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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.

Network4.136.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
4.136.0.0
Broadcast address
4.143.255.255
First usable
4.136.0.1
Last usable
4.143.255.254
Usable hosts
524,286 (524,288 less the network and broadcast addresses)
Subnet mask
255.248.0.0
Wildcard mask
0.7.255.255 (Cisco ACLs, OSPF)
Prefix length
/13
Type
Public public
Old class
A (default /8)
As numbers
Hex 04880000 · Integer 76021760 to 76546047
Reverse DNS zones
136.4.in-addr.arpa
137.4.in-addr.arpa
138.4.in-addr.arpa
139.4.in-addr.arpa
140.4.in-addr.arpa
141.4.in-addr.arpa
142.4.in-addr.arpa
143.4.in-addr.arpa
/13 is not on a 8-bit boundary, so it takes 8 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00000100.10001000.00000000.000000004.136.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network00000100.10001000.00000000.000000004.136.0.0
Broadcast00000100.10001111.11111111.111111114.143.255.255
Split into smaller subnets/24
/14 (2)/15 (4)/16 (8)/17 (16)/18 (32)/19 (64)/20 (128)/21 (256)/22 (512)/23 (1,024)/24 (2,048)/25 (4,096)

4.136.0.0/13 makes 2,048 subnets of /24; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
14.136.0.0/244.136.0.1 to 4.136.0.2544.136.0.255254
24.136.1.0/244.136.1.1 to 4.136.1.2544.136.1.255254
34.136.2.0/244.136.2.1 to 4.136.2.2544.136.2.255254
44.136.3.0/244.136.3.1 to 4.136.3.2544.136.3.255254
54.136.4.0/244.136.4.1 to 4.136.4.2544.136.4.255254
64.136.5.0/244.136.5.1 to 4.136.5.2544.136.5.255254
74.136.6.0/244.136.6.1 to 4.136.6.2544.136.6.255254
84.136.7.0/244.136.7.1 to 4.136.7.2544.136.7.255254
94.136.8.0/244.136.8.1 to 4.136.8.2544.136.8.255254
104.136.9.0/244.136.9.1 to 4.136.9.2544.136.9.255254
114.136.10.0/244.136.10.1 to 4.136.10.2544.136.10.255254
124.136.11.0/244.136.11.1 to 4.136.11.2544.136.11.255254
134.136.12.0/244.136.12.1 to 4.136.12.2544.136.12.255254
144.136.13.0/244.136.13.1 to 4.136.13.2544.136.13.255254
154.136.14.0/244.136.14.1 to 4.136.14.2544.136.14.255254
164.136.15.0/244.136.15.1 to 4.136.15.2544.136.15.255254
174.136.16.0/244.136.16.1 to 4.136.16.2544.136.16.255254
184.136.17.0/244.136.17.1 to 4.136.17.2544.136.17.255254
194.136.18.0/244.136.18.1 to 4.136.18.2544.136.18.255254
204.136.19.0/244.136.19.1 to 4.136.19.2544.136.19.255254
214.136.20.0/244.136.20.1 to 4.136.20.2544.136.20.255254
224.136.21.0/244.136.21.1 to 4.136.21.2544.136.21.255254
234.136.22.0/244.136.22.1 to 4.136.22.2544.136.22.255254
244.136.23.0/244.136.23.1 to 4.136.23.2544.136.23.255254
254.136.24.0/244.136.24.1 to 4.136.24.2544.136.24.255254
264.136.25.0/244.136.25.1 to 4.136.25.2544.136.25.255254
274.136.26.0/244.136.26.1 to 4.136.26.2544.136.26.255254
284.136.27.0/244.136.27.1 to 4.136.27.2544.136.27.255254
