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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.

Network3.64.0.0/11
Usable hosts2,097,150
Subnet mask255.224.0.0
Addresses2,097,152
Network address
3.64.0.0
Broadcast address
3.95.255.255
First usable
3.64.0.1
Last usable
3.95.255.254
Usable hosts
2,097,150 (2,097,152 less the network and broadcast addresses)
Subnet mask
255.224.0.0
Wildcard mask
0.31.255.255 (Cisco ACLs, OSPF)
Prefix length
/11
Type
Public public
Old class
A (default /8)
As numbers
Hex 03400000 · Integer 54525952 to 56623103
Reverse DNS zones
64.3.in-addr.arpa
65.3.in-addr.arpa
66.3.in-addr.arpa
67.3.in-addr.arpa
68.3.in-addr.arpa
69.3.in-addr.arpa
70.3.in-addr.arpa
71.3.in-addr.arpa
72.3.in-addr.arpa
73.3.in-addr.arpa
74.3.in-addr.arpa
75.3.in-addr.arpa
76.3.in-addr.arpa
77.3.in-addr.arpa
78.3.in-addr.arpa
79.3.in-addr.arpa
and 16 more
/11 is not on a 8-bit boundary, so it takes 32 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00000011.01000000.00000000.000000003.64.0.0
Subnet mask11111111.11100000.00000000.00000000255.224.0.0
Network00000011.01000000.00000000.000000003.64.0.0
Broadcast00000011.01011111.11111111.111111113.95.255.255
Split into smaller subnets/19
/12 (2)/13 (4)/14 (8)/15 (16)/16 (32)/17 (64)/18 (128)/19 (256)/20 (512)/21 (1,024)/22 (2,048)/23 (4,096)

3.64.0.0/11 makes 256 subnets of /19.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
13.64.0.0/193.64.0.1 to 3.64.31.2543.64.31.2558,190
23.64.32.0/193.64.32.1 to 3.64.63.2543.64.63.2558,190
33.64.64.0/193.64.64.1 to 3.64.95.2543.64.95.2558,190
43.64.96.0/193.64.96.1 to 3.64.127.2543.64.127.2558,190
53.64.128.0/193.64.128.1 to 3.64.159.2543.64.159.2558,190
63.64.160.0/193.64.160.1 to 3.64.191.2543.64.191.2558,190
73.64.192.0/193.64.192.1 to 3.64.223.2543.64.223.2558,190
83.64.224.0/193.64.224.1 to 3.64.255.2543.64.255.2558,190
93.65.0.0/193.65.0.1 to 3.65.31.2543.65.31.2558,190
103.65.32.0/193.65.32.1 to 3.65.63.2543.65.63.2558,190
113.65.64.0/193.65.64.1 to 3.65.95.2543.65.95.2558,190
123.65.96.0/193.65.96.1 to 3.65.127.2543.65.127.2558,190
133.65.128.0/193.65.128.1 to 3.65.159.2543.65.159.2558,190
143.65.160.0/193.65.160.1 to 3.65.191.2543.65.191.2558,190
153.65.192.0/193.65.192.1 to 3.65.223.2543.65.223.2558,190
163.65.224.0/193.65.224.1 to 3.65.255.2543.65.255.2558,190
173.66.0.0/193.66.0.1 to 3.66.31.2543.66.31.2558,190
183.66.32.0/193.66.32.1 to 3.66.63.2543.66.63.2558,190
193.66.64.0/193.66.64.1 to 3.66.95.2543.66.95.2558,190
203.66.96.0/193.66.96.1 to 3.66.127.2543.66.127.2558,190
213.66.128.0/193.66.128.1 to 3.66.159.2543.66.159.2558,190
223.66.160.0/193.66.160.1 to 3.66.191.2543.66.191.2558,190
233.66.192.0/193.66.192.1 to 3.66.223.2543.66.223.2558,190
