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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.

Network41.192.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
41.192.0.0
Broadcast address
41.193.255.255
First usable
41.192.0.1
Last usable
41.193.255.254
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 29C00000 · Integer 700448768 to 700579839
Reverse DNS zones
192.41.in-addr.arpa
193.41.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
Address00101001.11000000.00000000.0000000041.192.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network00101001.11000000.00000000.0000000041.192.0.0
Broadcast00101001.11000001.11111111.1111111141.193.255.255
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)

41.192.0.0/15 makes 256 subnets of /23.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
141.192.0.0/2341.192.0.1 to 41.192.1.25441.192.1.255510
241.192.2.0/2341.192.2.1 to 41.192.3.25441.192.3.255510
341.192.4.0/2341.192.4.1 to 41.192.5.25441.192.5.255510
441.192.6.0/2341.192.6.1 to 41.192.7.25441.192.7.255510
541.192.8.0/2341.192.8.1 to 41.192.9.25441.192.9.255510
641.192.10.0/2341.192.10.1 to 41.192.11.25441.192.11.255510
741.192.12.0/2341.192.12.1 to 41.192.13.25441.192.13.255510
841.192.14.0/2341.192.14.1 to 41.192.15.25441.192.15.255510
941.192.16.0/2341.192.16.1 to 41.192.17.25441.192.17.255510
1041.192.18.0/2341.192.18.1 to 41.192.19.25441.192.19.255510
1141.192.20.0/2341.192.20.1 to 41.192.21.25441.192.21.255510
1241.192.22.0/2341.192.22.1 to 41.192.23.25441.192.23.255510
1341.192.24.0/2341.192.24.1 to 41.192.25.25441.192.25.255510
1441.192.26.0/2341.192.26.1 to 41.192.27.25441.192.27.255510
1541.192.28.0/2341.192.28.1 to 41.192.29.25441.192.29.255510
1641.192.30.0/2341.192.30.1 to 41.192.31.25441.192.31.255510
1741.192.32.0/2341.192.32.1 to 41.192.33.25441.192.33.255510
1841.192.34.0/2341.192.34.1 to 41.192.35.25441.192.35.255510
1941.192.36.0/2341.192.36.1 to 41.192.37.25441.192.37.255510
2041.192.38.0/2341.192.38.1 to 41.192.39.25441.192.39.255510
2141.192.40.0/2341.192.40.1 to 41.192.41.25441.192.41.255510
2241.192.42.0/2341.192.42.1 to 41.192.43.25441.192.43.255510
2341.192.44.0/2341.192.44.1 to 41.192.45.25441.192.45.255510
2441.192.46.0/2341.192.46.1 to 41.192.47.25441.192.47.255510
2541.192.48.0/2341.192.48.1 to 41.192.49.25441.192.49.255510
2641.192.50.0/2341.192.50.1 to 41.192.51.25441.192.51.255510
2741.192.52.0/2341.192.52.1 to 41.192.53.25441.192.53.255510
2841.192.54.0/2341.192.54.1 to 41.192.55.25441.192.55.255510
2941.192.56.0/2341.192.56.1 to 41.192.57.25441.192.57.255510
3041.192.58.0/2341.192.58.1 to 41.192.59.25441.192.59.255510
3141.192.60.0/2341.192.60.1 to 41.192.61.25441.192.61.255510
3241.192.62.0/2341.192.62.1 to 41.192.63.25441.192.63.255510
3341.192.64.0/2341.192.64.1 to 41.192.65.25441.192.65.255510
3441.192.66.0/2341.192.66.1 to 41.192.67.25441.192.67.255510
