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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.

Network61.158.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
61.158.0.0
Broadcast address
61.159.255.255
First usable
61.158.0.1
Last usable
61.159.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
A (default /8)
As numbers
Hex 3D9E0000 · Integer 1033764864 to 1033895935
Reverse DNS zones
158.61.in-addr.arpa
159.61.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00111101.10011110.00000000.0000000061.158.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network00111101.10011110.00000000.0000000061.158.0.0
Broadcast00111101.10011111.11111111.1111111161.159.255.255
Split into smaller subnets/23
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

61.158.0.0/15 makes 256 subnets of /23.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
161.158.0.0/2361.158.0.1 to 61.158.1.25461.158.1.255510
261.158.2.0/2361.158.2.1 to 61.158.3.25461.158.3.255510
361.158.4.0/2361.158.4.1 to 61.158.5.25461.158.5.255510
461.158.6.0/2361.158.6.1 to 61.158.7.25461.158.7.255510
561.158.8.0/2361.158.8.1 to 61.158.9.25461.158.9.255510
661.158.10.0/2361.158.10.1 to 61.158.11.25461.158.11.255510
761.158.12.0/2361.158.12.1 to 61.158.13.25461.158.13.255510
861.158.14.0/2361.158.14.1 to 61.158.15.25461.158.15.255510
961.158.16.0/2361.158.16.1 to 61.158.17.25461.158.17.255510
1061.158.18.0/2361.158.18.1 to 61.158.19.25461.158.19.255510
1161.158.20.0/2361.158.20.1 to 61.158.21.25461.158.21.255510
1261.158.22.0/2361.158.22.1 to 61.158.23.25461.158.23.255510
1361.158.24.0/2361.158.24.1 to 61.158.25.25461.158.25.255510
1461.158.26.0/2361.158.26.1 to 61.158.27.25461.158.27.255510
1561.158.28.0/2361.158.28.1 to 61.158.29.25461.158.29.255510
1661.158.30.0/2361.158.30.1 to 61.158.31.25461.158.31.255510
1761.158.32.0/2361.158.32.1 to 61.158.33.25461.158.33.255510
1861.158.34.0/2361.158.34.1 to 61.158.35.25461.158.35.255510
1961.158.36.0/2361.158.36.1 to 61.158.37.25461.158.37.255510
2061.158.38.0/2361.158.38.1 to 61.158.39.25461.158.39.255510
2161.158.40.0/2361.158.40.1 to 61.158.41.25461.158.41.255510
2261.158.42.0/2361.158.42.1 to 61.158.43.25461.158.43.255510
2361.158.44.0/2361.158.44.1 to 61.158.45.25461.158.45.255510
2461.158.46.0/2361.158.46.1 to 61.158.47.25461.158.47.255510
2561.158.48.0/2361.158.48.1 to 61.158.49.25461.158.49.255510
2661.158.50.0/2361.158.50.1 to 61.158.51.25461.158.51.255510
2761.158.52.0/2361.158.52.1 to 61.158.53.25461.158.53.255510
2861.158.54.0/2361.158.54.1 to 61.158.55.25461.158.55.255510
2961.158.56.0/2361.158.56.1 to 61.158.57.25461.158.57.255510
3061.158.58.0/2361.158.58.1 to 61.158.59.25461.158.59.255510
3161.158.60.0/2361.158.60.1 to 61.158.61.25461.158.61.255510
3261.158.62.0/2361.158.62.1 to 61.158.63.25461.158.63.255510
3361.158.64.0/2361.158.64.1 to 61.158.65.25461.158.65.255510
