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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.

Network50.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
50.0.0.0
Broadcast address
51.255.255.255
First usable
50.0.0.1
Last usable
51.255.255.254
Usable hosts
33,554,430 (33,554,432 less the network and broadcast addresses)
Subnet mask
254.0.0.0
Wildcard mask
1.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/7
Type
Public public
Old class
A (default /8)
As numbers
Hex 32000000 · Integer 838860800 to 872415231
Reverse DNS zones
50.in-addr.arpa
51.in-addr.arpa
/7 is not on a 8-bit boundary, so it takes 2 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00110010.00000000.00000000.0000000050.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network00110010.00000000.00000000.0000000050.0.0.0
Broadcast00110011.11111111.11111111.1111111151.255.255.255
Split into smaller subnets/16
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

50.0.0.0/7 makes 512 subnets of /16; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
150.0.0.0/1650.0.0.1 to 50.0.255.25450.0.255.25565,534
250.1.0.0/1650.1.0.1 to 50.1.255.25450.1.255.25565,534
350.2.0.0/1650.2.0.1 to 50.2.255.25450.2.255.25565,534
450.3.0.0/1650.3.0.1 to 50.3.255.25450.3.255.25565,534
550.4.0.0/1650.4.0.1 to 50.4.255.25450.4.255.25565,534
650.5.0.0/1650.5.0.1 to 50.5.255.25450.5.255.25565,534
750.6.0.0/1650.6.0.1 to 50.6.255.25450.6.255.25565,534
850.7.0.0/1650.7.0.1 to 50.7.255.25450.7.255.25565,534
950.8.0.0/1650.8.0.1 to 50.8.255.25450.8.255.25565,534
1050.9.0.0/1650.9.0.1 to 50.9.255.25450.9.255.25565,534
1150.10.0.0/1650.10.0.1 to 50.10.255.25450.10.255.25565,534
1250.11.0.0/1650.11.0.1 to 50.11.255.25450.11.255.25565,534
1350.12.0.0/1650.12.0.1 to 50.12.255.25450.12.255.25565,534
1450.13.0.0/1650.13.0.1 to 50.13.255.25450.13.255.25565,534
1550.14.0.0/1650.14.0.1 to 50.14.255.25450.14.255.25565,534
1650.15.0.0/1650.15.0.1 to 50.15.255.25450.15.255.25565,534
1750.16.0.0/1650.16.0.1 to 50.16.255.25450.16.255.25565,534
1850.17.0.0/1650.17.0.1 to 50.17.255.25450.17.255.25565,534
1950.18.0.0/1650.18.0.1 to 50.18.255.25450.18.255.25565,534
2050.19.0.0/1650.19.0.1 to 50.19.255.25450.19.255.25565,534
2150.20.0.0/1650.20.0.1 to 50.20.255.25450.20.255.25565,534
2250.21.0.0/1650.21.0.1 to 50.21.255.25450.21.255.25565,534
2350.22.0.0/1650.22.0.1 to 50.22.255.25450.22.255.25565,534
2450.23.0.0/1650.23.0.1 to 50.23.255.25450.23.255.25565,534
2550.24.0.0/1650.24.0.1 to 50.24.255.25450.24.255.25565,534
2650.25.0.0/1650.25.0.1 to 50.25.255.25450.25.255.25565,534
2750.26.0.0/1650.26.0.1 to 50.26.255.25450.26.255.25565,534
2850.27.0.0/1650.27.0.1 to 50.27.255.25450.27.255.25565,534
2950.28.0.0/1650.28.0.1 to 50.28.255.25450.28.255.25565,534
3050.29.0.0/1650.29.0.1 to 50.29.255.25450.29.255.25565,534
3150.30.0.0/1650.30.0.1 to 50.30.255.25450.30.255.25565,534
