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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.

Network44.0.0.0/6
Usable hosts67,108,862
Subnet mask252.0.0.0
Addresses67,108,864
Network address
44.0.0.0
Broadcast address
47.255.255.255
First usable
44.0.0.1
Last usable
47.255.255.254
Usable hosts
67,108,862 (67,108,864 less the network and broadcast addresses)
Subnet mask
252.0.0.0
Wildcard mask
3.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/6
Type
Public public
Old class
A (default /8)
As numbers
Hex 2C000000 · Integer 738197504 to 805306367
Reverse DNS zones
44.in-addr.arpa
45.in-addr.arpa
46.in-addr.arpa
47.in-addr.arpa
/6 is not on a 8-bit boundary, so it takes 4 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00101100.00000000.00000000.0000000044.0.0.0
Subnet mask11111100.00000000.00000000.00000000252.0.0.0
Network00101100.00000000.00000000.0000000044.0.0.0
Broadcast00101111.11111111.11111111.1111111147.255.255.255
Split into smaller subnets/16
/7 (2)/8 (4)/9 (8)/10 (16)/11 (32)/12 (64)/13 (128)/14 (256)/15 (512)/16 (1,024)/17 (2,048)/18 (4,096)

44.0.0.0/6 makes 1,024 subnets of /16; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
144.0.0.0/1644.0.0.1 to 44.0.255.25444.0.255.25565,534
244.1.0.0/1644.1.0.1 to 44.1.255.25444.1.255.25565,534
344.2.0.0/1644.2.0.1 to 44.2.255.25444.2.255.25565,534
444.3.0.0/1644.3.0.1 to 44.3.255.25444.3.255.25565,534
544.4.0.0/1644.4.0.1 to 44.4.255.25444.4.255.25565,534
644.5.0.0/1644.5.0.1 to 44.5.255.25444.5.255.25565,534
744.6.0.0/1644.6.0.1 to 44.6.255.25444.6.255.25565,534
844.7.0.0/1644.7.0.1 to 44.7.255.25444.7.255.25565,534
944.8.0.0/1644.8.0.1 to 44.8.255.25444.8.255.25565,534
1044.9.0.0/1644.9.0.1 to 44.9.255.25444.9.255.25565,534
1144.10.0.0/1644.10.0.1 to 44.10.255.25444.10.255.25565,534
1244.11.0.0/1644.11.0.1 to 44.11.255.25444.11.255.25565,534
1344.12.0.0/1644.12.0.1 to 44.12.255.25444.12.255.25565,534
1444.13.0.0/1644.13.0.1 to 44.13.255.25444.13.255.25565,534
1544.14.0.0/1644.14.0.1 to 44.14.255.25444.14.255.25565,534
1644.15.0.0/1644.15.0.1 to 44.15.255.25444.15.255.25565,534
1744.16.0.0/1644.16.0.1 to 44.16.255.25444.16.255.25565,534
1844.17.0.0/1644.17.0.1 to 44.17.255.25444.17.255.25565,534
1944.18.0.0/1644.18.0.1 to 44.18.255.25444.18.255.25565,534
2044.19.0.0/1644.19.0.1 to 44.19.255.25444.19.255.25565,534
2144.20.0.0/1644.20.0.1 to 44.20.255.25444.20.255.25565,534
2244.21.0.0/1644.21.0.1 to 44.21.255.25444.21.255.25565,534
2344.22.0.0/1644.22.0.1 to 44.22.255.25444.22.255.25565,534
2444.23.0.0/1644.23.0.1 to 44.23.255.25444.23.255.25565,534
2544.24.0.0/1644.24.0.1 to 44.24.255.25444.24.255.25565,534
2644.25.0.0/1644.25.0.1 to 44.25.255.25444.25.255.25565,534
2744.26.0.0/1644.26.0.1 to 44.26.255.25444.26.255.25565,534
2844.27.0.0/1644.27.0.1 to 44.27.255.25444.27.255.25565,534
2944.28.0.0/1644.28.0.1 to 44.28.255.25444.28.255.25565,534