3461.158.66.0/2361.158.66.1 to 61.158.67.25461.158.67.255510
3561.158.68.0/2361.158.68.1 to 61.158.69.25461.158.69.255510
3661.158.70.0/2361.158.70.1 to 61.158.71.25461.158.71.255510
3761.158.72.0/2361.158.72.1 to 61.158.73.25461.158.73.255510
3861.158.74.0/2361.158.74.1 to 61.158.75.25461.158.75.255510
3961.158.76.0/2361.158.76.1 to 61.158.77.25461.158.77.255510
4061.158.78.0/2361.158.78.1 to 61.158.79.25461.158.79.255510
4161.158.80.0/2361.158.80.1 to 61.158.81.25461.158.81.255510
4261.158.82.0/2361.158.82.1 to 61.158.83.25461.158.83.255510
4361.158.84.0/2361.158.84.1 to 61.158.85.25461.158.85.255510
4461.158.86.0/2361.158.86.1 to 61.158.87.25461.158.87.255510
4561.158.88.0/2361.158.88.1 to 61.158.89.25461.158.89.255510
4661.158.90.0/2361.158.90.1 to 61.158.91.25461.158.91.255510
4761.158.92.0/2361.158.92.1 to 61.158.93.25461.158.93.255510
4861.158.94.0/2361.158.94.1 to 61.158.95.25461.158.95.255510
4961.158.96.0/2361.158.96.1 to 61.158.97.25461.158.97.255510
5061.158.98.0/2361.158.98.1 to 61.158.99.25461.158.99.255510
5161.158.100.0/2361.158.100.1 to 61.158.101.25461.158.101.255510
5261.158.102.0/2361.158.102.1 to 61.158.103.25461.158.103.255510
5361.158.104.0/2361.158.104.1 to 61.158.105.25461.158.105.255510
5461.158.106.0/2361.158.106.1 to 61.158.107.25461.158.107.255510
5561.158.108.0/2361.158.108.1 to 61.158.109.25461.158.109.255510
5661.158.110.0/2361.158.110.1 to 61.158.111.25461.158.111.255510
5761.158.112.0/2361.158.112.1 to 61.158.113.25461.158.113.255510
5861.158.114.0/2361.158.114.1 to 61.158.115.25461.158.115.255510
5961.158.116.0/2361.158.116.1 to 61.158.117.25461.158.117.255510
6061.158.118.0/2361.158.118.1 to 61.158.119.25461.158.119.255510
6161.158.120.0/2361.158.120.1 to 61.158.121.25461.158.121.255510
6261.158.122.0/2361.158.122.1 to 61.158.123.25461.158.123.255510
6361.158.124.0/2361.158.124.1 to 61.158.125.25461.158.125.255510
6461.158.126.0/2361.158.126.1 to 61.158.127.25461.158.127.255510
6561.158.128.0/2361.158.128.1 to 61.158.129.25461.158.129.255510
6661.158.130.0/2361.158.130.1 to 61.158.131.25461.158.131.255510
6761.158.132.0/2361.158.132.1 to 61.158.133.25461.158.133.255510
6861.158.134.0/2361.158.134.1 to 61.158.135.25461.158.135.255510
6961.158.136.0/2361.158.136.1 to 61.158.137.25461.158.137.255510
7061.158.138.0/2361.158.138.1 to 61.158.139.25461.158.139.255510
7161.158.140.0/2361.158.140.1 to 61.158.141.25461.158.141.255510
7261.158.142.0/2361.158.142.1 to 61.158.143.25461.158.143.255510
7361.158.144.0/2361.158.144.1 to 61.158.145.25461.158.145.255510
7461.158.146.0/2361.158.146.1 to 61.158.147.25461.158.147.255510
7561.158.148.0/2361.158.148.1 to 61.158.149.25461.158.149.255510
7661.158.150.0/2361.158.150.1 to 61.158.151.25461.158.151.255510
7761.158.152.0/2361.158.152.1 to 61.158.153.25461.158.153.255510
7861.158.154.0/2361.158.154.1 to 61.158.155.25461.158.155.255510
7961.158.156.0/2361.158.156.1 to 61.158.157.25461.158.157.255510