294.136.28.0/244.136.28.1 to 4.136.28.2544.136.28.255254
304.136.29.0/244.136.29.1 to 4.136.29.2544.136.29.255254
314.136.30.0/244.136.30.1 to 4.136.30.2544.136.30.255254
324.136.31.0/244.136.31.1 to 4.136.31.2544.136.31.255254
334.136.32.0/244.136.32.1 to 4.136.32.2544.136.32.255254
344.136.33.0/244.136.33.1 to 4.136.33.2544.136.33.255254
354.136.34.0/244.136.34.1 to 4.136.34.2544.136.34.255254
364.136.35.0/244.136.35.1 to 4.136.35.2544.136.35.255254
374.136.36.0/244.136.36.1 to 4.136.36.2544.136.36.255254
384.136.37.0/244.136.37.1 to 4.136.37.2544.136.37.255254
394.136.38.0/244.136.38.1 to 4.136.38.2544.136.38.255254
404.136.39.0/244.136.39.1 to 4.136.39.2544.136.39.255254
414.136.40.0/244.136.40.1 to 4.136.40.2544.136.40.255254
424.136.41.0/244.136.41.1 to 4.136.41.2544.136.41.255254
434.136.42.0/244.136.42.1 to 4.136.42.2544.136.42.255254
444.136.43.0/244.136.43.1 to 4.136.43.2544.136.43.255254
454.136.44.0/244.136.44.1 to 4.136.44.2544.136.44.255254
464.136.45.0/244.136.45.1 to 4.136.45.2544.136.45.255254
474.136.46.0/244.136.46.1 to 4.136.46.2544.136.46.255254
484.136.47.0/244.136.47.1 to 4.136.47.2544.136.47.255254
494.136.48.0/244.136.48.1 to 4.136.48.2544.136.48.255254
504.136.49.0/244.136.49.1 to 4.136.49.2544.136.49.255254
514.136.50.0/244.136.50.1 to 4.136.50.2544.136.50.255254
524.136.51.0/244.136.51.1 to 4.136.51.2544.136.51.255254
534.136.52.0/244.136.52.1 to 4.136.52.2544.136.52.255254
544.136.53.0/244.136.53.1 to 4.136.53.2544.136.53.255254
554.136.54.0/244.136.54.1 to 4.136.54.2544.136.54.255254
564.136.55.0/244.136.55.1 to 4.136.55.2544.136.55.255254
574.136.56.0/244.136.56.1 to 4.136.56.2544.136.56.255254
584.136.57.0/244.136.57.1 to 4.136.57.2544.136.57.255254
594.136.58.0/244.136.58.1 to 4.136.58.2544.136.58.255254
604.136.59.0/244.136.59.1 to 4.136.59.2544.136.59.255254
614.136.60.0/244.136.60.1 to 4.136.60.2544.136.60.255254
624.136.61.0/244.136.61.1 to 4.136.61.2544.136.61.255254
634.136.62.0/244.136.62.1 to 4.136.62.2544.136.62.255254
644.136.63.0/244.136.63.1 to 4.136.63.2544.136.63.255254
654.136.64.0/244.136.64.1 to 4.136.64.2544.136.64.255254
664.136.65.0/244.136.65.1 to 4.136.65.2544.136.65.255254
674.136.66.0/244.136.66.1 to 4.136.66.2544.136.66.255254
684.136.67.0/244.136.67.1 to 4.136.67.2544.136.67.255254
694.136.68.0/244.136.68.1 to 4.136.68.2544.136.68.255254
704.136.69.0/244.136.69.1 to 4.136.69.2544.136.69.255254
714.136.70.0/244.136.70.1 to 4.136.70.2544.136.70.255254
724.136.71.0/244.136.71.1 to 4.136.71.2544.136.71.255254
734.136.72.0/244.136.72.1 to 4.136.72.2544.136.72.255254
744.136.73.0/244.136.73.1 to 4.136.73.2544.136.73.255254
754.136.74.0/244.136.74.1 to 4.136.74.2544.136.74.255254
764.136.75.0/244.136.75.1 to 4.136.75.2544.136.75.255254