3044.29.0.0/1644.29.0.1 to 44.29.255.25444.29.255.25565,534
3144.30.0.0/1644.30.0.1 to 44.30.255.25444.30.255.25565,534
3244.31.0.0/1644.31.0.1 to 44.31.255.25444.31.255.25565,534
3344.32.0.0/1644.32.0.1 to 44.32.255.25444.32.255.25565,534
3444.33.0.0/1644.33.0.1 to 44.33.255.25444.33.255.25565,534
3544.34.0.0/1644.34.0.1 to 44.34.255.25444.34.255.25565,534
3644.35.0.0/1644.35.0.1 to 44.35.255.25444.35.255.25565,534
3744.36.0.0/1644.36.0.1 to 44.36.255.25444.36.255.25565,534
3844.37.0.0/1644.37.0.1 to 44.37.255.25444.37.255.25565,534
3944.38.0.0/1644.38.0.1 to 44.38.255.25444.38.255.25565,534
4044.39.0.0/1644.39.0.1 to 44.39.255.25444.39.255.25565,534
4144.40.0.0/1644.40.0.1 to 44.40.255.25444.40.255.25565,534
4244.41.0.0/1644.41.0.1 to 44.41.255.25444.41.255.25565,534
4344.42.0.0/1644.42.0.1 to 44.42.255.25444.42.255.25565,534
4444.43.0.0/1644.43.0.1 to 44.43.255.25444.43.255.25565,534
4544.44.0.0/1644.44.0.1 to 44.44.255.25444.44.255.25565,534
4644.45.0.0/1644.45.0.1 to 44.45.255.25444.45.255.25565,534
4744.46.0.0/1644.46.0.1 to 44.46.255.25444.46.255.25565,534
4844.47.0.0/1644.47.0.1 to 44.47.255.25444.47.255.25565,534
4944.48.0.0/1644.48.0.1 to 44.48.255.25444.48.255.25565,534
5044.49.0.0/1644.49.0.1 to 44.49.255.25444.49.255.25565,534
5144.50.0.0/1644.50.0.1 to 44.50.255.25444.50.255.25565,534
5244.51.0.0/1644.51.0.1 to 44.51.255.25444.51.255.25565,534
5344.52.0.0/1644.52.0.1 to 44.52.255.25444.52.255.25565,534
5444.53.0.0/1644.53.0.1 to 44.53.255.25444.53.255.25565,534
5544.54.0.0/1644.54.0.1 to 44.54.255.25444.54.255.25565,534
5644.55.0.0/1644.55.0.1 to 44.55.255.25444.55.255.25565,534
5744.56.0.0/1644.56.0.1 to 44.56.255.25444.56.255.25565,534
5844.57.0.0/1644.57.0.1 to 44.57.255.25444.57.255.25565,534
5944.58.0.0/1644.58.0.1 to 44.58.255.25444.58.255.25565,534
6044.59.0.0/1644.59.0.1 to 44.59.255.25444.59.255.25565,534
6144.60.0.0/1644.60.0.1 to 44.60.255.25444.60.255.25565,534
6244.61.0.0/1644.61.0.1 to 44.61.255.25444.61.255.25565,534
6344.62.0.0/1644.62.0.1 to 44.62.255.25444.62.255.25565,534
6444.63.0.0/1644.63.0.1 to 44.63.255.25444.63.255.25565,534
6544.64.0.0/1644.64.0.1 to 44.64.255.25444.64.255.25565,534
6644.65.0.0/1644.65.0.1 to 44.65.255.25444.65.255.25565,534
6744.66.0.0/1644.66.0.1 to 44.66.255.25444.66.255.25565,534
6844.67.0.0/1644.67.0.1 to 44.67.255.25444.67.255.25565,534
6944.68.0.0/1644.68.0.1 to 44.68.255.25444.68.255.25565,534
7044.69.0.0/1644.69.0.1 to 44.69.255.25444.69.255.25565,534
7144.70.0.0/1644.70.0.1 to 44.70.255.25444.70.255.25565,534
7244.71.0.0/1644.71.0.1 to 44.71.255.25444.71.255.25565,534
7344.72.0.0/1644.72.0.1 to 44.72.255.25444.72.255.25565,534
7444.73.0.0/1644.73.0.1 to 44.73.255.25444.73.255.25565,534
7544.74.0.0/1644.74.0.1 to 44.74.255.25444.74.255.25565,534
7644.75.0.0/1644.75.0.1 to 44.75.255.25444.75.255.25565,534
7744.76.0.0/1644.76.0.1 to 44.76.255.25444.76.255.25565,534
