255.25565,534
7777.76.0.0/1677.76.0.1 to 77.76.255.25477.76.255.25565,534
7877.77.0.0/1677.77.0.1 to 77.77.255.25477.77.255.25565,534
7977.78.0.0/1677.78.0.1 to 77.78.255.25477.78.255.25565,534
8077.79.0.0/1677.79.0.1 to 77.79.255.25477.79.255.25565,534
8177.80.0.0/1677.80.0.1 to 77.80.255.25477.80.255.25565,534
8277.81.0.0/1677.81.0.1 to 77.81.255.25477.81.255.25565,534
8377.82.0.0/1677.82.0.1 to 77.82.255.25477.82.255.25565,534
8477.83.0.0/1677.83.0.1 to 77.83.255.25477.83.255.25565,534
8577.84.0.0/1677.84.0.1 to 77.84.255.25477.84.255.25565,534
8677.85.0.0/1677.85.0.1 to 77.85.255.25477.85.255.25565,534
8777.86.0.0/1677.86.0.1 to 77.86.255.25477.86.255.25565,534
8877.87.0.0/1677.87.0.1 to 77.87.255.25477.87.255.25565,534
8977.88.0.0/1677.88.0.1 to 77.88.255.25477.88.255.25565,534
9077.89.0.0/1677.89.0.1 to 77.89.255.25477.89.255.25565,534
9177.90.0.0/1677.90.0.1 to 77.90.255.25477.90.255.25565,534
9277.91.0.0/1677.91.0.1 to 77.91.255.25477.91.255.25565,534
9377.92.0.0/1677.92.0.1 to 77.92.255.25477.92.255.25565,534
9477.93.0.0/1677.93.0.1 to 77.93.255.25477.93.255.25565,534
9577.94.0.0/1677.94.0.1 to 77.94.255.25477.94.255.25565,534
9677.95.0.0/1677.95.0.1 to 77.95.255.25477.95.255.25565,534
9777.96.0.0/1677.96.0.1 to 77.96.255.25477.96.255.25565,534
9877.97.0.0/1677.97.0.1 to 77.97.255.25477.97.255.25565,534
9977.98.0.0/1677.98.0.1 to 77.98.255.25477.98.255.25565,534
10077.99.0.0/1677.99.0.1 to 77.99.255.25477.99.255.25565,534
10177.100.0.0/1677.100.0.1 to 77.100.255.25477.100.255.25565,534
10277.101.0.0/1677.101.0.1 to 77.101.255.25477.101.255.25565,534
10377.102.0.0/1677.102.0.1 to 77.102.255.25477.102.255.25565,534
10477.103.0.0/1677.103.0.1 to 77.103.255.25477.103.255.25565,534
10577.104.0.0/1677.104.0.1 to 77.104.255.25477.104.255.25565,534
10677.105.0.0/1677.105.0.1 to 77.105.255.25477.105.255.25565,534
10777.106.0.0/1677.106.0.1 to 77.106.255.25477.106.255.25565,534
10877.107.0.0/1677.107.0.1 to 77.107.255.25477.107.255.25565,534
10977.108.0.0/1677.108.0.1 to 77.108.255.25477.108.255.25565,534
11077.109.0.0/1677.109.0.1 to 77.109.255.25477.109.255.25565,534
11177.110.0.0/1677.110.0.1 to 77.110.255.25477.110.255.25565,534
11277.111.0.0/1677.111.0.1 to 77.111.255.25477.111.255.25565,534
11377.112.0.0/1677.112.0.1 to 77.112.255.25477.112.255.25565,534
11477.113.0.0/1677.113.0.1 to 77.113.255.25477.113.255.25565,534
11577.114.0.0/1677.114.0.1 to 77.114.255.25477.114.255.25565,534
11677.115.0.0/1677.115.0.1 to 77.115.255.25477.115.255.25565,534
11777.116.0.0/1677.116.0.1 to 77.116.255.25477.116.255.25565,534
11877.117.0.0/1677.117.0.1 to 77.117.255.25477.117.255.25565,534
11977.118.0.0/1677.118.0.1 to 77.118.255.25477.118.255.25565,534
12077.119.0.0/1677.119.0.1 to 77.119.255.25477.119.255.25565,534
12177.120.0.0/1677.120.0.1 to 77.120.255.25477.120.255.25565,534
12277.121.0.0/1677.121.0.1 to 77.121.255.25477.121.255.25565,534
