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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.

Network48.0.0.0/6
Usable hosts67,108,862
Subnet mask252.0.0.0
Addresses67,108,864
Network address
48.0.0.0
Broadcast address
51.255.255.255
First usable
48.0.0.1
Last usable
51.255.255.254
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 30000000 · Integer 805306368 to 872415231
Reverse DNS zones
48.in-addr.arpa
49.in-addr.arpa
50.in-addr.arpa
51.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
Address00110000.00000000.00000000.0000000048.0.0.0
Subnet mask11111100.00000000.00000000.00000000252.0.0.0
Network00110000.00000000.00000000.0000000048.0.0.0
Broadcast00110011.11111111.11111111.1111111151.255.255.255
Split into smaller subnets/15
/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)

48.0.0.0/6 makes 512 subnets of /15; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
148.0.0.0/1548.0.0.1 to 48.1.255.25448.1.255.255131,070
248.2.0.0/1548.2.0.1 to 48.3.255.25448.3.255.255131,070
348.4.0.0/1548.4.0.1 to 48.5.255.25448.5.255.255131,070
448.6.0.0/1548.6.0.1 to 48.7.255.25448.7.255.255131,070
548.8.0.0/1548.8.0.1 to 48.9.255.25448.9.255.255131,070
648.10.0.0/1548.10.0.1 to 48.11.255.25448.11.255.255131,070
748.12.0.0/1548.12.0.1 to 48.13.255.25448.13.255.255131,070
848.14.0.0/1548.14.0.1 to 48.15.255.25448.15.255.255131,070
948.16.0.0/1548.16.0.1 to 48.17.255.25448.17.255.255131,070
1048.18.0.0/1548.18.0.1 to 48.19.255.25448.19.255.255131,070
1148.20.0.0/1548.20.0.1 to 48.21.255.25448.21.255.255131,070
1248.22.0.0/1548.22.0.1 to 48.23.255.25448.23.255.255131,070
1348.24.0.0/1548.24.0.1 to 48.25.255.25448.25.255.255131,070
1448.26.0.0/1548.26.0.1 to 48.27.255.25448.27.255.255131,070
1548.28.0.0/1548.28.0.1 to 48.29.255.25448.29.255.255131,070
1648.30.0.0/1548.30.0.1 to 48.31.255.25448.31.255.255131,070
1748.32.0.0/1548.32.0.1 to 48.33.255.25448.33.255.255131,070
1848.34.0.0/1548.34.0.1 to 48.35.255.25448.35.255.255131,070
1948.36.0.0/1548.36.0.1 to 48.37.255.25448.37.255.255131,070
2048.38.0.0/1548.38.0.1 to 48.39.255.25448.39.255.255131,070
2148.40.0.0/1548.40.0.1 to 48.41.255.25448.41.255.255131,070
2248.42.0.0/1548.42.0.1 to 48.43.255.25448.43.255.255131,070
2348.44.0.0/1548.44.0.1 to 48.45.255.25448.45.255.255131,070
2448.46.0.0/1548.46.0.1 to 48.47.255.25448.47.255.255131,070
2548.48.0.0/1548.48.0.1 to 48.49.255.25448.49.255.255131,070
2648.50.0.0/1548.50.0.1 to 48.51.255.25448.51.255.255131,070
2748.52.0.0/1548.52.0.1 to 48.53.255.25448.53.255.255131,070
2848.54.0.0/1548.54.0.1 to 48.55.255.25448.55.255.255131,070
2948.56.0.0/1548.56.0.1 to 48.57.255.25448.57.255.255131,070
3048.58.0.0/1548.58.0.1 to 48.59.255.25448.59.255.255131,070
3148.60.0.0/1548.60.0.1 to 48.61.255.25448.61.255.255131,070
3248.62.0.0/1548.62.0.1 to 48.63.255.25448.63.255.255131,070
3348.64.0.0/1548.64.0.1 to 48.65.255.25448.65.255.255131,070