3250.31.0.0/1650.31.0.1 to 50.31.255.25450.31.255.25565,534
3350.32.0.0/1650.32.0.1 to 50.32.255.25450.32.255.25565,534
3450.33.0.0/1650.33.0.1 to 50.33.255.25450.33.255.25565,534
3550.34.0.0/1650.34.0.1 to 50.34.255.25450.34.255.25565,534
3650.35.0.0/1650.35.0.1 to 50.35.255.25450.35.255.25565,534
3750.36.0.0/1650.36.0.1 to 50.36.255.25450.36.255.25565,534
3850.37.0.0/1650.37.0.1 to 50.37.255.25450.37.255.25565,534
3950.38.0.0/1650.38.0.1 to 50.38.255.25450.38.255.25565,534
4050.39.0.0/1650.39.0.1 to 50.39.255.25450.39.255.25565,534
4150.40.0.0/1650.40.0.1 to 50.40.255.25450.40.255.25565,534
4250.41.0.0/1650.41.0.1 to 50.41.255.25450.41.255.25565,534
4350.42.0.0/1650.42.0.1 to 50.42.255.25450.42.255.25565,534
4450.43.0.0/1650.43.0.1 to 50.43.255.25450.43.255.25565,534
4550.44.0.0/1650.44.0.1 to 50.44.255.25450.44.255.25565,534
4650.45.0.0/1650.45.0.1 to 50.45.255.25450.45.255.25565,534
4750.46.0.0/1650.46.0.1 to 50.46.255.25450.46.255.25565,534
4850.47.0.0/1650.47.0.1 to 50.47.255.25450.47.255.25565,534
4950.48.0.0/1650.48.0.1 to 50.48.255.25450.48.255.25565,534
5050.49.0.0/1650.49.0.1 to 50.49.255.25450.49.255.25565,534
5150.50.0.0/1650.50.0.1 to 50.50.255.25450.50.255.25565,534
5250.51.0.0/1650.51.0.1 to 50.51.255.25450.51.255.25565,534
5350.52.0.0/1650.52.0.1 to 50.52.255.25450.52.255.25565,534
5450.53.0.0/1650.53.0.1 to 50.53.255.25450.53.255.25565,534
5550.54.0.0/1650.54.0.1 to 50.54.255.25450.54.255.25565,534
5650.55.0.0/1650.55.0.1 to 50.55.255.25450.55.255.25565,534
5750.56.0.0/1650.56.0.1 to 50.56.255.25450.56.255.25565,534
5850.57.0.0/1650.57.0.1 to 50.57.255.25450.57.255.25565,534
5950.58.0.0/1650.58.0.1 to 50.58.255.25450.58.255.25565,534
6050.59.0.0/1650.59.0.1 to 50.59.255.25450.59.255.25565,534
6150.60.0.0/1650.60.0.1 to 50.60.255.25450.60.255.25565,534
6250.61.0.0/1650.61.0.1 to 50.61.255.25450.61.255.25565,534
6350.62.0.0/1650.62.0.1 to 50.62.255.25450.62.255.25565,534
6450.63.0.0/1650.63.0.1 to 50.63.255.25450.63.255.25565,534
6550.64.0.0/1650.64.0.1 to 50.64.255.25450.64.255.25565,534
6650.65.0.0/1650.65.0.1 to 50.65.255.25450.65.255.25565,534
6750.66.0.0/1650.66.0.1 to 50.66.255.25450.66.255.25565,534
6850.67.0.0/1650.67.0.1 to 50.67.255.25450.67.255.25565,534
6950.68.0.0/1650.68.0.1 to 50.68.255.25450.68.255.25565,534
7050.69.0.0/1650.69.0.1 to 50.69.255.25450.69.255.25565,534
7150.70.0.0/1650.70.0.1 to 50.70.255.25450.70.255.25565,534
7250.71.0.0/1650.71.0.1 to 50.71.255.25450.71.255.25565,534
7350.72.0.0/1650.72.0.1 to 50.72.255.25450.72.255.25565,534
7450.73.0.0/1650.73.0.1 to 50.73.255.25450.73.255.25565,534
7550.74.0.0/1650.74.0.1 to 50.74.255.25450.74.255.25565,534
7650.75.0.0/1650.75.0.1 to 50.75.255.25450.75.255.25565,534
7750.76.0.0/1650.76.0.1 to 50.76.255.25450.76.255.25565,534
7850.77.0.0/1650.77.0.1 to 50.77.255.25450.77.255.25565,534
7950.78.0.0/1650.78.0.1 to 50.78.255.25450.78.255.25565,534