243.66.224.0/193.66.224.1 to 3.66.255.2543.66.255.2558,190
253.67.0.0/193.67.0.1 to 3.67.31.2543.67.31.2558,190
263.67.32.0/193.67.32.1 to 3.67.63.2543.67.63.2558,190
273.67.64.0/193.67.64.1 to 3.67.95.2543.67.95.2558,190
283.67.96.0/193.67.96.1 to 3.67.127.2543.67.127.2558,190
293.67.128.0/193.67.128.1 to 3.67.159.2543.67.159.2558,190
303.67.160.0/193.67.160.1 to 3.67.191.2543.67.191.2558,190
313.67.192.0/193.67.192.1 to 3.67.223.2543.67.223.2558,190
323.67.224.0/193.67.224.1 to 3.67.255.2543.67.255.2558,190
333.68.0.0/193.68.0.1 to 3.68.31.2543.68.31.2558,190
343.68.32.0/193.68.32.1 to 3.68.63.2543.68.63.2558,190
353.68.64.0/193.68.64.1 to 3.68.95.2543.68.95.2558,190
363.68.96.0/193.68.96.1 to 3.68.127.2543.68.127.2558,190
373.68.128.0/193.68.128.1 to 3.68.159.2543.68.159.2558,190
383.68.160.0/193.68.160.1 to 3.68.191.2543.68.191.2558,190
393.68.192.0/193.68.192.1 to 3.68.223.2543.68.223.2558,190
403.68.224.0/193.68.224.1 to 3.68.255.2543.68.255.2558,190
413.69.0.0/193.69.0.1 to 3.69.31.2543.69.31.2558,190
423.69.32.0/193.69.32.1 to 3.69.63.2543.69.63.2558,190
433.69.64.0/193.69.64.1 to 3.69.95.2543.69.95.2558,190
443.69.96.0/193.69.96.1 to 3.69.127.2543.69.127.2558,190
453.69.128.0/193.69.128.1 to 3.69.159.2543.69.159.2558,190
463.69.160.0/193.69.160.1 to 3.69.191.2543.69.191.2558,190
473.69.192.0/193.69.192.1 to 3.69.223.2543.69.223.2558,190
483.69.224.0/193.69.224.1 to 3.69.255.2543.69.255.2558,190
493.70.0.0/193.70.0.1 to 3.70.31.2543.70.31.2558,190
503.70.32.0/193.70.32.1 to 3.70.63.2543.70.63.2558,190
513.70.64.0/193.70.64.1 to 3.70.95.2543.70.95.2558,190
523.70.96.0/193.70.96.1 to 3.70.127.2543.70.127.2558,190
533.70.128.0/193.70.128.1 to 3.70.159.2543.70.159.2558,190
543.70.160.0/193.70.160.1 to 3.70.191.2543.70.191.2558,190
553.70.192.0/193.70.192.1 to 3.70.223.2543.70.223.2558,190
563.70.224.0/193.70.224.1 to 3.70.255.2543.70.255.2558,190
573.71.0.0/193.71.0.1 to 3.71.31.2543.71.31.2558,190
583.71.32.0/193.71.32.1 to 3.71.63.2543.71.63.2558,190
593.71.64.0/193.71.64.1 to 3.71.95.2543.71.95.2558,190
603.71.96.0/193.71.96.1 to 3.71.127.2543.71.127.2558,190
613.71.128.0/193.71.128.1 to 3.71.159.2543.71.159.2558,190
623.71.160.0/193.71.160.1 to 3.71.191.2543.71.191.2558,190
633.71.192.0/193.71.192.1 to 3.71.223.2543.71.223.2558,190
643.71.224.0/193.71.224.1 to 3.71.255.2543.71.255.2558,190
653.72.0.0/193.72.0.1 to 3.72.31.2543.72.31.2558,190
663.72.32.0/193.72.32.1 to 3.72.63.2543.72.63.2558,190
673.72.64.0/193.72.64.1 to 3.72.95.2543.72.95.2558,190
683.72.96.0/193.72.96.1 to 3.72.127.2543.72.127.2558,190
693.72.128.0/193.72.128.1 to 3.72.159.2543.72.159.2558,190
703.72.160.0/193.72.160.1 to 3.72.191.2543.72.191.2558,190
