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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.

Network8.0.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
8.0.0.0
Broadcast address
8.63.255.255
First usable
8.0.0.1
Last usable
8.63.255.254
Usable hosts
4,194,302 (4,194,304 less the network and broadcast addresses)
Subnet mask
255.192.0.0
Wildcard mask
0.63.255.255 (Cisco ACLs, OSPF)
Prefix length
/10
Type
Public public
Old class
A (default /8)
As numbers
Hex 08000000 · Integer 134217728 to 138412031
Reverse DNS zones
0.8.in-addr.arpa
1.8.in-addr.arpa
2.8.in-addr.arpa
3.8.in-addr.arpa
4.8.in-addr.arpa
5.8.in-addr.arpa
6.8.in-addr.arpa
7.8.in-addr.arpa
8.8.in-addr.arpa
9.8.in-addr.arpa
10.8.in-addr.arpa
11.8.in-addr.arpa
12.8.in-addr.arpa
13.8.in-addr.arpa
14.8.in-addr.arpa
15.8.in-addr.arpa
and 48 more
/10 is not on a 8-bit boundary, so it takes 64 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00001000.00000000.00000000.000000008.0.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00001000.00000000.00000000.000000008.0.0.0
Broadcast00001000.00111111.11111111.111111118.63.255.255
Split into smaller subnets/20
/11 (2)/12 (4)/13 (8)/14 (16)/15 (32)/16 (64)/17 (128)/18 (256)/19 (512)/20 (1,024)/21 (2,048)/22 (4,096)

8.0.0.0/10 makes 1,024 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
18.0.0.0/208.0.0.1 to 8.0.15.2548.0.15.2554,094
28.0.16.0/208.0.16.1 to 8.0.31.2548.0.31.2554,094
38.0.32.0/208.0.32.1 to 8.0.47.2548.0.47.2554,094
48.0.48.0/208.0.48.1 to 8.0.63.2548.0.63.2554,094
58.0.64.0/208.0.64.1 to 8.0.79.2548.0.79.2554,094
68.0.80.0/208.0.80.1 to 8.0.95.2548.0.95.2554,094
78.0.96.0/208.0.96.1 to 8.0.111.2548.0.111.2554,094
88.0.112.0/208.0.112.1 to 8.0.127.2548.0.127.2554,094
98.0.128.0/208.0.128.1 to 8.0.143.2548.0.143.2554,094
108.0.144.0/208.0.144.1 to 8.0.159.2548.0.159.2554,094
118.0.160.0/208.0.160.1 to 8.0.175.2548.0.175.2554,094
128.0.176.0/208.0.176.1 to 8.0.191.2548.0.191.2554,094
138.0.192.0/208.0.192.1 to 8.0.207.2548.0.207.2554,094
148.0.208.0/208.0.208.1 to 8.0.223.2548.0.223.2554,094
158.0.224.0/208.0.224.1 to 8.0.239.2548.0.239.2554,094
168.0.240.0/208.0.240.1 to 8.0.255.2548.0.255.2554,094
178.1.0.0/208.1.0.1 to 8.1.15.2548.1.15.2554,094
188.1.16.0/208.1.16.1 to 8.1.31.2548.1.31.2554,094
198.1.32.0/208.1.32.1 to 8.1.47.2548.1.47.2554,094
208.1.48.0/208.1.48.1 to 8.1.63.2548.1.63.2554,094
218.1.64.0/208.1.64.1 to 8.1.79.2548.1.79.2554,094
228.1.80.0/208.1.80.1 to 8.1.95.2548.1.95.2554,094
238.1.96.0/208.1.96.1 to 8.1.111.2548.1.111.2554,094
248.1.112.0/208.1.112.1 to 8.1.127.2548.1.127.2554,094