774.136.76.0/244.136.76.1 to 4.136.76.2544.136.76.255254
784.136.77.0/244.136.77.1 to 4.136.77.2544.136.77.255254
794.136.78.0/244.136.78.1 to 4.136.78.2544.136.78.255254
804.136.79.0/244.136.79.1 to 4.136.79.2544.136.79.255254
814.136.80.0/244.136.80.1 to 4.136.80.2544.136.80.255254
824.136.81.0/244.136.81.1 to 4.136.81.2544.136.81.255254
834.136.82.0/244.136.82.1 to 4.136.82.2544.136.82.255254
844.136.83.0/244.136.83.1 to 4.136.83.2544.136.83.255254
854.136.84.0/244.136.84.1 to 4.136.84.2544.136.84.255254
864.136.85.0/244.136.85.1 to 4.136.85.2544.136.85.255254
874.136.86.0/244.136.86.1 to 4.136.86.2544.136.86.255254
884.136.87.0/244.136.87.1 to 4.136.87.2544.136.87.255254
894.136.88.0/244.136.88.1 to 4.136.88.2544.136.88.255254
904.136.89.0/244.136.89.1 to 4.136.89.2544.136.89.255254
914.136.90.0/244.136.90.1 to 4.136.90.2544.136.90.255254
924.136.91.0/244.136.91.1 to 4.136.91.2544.136.91.255254
934.136.92.0/244.136.92.1 to 4.136.92.2544.136.92.255254
944.136.93.0/244.136.93.1 to 4.136.93.2544.136.93.255254
954.136.94.0/244.136.94.1 to 4.136.94.2544.136.94.255254
964.136.95.0/244.136.95.1 to 4.136.95.2544.136.95.255254
974.136.96.0/244.136.96.1 to 4.136.96.2544.136.96.255254
984.136.97.0/244.136.97.1 to 4.136.97.2544.136.97.255254
994.136.98.0/244.136.98.1 to 4.136.98.2544.136.98.255254
1004.136.99.0/244.136.99.1 to 4.136.99.2544.136.99.255254
1014.136.100.0/244.136.100.1 to 4.136.100.2544.136.100.255254
1024.136.101.0/244.136.101.1 to 4.136.101.2544.136.101.255254
1034.136.102.0/244.136.102.1 to 4.136.102.2544.136.102.255254
1044.136.103.0/244.136.103.1 to 4.136.103.2544.136.103.255254
1054.136.104.0/244.136.104.1 to 4.136.104.2544.136.104.255254
1064.136.105.0/244.136.105.1 to 4.136.105.2544.136.105.255254
1074.136.106.0/244.136.106.1 to 4.136.106.2544.136.106.255254
1084.136.107.0/244.136.107.1 to 4.136.107.2544.136.107.255254
1094.136.108.0/244.136.108.1 to 4.136.108.2544.136.108.255254
1104.136.109.0/244.136.109.1 to 4.136.109.2544.136.109.255254
1114.136.110.0/244.136.110.1 to 4.136.110.2544.136.110.255254
1124.136.111.0/244.136.111.1 to 4.136.111.2544.136.111.255254
1134.136.112.0/244.136.112.1 to 4.136.112.2544.136.112.255254
1144.136.113.0/244.136.113.1 to 4.136.113.2544.136.113.255254
1154.136.114.0/244.136.114.1 to 4.136.114.2544.136.114.255254
1164.136.115.0/244.136.115.1 to 4.136.115.2544.136.115.255254
1174.136.116.0/244.136.116.1 to 4.136.116.2544.136.116.255254
1184.136.117.0/244.136.117.1 to 4.136.117.2544.136.117.255254
1194.136.118.0/244.136.118.1 to 4.136.118.2544.136.118.255254
1204.136.119.0/244.136.119.1 to 4.136.119.2544.136.119.255254
1214.136.120.0/244.136.120.1 to 4.136.120.2544.136.120.255254
1224.136.121.0/244.136.121.1 to 4.136.121.2544.136.121.255254
1234.136.122.0/244.136.122.1 to 4.136.122.2544.136.122.255254