8061.158.158.0/2361.158.158.1 to 61.158.159.25461.158.159.255510
8161.158.160.0/2361.158.160.1 to 61.158.161.25461.158.161.255510
8261.158.162.0/2361.158.162.1 to 61.158.163.25461.158.163.255510
8361.158.164.0/2361.158.164.1 to 61.158.165.25461.158.165.255510
8461.158.166.0/2361.158.166.1 to 61.158.167.25461.158.167.255510
8561.158.168.0/2361.158.168.1 to 61.158.169.25461.158.169.255510
8661.158.170.0/2361.158.170.1 to 61.158.171.25461.158.171.255510
8761.158.172.0/2361.158.172.1 to 61.158.173.25461.158.173.255510
8861.158.174.0/2361.158.174.1 to 61.158.175.25461.158.175.255510
8961.158.176.0/2361.158.176.1 to 61.158.177.25461.158.177.255510
9061.158.178.0/2361.158.178.1 to 61.158.179.25461.158.179.255510
9161.158.180.0/2361.158.180.1 to 61.158.181.25461.158.181.255510
9261.158.182.0/2361.158.182.1 to 61.158.183.25461.158.183.255510
9361.158.184.0/2361.158.184.1 to 61.158.185.25461.158.185.255510
9461.158.186.0/2361.158.186.1 to 61.158.187.25461.158.187.255510
9561.158.188.0/2361.158.188.1 to 61.158.189.25461.158.189.255510
9661.158.190.0/2361.158.190.1 to 61.158.191.25461.158.191.255510
9761.158.192.0/2361.158.192.1 to 61.158.193.25461.158.193.255510
9861.158.194.0/2361.158.194.1 to 61.158.195.25461.158.195.255510
9961.158.196.0/2361.158.196.1 to 61.158.197.25461.158.197.255510
10061.158.198.0/2361.158.198.1 to 61.158.199.25461.158.199.255510
10161.158.200.0/2361.158.200.1 to 61.158.201.25461.158.201.255510
10261.158.202.0/2361.158.202.1 to 61.158.203.25461.158.203.255510
10361.158.204.0/2361.158.204.1 to 61.158.205.25461.158.205.255510
10461.158.206.0/2361.158.206.1 to 61.158.207.25461.158.207.255510
10561.158.208.0/2361.158.208.1 to 61.158.209.25461.158.209.255510
10661.158.210.0/2361.158.210.1 to 61.158.211.25461.158.211.255510
10761.158.212.0/2361.158.212.1 to 61.158.213.25461.158.213.255510
10861.158.214.0/2361.158.214.1 to 61.158.215.25461.158.215.255510
10961.158.216.0/2361.158.216.1 to 61.158.217.25461.158.217.255510
11061.158.218.0/2361.158.218.1 to 61.158.219.25461.158.219.255510
11161.158.220.0/2361.158.220.1 to 61.158.221.25461.158.221.255510
11261.158.222.0/2361.158.222.1 to 61.158.223.25461.158.223.255510
11361.158.224.0/2361.158.224.1 to 61.158.225.25461.158.225.255510
11461.158.226.0/2361.158.226.1 to 61.158.227.25461.158.227.255510
11561.158.228.0/2361.158.228.1 to 61.158.229.25461.158.229.255510
11661.158.230.0/2361.158.230.1 to 61.158.231.25461.158.231.255510
11761.158.232.0/2361.158.232.1 to 61.158.233.25461.158.233.255510
11861.158.234.0/2361.158.234.1 to 61.158.235.25461.158.235.255510
11961.158.236.0/2361.158.236.1 to 61.158.237.25461.158.237.255510
12061.158.238.0/2361.158.238.1 to 61.158.239.25461.158.239.255510
12161.158.240.0/2361.158.240.1 to 61.158.241.25461.158.241.255510
12261.158.242.0/2361.158.242.1 to 61.158.243.25461.158.243.255510
12361.158.244.0/2361.158.244.1 to 61.158.245.25461.158.245.255510