7844.77.0.0/1644.77.0.1 to 44.77.255.25444.77.255.25565,534
7944.78.0.0/1644.78.0.1 to 44.78.255.25444.78.255.25565,534
8044.79.0.0/1644.79.0.1 to 44.79.255.25444.79.255.25565,534
8144.80.0.0/1644.80.0.1 to 44.80.255.25444.80.255.25565,534
8244.81.0.0/1644.81.0.1 to 44.81.255.25444.81.255.25565,534
8344.82.0.0/1644.82.0.1 to 44.82.255.25444.82.255.25565,534
8444.83.0.0/1644.83.0.1 to 44.83.255.25444.83.255.25565,534
8544.84.0.0/1644.84.0.1 to 44.84.255.25444.84.255.25565,534
8644.85.0.0/1644.85.0.1 to 44.85.255.25444.85.255.25565,534
8744.86.0.0/1644.86.0.1 to 44.86.255.25444.86.255.25565,534
8844.87.0.0/1644.87.0.1 to 44.87.255.25444.87.255.25565,534
8944.88.0.0/1644.88.0.1 to 44.88.255.25444.88.255.25565,534
9044.89.0.0/1644.89.0.1 to 44.89.255.25444.89.255.25565,534
9144.90.0.0/1644.90.0.1 to 44.90.255.25444.90.255.25565,534
9244.91.0.0/1644.91.0.1 to 44.91.255.25444.91.255.25565,534
9344.92.0.0/1644.92.0.1 to 44.92.255.25444.92.255.25565,534
9444.93.0.0/1644.93.0.1 to 44.93.255.25444.93.255.25565,534
9544.94.0.0/1644.94.0.1 to 44.94.255.25444.94.255.25565,534
9644.95.0.0/1644.95.0.1 to 44.95.255.25444.95.255.25565,534
9744.96.0.0/1644.96.0.1 to 44.96.255.25444.96.255.25565,534
9844.97.0.0/1644.97.0.1 to 44.97.255.25444.97.255.25565,534
9944.98.0.0/1644.98.0.1 to 44.98.255.25444.98.255.25565,534
10044.99.0.0/1644.99.0.1 to 44.99.255.25444.99.255.25565,534
10144.100.0.0/1644.100.0.1 to 44.100.255.25444.100.255.25565,534
10244.101.0.0/1644.101.0.1 to 44.101.255.25444.101.255.25565,534
10344.102.0.0/1644.102.0.1 to 44.102.255.25444.102.255.25565,534
10444.103.0.0/1644.103.0.1 to 44.103.255.25444.103.255.25565,534
10544.104.0.0/1644.104.0.1 to 44.104.255.25444.104.255.25565,534
10644.105.0.0/1644.105.0.1 to 44.105.255.25444.105.255.25565,534
10744.106.0.0/1644.106.0.1 to 44.106.255.25444.106.255.25565,534
10844.107.0.0/1644.107.0.1 to 44.107.255.25444.107.255.25565,534
10944.108.0.0/1644.108.0.1 to 44.108.255.25444.108.255.25565,534
11044.109.0.0/1644.109.0.1 to 44.109.255.25444.109.255.25565,534
11144.110.0.0/1644.110.0.1 to 44.110.255.25444.110.255.25565,534
11244.111.0.0/1644.111.0.1 to 44.111.255.25444.111.255.25565,534
11344.112.0.0/1644.112.0.1 to 44.112.255.25444.112.255.25565,534
11444.113.0.0/1644.113.0.1 to 44.113.255.25444.113.255.25565,534
11544.114.0.0/1644.114.0.1 to 44.114.255.25444.114.255.25565,534
11644.115.0.0/1644.115.0.1 to 44.115.255.25444.115.255.25565,534
11744.116.0.0/1644.116.0.1 to 44.116.255.25444.116.255.25565,534
11844.117.0.0/1644.117.0.1 to 44.117.255.25444.117.255.25565,534
11944.118.0.0/1644.118.0.1 to 44.118.255.25444.118.255.25565,534
12044.119.0.0/1644.119.0.1 to 44.119.255.25444.119.255.25565,534
12144.120.0.0/1644.120.0.1 to 44.120.255.25444.120.255.25565,534
12244.121.0.0/1644.121.0.1 to 44.121.255.25444.121.255.25565,534
12344.122.0.0/1644.122.0.1 to 44.122.255.25444.122.255.25565,534
12444.123.0.0/1644.123.0.1 to 44.123.255.25444.123.255.25565,534