8050.79.0.0/1650.79.0.1 to 50.79.255.25450.79.255.25565,534
8150.80.0.0/1650.80.0.1 to 50.80.255.25450.80.255.25565,534
8250.81.0.0/1650.81.0.1 to 50.81.255.25450.81.255.25565,534
8350.82.0.0/1650.82.0.1 to 50.82.255.25450.82.255.25565,534
8450.83.0.0/1650.83.0.1 to 50.83.255.25450.83.255.25565,534
8550.84.0.0/1650.84.0.1 to 50.84.255.25450.84.255.25565,534
8650.85.0.0/1650.85.0.1 to 50.85.255.25450.85.255.25565,534
8750.86.0.0/1650.86.0.1 to 50.86.255.25450.86.255.25565,534
8850.87.0.0/1650.87.0.1 to 50.87.255.25450.87.255.25565,534
8950.88.0.0/1650.88.0.1 to 50.88.255.25450.88.255.25565,534
9050.89.0.0/1650.89.0.1 to 50.89.255.25450.89.255.25565,534
9150.90.0.0/1650.90.0.1 to 50.90.255.25450.90.255.25565,534
9250.91.0.0/1650.91.0.1 to 50.91.255.25450.91.255.25565,534
9350.92.0.0/1650.92.0.1 to 50.92.255.25450.92.255.25565,534
9450.93.0.0/1650.93.0.1 to 50.93.255.25450.93.255.25565,534
9550.94.0.0/1650.94.0.1 to 50.94.255.25450.94.255.25565,534
9650.95.0.0/1650.95.0.1 to 50.95.255.25450.95.255.25565,534
9750.96.0.0/1650.96.0.1 to 50.96.255.25450.96.255.25565,534
9850.97.0.0/1650.97.0.1 to 50.97.255.25450.97.255.25565,534
9950.98.0.0/1650.98.0.1 to 50.98.255.25450.98.255.25565,534
10050.99.0.0/1650.99.0.1 to 50.99.255.25450.99.255.25565,534
10150.100.0.0/1650.100.0.1 to 50.100.255.25450.100.255.25565,534
10250.101.0.0/1650.101.0.1 to 50.101.255.25450.101.255.25565,534
10350.102.0.0/1650.102.0.1 to 50.102.255.25450.102.255.25565,534
10450.103.0.0/1650.103.0.1 to 50.103.255.25450.103.255.25565,534
10550.104.0.0/1650.104.0.1 to 50.104.255.25450.104.255.25565,534
10650.105.0.0/1650.105.0.1 to 50.105.255.25450.105.255.25565,534
10750.106.0.0/1650.106.0.1 to 50.106.255.25450.106.255.25565,534
10850.107.0.0/1650.107.0.1 to 50.107.255.25450.107.255.25565,534
10950.108.0.0/1650.108.0.1 to 50.108.255.25450.108.255.25565,534
11050.109.0.0/1650.109.0.1 to 50.109.255.25450.109.255.25565,534
11150.110.0.0/1650.110.0.1 to 50.110.255.25450.110.255.25565,534
11250.111.0.0/1650.111.0.1 to 50.111.255.25450.111.255.25565,534
11350.112.0.0/1650.112.0.1 to 50.112.255.25450.112.255.25565,534
11450.113.0.0/1650.113.0.1 to 50.113.255.25450.113.255.25565,534
11550.114.0.0/1650.114.0.1 to 50.114.255.25450.114.255.25565,534
11650.115.0.0/1650.115.0.1 to 50.115.255.25450.115.255.25565,534
11750.116.0.0/1650.116.0.1 to 50.116.255.25450.116.255.25565,534
11850.117.0.0/1650.117.0.1 to 50.117.255.25450.117.255.25565,534
11950.118.0.0/1650.118.0.1 to 50.118.255.25450.118.255.25565,534
12050.119.0.0/1650.119.0.1 to 50.119.255.25450.119.255.25565,534
12150.120.0.0/1650.120.0.1 to 50.120.255.25450.120.255.25565,534
12250.121.0.0/1650.121.0.1 to 50.121.255.25450.121.255.25565,534
12350.122.0.0/1650.122.0.1 to 50.122.255.25450.122.255.25565,534
12450.123.0.0/1650.123.0.1 to 50.123.255.25450.123.255.25565,534