12461.158.246.0/2361.158.246.1 to 61.158.247.25461.158.247.255510
12561.158.248.0/2361.158.248.1 to 61.158.249.25461.158.249.255510
12661.158.250.0/2361.158.250.1 to 61.158.251.25461.158.251.255510
12761.158.252.0/2361.158.252.1 to 61.158.253.25461.158.253.255510
12861.158.254.0/2361.158.254.1 to 61.158.255.25461.158.255.255510
12961.159.0.0/2361.159.0.1 to 61.159.1.25461.159.1.255510
13061.159.2.0/2361.159.2.1 to 61.159.3.25461.159.3.255510
13161.159.4.0/2361.159.4.1 to 61.159.5.25461.159.5.255510
13261.159.6.0/2361.159.6.1 to 61.159.7.25461.159.7.255510
13361.159.8.0/2361.159.8.1 to 61.159.9.25461.159.9.255510
13461.159.10.0/2361.159.10.1 to 61.159.11.25461.159.11.255510
13561.159.12.0/2361.159.12.1 to 61.159.13.25461.159.13.255510
13661.159.14.0/2361.159.14.1 to 61.159.15.25461.159.15.255510
13761.159.16.0/2361.159.16.1 to 61.159.17.25461.159.17.255510
13861.159.18.0/2361.159.18.1 to 61.159.19.25461.159.19.255510
13961.159.20.0/2361.159.20.1 to 61.159.21.25461.159.21.255510
14061.159.22.0/2361.159.22.1 to 61.159.23.25461.159.23.255510
14161.159.24.0/2361.159.24.1 to 61.159.25.25461.159.25.255510
14261.159.26.0/2361.159.26.1 to 61.159.27.25461.159.27.255510
14361.159.28.0/2361.159.28.1 to 61.159.29.25461.159.29.255510
14461.159.30.0/2361.159.30.1 to 61.159.31.25461.159.31.255510
14561.159.32.0/2361.159.32.1 to 61.159.33.25461.159.33.255510
14661.159.34.0/2361.159.34.1 to 61.159.35.25461.159.35.255510
14761.159.36.0/2361.159.36.1 to 61.159.37.25461.159.37.255510
14861.159.38.0/2361.159.38.1 to 61.159.39.25461.159.39.255510
14961.159.40.0/2361.159.40.1 to 61.159.41.25461.159.41.255510
15061.159.42.0/2361.159.42.1 to 61.159.43.25461.159.43.255510
15161.159.44.0/2361.159.44.1 to 61.159.45.25461.159.45.255510
15261.159.46.0/2361.159.46.1 to 61.159.47.25461.159.47.255510
15361.159.48.0/2361.159.48.1 to 61.159.49.25461.159.49.255510
15461.159.50.0/2361.159.50.1 to 61.159.51.25461.159.51.255510
15561.159.52.0/2361.159.52.1 to 61.159.53.25461.159.53.255510
15661.159.54.0/2361.159.54.1 to 61.159.55.25461.159.55.255510
15761.159.56.0/2361.159.56.1 to 61.159.57.25461.159.57.255510
15861.159.58.0/2361.159.58.1 to 61.159.59.25461.159.59.255510
15961.159.60.0/2361.159.60.1 to 61.159.61.25461.159.61.255510
16061.159.62.0/2361.159.62.1 to 61.159.63.25461.159.63.255510
16161.159.64.0/2361.159.64.1 to 61.159.65.25461.159.65.255510
16261.159.66.0/2361.159.66.1 to 61.159.67.25461.159.67.255510
16361.159.68.0/2361.159.68.1 to 61.159.69.25461.159.69.255510
16461.159.70.0/2361.159.70.1 to 61.159.71.25461.159.71.255510
16561.159.72.0/2361.159.72.1 to 61.159.73.25461.159.73.255510
16661.159.74.0/2361.159.74.1 to 61.159.75.25461.159.75.255510
16761.159.76.0/2361.159.76.1 to 61.159.77.25461.159.77.255510
16861.159.78.0/2361.159.78.1 to 61.159.79.25461.159.79.255510
16961.159.80.0/2361.159.80.1 to 61.159.81.25461.159.81.255510