713.72.192.0/193.72.192.1 to 3.72.223.2543.72.223.2558,190
723.72.224.0/193.72.224.1 to 3.72.255.2543.72.255.2558,190
733.73.0.0/193.73.0.1 to 3.73.31.2543.73.31.2558,190
743.73.32.0/193.73.32.1 to 3.73.63.2543.73.63.2558,190
753.73.64.0/193.73.64.1 to 3.73.95.2543.73.95.2558,190
763.73.96.0/193.73.96.1 to 3.73.127.2543.73.127.2558,190
773.73.128.0/193.73.128.1 to 3.73.159.2543.73.159.2558,190
783.73.160.0/193.73.160.1 to 3.73.191.2543.73.191.2558,190
793.73.192.0/193.73.192.1 to 3.73.223.2543.73.223.2558,190
803.73.224.0/193.73.224.1 to 3.73.255.2543.73.255.2558,190
813.74.0.0/193.74.0.1 to 3.74.31.2543.74.31.2558,190
823.74.32.0/193.74.32.1 to 3.74.63.2543.74.63.2558,190
833.74.64.0/193.74.64.1 to 3.74.95.2543.74.95.2558,190
843.74.96.0/193.74.96.1 to 3.74.127.2543.74.127.2558,190
853.74.128.0/193.74.128.1 to 3.74.159.2543.74.159.2558,190
863.74.160.0/193.74.160.1 to 3.74.191.2543.74.191.2558,190
873.74.192.0/193.74.192.1 to 3.74.223.2543.74.223.2558,190
883.74.224.0/193.74.224.1 to 3.74.255.2543.74.255.2558,190
893.75.0.0/193.75.0.1 to 3.75.31.2543.75.31.2558,190
903.75.32.0/193.75.32.1 to 3.75.63.2543.75.63.2558,190
913.75.64.0/193.75.64.1 to 3.75.95.2543.75.95.2558,190
923.75.96.0/193.75.96.1 to 3.75.127.2543.75.127.2558,190
933.75.128.0/193.75.128.1 to 3.75.159.2543.75.159.2558,190
943.75.160.0/193.75.160.1 to 3.75.191.2543.75.191.2558,190
953.75.192.0/193.75.192.1 to 3.75.223.2543.75.223.2558,190
963.75.224.0/193.75.224.1 to 3.75.255.2543.75.255.2558,190
973.76.0.0/193.76.0.1 to 3.76.31.2543.76.31.2558,190
983.76.32.0/193.76.32.1 to 3.76.63.2543.76.63.2558,190
993.76.64.0/193.76.64.1 to 3.76.95.2543.76.95.2558,190
1003.76.96.0/193.76.96.1 to 3.76.127.2543.76.127.2558,190
1013.76.128.0/193.76.128.1 to 3.76.159.2543.76.159.2558,190
1023.76.160.0/193.76.160.1 to 3.76.191.2543.76.191.2558,190
1033.76.192.0/193.76.192.1 to 3.76.223.2543.76.223.2558,190
1043.76.224.0/193.76.224.1 to 3.76.255.2543.76.255.2558,190
1053.77.0.0/193.77.0.1 to 3.77.31.2543.77.31.2558,190
1063.77.32.0/193.77.32.1 to 3.77.63.2543.77.63.2558,190
1073.77.64.0/193.77.64.1 to 3.77.95.2543.77.95.2558,190
1083.77.96.0/193.77.96.1 to 3.77.127.2543.77.127.2558,190
1093.77.128.0/193.77.128.1 to 3.77.159.2543.77.159.2558,190
1103.77.160.0/193.77.160.1 to 3.77.191.2543.77.191.2558,190
1113.77.192.0/193.77.192.1 to 3.77.223.2543.77.223.2558,190
1123.77.224.0/193.77.224.1 to 3.77.255.2543.77.255.2558,190
1133.78.0.0/193.78.0.1 to 3.78.31.2543.78.31.2558,190
1143.78.32.0/193.78.32.1 to 3.78.63.2543.78.63.2558,190
1153.78.64.0/193.78.64.1 to 3.78.95.2543.78.95.2558,190
1163.78.96.0/193.78.96.1 to 3.78.127.2543.78.127.2558,190
1173.78.128.0/193.78.128.1 to 3.78.159.2543.78.159.2558,190