1244.136.123.0/244.136.123.1 to 4.136.123.2544.136.123.255254
1254.136.124.0/244.136.124.1 to 4.136.124.2544.136.124.255254
1264.136.125.0/244.136.125.1 to 4.136.125.2544.136.125.255254
1274.136.126.0/244.136.126.1 to 4.136.126.2544.136.126.255254
1284.136.127.0/244.136.127.1 to 4.136.127.2544.136.127.255254
1294.136.128.0/244.136.128.1 to 4.136.128.2544.136.128.255254
1304.136.129.0/244.136.129.1 to 4.136.129.2544.136.129.255254
1314.136.130.0/244.136.130.1 to 4.136.130.2544.136.130.255254
1324.136.131.0/244.136.131.1 to 4.136.131.2544.136.131.255254
1334.136.132.0/244.136.132.1 to 4.136.132.2544.136.132.255254
1344.136.133.0/244.136.133.1 to 4.136.133.2544.136.133.255254
1354.136.134.0/244.136.134.1 to 4.136.134.2544.136.134.255254
1364.136.135.0/244.136.135.1 to 4.136.135.2544.136.135.255254
1374.136.136.0/244.136.136.1 to 4.136.136.2544.136.136.255254
1384.136.137.0/244.136.137.1 to 4.136.137.2544.136.137.255254
1394.136.138.0/244.136.138.1 to 4.136.138.2544.136.138.255254
1404.136.139.0/244.136.139.1 to 4.136.139.2544.136.139.255254
1414.136.140.0/244.136.140.1 to 4.136.140.2544.136.140.255254
1424.136.141.0/244.136.141.1 to 4.136.141.2544.136.141.255254
1434.136.142.0/244.136.142.1 to 4.136.142.2544.136.142.255254
1444.136.143.0/244.136.143.1 to 4.136.143.2544.136.143.255254
1454.136.144.0/244.136.144.1 to 4.136.144.2544.136.144.255254
1464.136.145.0/244.136.145.1 to 4.136.145.2544.136.145.255254
1474.136.146.0/244.136.146.1 to 4.136.146.2544.136.146.255254
1484.136.147.0/244.136.147.1 to 4.136.147.2544.136.147.255254
1494.136.148.0/244.136.148.1 to 4.136.148.2544.136.148.255254
1504.136.149.0/244.136.149.1 to 4.136.149.2544.136.149.255254
1514.136.150.0/244.136.150.1 to 4.136.150.2544.136.150.255254
1524.136.151.0/244.136.151.1 to 4.136.151.2544.136.151.255254
1534.136.152.0/244.136.152.1 to 4.136.152.2544.136.152.255254
1544.136.153.0/244.136.153.1 to 4.136.153.2544.136.153.255254
1554.136.154.0/244.136.154.1 to 4.136.154.2544.136.154.255254
1564.136.155.0/244.136.155.1 to 4.136.155.2544.136.155.255254
1574.136.156.0/244.136.156.1 to 4.136.156.2544.136.156.255254
1584.136.157.0/244.136.157.1 to 4.136.157.2544.136.157.255254
1594.136.158.0/244.136.158.1 to 4.136.158.2544.136.158.255254
1604.136.159.0/244.136.159.1 to 4.136.159.2544.136.159.255254
1614.136.160.0/244.136.160.1 to 4.136.160.2544.136.160.255254
1624.136.161.0/244.136.161.1 to 4.136.161.2544.136.161.255254
1634.136.162.0/244.136.162.1 to 4.136.162.2544.136.162.255254
1644.136.163.0/244.136.163.1 to 4.136.163.2544.136.163.255254
1654.136.164.0/244.136.164.1 to 4.136.164.2544.136.164.255254
1664.136.165.0/244.136.165.1 to 4.136.165.2544.136.165.255254
1674.136.166.0/244.136.166.1 to 4.136.166.2544.136.166.255254
1684.136.167.0/244.136.167.1 to 4.136.167.2544.136.167.255254