258.1.128.0/208.1.128.1 to 8.1.143.2548.1.143.2554,094
268.1.144.0/208.1.144.1 to 8.1.159.2548.1.159.2554,094
278.1.160.0/208.1.160.1 to 8.1.175.2548.1.175.2554,094
288.1.176.0/208.1.176.1 to 8.1.191.2548.1.191.2554,094
298.1.192.0/208.1.192.1 to 8.1.207.2548.1.207.2554,094
308.1.208.0/208.1.208.1 to 8.1.223.2548.1.223.2554,094
318.1.224.0/208.1.224.1 to 8.1.239.2548.1.239.2554,094
328.1.240.0/208.1.240.1 to 8.1.255.2548.1.255.2554,094
338.2.0.0/208.2.0.1 to 8.2.15.2548.2.15.2554,094
348.2.16.0/208.2.16.1 to 8.2.31.2548.2.31.2554,094
358.2.32.0/208.2.32.1 to 8.2.47.2548.2.47.2554,094
368.2.48.0/208.2.48.1 to 8.2.63.2548.2.63.2554,094
378.2.64.0/208.2.64.1 to 8.2.79.2548.2.79.2554,094
388.2.80.0/208.2.80.1 to 8.2.95.2548.2.95.2554,094
398.2.96.0/208.2.96.1 to 8.2.111.2548.2.111.2554,094
408.2.112.0/208.2.112.1 to 8.2.127.2548.2.127.2554,094
418.2.128.0/208.2.128.1 to 8.2.143.2548.2.143.2554,094
428.2.144.0/208.2.144.1 to 8.2.159.2548.2.159.2554,094
438.2.160.0/208.2.160.1 to 8.2.175.2548.2.175.2554,094
448.2.176.0/208.2.176.1 to 8.2.191.2548.2.191.2554,094
458.2.192.0/208.2.192.1 to 8.2.207.2548.2.207.2554,094
468.2.208.0/208.2.208.1 to 8.2.223.2548.2.223.2554,094
478.2.224.0/208.2.224.1 to 8.2.239.2548.2.239.2554,094
488.2.240.0/208.2.240.1 to 8.2.255.2548.2.255.2554,094
498.3.0.0/208.3.0.1 to 8.3.15.2548.3.15.2554,094
508.3.16.0/208.3.16.1 to 8.3.31.2548.3.31.2554,094
518.3.32.0/208.3.32.1 to 8.3.47.2548.3.47.2554,094
528.3.48.0/208.3.48.1 to 8.3.63.2548.3.63.2554,094
538.3.64.0/208.3.64.1 to 8.3.79.2548.3.79.2554,094
548.3.80.0/208.3.80.1 to 8.3.95.2548.3.95.2554,094
558.3.96.0/208.3.96.1 to 8.3.111.2548.3.111.2554,094
568.3.112.0/208.3.112.1 to 8.3.127.2548.3.127.2554,094
578.3.128.0/208.3.128.1 to 8.3.143.2548.3.143.2554,094
588.3.144.0/208.3.144.1 to 8.3.159.2548.3.159.2554,094
598.3.160.0/208.3.160.1 to 8.3.175.2548.3.175.2554,094
608.3.176.0/208.3.176.1 to 8.3.191.2548.3.191.2554,094
618.3.192.0/208.3.192.1 to 8.3.207.2548.3.207.2554,094
628.3.208.0/208.3.208.1 to 8.3.223.2548.3.223.2554,094
638.3.224.0/208.3.224.1 to 8.3.239.2548.3.239.2554,094
648.3.240.0/208.3.240.1 to 8.3.255.2548.3.255.2554,094
658.4.0.0/208.4.0.1 to 8.4.15.2548.4.15.2554,094
668.4.16.0/208.4.16.1 to 8.4.31.2548.4.31.2554,094
678.4.32.0/208.4.32.1 to 8.4.47.2548.4.47.2554,094
688.4.48.0/208.4.48.1 to 8.4.63.2548.4.63.2554,094
698.4.64.0/208.4.64.1 to 8.4.79.2548.4.79.2554,094
708.4.80.0/208.4.80.1 to 8.4.95.2548.4.95.2554,094
718.4.96.0/208.4.96.1 to 8.4.111.2548.4.111.2554,094
728.4.112.0/208.4.112.1 to 8.4.127.2548.4.127.2554,094
738.4.128.0/208.4.128.1 to 8.4.143.2548.4.143.2554,094