3541.192.68.0/2341.192.68.1 to 41.192.69.25441.192.69.255510
3641.192.70.0/2341.192.70.1 to 41.192.71.25441.192.71.255510
3741.192.72.0/2341.192.72.1 to 41.192.73.25441.192.73.255510
3841.192.74.0/2341.192.74.1 to 41.192.75.25441.192.75.255510
3941.192.76.0/2341.192.76.1 to 41.192.77.25441.192.77.255510
4041.192.78.0/2341.192.78.1 to 41.192.79.25441.192.79.255510
4141.192.80.0/2341.192.80.1 to 41.192.81.25441.192.81.255510
4241.192.82.0/2341.192.82.1 to 41.192.83.25441.192.83.255510
4341.192.84.0/2341.192.84.1 to 41.192.85.25441.192.85.255510
4441.192.86.0/2341.192.86.1 to 41.192.87.25441.192.87.255510
4541.192.88.0/2341.192.88.1 to 41.192.89.25441.192.89.255510
4641.192.90.0/2341.192.90.1 to 41.192.91.25441.192.91.255510
4741.192.92.0/2341.192.92.1 to 41.192.93.25441.192.93.255510
4841.192.94.0/2341.192.94.1 to 41.192.95.25441.192.95.255510
4941.192.96.0/2341.192.96.1 to 41.192.97.25441.192.97.255510
5041.192.98.0/2341.192.98.1 to 41.192.99.25441.192.99.255510
5141.192.100.0/2341.192.100.1 to 41.192.101.25441.192.101.255510
5241.192.102.0/2341.192.102.1 to 41.192.103.25441.192.103.255510
5341.192.104.0/2341.192.104.1 to 41.192.105.25441.192.105.255510
5441.192.106.0/2341.192.106.1 to 41.192.107.25441.192.107.255510
5541.192.108.0/2341.192.108.1 to 41.192.109.25441.192.109.255510
5641.192.110.0/2341.192.110.1 to 41.192.111.25441.192.111.255510
5741.192.112.0/2341.192.112.1 to 41.192.113.25441.192.113.255510
5841.192.114.0/2341.192.114.1 to 41.192.115.25441.192.115.255510
5941.192.116.0/2341.192.116.1 to 41.192.117.25441.192.117.255510
6041.192.118.0/2341.192.118.1 to 41.192.119.25441.192.119.255510
6141.192.120.0/2341.192.120.1 to 41.192.121.25441.192.121.255510
6241.192.122.0/2341.192.122.1 to 41.192.123.25441.192.123.255510
6341.192.124.0/2341.192.124.1 to 41.192.125.25441.192.125.255510
6441.192.126.0/2341.192.126.1 to 41.192.127.25441.192.127.255510
6541.192.128.0/2341.192.128.1 to 41.192.129.25441.192.129.255510
6641.192.130.0/2341.192.130.1 to 41.192.131.25441.192.131.255510
6741.192.132.0/2341.192.132.1 to 41.192.133.25441.192.133.255510
6841.192.134.0/2341.192.134.1 to 41.192.135.25441.192.135.255510
6941.192.136.0/2341.192.136.1 to 41.192.137.25441.192.137.255510
7041.192.138.0/2341.192.138.1 to 41.192.139.25441.192.139.255510
7141.192.140.0/2341.192.140.1 to 41.192.141.25441.192.141.255510
7241.192.142.0/2341.192.142.1 to 41.192.143.25441.192.143.255510
7341.192.144.0/2341.192.144.1 to 41.192.145.25441.192.145.255510
7441.192.146.0/2341.192.146.1 to 41.192.147.25441.192.147.255510
7541.192.148.0/2341.192.148.1 to 41.192.149.25441.192.149.255510
7641.192.150.0/2341.192.150.1 to 41.192.151.25441.192.151.255510
7741.192.152.0/2341.192.152.1 to 41.192.153.25441.192.153.255510
7841.192.154.0/2341.192.154.1 to 41.192.155.25441.192.155.255510
7941.192.156.0/2341.192.156.1 to 41.192.157.25441.192.157.255510