12550.124.0.0/1650.124.0.1 to 50.124.255.25450.124.255.25565,534
12650.125.0.0/1650.125.0.1 to 50.125.255.25450.125.255.25565,534
12750.126.0.0/1650.126.0.1 to 50.126.255.25450.126.255.25565,534
12850.127.0.0/1650.127.0.1 to 50.127.255.25450.127.255.25565,534
12950.128.0.0/1650.128.0.1 to 50.128.255.25450.128.255.25565,534
13050.129.0.0/1650.129.0.1 to 50.129.255.25450.129.255.25565,534
13150.130.0.0/1650.130.0.1 to 50.130.255.25450.130.255.25565,534
13250.131.0.0/1650.131.0.1 to 50.131.255.25450.131.255.25565,534
13350.132.0.0/1650.132.0.1 to 50.132.255.25450.132.255.25565,534
13450.133.0.0/1650.133.0.1 to 50.133.255.25450.133.255.25565,534
13550.134.0.0/1650.134.0.1 to 50.134.255.25450.134.255.25565,534
13650.135.0.0/1650.135.0.1 to 50.135.255.25450.135.255.25565,534
13750.136.0.0/1650.136.0.1 to 50.136.255.25450.136.255.25565,534
13850.137.0.0/1650.137.0.1 to 50.137.255.25450.137.255.25565,534
13950.138.0.0/1650.138.0.1 to 50.138.255.25450.138.255.25565,534
14050.139.0.0/1650.139.0.1 to 50.139.255.25450.139.255.25565,534
14150.140.0.0/1650.140.0.1 to 50.140.255.25450.140.255.25565,534
14250.141.0.0/1650.141.0.1 to 50.141.255.25450.141.255.25565,534
14350.142.0.0/1650.142.0.1 to 50.142.255.25450.142.255.25565,534
14450.143.0.0/1650.143.0.1 to 50.143.255.25450.143.255.25565,534
14550.144.0.0/1650.144.0.1 to 50.144.255.25450.144.255.25565,534
14650.145.0.0/1650.145.0.1 to 50.145.255.25450.145.255.25565,534
14750.146.0.0/1650.146.0.1 to 50.146.255.25450.146.255.25565,534
14850.147.0.0/1650.147.0.1 to 50.147.255.25450.147.255.25565,534
14950.148.0.0/1650.148.0.1 to 50.148.255.25450.148.255.25565,534
15050.149.0.0/1650.149.0.1 to 50.149.255.25450.149.255.25565,534
15150.150.0.0/1650.150.0.1 to 50.150.255.25450.150.255.25565,534
15250.151.0.0/1650.151.0.1 to 50.151.255.25450.151.255.25565,534
15350.152.0.0/1650.152.0.1 to 50.152.255.25450.152.255.25565,534
15450.153.0.0/1650.153.0.1 to 50.153.255.25450.153.255.25565,534
15550.154.0.0/1650.154.0.1 to 50.154.255.25450.154.255.25565,534
15650.155.0.0/1650.155.0.1 to 50.155.255.25450.155.255.25565,534
15750.156.0.0/1650.156.0.1 to 50.156.255.25450.156.255.25565,534
15850.157.0.0/1650.157.0.1 to 50.157.255.25450.157.255.25565,534
15950.158.0.0/1650.158.0.1 to 50.158.255.25450.158.255.25565,534
16050.159.0.0/1650.159.0.1 to 50.159.255.25450.159.255.25565,534
16150.160.0.0/1650.160.0.1 to 50.160.255.25450.160.255.25565,534
16250.161.0.0/1650.161.0.1 to 50.161.255.25450.161.255.25565,534
16350.162.0.0/1650.162.0.1 to 50.162.255.25450.162.255.25565,534
16450.163.0.0/1650.163.0.1 to 50.163.255.25450.163.255.25565,534
16550.164.0.0/1650.164.0.1 to 50.164.255.25450.164.255.25565,534
16650.165.0.0/1650.165.0.1 to 50.165.255.25450.165.255.25565,534
16750.166.0.0/1650.166.0.1 to 50.166.255.25450.166.255.25565,534
16850.167.0.0/1650.167.0.1 to 50.167.255.25450.167.255.25565,534
16950.168.0.0/1650.168.0.1 to 50.168.255.25450.168.255.25565,534