748.4.144.0/208.4.144.1 to 8.4.159.2548.4.159.2554,094
758.4.160.0/208.4.160.1 to 8.4.175.2548.4.175.2554,094
768.4.176.0/208.4.176.1 to 8.4.191.2548.4.191.2554,094
778.4.192.0/208.4.192.1 to 8.4.207.2548.4.207.2554,094
788.4.208.0/208.4.208.1 to 8.4.223.2548.4.223.2554,094
798.4.224.0/208.4.224.1 to 8.4.239.2548.4.239.2554,094
808.4.240.0/208.4.240.1 to 8.4.255.2548.4.255.2554,094
818.5.0.0/208.5.0.1 to 8.5.15.2548.5.15.2554,094
828.5.16.0/208.5.16.1 to 8.5.31.2548.5.31.2554,094
838.5.32.0/208.5.32.1 to 8.5.47.2548.5.47.2554,094
848.5.48.0/208.5.48.1 to 8.5.63.2548.5.63.2554,094
858.5.64.0/208.5.64.1 to 8.5.79.2548.5.79.2554,094
868.5.80.0/208.5.80.1 to 8.5.95.2548.5.95.2554,094
878.5.96.0/208.5.96.1 to 8.5.111.2548.5.111.2554,094
888.5.112.0/208.5.112.1 to 8.5.127.2548.5.127.2554,094
898.5.128.0/208.5.128.1 to 8.5.143.2548.5.143.2554,094
908.5.144.0/208.5.144.1 to 8.5.159.2548.5.159.2554,094
918.5.160.0/208.5.160.1 to 8.5.175.2548.5.175.2554,094
928.5.176.0/208.5.176.1 to 8.5.191.2548.5.191.2554,094
938.5.192.0/208.5.192.1 to 8.5.207.2548.5.207.2554,094
948.5.208.0/208.5.208.1 to 8.5.223.2548.5.223.2554,094
958.5.224.0/208.5.224.1 to 8.5.239.2548.5.239.2554,094
968.5.240.0/208.5.240.1 to 8.5.255.2548.5.255.2554,094
978.6.0.0/208.6.0.1 to 8.6.15.2548.6.15.2554,094
988.6.16.0/208.6.16.1 to 8.6.31.2548.6.31.2554,094
998.6.32.0/208.6.32.1 to 8.6.47.2548.6.47.2554,094
1008.6.48.0/208.6.48.1 to 8.6.63.2548.6.63.2554,094
1018.6.64.0/208.6.64.1 to 8.6.79.2548.6.79.2554,094
1028.6.80.0/208.6.80.1 to 8.6.95.2548.6.95.2554,094
1038.6.96.0/208.6.96.1 to 8.6.111.2548.6.111.2554,094
1048.6.112.0/208.6.112.1 to 8.6.127.2548.6.127.2554,094
1058.6.128.0/208.6.128.1 to 8.6.143.2548.6.143.2554,094
1068.6.144.0/208.6.144.1 to 8.6.159.2548.6.159.2554,094
1078.6.160.0/208.6.160.1 to 8.6.175.2548.6.175.2554,094
1088.6.176.0/208.6.176.1 to 8.6.191.2548.6.191.2554,094
1098.6.192.0/208.6.192.1 to 8.6.207.2548.6.207.2554,094
1108.6.208.0/208.6.208.1 to 8.6.223.2548.6.223.2554,094
1118.6.224.0/208.6.224.1 to 8.6.239.2548.6.239.2554,094
1128.6.240.0/208.6.240.1 to 8.6.255.2548.6.255.2554,094
1138.7.0.0/208.7.0.1 to 8.7.15.2548.7.15.2554,094
1148.7.16.0/208.7.16.1 to 8.7.31.2548.7.31.2554,094
1158.7.32.0/208.7.32.1 to 8.7.47.2548.7.47.2554,094
1168.7.48.0/208.7.48.1 to 8.7.63.2548.7.63.2554,094
1178.7.64.0/208.7.64.1 to 8.7.79.2548.7.79.2554,094
1188.7.80.0/208.7.80.1 to 8.7.95.2548.7.95.2554,094
1198.7.96.0/208.7.96.1 to 8.7.111.2548.7.111.2554,094
1208.7.112.0/208.7.112.1 to 8.7.127.2548.7.127.2554,094
1218.7.128.0/208.7.128.1 to 8.7.143.2548.7.143.2554,094