8041.192.158.0/2341.192.158.1 to 41.192.159.25441.192.159.255510
8141.192.160.0/2341.192.160.1 to 41.192.161.25441.192.161.255510
8241.192.162.0/2341.192.162.1 to 41.192.163.25441.192.163.255510
8341.192.164.0/2341.192.164.1 to 41.192.165.25441.192.165.255510
8441.192.166.0/2341.192.166.1 to 41.192.167.25441.192.167.255510
8541.192.168.0/2341.192.168.1 to 41.192.169.25441.192.169.255510
8641.192.170.0/2341.192.170.1 to 41.192.171.25441.192.171.255510
8741.192.172.0/2341.192.172.1 to 41.192.173.25441.192.173.255510
8841.192.174.0/2341.192.174.1 to 41.192.175.25441.192.175.255510
8941.192.176.0/2341.192.176.1 to 41.192.177.25441.192.177.255510
9041.192.178.0/2341.192.178.1 to 41.192.179.25441.192.179.255510
9141.192.180.0/2341.192.180.1 to 41.192.181.25441.192.181.255510
9241.192.182.0/2341.192.182.1 to 41.192.183.25441.192.183.255510
9341.192.184.0/2341.192.184.1 to 41.192.185.25441.192.185.255510
9441.192.186.0/2341.192.186.1 to 41.192.187.25441.192.187.255510
9541.192.188.0/2341.192.188.1 to 41.192.189.25441.192.189.255510
9641.192.190.0/2341.192.190.1 to 41.192.191.25441.192.191.255510
9741.192.192.0/2341.192.192.1 to 41.192.193.25441.192.193.255510
9841.192.194.0/2341.192.194.1 to 41.192.195.25441.192.195.255510
9941.192.196.0/2341.192.196.1 to 41.192.197.25441.192.197.255510
10041.192.198.0/2341.192.198.1 to 41.192.199.25441.192.199.255510
10141.192.200.0/2341.192.200.1 to 41.192.201.25441.192.201.255510
10241.192.202.0/2341.192.202.1 to 41.192.203.25441.192.203.255510
10341.192.204.0/2341.192.204.1 to 41.192.205.25441.192.205.255510
10441.192.206.0/2341.192.206.1 to 41.192.207.25441.192.207.255510
10541.192.208.0/2341.192.208.1 to 41.192.209.25441.192.209.255510
10641.192.210.0/2341.192.210.1 to 41.192.211.25441.192.211.255510
10741.192.212.0/2341.192.212.1 to 41.192.213.25441.192.213.255510
10841.192.214.0/2341.192.214.1 to 41.192.215.25441.192.215.255510
10941.192.216.0/2341.192.216.1 to 41.192.217.25441.192.217.255510
11041.192.218.0/2341.192.218.1 to 41.192.219.25441.192.219.255510
11141.192.220.0/2341.192.220.1 to 41.192.221.25441.192.221.255510
11241.192.222.0/2341.192.222.1 to 41.192.223.25441.192.223.255510
11341.192.224.0/2341.192.224.1 to 41.192.225.25441.192.225.255510
11441.192.226.0/2341.192.226.1 to 41.192.227.25441.192.227.255510
11541.192.228.0/2341.192.228.1 to 41.192.229.25441.192.229.255510
11641.192.230.0/2341.192.230.1 to 41.192.231.25441.192.231.255510
11741.192.232.0/2341.192.232.1 to 41.192.233.25441.192.233.255510
11841.192.234.0/2341.192.234.1 to 41.192.235.25441.192.235.255510
11941.192.236.0/2341.192.236.1 to 41.192.237.25441.192.237.255510
12041.192.238.0/2341.192.238.1 to 41.192.239.25441.192.239.255510
12141.192.240.0/2341.192.240.1 to 41.192.241.25441.192.241.255510
12241.192.242.0/2341.192.242.1 to 41.192.243.25441.192.243.255510
12341.192.244.0/2341.192.244.1 to 41.192.245.25441.192.245.255510