1183.78.160.0/193.78.160.1 to 3.78.191.2543.78.191.2558,190
1193.78.192.0/193.78.192.1 to 3.78.223.2543.78.223.2558,190
1203.78.224.0/193.78.224.1 to 3.78.255.2543.78.255.2558,190
1213.79.0.0/193.79.0.1 to 3.79.31.2543.79.31.2558,190
1223.79.32.0/193.79.32.1 to 3.79.63.2543.79.63.2558,190
1233.79.64.0/193.79.64.1 to 3.79.95.2543.79.95.2558,190
1243.79.96.0/193.79.96.1 to 3.79.127.2543.79.127.2558,190
1253.79.128.0/193.79.128.1 to 3.79.159.2543.79.159.2558,190
1263.79.160.0/193.79.160.1 to 3.79.191.2543.79.191.2558,190
1273.79.192.0/193.79.192.1 to 3.79.223.2543.79.223.2558,190
1283.79.224.0/193.79.224.1 to 3.79.255.2543.79.255.2558,190
1293.80.0.0/193.80.0.1 to 3.80.31.2543.80.31.2558,190
1303.80.32.0/193.80.32.1 to 3.80.63.2543.80.63.2558,190
1313.80.64.0/193.80.64.1 to 3.80.95.2543.80.95.2558,190
1323.80.96.0/193.80.96.1 to 3.80.127.2543.80.127.2558,190
1333.80.128.0/193.80.128.1 to 3.80.159.2543.80.159.2558,190
1343.80.160.0/193.80.160.1 to 3.80.191.2543.80.191.2558,190
1353.80.192.0/193.80.192.1 to 3.80.223.2543.80.223.2558,190
1363.80.224.0/193.80.224.1 to 3.80.255.2543.80.255.2558,190
1373.81.0.0/193.81.0.1 to 3.81.31.2543.81.31.2558,190
1383.81.32.0/193.81.32.1 to 3.81.63.2543.81.63.2558,190
1393.81.64.0/193.81.64.1 to 3.81.95.2543.81.95.2558,190
1403.81.96.0/193.81.96.1 to 3.81.127.2543.81.127.2558,190
1413.81.128.0/193.81.128.1 to 3.81.159.2543.81.159.2558,190
1423.81.160.0/193.81.160.1 to 3.81.191.2543.81.191.2558,190
1433.81.192.0/193.81.192.1 to 3.81.223.2543.81.223.2558,190
1443.81.224.0/193.81.224.1 to 3.81.255.2543.81.255.2558,190
1453.82.0.0/193.82.0.1 to 3.82.31.2543.82.31.2558,190
1463.82.32.0/193.82.32.1 to 3.82.63.2543.82.63.2558,190
1473.82.64.0/193.82.64.1 to 3.82.95.2543.82.95.2558,190
1483.82.96.0/193.82.96.1 to 3.82.127.2543.82.127.2558,190
1493.82.128.0/193.82.128.1 to 3.82.159.2543.82.159.2558,190
1503.82.160.0/193.82.160.1 to 3.82.191.2543.82.191.2558,190
1513.82.192.0/193.82.192.1 to 3.82.223.2543.82.223.2558,190
1523.82.224.0/193.82.224.1 to 3.82.255.2543.82.255.2558,190
1533.83.0.0/193.83.0.1 to 3.83.31.2543.83.31.2558,190
1543.83.32.0/193.83.32.1 to 3.83.63.2543.83.63.2558,190
1553.83.64.0/193.83.64.1 to 3.83.95.2543.83.95.2558,190
1563.83.96.0/193.83.96.1 to 3.83.127.2543.83.127.2558,190
1573.83.128.0/193.83.128.1 to 3.83.159.2543.83.159.2558,190
1583.83.160.0/193.83.160.1 to 3.83.191.2543.83.191.2558,190
1593.83.192.0/193.83.192.1 to 3.83.223.2543.83.223.2558,190
1603.83.224.0/193.83.224.1 to 3.83.255.2543.83.255.2558,190
1613.84.0.0/193.84.0.1 to 3.84.31.2543.84.31.2558,190
1623.84.32.0/193.84.32.1 to 3.84.63.2543.84.63.2558,190
1633.84.64.0/193.84.64.1 to 3.84.95.2543.84.95.2558,190
1643.84.96.0/193.84.96.1 to 3.84.127.2543.84.127.2558,190