1694.136.168.0/244.136.168.1 to 4.136.168.2544.136.168.255254
1704.136.169.0/244.136.169.1 to 4.136.169.2544.136.169.255254
1714.136.170.0/244.136.170.1 to 4.136.170.2544.136.170.255254
1724.136.171.0/244.136.171.1 to 4.136.171.2544.136.171.255254
1734.136.172.0/244.136.172.1 to 4.136.172.2544.136.172.255254
1744.136.173.0/244.136.173.1 to 4.136.173.2544.136.173.255254
1754.136.174.0/244.136.174.1 to 4.136.174.2544.136.174.255254
1764.136.175.0/244.136.175.1 to 4.136.175.2544.136.175.255254
1774.136.176.0/244.136.176.1 to 4.136.176.2544.136.176.255254
1784.136.177.0/244.136.177.1 to 4.136.177.2544.136.177.255254
1794.136.178.0/244.136.178.1 to 4.136.178.2544.136.178.255254
1804.136.179.0/244.136.179.1 to 4.136.179.2544.136.179.255254
1814.136.180.0/244.136.180.1 to 4.136.180.2544.136.180.255254
1824.136.181.0/244.136.181.1 to 4.136.181.2544.136.181.255254
1834.136.182.0/244.136.182.1 to 4.136.182.2544.136.182.255254
1844.136.183.0/244.136.183.1 to 4.136.183.2544.136.183.255254
1854.136.184.0/244.136.184.1 to 4.136.184.2544.136.184.255254
1864.136.185.0/244.136.185.1 to 4.136.185.2544.136.185.255254
1874.136.186.0/244.136.186.1 to 4.136.186.2544.136.186.255254
1884.136.187.0/244.136.187.1 to 4.136.187.2544.136.187.255254
1894.136.188.0/244.136.188.1 to 4.136.188.2544.136.188.255254
1904.136.189.0/244.136.189.1 to 4.136.189.2544.136.189.255254
1914.136.190.0/244.136.190.1 to 4.136.190.2544.136.190.255254
1924.136.191.0/244.136.191.1 to 4.136.191.2544.136.191.255254
1934.136.192.0/244.136.192.1 to 4.136.192.2544.136.192.255254
1944.136.193.0/244.136.193.1 to 4.136.193.2544.136.193.255254
1954.136.194.0/244.136.194.1 to 4.136.194.2544.136.194.255254
1964.136.195.0/244.136.195.1 to 4.136.195.2544.136.195.255254
1974.136.196.0/244.136.196.1 to 4.136.196.2544.136.196.255254
1984.136.197.0/244.136.197.1 to 4.136.197.2544.136.197.255254
1994.136.198.0/244.136.198.1 to 4.136.198.2544.136.198.255254
2004.136.199.0/244.136.199.1 to 4.136.199.2544.136.199.255254
2014.136.200.0/244.136.200.1 to 4.136.200.2544.136.200.255254
2024.136.201.0/244.136.201.1 to 4.136.201.2544.136.201.255254
2034.136.202.0/244.136.202.1 to 4.136.202.2544.136.202.255254
2044.136.203.0/244.136.203.1 to 4.136.203.2544.136.203.255254
2054.136.204.0/244.136.204.1 to 4.136.204.2544.136.204.255254
2064.136.205.0/244.136.205.1 to 4.136.205.2544.136.205.255254
2074.136.206.0/244.136.206.1 to 4.136.206.2544.136.206.255254
2084.136.207.0/244.136.207.1 to 4.136.207.2544.136.207.255254
2094.136.208.0/244.136.208.1 to 4.136.208.2544.136.208.255254
2104.136.209.0/244.136.209.1 to 4.136.209.2544.136.209.255254
2114.136.210.0/244.136.210.1 to 4.136.210.2544.136.210.255254
2124.136.211.0/244.136.211.1 to 4.136.211.2544.136.211.255254