3448.66.0.0/1548.66.0.1 to 48.67.255.25448.67.255.255131,070
3548.68.0.0/1548.68.0.1 to 48.69.255.25448.69.255.255131,070
3648.70.0.0/1548.70.0.1 to 48.71.255.25448.71.255.255131,070
3748.72.0.0/1548.72.0.1 to 48.73.255.25448.73.255.255131,070
3848.74.0.0/1548.74.0.1 to 48.75.255.25448.75.255.255131,070
3948.76.0.0/1548.76.0.1 to 48.77.255.25448.77.255.255131,070
4048.78.0.0/1548.78.0.1 to 48.79.255.25448.79.255.255131,070
4148.80.0.0/1548.80.0.1 to 48.81.255.25448.81.255.255131,070
4248.82.0.0/1548.82.0.1 to 48.83.255.25448.83.255.255131,070
4348.84.0.0/1548.84.0.1 to 48.85.255.25448.85.255.255131,070
4448.86.0.0/1548.86.0.1 to 48.87.255.25448.87.255.255131,070
4548.88.0.0/1548.88.0.1 to 48.89.255.25448.89.255.255131,070
4648.90.0.0/1548.90.0.1 to 48.91.255.25448.91.255.255131,070
4748.92.0.0/1548.92.0.1 to 48.93.255.25448.93.255.255131,070
4848.94.0.0/1548.94.0.1 to 48.95.255.25448.95.255.255131,070
4948.96.0.0/1548.96.0.1 to 48.97.255.25448.97.255.255131,070
5048.98.0.0/1548.98.0.1 to 48.99.255.25448.99.255.255131,070
5148.100.0.0/1548.100.0.1 to 48.101.255.25448.101.255.255131,070
5248.102.0.0/1548.102.0.1 to 48.103.255.25448.103.255.255131,070
5348.104.0.0/1548.104.0.1 to 48.105.255.25448.105.255.255131,070
5448.106.0.0/1548.106.0.1 to 48.107.255.25448.107.255.255131,070
5548.108.0.0/1548.108.0.1 to 48.109.255.25448.109.255.255131,070
5648.110.0.0/1548.110.0.1 to 48.111.255.25448.111.255.255131,070
5748.112.0.0/1548.112.0.1 to 48.113.255.25448.113.255.255131,070
5848.114.0.0/1548.114.0.1 to 48.115.255.25448.115.255.255131,070
5948.116.0.0/1548.116.0.1 to 48.117.255.25448.117.255.255131,070
6048.118.0.0/1548.118.0.1 to 48.119.255.25448.119.255.255131,070
6148.120.0.0/1548.120.0.1 to 48.121.255.25448.121.255.255131,070
6248.122.0.0/1548.122.0.1 to 48.123.255.25448.123.255.255131,070
6348.124.0.0/1548.124.0.1 to 48.125.255.25448.125.255.255131,070
6448.126.0.0/1548.126.0.1 to 48.127.255.25448.127.255.255131,070
6548.128.0.0/1548.128.0.1 to 48.129.255.25448.129.255.255131,070
6648.130.0.0/1548.130.0.1 to 48.131.255.25448.131.255.255131,070
6748.132.0.0/1548.132.0.1 to 48.133.255.25448.133.255.255131,070
6848.134.0.0/1548.134.0.1 to 48.135.255.25448.135.255.255131,070
6948.136.0.0/1548.136.0.1 to 48.137.255.25448.137.255.255131,070
7048.138.0.0/1548.138.0.1 to 48.139.255.25448.139.255.255131,070
7148.140.0.0/1548.140.0.1 to 48.141.255.25448.141.255.255131,070
7248.142.0.0/1548.142.0.1 to 48.143.255.25448.143.255.255131,070
7348.144.0.0/1548.144.0.1 to 48.145.255.25448.145.255.255131,070
7448.146.0.0/1548.146.0.1 to 48.147.255.25448.147.255.255131,070
7548.148.0.0/1548.148.0.1 to 48.149.255.25448.149.255.255131,070
7648.150.0.0/1548.150.0.1 to 48.151.255.25448.151.255.255131,070
7748.152.0.0/1548.152.0.1 to 48.153.255.25448.153.255.255131,070
7848.154.0.0/1548.154.0.1 to 48.155.255.25448.155.255.255131,070