1653.84.128.0/193.84.128.1 to 3.84.159.2543.84.159.2558,190
1663.84.160.0/193.84.160.1 to 3.84.191.2543.84.191.2558,190
1673.84.192.0/193.84.192.1 to 3.84.223.2543.84.223.2558,190
1683.84.224.0/193.84.224.1 to 3.84.255.2543.84.255.2558,190
1693.85.0.0/193.85.0.1 to 3.85.31.2543.85.31.2558,190
1703.85.32.0/193.85.32.1 to 3.85.63.2543.85.63.2558,190
1713.85.64.0/193.85.64.1 to 3.85.95.2543.85.95.2558,190
1723.85.96.0/193.85.96.1 to 3.85.127.2543.85.127.2558,190
1733.85.128.0/193.85.128.1 to 3.85.159.2543.85.159.2558,190
1743.85.160.0/193.85.160.1 to 3.85.191.2543.85.191.2558,190
1753.85.192.0/193.85.192.1 to 3.85.223.2543.85.223.2558,190
1763.85.224.0/193.85.224.1 to 3.85.255.2543.85.255.2558,190
1773.86.0.0/193.86.0.1 to 3.86.31.2543.86.31.2558,190
1783.86.32.0/193.86.32.1 to 3.86.63.2543.86.63.2558,190
1793.86.64.0/193.86.64.1 to 3.86.95.2543.86.95.2558,190
1803.86.96.0/193.86.96.1 to 3.86.127.2543.86.127.2558,190
1813.86.128.0/193.86.128.1 to 3.86.159.2543.86.159.2558,190
1823.86.160.0/193.86.160.1 to 3.86.191.2543.86.191.2558,190
1833.86.192.0/193.86.192.1 to 3.86.223.2543.86.223.2558,190
1843.86.224.0/193.86.224.1 to 3.86.255.2543.86.255.2558,190
1853.87.0.0/193.87.0.1 to 3.87.31.2543.87.31.2558,190
1863.87.32.0/193.87.32.1 to 3.87.63.2543.87.63.2558,190
1873.87.64.0/193.87.64.1 to 3.87.95.2543.87.95.2558,190
1883.87.96.0/193.87.96.1 to 3.87.127.2543.87.127.2558,190
1893.87.128.0/193.87.128.1 to 3.87.159.2543.87.159.2558,190
1903.87.160.0/193.87.160.1 to 3.87.191.2543.87.191.2558,190
1913.87.192.0/193.87.192.1 to 3.87.223.2543.87.223.2558,190
1923.87.224.0/193.87.224.1 to 3.87.255.2543.87.255.2558,190
1933.88.0.0/193.88.0.1 to 3.88.31.2543.88.31.2558,190
1943.88.32.0/193.88.32.1 to 3.88.63.2543.88.63.2558,190
1953.88.64.0/193.88.64.1 to 3.88.95.2543.88.95.2558,190
1963.88.96.0/193.88.96.1 to 3.88.127.2543.88.127.2558,190
1973.88.128.0/193.88.128.1 to 3.88.159.2543.88.159.2558,190
1983.88.160.0/193.88.160.1 to 3.88.191.2543.88.191.2558,190
1993.88.192.0/193.88.192.1 to 3.88.223.2543.88.223.2558,190
2003.88.224.0/193.88.224.1 to 3.88.255.2543.88.255.2558,190
2013.89.0.0/193.89.0.1 to 3.89.31.2543.89.31.2558,190
2023.89.32.0/193.89.32.1 to 3.89.63.2543.89.63.2558,190
2033.89.64.0/193.89.64.1 to 3.89.95.2543.89.95.2558,190
2043.89.96.0/193.89.96.1 to 3.89.127.2543.89.127.2558,190
2053.89.128.0/193.89.128.1 to 3.89.159.2543.89.159.2558,190
2063.89.160.0/193.89.160.1 to 3.89.191.2543.89.191.2558,190
2073.89.192.0/193.89.192.1 to 3.89.223.2543.89.223.2558,190
2083.89.224.0/193.89.224.1 to 3.89.255.2543.89.255.2558,190
2093.90.0.0/193.90.0.1 to 3.90.31.2543.90.31.2558,190
2103.90.32.0/193.90.32.1 to 3.90.63.2543.90.63.2558,190