17050.169.0.0/1650.169.0.1 to 50.169.255.25450.169.255.25565,534
17150.170.0.0/1650.170.0.1 to 50.170.255.25450.170.255.25565,534
17250.171.0.0/1650.171.0.1 to 50.171.255.25450.171.255.25565,534
17350.172.0.0/1650.172.0.1 to 50.172.255.25450.172.255.25565,534
17450.173.0.0/1650.173.0.1 to 50.173.255.25450.173.255.25565,534
17550.174.0.0/1650.174.0.1 to 50.174.255.25450.174.255.25565,534
17650.175.0.0/1650.175.0.1 to 50.175.255.25450.175.255.25565,534
17750.176.0.0/1650.176.0.1 to 50.176.255.25450.176.255.25565,534
17850.177.0.0/1650.177.0.1 to 50.177.255.25450.177.255.25565,534
17950.178.0.0/1650.178.0.1 to 50.178.255.25450.178.255.25565,534
18050.179.0.0/1650.179.0.1 to 50.179.255.25450.179.255.25565,534
18150.180.0.0/1650.180.0.1 to 50.180.255.25450.180.255.25565,534
18250.181.0.0/1650.181.0.1 to 50.181.255.25450.181.255.25565,534
18350.182.0.0/1650.182.0.1 to 50.182.255.25450.182.255.25565,534
18450.183.0.0/1650.183.0.1 to 50.183.255.25450.183.255.25565,534
18550.184.0.0/1650.184.0.1 to 50.184.255.25450.184.255.25565,534
18650.185.0.0/1650.185.0.1 to 50.185.255.25450.185.255.25565,534
18750.186.0.0/1650.186.0.1 to 50.186.255.25450.186.255.25565,534
18850.187.0.0/1650.187.0.1 to 50.187.255.25450.187.255.25565,534
18950.188.0.0/1650.188.0.1 to 50.188.255.25450.188.255.25565,534
19050.189.0.0/1650.189.0.1 to 50.189.255.25450.189.255.25565,534
19150.190.0.0/1650.190.0.1 to 50.190.255.25450.190.255.25565,534
19250.191.0.0/1650.191.0.1 to 50.191.255.25450.191.255.25565,534
19350.192.0.0/1650.192.0.1 to 50.192.255.25450.192.255.25565,534
19450.193.0.0/1650.193.0.1 to 50.193.255.25450.193.255.25565,534
19550.194.0.0/1650.194.0.1 to 50.194.255.25450.194.255.25565,534
19650.195.0.0/1650.195.0.1 to 50.195.255.25450.195.255.25565,534
19750.196.0.0/1650.196.0.1 to 50.196.255.25450.196.255.25565,534
19850.197.0.0/1650.197.0.1 to 50.197.255.25450.197.255.25565,534
19950.198.0.0/1650.198.0.1 to 50.198.255.25450.198.255.25565,534
20050.199.0.0/1650.199.0.1 to 50.199.255.25450.199.255.25565,534
20150.200.0.0/1650.200.0.1 to 50.200.255.25450.200.255.25565,534
20250.201.0.0/1650.201.0.1 to 50.201.255.25450.201.255.25565,534
20350.202.0.0/1650.202.0.1 to 50.202.255.25450.202.255.25565,534
20450.203.0.0/1650.203.0.1 to 50.203.255.25450.203.255.25565,534
20550.204.0.0/1650.204.0.1 to 50.204.255.25450.204.255.25565,534
20650.205.0.0/1650.205.0.1 to 50.205.255.25450.205.255.25565,534
20750.206.0.0/1650.206.0.1 to 50.206.255.25450.206.255.25565,534
20850.207.0.0/1650.207.0.1 to 50.207.255.25450.207.255.25565,534
20950.208.0.0/1650.208.0.1 to 50.208.255.25450.208.255.25565,534
21050.209.0.0/1650.209.0.1 to 50.209.255.25450.209.255.25565,534
21150.210.0.0/1650.210.0.1 to 50.210.255.25450.210.255.25565,534
21250.211.0.0/1650.211.0.1 to 50.211.255.25450.211.255.25565,534
21350.212.0.0/1650.212.0.1 to 50.212.255.25450.212.255.25565,534