7948.156.0.0/1548.156.0.1 to 48.157.255.25448.157.255.255131,070
8048.158.0.0/1548.158.0.1 to 48.159.255.25448.159.255.255131,070
8148.160.0.0/1548.160.0.1 to 48.161.255.25448.161.255.255131,070
8248.162.0.0/1548.162.0.1 to 48.163.255.25448.163.255.255131,070
8348.164.0.0/1548.164.0.1 to 48.165.255.25448.165.255.255131,070
8448.166.0.0/1548.166.0.1 to 48.167.255.25448.167.255.255131,070
8548.168.0.0/1548.168.0.1 to 48.169.255.25448.169.255.255131,070
8648.170.0.0/1548.170.0.1 to 48.171.255.25448.171.255.255131,070
8748.172.0.0/1548.172.0.1 to 48.173.255.25448.173.255.255131,070
8848.174.0.0/1548.174.0.1 to 48.175.255.25448.175.255.255131,070
8948.176.0.0/1548.176.0.1 to 48.177.255.25448.177.255.255131,070
9048.178.0.0/1548.178.0.1 to 48.179.255.25448.179.255.255131,070
9148.180.0.0/1548.180.0.1 to 48.181.255.25448.181.255.255131,070
9248.182.0.0/1548.182.0.1 to 48.183.255.25448.183.255.255131,070
9348.184.0.0/1548.184.0.1 to 48.185.255.25448.185.255.255131,070
9448.186.0.0/1548.186.0.1 to 48.187.255.25448.187.255.255131,070
9548.188.0.0/1548.188.0.1 to 48.189.255.25448.189.255.255131,070
9648.190.0.0/1548.190.0.1 to 48.191.255.25448.191.255.255131,070
9748.192.0.0/1548.192.0.1 to 48.193.255.25448.193.255.255131,070
9848.194.0.0/1548.194.0.1 to 48.195.255.25448.195.255.255131,070
9948.196.0.0/1548.196.0.1 to 48.197.255.25448.197.255.255131,070
10048.198.0.0/1548.198.0.1 to 48.199.255.25448.199.255.255131,070
10148.200.0.0/1548.200.0.1 to 48.201.255.25448.201.255.255131,070
10248.202.0.0/1548.202.0.1 to 48.203.255.25448.203.255.255131,070
10348.204.0.0/1548.204.0.1 to 48.205.255.25448.205.255.255131,070
10448.206.0.0/1548.206.0.1 to 48.207.255.25448.207.255.255131,070
10548.208.0.0/1548.208.0.1 to 48.209.255.25448.209.255.255131,070
10648.210.0.0/1548.210.0.1 to 48.211.255.25448.211.255.255131,070
10748.212.0.0/1548.212.0.1 to 48.213.255.25448.213.255.255131,070
10848.214.0.0/1548.214.0.1 to 48.215.255.25448.215.255.255131,070
10948.216.0.0/1548.216.0.1 to 48.217.255.25448.217.255.255131,070
11048.218.0.0/1548.218.0.1 to 48.219.255.25448.219.255.255131,070
11148.220.0.0/1548.220.0.1 to 48.221.255.25448.221.255.255131,070
11248.222.0.0/1548.222.0.1 to 48.223.255.25448.223.255.255131,070
11348.224.0.0/1548.224.0.1 to 48.225.255.25448.225.255.255131,070
11448.226.0.0/1548.226.0.1 to 48.227.255.25448.227.255.255131,070
11548.228.0.0/1548.228.0.1 to 48.229.255.25448.229.255.255131,070
11648.230.0.0/1548.230.0.1 to 48.231.255.25448.231.255.255131,070
11748.232.0.0/1548.232.0.1 to 48.233.255.25448.233.255.255131,070
11848.234.0.0/1548.234.0.1 to 48.235.255.25448.235.255.255131,070
11948.236.0.0/1548.236.0.1 to 48.237.255.25448.237.255.255131,070
12048.238.0.0/1548.238.0.1 to 48.239.255.25448.239.255.255131,070
12148.240.0.0/1548.240.0.1 to 48.241.255.25448.241.255.255131,070
12248.242.0.0/1548.242.0.1 to 48.243.255.25448.243.255.255131,070