12377.122.0.0/1677.122.0.1 to 77.122.255.25477.122.255.25565,534
12477.123.0.0/1677.123.0.1 to 77.123.255.25477.123.255.25565,534
12577.124.0.0/1677.124.0.1 to 77.124.255.25477.124.255.25565,534
12677.125.0.0/1677.125.0.1 to 77.125.255.25477.125.255.25565,534
12777.126.0.0/1677.126.0.1 to 77.126.255.25477.126.255.25565,534
12877.127.0.0/1677.127.0.1 to 77.127.255.25477.127.255.25565,534
12977.128.0.0/1677.128.0.1 to 77.128.255.25477.128.255.25565,534
13077.129.0.0/1677.129.0.1 to 77.129.255.25477.129.255.25565,534
13177.130.0.0/1677.130.0.1 to 77.130.255.25477.130.255.25565,534
13277.131.0.0/1677.131.0.1 to 77.131.255.25477.131.255.25565,534
13377.132.0.0/1677.132.0.1 to 77.132.255.25477.132.255.25565,534
13477.133.0.0/1677.133.0.1 to 77.133.255.25477.133.255.25565,534
13577.134.0.0/1677.134.0.1 to 77.134.255.25477.134.255.25565,534
13677.135.0.0/1677.135.0.1 to 77.135.255.25477.135.255.25565,534
13777.136.0.0/1677.136.0.1 to 77.136.255.25477.136.255.25565,534
13877.137.0.0/1677.137.0.1 to 77.137.255.25477.137.255.25565,534
13977.138.0.0/1677.138.0.1 to 77.138.255.25477.138.255.25565,534
14077.139.0.0/1677.139.0.1 to 77.139.255.25477.139.255.25565,534
14177.140.0.0/1677.140.0.1 to 77.140.255.25477.140.255.25565,534
14277.141.0.0/1677.141.0.1 to 77.141.255.25477.141.255.25565,534
14377.142.0.0/1677.142.0.1 to 77.142.255.25477.142.255.25565,534
14477.143.0.0/1677.143.0.1 to 77.143.255.25477.143.255.25565,534
14577.144.0.0/1677.144.0.1 to 77.144.255.25477.144.255.25565,534
14677.145.0.0/1677.145.0.1 to 77.145.255.25477.145.255.25565,534
14777.146.0.0/1677.146.0.1 to 77.146.255.25477.146.255.25565,534
14877.147.0.0/1677.147.0.1 to 77.147.255.25477.147.255.25565,534
14977.148.0.0/1677.148.0.1 to 77.148.255.25477.148.255.25565,534
15077.149.0.0/1677.149.0.1 to 77.149.255.25477.149.255.25565,534
15177.150.0.0/1677.150.0.1 to 77.150.255.25477.150.255.25565,534
15277.151.0.0/1677.151.0.1 to 77.151.255.25477.151.255.25565,534
15377.152.0.0/1677.152.0.1 to 77.152.255.25477.152.255.25565,534
15477.153.0.0/1677.153.0.1 to 77.153.255.25477.153.255.25565,534
15577.154.0.0/1677.154.0.1 to 77.154.255.25477.154.255.25565,534
15677.155.0.0/1677.155.0.1 to 77.155.255.25477.155.255.25565,534
15777.156.0.0/1677.156.0.1 to 77.156.255.25477.156.255.25565,534
15877.157.0.0/1677.157.0.1 to 77.157.255.25477.157.255.25565,534
15977.158.0.0/1677.158.0.1 to 77.158.255.25477.158.255.25565,534
16077.159.0.0/1677.159.0.1 to 77.159.255.25477.159.255.25565,534
16177.160.0.0/1677.160.0.1 to 77.160.255.25477.160.255.25565,534
16277.161.0.0/1677.161.0.1 to 77.161.255.25477.161.255.25565,534
16377.162.0.0/1677.162.0.1 to 77.162.255.25477.162.255.25565,534
16477.163.0.0/1677.163.0.1 to 77.163.255.25477.163.255.25565,534
16577.164.0.0/1677.164.0.1 to 77.164.255.25477.164.255.25565,534
16677.165.0.0/1677.165.0.1 to 77.165.255.25477.165.255.25565,534
16777.166.0.0/1677.166.0.1 to 77.166.255.25477.166.255.25565,534