17061.159.82.0/2361.159.82.1 to 61.159.83.25461.159.83.255510
17161.159.84.0/2361.159.84.1 to 61.159.85.25461.159.85.255510
17261.159.86.0/2361.159.86.1 to 61.159.87.25461.159.87.255510
17361.159.88.0/2361.159.88.1 to 61.159.89.25461.159.89.255510
17461.159.90.0/2361.159.90.1 to 61.159.91.25461.159.91.255510
17561.159.92.0/2361.159.92.1 to 61.159.93.25461.159.93.255510
17661.159.94.0/2361.159.94.1 to 61.159.95.25461.159.95.255510
17761.159.96.0/2361.159.96.1 to 61.159.97.25461.159.97.255510
17861.159.98.0/2361.159.98.1 to 61.159.99.25461.159.99.255510
17961.159.100.0/2361.159.100.1 to 61.159.101.25461.159.101.255510
18061.159.102.0/2361.159.102.1 to 61.159.103.25461.159.103.255510
18161.159.104.0/2361.159.104.1 to 61.159.105.25461.159.105.255510
18261.159.106.0/2361.159.106.1 to 61.159.107.25461.159.107.255510
18361.159.108.0/2361.159.108.1 to 61.159.109.25461.159.109.255510
18461.159.110.0/2361.159.110.1 to 61.159.111.25461.159.111.255510
18561.159.112.0/2361.159.112.1 to 61.159.113.25461.159.113.255510
18661.159.114.0/2361.159.114.1 to 61.159.115.25461.159.115.255510
18761.159.116.0/2361.159.116.1 to 61.159.117.25461.159.117.255510
18861.159.118.0/2361.159.118.1 to 61.159.119.25461.159.119.255510
18961.159.120.0/2361.159.120.1 to 61.159.121.25461.159.121.255510
19061.159.122.0/2361.159.122.1 to 61.159.123.25461.159.123.255510
19161.159.124.0/2361.159.124.1 to 61.159.125.25461.159.125.255510
19261.159.126.0/2361.159.126.1 to 61.159.127.25461.159.127.255510
19361.159.128.0/2361.159.128.1 to 61.159.129.25461.159.129.255510
19461.159.130.0/2361.159.130.1 to 61.159.131.25461.159.131.255510
19561.159.132.0/2361.159.132.1 to 61.159.133.25461.159.133.255510
19661.159.134.0/2361.159.134.1 to 61.159.135.25461.159.135.255510
19761.159.136.0/2361.159.136.1 to 61.159.137.25461.159.137.255510
19861.159.138.0/2361.159.138.1 to 61.159.139.25461.159.139.255510
19961.159.140.0/2361.159.140.1 to 61.159.141.25461.159.141.255510
20061.159.142.0/2361.159.142.1 to 61.159.143.25461.159.143.255510
20161.159.144.0/2361.159.144.1 to 61.159.145.25461.159.145.255510
20261.159.146.0/2361.159.146.1 to 61.159.147.25461.159.147.255510
20361.159.148.0/2361.159.148.1 to 61.159.149.25461.159.149.255510
20461.159.150.0/2361.159.150.1 to 61.159.151.25461.159.151.255510
20561.159.152.0/2361.159.152.1 to 61.159.153.25461.159.153.255510
20661.159.154.0/2361.159.154.1 to 61.159.155.25461.159.155.255510
20761.159.156.0/2361.159.156.1 to 61.159.157.25461.159.157.255510
20861.159.158.0/2361.159.158.1 to 61.159.159.25461.159.159.255510
20961.159.160.0/2361.159.160.1 to 61.159.161.25461.159.161.255510
21061.159.162.0/2361.159.162.1 to 61.159.163.25461.159.163.255510
21161.159.164.0/2361.159.164.1 to 61.159.165.25461.159.165.255510
21261.159.166.0/2361.159.166.1 to 61.159.167.25461.159.167.255510
21361.159.168.0/2361.159.168.1 to 61.159.169.25461.159.169.255510