12348.244.0.0/1548.244.0.1 to 48.245.255.25448.245.255.255131,070
12448.246.0.0/1548.246.0.1 to 48.247.255.25448.247.255.255131,070
12548.248.0.0/1548.248.0.1 to 48.249.255.25448.249.255.255131,070
12648.250.0.0/1548.250.0.1 to 48.251.255.25448.251.255.255131,070
12748.252.0.0/1548.252.0.1 to 48.253.255.25448.253.255.255131,070
12848.254.0.0/1548.254.0.1 to 48.255.255.25448.255.255.255131,070
12949.0.0.0/1549.0.0.1 to 49.1.255.25449.1.255.255131,070
13049.2.0.0/1549.2.0.1 to 49.3.255.25449.3.255.255131,070
13149.4.0.0/1549.4.0.1 to 49.5.255.25449.5.255.255131,070
13249.6.0.0/1549.6.0.1 to 49.7.255.25449.7.255.255131,070
13349.8.0.0/1549.8.0.1 to 49.9.255.25449.9.255.255131,070
13449.10.0.0/1549.10.0.1 to 49.11.255.25449.11.255.255131,070
13549.12.0.0/1549.12.0.1 to 49.13.255.25449.13.255.255131,070
13649.14.0.0/1549.14.0.1 to 49.15.255.25449.15.255.255131,070
13749.16.0.0/1549.16.0.1 to 49.17.255.25449.17.255.255131,070
13849.18.0.0/1549.18.0.1 to 49.19.255.25449.19.255.255131,070
13949.20.0.0/1549.20.0.1 to 49.21.255.25449.21.255.255131,070
14049.22.0.0/1549.22.0.1 to 49.23.255.25449.23.255.255131,070
14149.24.0.0/1549.24.0.1 to 49.25.255.25449.25.255.255131,070
14249.26.0.0/1549.26.0.1 to 49.27.255.25449.27.255.255131,070
14349.28.0.0/1549.28.0.1 to 49.29.255.25449.29.255.255131,070
14449.30.0.0/1549.30.0.1 to 49.31.255.25449.31.255.255131,070
14549.32.0.0/1549.32.0.1 to 49.33.255.25449.33.255.255131,070
14649.34.0.0/1549.34.0.1 to 49.35.255.25449.35.255.255131,070
14749.36.0.0/1549.36.0.1 to 49.37.255.25449.37.255.255131,070
14849.38.0.0/1549.38.0.1 to 49.39.255.25449.39.255.255131,070
14949.40.0.0/1549.40.0.1 to 49.41.255.25449.41.255.255131,070
15049.42.0.0/1549.42.0.1 to 49.43.255.25449.43.255.255131,070
15149.44.0.0/1549.44.0.1 to 49.45.255.25449.45.255.255131,070
15249.46.0.0/1549.46.0.1 to 49.47.255.25449.47.255.255131,070
15349.48.0.0/1549.48.0.1 to 49.49.255.25449.49.255.255131,070
15449.50.0.0/1549.50.0.1 to 49.51.255.25449.51.255.255131,070
15549.52.0.0/1549.52.0.1 to 49.53.255.25449.53.255.255131,070
15649.54.0.0/1549.54.0.1 to 49.55.255.25449.55.255.255131,070
15749.56.0.0/1549.56.0.1 to 49.57.255.25449.57.255.255131,070
15849.58.0.0/1549.58.0.1 to 49.59.255.25449.59.255.255131,070
15949.60.0.0/1549.60.0.1 to 49.61.255.25449.61.255.255131,070
16049.62.0.0/1549.62.0.1 to 49.63.255.25449.63.255.255131,070
16149.64.0.0/1549.64.0.1 to 49.65.255.25449.65.255.255131,070
16249.66.0.0/1549.66.0.1 to 49.67.255.25449.67.255.255131,070
16349.68.0.0/1549.68.0.1 to 49.69.255.25449.69.255.255131,070
16449.70.0.0/1549.70.0.1 to 49.71.255.25449.71.255.255131,070
16549.72.0.0/1549.72.0.1 to 49.73.255.25449.73.255.255131,070
16649.74.0.0/1549.74.0.1 to 49.75.255.25449.75.255.255131,070
16749.76.0.0/1549.76.0.1 to 49.77.255.25449.77.255.255131,070
16849.78.0.0/1549.78.0.1 to 49.79.255.25449.79.255.255131,070
16949.80.0.0/1549.80.0.1 to 49.81.255.25449.81.255.255131,070