16877.167.0.0/1677.167.0.1 to 77.167.255.25477.167.255.25565,534
16977.168.0.0/1677.168.0.1 to 77.168.255.25477.168.255.25565,534
17077.169.0.0/1677.169.0.1 to 77.169.255.25477.169.255.25565,534
17177.170.0.0/1677.170.0.1 to 77.170.255.25477.170.255.25565,534
17277.171.0.0/1677.171.0.1 to 77.171.255.25477.171.255.25565,534
17377.172.0.0/1677.172.0.1 to 77.172.255.25477.172.255.25565,534
17477.173.0.0/1677.173.0.1 to 77.173.255.25477.173.255.25565,534
17577.174.0.0/1677.174.0.1 to 77.174.255.25477.174.255.25565,534
17677.175.0.0/1677.175.0.1 to 77.175.255.25477.175.255.25565,534
17777.176.0.0/1677.176.0.1 to 77.176.255.25477.176.255.25565,534
17877.177.0.0/1677.177.0.1 to 77.177.255.25477.177.255.25565,534
17977.178.0.0/1677.178.0.1 to 77.178.255.25477.178.255.25565,534
18077.179.0.0/1677.179.0.1 to 77.179.255.25477.179.255.25565,534
18177.180.0.0/1677.180.0.1 to 77.180.255.25477.180.255.25565,534
18277.181.0.0/1677.181.0.1 to 77.181.255.25477.181.255.25565,534
18377.182.0.0/1677.182.0.1 to 77.182.255.25477.182.255.25565,534
18477.183.0.0/1677.183.0.1 to 77.183.255.25477.183.255.25565,534
18577.184.0.0/1677.184.0.1 to 77.184.255.25477.184.255.25565,534
18677.185.0.0/1677.185.0.1 to 77.185.255.25477.185.255.25565,534
18777.186.0.0/1677.186.0.1 to 77.186.255.25477.186.255.25565,534
18877.187.0.0/1677.187.0.1 to 77.187.255.25477.187.255.25565,534
18977.188.0.0/1677.188.0.1 to 77.188.255.25477.188.255.25565,534
19077.189.0.0/1677.189.0.1 to 77.189.255.25477.189.255.25565,534
19177.190.0.0/1677.190.0.1 to 77.190.255.25477.190.255.25565,534
19277.191.0.0/1677.191.0.1 to 77.191.255.25477.191.255.25565,534
19377.192.0.0/1677.192.0.1 to 77.192.255.25477.192.255.25565,534
19477.193.0.0/1677.193.0.1 to 77.193.255.25477.193.255.25565,534
19577.194.0.0/1677.194.0.1 to 77.194.255.25477.194.255.25565,534
19677.195.0.0/1677.195.0.1 to 77.195.255.25477.195.255.25565,534
19777.196.0.0/1677.196.0.1 to 77.196.255.25477.196.255.25565,534
19877.197.0.0/1677.197.0.1 to 77.197.255.25477.197.255.25565,534
19977.198.0.0/1677.198.0.1 to 77.198.255.25477.198.255.25565,534
20077.199.0.0/1677.199.0.1 to 77.199.255.25477.199.255.25565,534
20177.200.0.0/1677.200.0.1 to 77.200.255.25477.200.255.25565,534
20277.201.0.0/1677.201.0.1 to 77.201.255.25477.201.255.25565,534
20377.202.0.0/1677.202.0.1 to 77.202.255.25477.202.255.25565,534
20477.203.0.0/1677.203.0.1 to 77.203.255.25477.203.255.25565,534
20577.204.0.0/1677.204.0.1 to 77.204.255.25477.204.255.25565,534
20677.205.0.0/1677.205.0.1 to 77.205.255.25477.205.255.25565,534
20777.206.0.0/1677.206.0.1 to 77.206.255.25477.206.255.25565,534
20877.207.0.0/1677.207.0.1 to 77.207.255.25477.207.255.25565,534
20977.208.0.0/1677.208.0.1 to 77.208.255.25477.208.255.25565,534
21077.209.0.0/1677.209.0.1 to 77.209.255.25477.209.255.25565,534
21177.210.0.0/1677.210.0.1 to 77.210.255.25477.210.255.25565,534
21277.211.0.0/1677.211.0.1 to 77.211.255.25477.211.255.25565,534