12544.124.0.0/1644.124.0.1 to 44.124.255.25444.124.255.25565,534
12644.125.0.0/1644.125.0.1 to 44.125.255.25444.125.255.25565,534
12744.126.0.0/1644.126.0.1 to 44.126.255.25444.126.255.25565,534
12844.127.0.0/1644.127.0.1 to 44.127.255.25444.127.255.25565,534
12944.128.0.0/1644.128.0.1 to 44.128.255.25444.128.255.25565,534
13044.129.0.0/1644.129.0.1 to 44.129.255.25444.129.255.25565,534
13144.130.0.0/1644.130.0.1 to 44.130.255.25444.130.255.25565,534
13244.131.0.0/1644.131.0.1 to 44.131.255.25444.131.255.25565,534
13344.132.0.0/1644.132.0.1 to 44.132.255.25444.132.255.25565,534
13444.133.0.0/1644.133.0.1 to 44.133.255.25444.133.255.25565,534
13544.134.0.0/1644.134.0.1 to 44.134.255.25444.134.255.25565,534
13644.135.0.0/1644.135.0.1 to 44.135.255.25444.135.255.25565,534
13744.136.0.0/1644.136.0.1 to 44.136.255.25444.136.255.25565,534
13844.137.0.0/1644.137.0.1 to 44.137.255.25444.137.255.25565,534
13944.138.0.0/1644.138.0.1 to 44.138.255.25444.138.255.25565,534
14044.139.0.0/1644.139.0.1 to 44.139.255.25444.139.255.25565,534
14144.140.0.0/1644.140.0.1 to 44.140.255.25444.140.255.25565,534
14244.141.0.0/1644.141.0.1 to 44.141.255.25444.141.255.25565,534
14344.142.0.0/1644.142.0.1 to 44.142.255.25444.142.255.25565,534
14444.143.0.0/1644.143.0.1 to 44.143.255.25444.143.255.25565,534
14544.144.0.0/1644.144.0.1 to 44.144.255.25444.144.255.25565,534
14644.145.0.0/1644.145.0.1 to 44.145.255.25444.145.255.25565,534
14744.146.0.0/1644.146.0.1 to 44.146.255.25444.146.255.25565,534
14844.147.0.0/1644.147.0.1 to 44.147.255.25444.147.255.25565,534
14944.148.0.0/1644.148.0.1 to 44.148.255.25444.148.255.25565,534
15044.149.0.0/1644.149.0.1 to 44.149.255.25444.149.255.25565,534
15144.150.0.0/1644.150.0.1 to 44.150.255.25444.150.255.25565,534
15244.151.0.0/1644.151.0.1 to 44.151.255.25444.151.255.25565,534
15344.152.0.0/1644.152.0.1 to 44.152.255.25444.152.255.25565,534
15444.153.0.0/1644.153.0.1 to 44.153.255.25444.153.255.25565,534
15544.154.0.0/1644.154.0.1 to 44.154.255.25444.154.255.25565,534
15644.155.0.0/1644.155.0.1 to 44.155.255.25444.155.255.25565,534
15744.156.0.0/1644.156.0.1 to 44.156.255.25444.156.255.25565,534
15844.157.0.0/1644.157.0.1 to 44.157.255.25444.157.255.25565,534
15944.158.0.0/1644.158.0.1 to 44.158.255.25444.158.255.25565,534
16044.159.0.0/1644.159.0.1 to 44.159.255.25444.159.255.25565,534
16144.160.0.0/1644.160.0.1 to 44.160.255.25444.160.255.25565,534
16244.161.0.0/1644.161.0.1 to 44.161.255.25444.161.255.25565,534
16344.162.0.0/1644.162.0.1 to 44.162.255.25444.162.255.25565,534
16444.163.0.0/1644.163.0.1 to 44.163.255.25444.163.255.25565,534
16544.164.0.0/1644.164.0.1 to 44.164.255.25444.164.255.25565,534
16644.165.0.0/1644.165.0.1 to 44.165.255.25444.165.255.25565,534
16744.166.0.0/1644.166.0.1 to 44.166.255.25444.166.255.25565,534
16844.167.0.0/1644.167.0.1 to 44.167.255.25444.167.255.25565,534