17049.82.0.0/1549.82.0.1 to 49.83.255.25449.83.255.255131,070
17149.84.0.0/1549.84.0.1 to 49.85.255.25449.85.255.255131,070
17249.86.0.0/1549.86.0.1 to 49.87.255.25449.87.255.255131,070
17349.88.0.0/1549.88.0.1 to 49.89.255.25449.89.255.255131,070
17449.90.0.0/1549.90.0.1 to 49.91.255.25449.91.255.255131,070
17549.92.0.0/1549.92.0.1 to 49.93.255.25449.93.255.255131,070
17649.94.0.0/1549.94.0.1 to 49.95.255.25449.95.255.255131,070
17749.96.0.0/1549.96.0.1 to 49.97.255.25449.97.255.255131,070
17849.98.0.0/1549.98.0.1 to 49.99.255.25449.99.255.255131,070
17949.100.0.0/1549.100.0.1 to 49.101.255.25449.101.255.255131,070
18049.102.0.0/1549.102.0.1 to 49.103.255.25449.103.255.255131,070
18149.104.0.0/1549.104.0.1 to 49.105.255.25449.105.255.255131,070
18249.106.0.0/1549.106.0.1 to 49.107.255.25449.107.255.255131,070
18349.108.0.0/1549.108.0.1 to 49.109.255.25449.109.255.255131,070
18449.110.0.0/1549.110.0.1 to 49.111.255.25449.111.255.255131,070
18549.112.0.0/1549.112.0.1 to 49.113.255.25449.113.255.255131,070
18649.114.0.0/1549.114.0.1 to 49.115.255.25449.115.255.255131,070
18749.116.0.0/1549.116.0.1 to 49.117.255.25449.117.255.255131,070
18849.118.0.0/1549.118.0.1 to 49.119.255.25449.119.255.255131,070
18949.120.0.0/1549.120.0.1 to 49.121.255.25449.121.255.255131,070
19049.122.0.0/1549.122.0.1 to 49.123.255.25449.123.255.255131,070
19149.124.0.0/1549.124.0.1 to 49.125.255.25449.125.255.255131,070
19249.126.0.0/1549.126.0.1 to 49.127.255.25449.127.255.255131,070
19349.128.0.0/1549.128.0.1 to 49.129.255.25449.129.255.255131,070
19449.130.0.0/1549.130.0.1 to 49.131.255.25449.131.255.255131,070
19549.132.0.0/1549.132.0.1 to 49.133.255.25449.133.255.255131,070
19649.134.0.0/1549.134.0.1 to 49.135.255.25449.135.255.255131,070
19749.136.0.0/1549.136.0.1 to 49.137.255.25449.137.255.255131,070
19849.138.0.0/1549.138.0.1 to 49.139.255.25449.139.255.255131,070
19949.140.0.0/1549.140.0.1 to 49.141.255.25449.141.255.255131,070
20049.142.0.0/1549.142.0.1 to 49.143.255.25449.143.255.255131,070
20149.144.0.0/1549.144.0.1 to 49.145.255.25449.145.255.255131,070
20249.146.0.0/1549.146.0.1 to 49.147.255.25449.147.255.255131,070
20349.148.0.0/1549.148.0.1 to 49.149.255.25449.149.255.255131,070
20449.150.0.0/1549.150.0.1 to 49.151.255.25449.151.255.255131,070
20549.152.0.0/1549.152.0.1 to 49.153.255.25449.153.255.255131,070
20649.154.0.0/1549.154.0.1 to 49.155.255.25449.155.255.255131,070
20749.156.0.0/1549.156.0.1 to 49.157.255.25449.157.255.255131,070
20849.158.0.0/1549.158.0.1 to 49.159.255.25449.159.255.255131,070
20949.160.0.0/1549.160.0.1 to 49.161.255.25449.161.255.255131,070
21049.162.0.0/1549.162.0.1 to 49.163.255.25449.163.255.255131,070
21149.164.0.0/1549.164.0.1 to 49.165.255.25449.165.255.255131,070
21249.166.0.0/1549.166.0.1 to 49.167.255.25449.167.255.255131,070
21349.168.0.0/1549.168.0.1 to 49.169.255.25449.169.255.255131,070