2113.90.64.0/193.90.64.1 to 3.90.95.2543.90.95.2558,190
2123.90.96.0/193.90.96.1 to 3.90.127.2543.90.127.2558,190
2133.90.128.0/193.90.128.1 to 3.90.159.2543.90.159.2558,190
2143.90.160.0/193.90.160.1 to 3.90.191.2543.90.191.2558,190
2153.90.192.0/193.90.192.1 to 3.90.223.2543.90.223.2558,190
2163.90.224.0/193.90.224.1 to 3.90.255.2543.90.255.2558,190
2173.91.0.0/193.91.0.1 to 3.91.31.2543.91.31.2558,190
2183.91.32.0/193.91.32.1 to 3.91.63.2543.91.63.2558,190
2193.91.64.0/193.91.64.1 to 3.91.95.2543.91.95.2558,190
2203.91.96.0/193.91.96.1 to 3.91.127.2543.91.127.2558,190
2213.91.128.0/193.91.128.1 to 3.91.159.2543.91.159.2558,190
2223.91.160.0/193.91.160.1 to 3.91.191.2543.91.191.2558,190
2233.91.192.0/193.91.192.1 to 3.91.223.2543.91.223.2558,190
2243.91.224.0/193.91.224.1 to 3.91.255.2543.91.255.2558,190
2253.92.0.0/193.92.0.1 to 3.92.31.2543.92.31.2558,190
2263.92.32.0/193.92.32.1 to 3.92.63.2543.92.63.2558,190
2273.92.64.0/193.92.64.1 to 3.92.95.2543.92.95.2558,190
2283.92.96.0/193.92.96.1 to 3.92.127.2543.92.127.2558,190
2293.92.128.0/193.92.128.1 to 3.92.159.2543.92.159.2558,190
2303.92.160.0/193.92.160.1 to 3.92.191.2543.92.191.2558,190
2313.92.192.0/193.92.192.1 to 3.92.223.2543.92.223.2558,190
2323.92.224.0/193.92.224.1 to 3.92.255.2543.92.255.2558,190
2333.93.0.0/193.93.0.1 to 3.93.31.2543.93.31.2558,190
2343.93.32.0/193.93.32.1 to 3.93.63.2543.93.63.2558,190
2353.93.64.0/193.93.64.1 to 3.93.95.2543.93.95.2558,190
2363.93.96.0/193.93.96.1 to 3.93.127.2543.93.127.2558,190
2373.93.128.0/193.93.128.1 to 3.93.159.2543.93.159.2558,190
2383.93.160.0/193.93.160.1 to 3.93.191.2543.93.191.2558,190
2393.93.192.0/193.93.192.1 to 3.93.223.2543.93.223.2558,190
2403.93.224.0/193.93.224.1 to 3.93.255.2543.93.255.2558,190
2413.94.0.0/193.94.0.1 to 3.94.31.2543.94.31.2558,190
2423.94.32.0/193.94.32.1 to 3.94.63.2543.94.63.2558,190
2433.94.64.0/193.94.64.1 to 3.94.95.2543.94.95.2558,190
2443.94.96.0/193.94.96.1 to 3.94.127.2543.94.127.2558,190
2453.94.128.0/193.94.128.1 to 3.94.159.2543.94.159.2558,190
2463.94.160.0/193.94.160.1 to 3.94.191.2543.94.191.2558,190
2473.94.192.0/193.94.192.1 to 3.94.223.2543.94.223.2558,190
2483.94.224.0/193.94.224.1 to 3.94.255.2543.94.255.2558,190
2493.95.0.0/193.95.0.1 to 3.95.31.2543.95.31.2558,190
2503.95.32.0/193.95.32.1 to 3.95.63.2543.95.63.2558,190
2513.95.64.0/193.95.64.1 to 3.95.95.2543.95.95.2558,190
2523.95.96.0/193.95.96.1 to 3.95.127.2543.95.127.2558,190
2533.95.128.0/193.95.128.1 to 3.95.159.2543.95.159.2558,190
2543.95.160.0/193.95.160.1 to 3.95.191.2543.95.191.2558,190
2553.95.192.0/193.95.192.1 to 3.95.223.2543.95.223.2558,190
2563.95.224.0/193.95.224.1 to 3.95.255.2543.95.255.2558,190

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.