12441.192.246.0/2341.192.246.1 to 41.192.247.25441.192.247.255510
12541.192.248.0/2341.192.248.1 to 41.192.249.25441.192.249.255510
12641.192.250.0/2341.192.250.1 to 41.192.251.25441.192.251.255510
12741.192.252.0/2341.192.252.1 to 41.192.253.25441.192.253.255510
12841.192.254.0/2341.192.254.1 to 41.192.255.25441.192.255.255510
12941.193.0.0/2341.193.0.1 to 41.193.1.25441.193.1.255510
13041.193.2.0/2341.193.2.1 to 41.193.3.25441.193.3.255510
13141.193.4.0/2341.193.4.1 to 41.193.5.25441.193.5.255510
13241.193.6.0/2341.193.6.1 to 41.193.7.25441.193.7.255510
13341.193.8.0/2341.193.8.1 to 41.193.9.25441.193.9.255510
13441.193.10.0/2341.193.10.1 to 41.193.11.25441.193.11.255510
13541.193.12.0/2341.193.12.1 to 41.193.13.25441.193.13.255510
13641.193.14.0/2341.193.14.1 to 41.193.15.25441.193.15.255510
13741.193.16.0/2341.193.16.1 to 41.193.17.25441.193.17.255510
13841.193.18.0/2341.193.18.1 to 41.193.19.25441.193.19.255510
13941.193.20.0/2341.193.20.1 to 41.193.21.25441.193.21.255510
14041.193.22.0/2341.193.22.1 to 41.193.23.25441.193.23.255510
14141.193.24.0/2341.193.24.1 to 41.193.25.25441.193.25.255510
14241.193.26.0/2341.193.26.1 to 41.193.27.25441.193.27.255510
14341.193.28.0/2341.193.28.1 to 41.193.29.25441.193.29.255510
14441.193.30.0/2341.193.30.1 to 41.193.31.25441.193.31.255510
14541.193.32.0/2341.193.32.1 to 41.193.33.25441.193.33.255510
14641.193.34.0/2341.193.34.1 to 41.193.35.25441.193.35.255510
14741.193.36.0/2341.193.36.1 to 41.193.37.25441.193.37.255510
14841.193.38.0/2341.193.38.1 to 41.193.39.25441.193.39.255510
14941.193.40.0/2341.193.40.1 to 41.193.41.25441.193.41.255510
15041.193.42.0/2341.193.42.1 to 41.193.43.25441.193.43.255510
15141.193.44.0/2341.193.44.1 to 41.193.45.25441.193.45.255510
15241.193.46.0/2341.193.46.1 to 41.193.47.25441.193.47.255510
15341.193.48.0/2341.193.48.1 to 41.193.49.25441.193.49.255510
15441.193.50.0/2341.193.50.1 to 41.193.51.25441.193.51.255510
15541.193.52.0/2341.193.52.1 to 41.193.53.25441.193.53.255510
15641.193.54.0/2341.193.54.1 to 41.193.55.25441.193.55.255510
15741.193.56.0/2341.193.56.1 to 41.193.57.25441.193.57.255510
15841.193.58.0/2341.193.58.1 to 41.193.59.25441.193.59.255510
15941.193.60.0/2341.193.60.1 to 41.193.61.25441.193.61.255510
16041.193.62.0/2341.193.62.1 to 41.193.63.25441.193.63.255510
16141.193.64.0/2341.193.64.1 to 41.193.65.25441.193.65.255510
16241.193.66.0/2341.193.66.1 to 41.193.67.25441.193.67.255510
16341.193.68.0/2341.193.68.1 to 41.193.69.25441.193.69.255510
16441.193.70.0/2341.193.70.1 to 41.193.71.25441.193.71.255510
16541.193.72.0/2341.193.72.1 to 41.193.73.25441.193.73.255510
16641.193.74.0/2341.193.74.1 to 41.193.75.25441.193.75.255510
16741.193.76.0/2341.193.76.1 to 41.193.77.25441.193.77.255510
16841.193.78.0/2341.193.78.1 to 41.193.79.25441.193.79.255510
16941.193.80.0/2341.193.80.1 to 41.193.81.25441.193.81.255510