2134.136.212.0/244.136.212.1 to 4.136.212.2544.136.212.255254
2144.136.213.0/244.136.213.1 to 4.136.213.2544.136.213.255254
2154.136.214.0/244.136.214.1 to 4.136.214.2544.136.214.255254
2164.136.215.0/244.136.215.1 to 4.136.215.2544.136.215.255254
2174.136.216.0/244.136.216.1 to 4.136.216.2544.136.216.255254
2184.136.217.0/244.136.217.1 to 4.136.217.2544.136.217.255254
2194.136.218.0/244.136.218.1 to 4.136.218.2544.136.218.255254
2204.136.219.0/244.136.219.1 to 4.136.219.2544.136.219.255254
2214.136.220.0/244.136.220.1 to 4.136.220.2544.136.220.255254
2224.136.221.0/244.136.221.1 to 4.136.221.2544.136.221.255254
2234.136.222.0/244.136.222.1 to 4.136.222.2544.136.222.255254
2244.136.223.0/244.136.223.1 to 4.136.223.2544.136.223.255254
2254.136.224.0/244.136.224.1 to 4.136.224.2544.136.224.255254
2264.136.225.0/244.136.225.1 to 4.136.225.2544.136.225.255254
2274.136.226.0/244.136.226.1 to 4.136.226.2544.136.226.255254
2284.136.227.0/244.136.227.1 to 4.136.227.2544.136.227.255254
2294.136.228.0/244.136.228.1 to 4.136.228.2544.136.228.255254
2304.136.229.0/244.136.229.1 to 4.136.229.2544.136.229.255254
2314.136.230.0/244.136.230.1 to 4.136.230.2544.136.230.255254
2324.136.231.0/244.136.231.1 to 4.136.231.2544.136.231.255254
2334.136.232.0/244.136.232.1 to 4.136.232.2544.136.232.255254
2344.136.233.0/244.136.233.1 to 4.136.233.2544.136.233.255254
2354.136.234.0/244.136.234.1 to 4.136.234.2544.136.234.255254
2364.136.235.0/244.136.235.1 to 4.136.235.2544.136.235.255254
2374.136.236.0/244.136.236.1 to 4.136.236.2544.136.236.255254
2384.136.237.0/244.136.237.1 to 4.136.237.2544.136.237.255254
2394.136.238.0/244.136.238.1 to 4.136.238.2544.136.238.255254
2404.136.239.0/244.136.239.1 to 4.136.239.2544.136.239.255254
2414.136.240.0/244.136.240.1 to 4.136.240.2544.136.240.255254
2424.136.241.0/244.136.241.1 to 4.136.241.2544.136.241.255254
2434.136.242.0/244.136.242.1 to 4.136.242.2544.136.242.255254
2444.136.243.0/244.136.243.1 to 4.136.243.2544.136.243.255254
2454.136.244.0/244.136.244.1 to 4.136.244.2544.136.244.255254
2464.136.245.0/244.136.245.1 to 4.136.245.2544.136.245.255254
2474.136.246.0/244.136.246.1 to 4.136.246.2544.136.246.255254
2484.136.247.0/244.136.247.1 to 4.136.247.2544.136.247.255254
2494.136.248.0/244.136.248.1 to 4.136.248.2544.136.248.255254
2504.136.249.0/244.136.249.1 to 4.136.249.2544.136.249.255254
2514.136.250.0/244.136.250.1 to 4.136.250.2544.136.250.255254
2524.136.251.0/244.136.251.1 to 4.136.251.2544.136.251.255254
2534.136.252.0/244.136.252.1 to 4.136.252.2544.136.252.255254
2544.136.253.0/244.136.253.1 to 4.136.253.2544.136.253.255254
2554.136.254.0/244.136.254.1 to 4.136.254.2544.136.254.255254
2564.136.255.0/244.136.255.1 to 4.136.255.2544.136.255.255254

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.