21450.213.0.0/1650.213.0.1 to 50.213.255.25450.213.255.25565,534
21550.214.0.0/1650.214.0.1 to 50.214.255.25450.214.255.25565,534
21650.215.0.0/1650.215.0.1 to 50.215.255.25450.215.255.25565,534
21750.216.0.0/1650.216.0.1 to 50.216.255.25450.216.255.25565,534
21850.217.0.0/1650.217.0.1 to 50.217.255.25450.217.255.25565,534
21950.218.0.0/1650.218.0.1 to 50.218.255.25450.218.255.25565,534
22050.219.0.0/1650.219.0.1 to 50.219.255.25450.219.255.25565,534
22150.220.0.0/1650.220.0.1 to 50.220.255.25450.220.255.25565,534
22250.221.0.0/1650.221.0.1 to 50.221.255.25450.221.255.25565,534
22350.222.0.0/1650.222.0.1 to 50.222.255.25450.222.255.25565,534
22450.223.0.0/1650.223.0.1 to 50.223.255.25450.223.255.25565,534
22550.224.0.0/1650.224.0.1 to 50.224.255.25450.224.255.25565,534
22650.225.0.0/1650.225.0.1 to 50.225.255.25450.225.255.25565,534
22750.226.0.0/1650.226.0.1 to 50.226.255.25450.226.255.25565,534
22850.227.0.0/1650.227.0.1 to 50.227.255.25450.227.255.25565,534
22950.228.0.0/1650.228.0.1 to 50.228.255.25450.228.255.25565,534
23050.229.0.0/1650.229.0.1 to 50.229.255.25450.229.255.25565,534
23150.230.0.0/1650.230.0.1 to 50.230.255.25450.230.255.25565,534
23250.231.0.0/1650.231.0.1 to 50.231.255.25450.231.255.25565,534
23350.232.0.0/1650.232.0.1 to 50.232.255.25450.232.255.25565,534
23450.233.0.0/1650.233.0.1 to 50.233.255.25450.233.255.25565,534
23550.234.0.0/1650.234.0.1 to 50.234.255.25450.234.255.25565,534
23650.235.0.0/1650.235.0.1 to 50.235.255.25450.235.255.25565,534
23750.236.0.0/1650.236.0.1 to 50.236.255.25450.236.255.25565,534
23850.237.0.0/1650.237.0.1 to 50.237.255.25450.237.255.25565,534
23950.238.0.0/1650.238.0.1 to 50.238.255.25450.238.255.25565,534
24050.239.0.0/1650.239.0.1 to 50.239.255.25450.239.255.25565,534
24150.240.0.0/1650.240.0.1 to 50.240.255.25450.240.255.25565,534
24250.241.0.0/1650.241.0.1 to 50.241.255.25450.241.255.25565,534
24350.242.0.0/1650.242.0.1 to 50.242.255.25450.242.255.25565,534
24450.243.0.0/1650.243.0.1 to 50.243.255.25450.243.255.25565,534
24550.244.0.0/1650.244.0.1 to 50.244.255.25450.244.255.25565,534
24650.245.0.0/1650.245.0.1 to 50.245.255.25450.245.255.25565,534
24750.246.0.0/1650.246.0.1 to 50.246.255.25450.246.255.25565,534
24850.247.0.0/1650.247.0.1 to 50.247.255.25450.247.255.25565,534
24950.248.0.0/1650.248.0.1 to 50.248.255.25450.248.255.25565,534
25050.249.0.0/1650.249.0.1 to 50.249.255.25450.249.255.25565,534
25150.250.0.0/1650.250.0.1 to 50.250.255.25450.250.255.25565,534
25250.251.0.0/1650.251.0.1 to 50.251.255.25450.251.255.25565,534
25350.252.0.0/1650.252.0.1 to 50.252.255.25450.252.255.25565,534
25450.253.0.0/1650.253.0.1 to 50.253.255.25450.253.255.25565,534
25550.254.0.0/1650.254.0.1 to 50.254.255.25450.254.255.25565,534
25650.255.0.0/1650.255.0.1 to 50.255.255.25450.255.255.25565,534

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.