17041.193.82.0/2341.193.82.1 to 41.193.83.25441.193.83.255510
17141.193.84.0/2341.193.84.1 to 41.193.85.25441.193.85.255510
17241.193.86.0/2341.193.86.1 to 41.193.87.25441.193.87.255510
17341.193.88.0/2341.193.88.1 to 41.193.89.25441.193.89.255510
17441.193.90.0/2341.193.90.1 to 41.193.91.25441.193.91.255510
17541.193.92.0/2341.193.92.1 to 41.193.93.25441.193.93.255510
17641.193.94.0/2341.193.94.1 to 41.193.95.25441.193.95.255510
17741.193.96.0/2341.193.96.1 to 41.193.97.25441.193.97.255510
17841.193.98.0/2341.193.98.1 to 41.193.99.25441.193.99.255510
17941.193.100.0/2341.193.100.1 to 41.193.101.25441.193.101.255510
18041.193.102.0/2341.193.102.1 to 41.193.103.25441.193.103.255510
18141.193.104.0/2341.193.104.1 to 41.193.105.25441.193.105.255510
18241.193.106.0/2341.193.106.1 to 41.193.107.25441.193.107.255510
18341.193.108.0/2341.193.108.1 to 41.193.109.25441.193.109.255510
18441.193.110.0/2341.193.110.1 to 41.193.111.25441.193.111.255510
18541.193.112.0/2341.193.112.1 to 41.193.113.25441.193.113.255510
18641.193.114.0/2341.193.114.1 to 41.193.115.25441.193.115.255510
18741.193.116.0/2341.193.116.1 to 41.193.117.25441.193.117.255510
18841.193.118.0/2341.193.118.1 to 41.193.119.25441.193.119.255510
18941.193.120.0/2341.193.120.1 to 41.193.121.25441.193.121.255510
19041.193.122.0/2341.193.122.1 to 41.193.123.25441.193.123.255510
19141.193.124.0/2341.193.124.1 to 41.193.125.25441.193.125.255510
19241.193.126.0/2341.193.126.1 to 41.193.127.25441.193.127.255510
19341.193.128.0/2341.193.128.1 to 41.193.129.25441.193.129.255510
19441.193.130.0/2341.193.130.1 to 41.193.131.25441.193.131.255510
19541.193.132.0/2341.193.132.1 to 41.193.133.25441.193.133.255510
19641.193.134.0/2341.193.134.1 to 41.193.135.25441.193.135.255510
19741.193.136.0/2341.193.136.1 to 41.193.137.25441.193.137.255510
19841.193.138.0/2341.193.138.1 to 41.193.139.25441.193.139.255510
19941.193.140.0/2341.193.140.1 to 41.193.141.25441.193.141.255510
20041.193.142.0/2341.193.142.1 to 41.193.143.25441.193.143.255510
20141.193.144.0/2341.193.144.1 to 41.193.145.25441.193.145.255510
20241.193.146.0/2341.193.146.1 to 41.193.147.25441.193.147.255510
20341.193.148.0/2341.193.148.1 to 41.193.149.25441.193.149.255510
20441.193.150.0/2341.193.150.1 to 41.193.151.25441.193.151.255510
20541.193.152.0/2341.193.152.1 to 41.193.153.25441.193.153.255510
20641.193.154.0/2341.193.154.1 to 41.193.155.25441.193.155.255510
20741.193.156.0/2341.193.156.1 to 41.193.157.25441.193.157.255510
20841.193.158.0/2341.193.158.1 to 41.193.159.25441.193.159.255510
20941.193.160.0/2341.193.160.1 to 41.193.161.25441.193.161.255510
21041.193.162.0/2341.193.162.1 to 41.193.163.25441.193.163.255510
21141.193.164.0/2341.193.164.1 to 41.193.165.25441.193.165.255510
21241.193.166.0/2341.193.166.1 to 41.193.167.25441.193.167.255510
21341.193.168.0/2341.193.168.1 to 41.193.169.25441.193.169.255510