21377.212.0.0/1677.212.0.1 to 77.212.255.25477.212.255.25565,534
21477.213.0.0/1677.213.0.1 to 77.213.255.25477.213.255.25565,534
21577.214.0.0/1677.214.0.1 to 77.214.255.25477.214.255.25565,534
21677.215.0.0/1677.215.0.1 to 77.215.255.25477.215.255.25565,534
21777.216.0.0/1677.216.0.1 to 77.216.255.25477.216.255.25565,534
21877.217.0.0/1677.217.0.1 to 77.217.255.25477.217.255.25565,534
21977.218.0.0/1677.218.0.1 to 77.218.255.25477.218.255.25565,534
22077.219.0.0/1677.219.0.1 to 77.219.255.25477.219.255.25565,534
22177.220.0.0/1677.220.0.1 to 77.220.255.25477.220.255.25565,534
22277.221.0.0/1677.221.0.1 to 77.221.255.25477.221.255.25565,534
22377.222.0.0/1677.222.0.1 to 77.222.255.25477.222.255.25565,534
22477.223.0.0/1677.223.0.1 to 77.223.255.25477.223.255.25565,534
22577.224.0.0/1677.224.0.1 to 77.224.255.25477.224.255.25565,534
22677.225.0.0/1677.225.0.1 to 77.225.255.25477.225.255.25565,534
22777.226.0.0/1677.226.0.1 to 77.226.255.25477.226.255.25565,534
22877.227.0.0/1677.227.0.1 to 77.227.255.25477.227.255.25565,534
22977.228.0.0/1677.228.0.1 to 77.228.255.25477.228.255.25565,534
23077.229.0.0/1677.229.0.1 to 77.229.255.25477.229.255.25565,534
23177.230.0.0/1677.230.0.1 to 77.230.255.25477.230.255.25565,534
23277.231.0.0/1677.231.0.1 to 77.231.255.25477.231.255.25565,534
23377.232.0.0/1677.232.0.1 to 77.232.255.25477.232.255.25565,534
23477.233.0.0/1677.233.0.1 to 77.233.255.25477.233.255.25565,534
23577.234.0.0/1677.234.0.1 to 77.234.255.25477.234.255.25565,534
23677.235.0.0/1677.235.0.1 to 77.235.255.25477.235.255.25565,534
23777.236.0.0/1677.236.0.1 to 77.236.255.25477.236.255.25565,534
23877.237.0.0/1677.237.0.1 to 77.237.255.25477.237.255.25565,534
23977.238.0.0/1677.238.0.1 to 77.238.255.25477.238.255.25565,534
24077.239.0.0/1677.239.0.1 to 77.239.255.25477.239.255.25565,534
24177.240.0.0/1677.240.0.1 to 77.240.255.25477.240.255.25565,534
24277.241.0.0/1677.241.0.1 to 77.241.255.25477.241.255.25565,534
24377.242.0.0/1677.242.0.1 to 77.242.255.25477.242.255.25565,534
24477.243.0.0/1677.243.0.1 to 77.243.255.25477.243.255.25565,534
24577.244.0.0/1677.244.0.1 to 77.244.255.25477.244.255.25565,534
24677.245.0.0/1677.245.0.1 to 77.245.255.25477.245.255.25565,534
24777.246.0.0/1677.246.0.1 to 77.246.255.25477.246.255.25565,534
24877.247.0.0/1677.247.0.1 to 77.247.255.25477.247.255.25565,534
24977.248.0.0/1677.248.0.1 to 77.248.255.25477.248.255.25565,534
25077.249.0.0/1677.249.0.1 to 77.249.255.25477.249.255.25565,534
25177.250.0.0/1677.250.0.1 to 77.250.255.25477.250.255.25565,534
25277.251.0.0/1677.251.0.1 to 77.251.255.25477.251.255.25565,534
25377.252.0.0/1677.252.0.1 to 77.252.255.25477.252.255.25565,534
25477.253.0.0/1677.253.0.1 to 77.253.255.25477.253.255.25565,534
25577.254.0.0/1677.254.0.1 to 77.254.255.25477.254.255.25565,534
25677.255.0.0/1677.255.0.1 to 77.255.255.25477.255.255.25565,534

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.