21449.170.0.0/1549.170.0.1 to 49.171.255.25449.171.255.255131,070
21549.172.0.0/1549.172.0.1 to 49.173.255.25449.173.255.255131,070
21649.174.0.0/1549.174.0.1 to 49.175.255.25449.175.255.255131,070
21749.176.0.0/1549.176.0.1 to 49.177.255.25449.177.255.255131,070
21849.178.0.0/1549.178.0.1 to 49.179.255.25449.179.255.255131,070
21949.180.0.0/1549.180.0.1 to 49.181.255.25449.181.255.255131,070
22049.182.0.0/1549.182.0.1 to 49.183.255.25449.183.255.255131,070
22149.184.0.0/1549.184.0.1 to 49.185.255.25449.185.255.255131,070
22249.186.0.0/1549.186.0.1 to 49.187.255.25449.187.255.255131,070
22349.188.0.0/1549.188.0.1 to 49.189.255.25449.189.255.255131,070
22449.190.0.0/1549.190.0.1 to 49.191.255.25449.191.255.255131,070
22549.192.0.0/1549.192.0.1 to 49.193.255.25449.193.255.255131,070
22649.194.0.0/1549.194.0.1 to 49.195.255.25449.195.255.255131,070
22749.196.0.0/1549.196.0.1 to 49.197.255.25449.197.255.255131,070
22849.198.0.0/1549.198.0.1 to 49.199.255.25449.199.255.255131,070
22949.200.0.0/1549.200.0.1 to 49.201.255.25449.201.255.255131,070
23049.202.0.0/1549.202.0.1 to 49.203.255.25449.203.255.255131,070
23149.204.0.0/1549.204.0.1 to 49.205.255.25449.205.255.255131,070
23249.206.0.0/1549.206.0.1 to 49.207.255.25449.207.255.255131,070
23349.208.0.0/1549.208.0.1 to 49.209.255.25449.209.255.255131,070
23449.210.0.0/1549.210.0.1 to 49.211.255.25449.211.255.255131,070
23549.212.0.0/1549.212.0.1 to 49.213.255.25449.213.255.255131,070
23649.214.0.0/1549.214.0.1 to 49.215.255.25449.215.255.255131,070
23749.216.0.0/1549.216.0.1 to 49.217.255.25449.217.255.255131,070
23849.218.0.0/1549.218.0.1 to 49.219.255.25449.219.255.255131,070
23949.220.0.0/1549.220.0.1 to 49.221.255.25449.221.255.255131,070
24049.222.0.0/1549.222.0.1 to 49.223.255.25449.223.255.255131,070
24149.224.0.0/1549.224.0.1 to 49.225.255.25449.225.255.255131,070
24249.226.0.0/1549.226.0.1 to 49.227.255.25449.227.255.255131,070
24349.228.0.0/1549.228.0.1 to 49.229.255.25449.229.255.255131,070
24449.230.0.0/1549.230.0.1 to 49.231.255.25449.231.255.255131,070
24549.232.0.0/1549.232.0.1 to 49.233.255.25449.233.255.255131,070
24649.234.0.0/1549.234.0.1 to 49.235.255.25449.235.255.255131,070
24749.236.0.0/1549.236.0.1 to 49.237.255.25449.237.255.255131,070
24849.238.0.0/1549.238.0.1 to 49.239.255.25449.239.255.255131,070
24949.240.0.0/1549.240.0.1 to 49.241.255.25449.241.255.255131,070
25049.242.0.0/1549.242.0.1 to 49.243.255.25449.243.255.255131,070
25149.244.0.0/1549.244.0.1 to 49.245.255.25449.245.255.255131,070
25249.246.0.0/1549.246.0.1 to 49.247.255.25449.247.255.255131,070
25349.248.0.0/1549.248.0.1 to 49.249.255.25449.249.255.255131,070
25449.250.0.0/1549.250.0.1 to 49.251.255.25449.251.255.255131,070
25549.252.0.0/1549.252.0.1 to 49.253.255.25449.253.255.255131,070
25649.254.0.0/1549.254.0.1 to 49.255.255.25449.255.255.255131,070

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.