21441.193.170.0/2341.193.170.1 to 41.193.171.25441.193.171.255510
21541.193.172.0/2341.193.172.1 to 41.193.173.25441.193.173.255510
21641.193.174.0/2341.193.174.1 to 41.193.175.25441.193.175.255510
21741.193.176.0/2341.193.176.1 to 41.193.177.25441.193.177.255510
21841.193.178.0/2341.193.178.1 to 41.193.179.25441.193.179.255510
21941.193.180.0/2341.193.180.1 to 41.193.181.25441.193.181.255510
22041.193.182.0/2341.193.182.1 to 41.193.183.25441.193.183.255510
22141.193.184.0/2341.193.184.1 to 41.193.185.25441.193.185.255510
22241.193.186.0/2341.193.186.1 to 41.193.187.25441.193.187.255510
22341.193.188.0/2341.193.188.1 to 41.193.189.25441.193.189.255510
22441.193.190.0/2341.193.190.1 to 41.193.191.25441.193.191.255510
22541.193.192.0/2341.193.192.1 to 41.193.193.25441.193.193.255510
22641.193.194.0/2341.193.194.1 to 41.193.195.25441.193.195.255510
22741.193.196.0/2341.193.196.1 to 41.193.197.25441.193.197.255510
22841.193.198.0/2341.193.198.1 to 41.193.199.25441.193.199.255510
22941.193.200.0/2341.193.200.1 to 41.193.201.25441.193.201.255510
23041.193.202.0/2341.193.202.1 to 41.193.203.25441.193.203.255510
23141.193.204.0/2341.193.204.1 to 41.193.205.25441.193.205.255510
23241.193.206.0/2341.193.206.1 to 41.193.207.25441.193.207.255510
23341.193.208.0/2341.193.208.1 to 41.193.209.25441.193.209.255510
23441.193.210.0/2341.193.210.1 to 41.193.211.25441.193.211.255510
23541.193.212.0/2341.193.212.1 to 41.193.213.25441.193.213.255510
23641.193.214.0/2341.193.214.1 to 41.193.215.25441.193.215.255510
23741.193.216.0/2341.193.216.1 to 41.193.217.25441.193.217.255510
23841.193.218.0/2341.193.218.1 to 41.193.219.25441.193.219.255510
23941.193.220.0/2341.193.220.1 to 41.193.221.25441.193.221.255510
24041.193.222.0/2341.193.222.1 to 41.193.223.25441.193.223.255510
24141.193.224.0/2341.193.224.1 to 41.193.225.25441.193.225.255510
24241.193.226.0/2341.193.226.1 to 41.193.227.25441.193.227.255510
24341.193.228.0/2341.193.228.1 to 41.193.229.25441.193.229.255510
24441.193.230.0/2341.193.230.1 to 41.193.231.25441.193.231.255510
24541.193.232.0/2341.193.232.1 to 41.193.233.25441.193.233.255510
24641.193.234.0/2341.193.234.1 to 41.193.235.25441.193.235.255510
24741.193.236.0/2341.193.236.1 to 41.193.237.25441.193.237.255510
24841.193.238.0/2341.193.238.1 to 41.193.239.25441.193.239.255510
24941.193.240.0/2341.193.240.1 to 41.193.241.25441.193.241.255510
25041.193.242.0/2341.193.242.1 to 41.193.243.25441.193.243.255510
25141.193.244.0/2341.193.244.1 to 41.193.245.25441.193.245.255510
25241.193.246.0/2341.193.246.1 to 41.193.247.25441.193.247.255510
25341.193.248.0/2341.193.248.1 to 41.193.249.25441.193.249.255510
25441.193.250.0/2341.193.250.1 to 41.193.251.25441.193.251.255510
25541.193.252.0/2341.193.252.1 to 41.193.253.25441.193.253.255510
25641.193.254.0/2341.193.254.1 to 41.193.255.25441.193.255.255510

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.