16944.168.0.0/1644.168.0.1 to 44.168.255.25444.168.255.25565,534
17044.169.0.0/1644.169.0.1 to 44.169.255.25444.169.255.25565,534
17144.170.0.0/1644.170.0.1 to 44.170.255.25444.170.255.25565,534
17244.171.0.0/1644.171.0.1 to 44.171.255.25444.171.255.25565,534
17344.172.0.0/1644.172.0.1 to 44.172.255.25444.172.255.25565,534
17444.173.0.0/1644.173.0.1 to 44.173.255.25444.173.255.25565,534
17544.174.0.0/1644.174.0.1 to 44.174.255.25444.174.255.25565,534
17644.175.0.0/1644.175.0.1 to 44.175.255.25444.175.255.25565,534
17744.176.0.0/1644.176.0.1 to 44.176.255.25444.176.255.25565,534
17844.177.0.0/1644.177.0.1 to 44.177.255.25444.177.255.25565,534
17944.178.0.0/1644.178.0.1 to 44.178.255.25444.178.255.25565,534
18044.179.0.0/1644.179.0.1 to 44.179.255.25444.179.255.25565,534
18144.180.0.0/1644.180.0.1 to 44.180.255.25444.180.255.25565,534
18244.181.0.0/1644.181.0.1 to 44.181.255.25444.181.255.25565,534
18344.182.0.0/1644.182.0.1 to 44.182.255.25444.182.255.25565,534
18444.183.0.0/1644.183.0.1 to 44.183.255.25444.183.255.25565,534
18544.184.0.0/1644.184.0.1 to 44.184.255.25444.184.255.25565,534
18644.185.0.0/1644.185.0.1 to 44.185.255.25444.185.255.25565,534
18744.186.0.0/1644.186.0.1 to 44.186.255.25444.186.255.25565,534
18844.187.0.0/1644.187.0.1 to 44.187.255.25444.187.255.25565,534
18944.188.0.0/1644.188.0.1 to 44.188.255.25444.188.255.25565,534
19044.189.0.0/1644.189.0.1 to 44.189.255.25444.189.255.25565,534
19144.190.0.0/1644.190.0.1 to 44.190.255.25444.190.255.25565,534
19244.191.0.0/1644.191.0.1 to 44.191.255.25444.191.255.25565,534
19344.192.0.0/1644.192.0.1 to 44.192.255.25444.192.255.25565,534
19444.193.0.0/1644.193.0.1 to 44.193.255.25444.193.255.25565,534
19544.194.0.0/1644.194.0.1 to 44.194.255.25444.194.255.25565,534
19644.195.0.0/1644.195.0.1 to 44.195.255.25444.195.255.25565,534
19744.196.0.0/1644.196.0.1 to 44.196.255.25444.196.255.25565,534
19844.197.0.0/1644.197.0.1 to 44.197.255.25444.197.255.25565,534
19944.198.0.0/1644.198.0.1 to 44.198.255.25444.198.255.25565,534
20044.199.0.0/1644.199.0.1 to 44.199.255.25444.199.255.25565,534
20144.200.0.0/1644.200.0.1 to 44.200.255.25444.200.255.25565,534
20244.201.0.0/1644.201.0.1 to 44.201.255.25444.201.255.25565,534
20344.202.0.0/1644.202.0.1 to 44.202.255.25444.202.255.25565,534
20444.203.0.0/1644.203.0.1 to 44.203.255.25444.203.255.25565,534
20544.204.0.0/1644.204.0.1 to 44.204.255.25444.204.255.25565,534
20644.205.0.0/1644.205.0.1 to 44.205.255.25444.205.255.25565,534
20744.206.0.0/1644.206.0.1 to 44.206.255.25444.206.255.25565,534
20844.207.0.0/1644.207.0.1 to 44.207.255.25444.207.255.25565,534
20944.208.0.0/1644.208.0.1 to 44.208.255.25444.208.255.25565,534
21044.209.0.0/1644.209.0.1 to 44.209.255.25444.209.255.25565,534
21144.210.0.0/1644.210.0.1 to 44.210.255.25444.210.255.25565,534
21244.211.0.0/1644.211.0.1 to 44.211.255.25444.211.255.25565,534