1228.7.144.0/208.7.144.1 to 8.7.159.2548.7.159.2554,094
1238.7.160.0/208.7.160.1 to 8.7.175.2548.7.175.2554,094
1248.7.176.0/208.7.176.1 to 8.7.191.2548.7.191.2554,094
1258.7.192.0/208.7.192.1 to 8.7.207.2548.7.207.2554,094
1268.7.208.0/208.7.208.1 to 8.7.223.2548.7.223.2554,094
1278.7.224.0/208.7.224.1 to 8.7.239.2548.7.239.2554,094
1288.7.240.0/208.7.240.1 to 8.7.255.2548.7.255.2554,094
1298.8.0.0/208.8.0.1 to 8.8.15.2548.8.15.2554,094
1308.8.16.0/208.8.16.1 to 8.8.31.2548.8.31.2554,094
1318.8.32.0/208.8.32.1 to 8.8.47.2548.8.47.2554,094
1328.8.48.0/208.8.48.1 to 8.8.63.2548.8.63.2554,094
1338.8.64.0/208.8.64.1 to 8.8.79.2548.8.79.2554,094
1348.8.80.0/208.8.80.1 to 8.8.95.2548.8.95.2554,094
1358.8.96.0/208.8.96.1 to 8.8.111.2548.8.111.2554,094
1368.8.112.0/208.8.112.1 to 8.8.127.2548.8.127.2554,094
1378.8.128.0/208.8.128.1 to 8.8.143.2548.8.143.2554,094
1388.8.144.0/208.8.144.1 to 8.8.159.2548.8.159.2554,094
1398.8.160.0/208.8.160.1 to 8.8.175.2548.8.175.2554,094
1408.8.176.0/208.8.176.1 to 8.8.191.2548.8.191.2554,094
1418.8.192.0/208.8.192.1 to 8.8.207.2548.8.207.2554,094
1428.8.208.0/208.8.208.1 to 8.8.223.2548.8.223.2554,094
1438.8.224.0/208.8.224.1 to 8.8.239.2548.8.239.2554,094
1448.8.240.0/208.8.240.1 to 8.8.255.2548.8.255.2554,094
1458.9.0.0/208.9.0.1 to 8.9.15.2548.9.15.2554,094
1468.9.16.0/208.9.16.1 to 8.9.31.2548.9.31.2554,094
1478.9.32.0/208.9.32.1 to 8.9.47.2548.9.47.2554,094
1488.9.48.0/208.9.48.1 to 8.9.63.2548.9.63.2554,094
1498.9.64.0/208.9.64.1 to 8.9.79.2548.9.79.2554,094
1508.9.80.0/208.9.80.1 to 8.9.95.2548.9.95.2554,094
1518.9.96.0/208.9.96.1 to 8.9.111.2548.9.111.2554,094
1528.9.112.0/208.9.112.1 to 8.9.127.2548.9.127.2554,094
1538.9.128.0/208.9.128.1 to 8.9.143.2548.9.143.2554,094
1548.9.144.0/208.9.144.1 to 8.9.159.2548.9.159.2554,094
1558.9.160.0/208.9.160.1 to 8.9.175.2548.9.175.2554,094
1568.9.176.0/208.9.176.1 to 8.9.191.2548.9.191.2554,094
1578.9.192.0/208.9.192.1 to 8.9.207.2548.9.207.2554,094
1588.9.208.0/208.9.208.1 to 8.9.223.2548.9.223.2554,094
1598.9.224.0/208.9.224.1 to 8.9.239.2548.9.239.2554,094
1608.9.240.0/208.9.240.1 to 8.9.255.2548.9.255.2554,094
1618.10.0.0/208.10.0.1 to 8.10.15.2548.10.15.2554,094
1628.10.16.0/208.10.16.1 to 8.10.31.2548.10.31.2554,094
1638.10.32.0/208.10.32.1 to 8.10.47.2548.10.47.2554,094
1648.10.48.0/208.10.48.1 to 8.10.63.2548.10.63.2554,094
1658.10.64.0/208.10.64.1 to 8.10.79.2548.10.79.2554,094
1668.10.80.0/208.10.80.1 to 8.10.95.2548.10.95.2554,094
1678.10.96.0/208.10.96.1 to 8.10.111.2548.10.111.2554,094
1688.10.112.0/208.10.112.1 to 8.10.127.2548.10.127.2554,094