21461.159.170.0/2361.159.170.1 to 61.159.171.25461.159.171.255510
21561.159.172.0/2361.159.172.1 to 61.159.173.25461.159.173.255510
21661.159.174.0/2361.159.174.1 to 61.159.175.25461.159.175.255510
21761.159.176.0/2361.159.176.1 to 61.159.177.25461.159.177.255510
21861.159.178.0/2361.159.178.1 to 61.159.179.25461.159.179.255510
21961.159.180.0/2361.159.180.1 to 61.159.181.25461.159.181.255510
22061.159.182.0/2361.159.182.1 to 61.159.183.25461.159.183.255510
22161.159.184.0/2361.159.184.1 to 61.159.185.25461.159.185.255510
22261.159.186.0/2361.159.186.1 to 61.159.187.25461.159.187.255510
22361.159.188.0/2361.159.188.1 to 61.159.189.25461.159.189.255510
22461.159.190.0/2361.159.190.1 to 61.159.191.25461.159.191.255510
22561.159.192.0/2361.159.192.1 to 61.159.193.25461.159.193.255510
22661.159.194.0/2361.159.194.1 to 61.159.195.25461.159.195.255510
22761.159.196.0/2361.159.196.1 to 61.159.197.25461.159.197.255510
22861.159.198.0/2361.159.198.1 to 61.159.199.25461.159.199.255510
22961.159.200.0/2361.159.200.1 to 61.159.201.25461.159.201.255510
23061.159.202.0/2361.159.202.1 to 61.159.203.25461.159.203.255510
23161.159.204.0/2361.159.204.1 to 61.159.205.25461.159.205.255510
23261.159.206.0/2361.159.206.1 to 61.159.207.25461.159.207.255510
23361.159.208.0/2361.159.208.1 to 61.159.209.25461.159.209.255510
23461.159.210.0/2361.159.210.1 to 61.159.211.25461.159.211.255510
23561.159.212.0/2361.159.212.1 to 61.159.213.25461.159.213.255510
23661.159.214.0/2361.159.214.1 to 61.159.215.25461.159.215.255510
23761.159.216.0/2361.159.216.1 to 61.159.217.25461.159.217.255510
23861.159.218.0/2361.159.218.1 to 61.159.219.25461.159.219.255510
23961.159.220.0/2361.159.220.1 to 61.159.221.25461.159.221.255510
24061.159.222.0/2361.159.222.1 to 61.159.223.25461.159.223.255510
24161.159.224.0/2361.159.224.1 to 61.159.225.25461.159.225.255510
24261.159.226.0/2361.159.226.1 to 61.159.227.25461.159.227.255510
24361.159.228.0/2361.159.228.1 to 61.159.229.25461.159.229.255510
24461.159.230.0/2361.159.230.1 to 61.159.231.25461.159.231.255510
24561.159.232.0/2361.159.232.1 to 61.159.233.25461.159.233.255510
24661.159.234.0/2361.159.234.1 to 61.159.235.25461.159.235.255510
24761.159.236.0/2361.159.236.1 to 61.159.237.25461.159.237.255510
24861.159.238.0/2361.159.238.1 to 61.159.239.25461.159.239.255510
24961.159.240.0/2361.159.240.1 to 61.159.241.25461.159.241.255510
25061.159.242.0/2361.159.242.1 to 61.159.243.25461.159.243.255510
25161.159.244.0/2361.159.244.1 to 61.159.245.25461.159.245.255510
25261.159.246.0/2361.159.246.1 to 61.159.247.25461.159.247.255510
25361.159.248.0/2361.159.248.1 to 61.159.249.25461.159.249.255510
25461.159.250.0/2361.159.250.1 to 61.159.251.25461.159.251.255510
25561.159.252.0/2361.159.252.1 to 61.159.253.25461.159.253.255510
25661.159.254.0/2361.159.254.1 to 61.159.255.25461.159.255.255510

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.