21344.212.0.0/1644.212.0.1 to 44.212.255.25444.212.255.25565,534
21444.213.0.0/1644.213.0.1 to 44.213.255.25444.213.255.25565,534
21544.214.0.0/1644.214.0.1 to 44.214.255.25444.214.255.25565,534
21644.215.0.0/1644.215.0.1 to 44.215.255.25444.215.255.25565,534
21744.216.0.0/1644.216.0.1 to 44.216.255.25444.216.255.25565,534
21844.217.0.0/1644.217.0.1 to 44.217.255.25444.217.255.25565,534
21944.218.0.0/1644.218.0.1 to 44.218.255.25444.218.255.25565,534
22044.219.0.0/1644.219.0.1 to 44.219.255.25444.219.255.25565,534
22144.220.0.0/1644.220.0.1 to 44.220.255.25444.220.255.25565,534
22244.221.0.0/1644.221.0.1 to 44.221.255.25444.221.255.25565,534
22344.222.0.0/1644.222.0.1 to 44.222.255.25444.222.255.25565,534
22444.223.0.0/1644.223.0.1 to 44.223.255.25444.223.255.25565,534
22544.224.0.0/1644.224.0.1 to 44.224.255.25444.224.255.25565,534
22644.225.0.0/1644.225.0.1 to 44.225.255.25444.225.255.25565,534
22744.226.0.0/1644.226.0.1 to 44.226.255.25444.226.255.25565,534
22844.227.0.0/1644.227.0.1 to 44.227.255.25444.227.255.25565,534
22944.228.0.0/1644.228.0.1 to 44.228.255.25444.228.255.25565,534
23044.229.0.0/1644.229.0.1 to 44.229.255.25444.229.255.25565,534
23144.230.0.0/1644.230.0.1 to 44.230.255.25444.230.255.25565,534
23244.231.0.0/1644.231.0.1 to 44.231.255.25444.231.255.25565,534
23344.232.0.0/1644.232.0.1 to 44.232.255.25444.232.255.25565,534
23444.233.0.0/1644.233.0.1 to 44.233.255.25444.233.255.25565,534
23544.234.0.0/1644.234.0.1 to 44.234.255.25444.234.255.25565,534
23644.235.0.0/1644.235.0.1 to 44.235.255.25444.235.255.25565,534
23744.236.0.0/1644.236.0.1 to 44.236.255.25444.236.255.25565,534
23844.237.0.0/1644.237.0.1 to 44.237.255.25444.237.255.25565,534
23944.238.0.0/1644.238.0.1 to 44.238.255.25444.238.255.25565,534
24044.239.0.0/1644.239.0.1 to 44.239.255.25444.239.255.25565,534
24144.240.0.0/1644.240.0.1 to 44.240.255.25444.240.255.25565,534
24244.241.0.0/1644.241.0.1 to 44.241.255.25444.241.255.25565,534
24344.242.0.0/1644.242.0.1 to 44.242.255.25444.242.255.25565,534
24444.243.0.0/1644.243.0.1 to 44.243.255.25444.243.255.25565,534
24544.244.0.0/1644.244.0.1 to 44.244.255.25444.244.255.25565,534
24644.245.0.0/1644.245.0.1 to 44.245.255.25444.245.255.25565,534
24744.246.0.0/1644.246.0.1 to 44.246.255.25444.246.255.25565,534
24844.247.0.0/1644.247.0.1 to 44.247.255.25444.247.255.25565,534
24944.248.0.0/1644.248.0.1 to 44.248.255.25444.248.255.25565,534
25044.249.0.0/1644.249.0.1 to 44.249.255.25444.249.255.25565,534
25144.250.0.0/1644.250.0.1 to 44.250.255.25444.250.255.25565,534
25244.251.0.0/1644.251.0.1 to 44.251.255.25444.251.255.25565,534
25344.252.0.0/1644.252.0.1 to 44.252.255.25444.252.255.25565,534
25444.253.0.0/1644.253.0.1 to 44.253.255.25444.253.255.25565,534
25544.254.0.0/1644.254.0.1 to 44.254.255.25444.254.255.25565,534
25644.255.0.0/1644.255.0.1 to 44.255.255.25444.255.255.25565,534

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.