1698.10.128.0/208.10.128.1 to 8.10.143.2548.10.143.2554,094
1708.10.144.0/208.10.144.1 to 8.10.159.2548.10.159.2554,094
1718.10.160.0/208.10.160.1 to 8.10.175.2548.10.175.2554,094
1728.10.176.0/208.10.176.1 to 8.10.191.2548.10.191.2554,094
1738.10.192.0/208.10.192.1 to 8.10.207.2548.10.207.2554,094
1748.10.208.0/208.10.208.1 to 8.10.223.2548.10.223.2554,094
1758.10.224.0/208.10.224.1 to 8.10.239.2548.10.239.2554,094
1768.10.240.0/208.10.240.1 to 8.10.255.2548.10.255.2554,094
1778.11.0.0/208.11.0.1 to 8.11.15.2548.11.15.2554,094
1788.11.16.0/208.11.16.1 to 8.11.31.2548.11.31.2554,094
1798.11.32.0/208.11.32.1 to 8.11.47.2548.11.47.2554,094
1808.11.48.0/208.11.48.1 to 8.11.63.2548.11.63.2554,094
1818.11.64.0/208.11.64.1 to 8.11.79.2548.11.79.2554,094
1828.11.80.0/208.11.80.1 to 8.11.95.2548.11.95.2554,094
1838.11.96.0/208.11.96.1 to 8.11.111.2548.11.111.2554,094
1848.11.112.0/208.11.112.1 to 8.11.127.2548.11.127.2554,094
1858.11.128.0/208.11.128.1 to 8.11.143.2548.11.143.2554,094
1868.11.144.0/208.11.144.1 to 8.11.159.2548.11.159.2554,094
1878.11.160.0/208.11.160.1 to 8.11.175.2548.11.175.2554,094
1888.11.176.0/208.11.176.1 to 8.11.191.2548.11.191.2554,094
1898.11.192.0/208.11.192.1 to 8.11.207.2548.11.207.2554,094
1908.11.208.0/208.11.208.1 to 8.11.223.2548.11.223.2554,094
1918.11.224.0/208.11.224.1 to 8.11.239.2548.11.239.2554,094
1928.11.240.0/208.11.240.1 to 8.11.255.2548.11.255.2554,094
1938.12.0.0/208.12.0.1 to 8.12.15.2548.12.15.2554,094
1948.12.16.0/208.12.16.1 to 8.12.31.2548.12.31.2554,094
1958.12.32.0/208.12.32.1 to 8.12.47.2548.12.47.2554,094
1968.12.48.0/208.12.48.1 to 8.12.63.2548.12.63.2554,094
1978.12.64.0/208.12.64.1 to 8.12.79.2548.12.79.2554,094
1988.12.80.0/208.12.80.1 to 8.12.95.2548.12.95.2554,094
1998.12.96.0/208.12.96.1 to 8.12.111.2548.12.111.2554,094
2008.12.112.0/208.12.112.1 to 8.12.127.2548.12.127.2554,094
2018.12.128.0/208.12.128.1 to 8.12.143.2548.12.143.2554,094
2028.12.144.0/208.12.144.1 to 8.12.159.2548.12.159.2554,094
2038.12.160.0/208.12.160.1 to 8.12.175.2548.12.175.2554,094
2048.12.176.0/208.12.176.1 to 8.12.191.2548.12.191.2554,094
2058.12.192.0/208.12.192.1 to 8.12.207.2548.12.207.2554,094
2068.12.208.0/208.12.208.1 to 8.12.223.2548.12.223.2554,094
2078.12.224.0/208.12.224.1 to 8.12.239.2548.12.239.2554,094
2088.12.240.0/208.12.240.1 to 8.12.255.2548.12.255.2554,094
2098.13.0.0/208.13.0.1 to 8.13.15.2548.13.15.2554,094
2108.13.16.0/208.13.16.1 to 8.13.31.2548.13.31.2554,094
2118.13.32.0/208.13.32.1 to 8.13.47.2548.13.47.2554,094
2128.13.48.0/208.13.48.1 to 8.13.63.2548.13.63.2554,094
2138.13.64.0/208.13.64.1 to 8.13.79.2548.13.79.2554,094
2148.13.80.0/208.13.80.1 to 8.13.95.2548.13.95.2554,094
2158.13.96.0/208.13.96.1 to 8.13.111.2548.13.111.2554,094
2168.13.112.0/208.13.112.1 to 8.13.127.2548.13.127.2554,094
2178.13.128.0/208.13.128.1 to 8.13.143.2548.13.143.2554,094
2188.13.144.0/208.13.144.1 to 8.13.159.2548.13.159.2554,094
2198.13.160.0/208.13.160.1 to 8.13.175.2548.13.175.2554,094
2208.13.176.0/208.13.176.1 to 8.13.191.2548.13.191.2554,094
2218.13.192.0/208.13.192.1 to 8.13.207.2548.13.207.2554,094
2228.13.208.0/208.13.208.1 to 8.13.223.2548.13.223.2554,094
2238.13.224.0/208.13.224.1 to 8.13.239.2548.13.239.2554,094
2248.13.240.0/208.13.240.1 to 8.13.255.2548.13.255.2554,094
2258.14.0.0/208.14.0.1 to 8.14.15.2548.14.15.2554,094
2268.14.16.0/208.14.16.1 to 8.14.31.2548.14.31.2554,094
2278.14.32.0/208.14.32.1 to 8.14.47.2548.14.47.2554,094
2288.14.48.0/208.14.48.1 to 8.14.63.2548.14.63.2554,094
2298.14.64.0/208.14.64.1 to 8.14.79.2548.14.79.2554,094
2308.14.80.0/208.14.80.1 to 8.14.95.2548.14.95.2554,094
2318.14.96.0/208.14.96.1 to 8.14.111.2548.14.111.2554,094
2328.14.112.0/208.14.112.1 to 8.14.127.2548.14.127.2554,094
2338.14.128.0/208.14.128.1 to 8.14.143.2548.14.143.2554,094
2348.14.144.0/208.14.144.1 to 8.14.159.2548.14.159.2554,094
2358.14.160.0/208.14.160.1 to 8.14.175.2548.14.175.2554,094
2368.14.176.0/208.14.176.1 to 8.14.191.2548.14.191.2554,094
2378.14.192.0/208.14.192.1 to 8.14.207.2548.14.207.2554,094
2388.14.208.0/208.14.208.1 to 8.14.223.2548.14.223.2554,094
2398.14.224.0/208.14.224.1 to 8.14.239.2548.14.239.2554,094
2408.14.240.0/208.14.240.1 to 8.14.255.2548.14.255.2554,094
2418.15.0.0/208.15.0.1 to 8.15.15.2548.15.15.2554,094
2428.15.16.0/208.15.16.1 to 8.15.31.2548.15.31.2554,094
2438.15.32.0/208.15.32.1 to 8.15.47.2548.15.47.2554,094
2448.15.48.0/208.15.48.1 to 8.15.63.2548.15.63.2554,094
2458.15.64.0/208.15.64.1 to 8.15.79.2548.15.79.2554,094
2468.15.80.0/208.15.80.1 to 8.15.95.2548.15.95.2554,094
2478.15.96.0/208.15.96.1 to 8.15.111.2548.15.111.2554,094
2488.15.112.0/208.15.112.1 to 8.15.127.2548.15.127.2554,094
2498.15.128.0/208.15.128.1 to 8.15.143.2548.15.143.2554,094
2508.15.144.0/208.15.144.1 to 8.15.159.2548.15.159.2554,094
2518.15.160.0/208.15.160.1 to 8.15.175.2548.15.175.2554,094
2528.15.176.0/208.15.176.1 to 8.15.191.2548.15.191.2554,094
2538.15.192.0/208.15.192.1 to 8.15.207.2548.15.207.2554,094
2548.15.208.0/208.15.208.1 to 8.15.223.2548.15.223.2554,094
2558.15.224.0/208.15.224.1 to 8.15.239.2548.15.239.2554,094
2568.15.240.0/208.15.240.1 to 8.15.255.2548.15.255.2554,094

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.