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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.

Network9.64.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
9.64.0.0
Broadcast address
9.127.255.255
First usable
9.64.0.1
Last usable
9.127.255.254
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 09400000 · Integer 155189248 to 159383551
Reverse DNS zones
64.9.in-addr.arpa
65.9.in-addr.arpa
66.9.in-addr.arpa
67.9.in-addr.arpa
68.9.in-addr.arpa
69.9.in-addr.arpa
70.9.in-addr.arpa
71.9.in-addr.arpa
72.9.in-addr.arpa
73.9.in-addr.arpa
74.9.in-addr.arpa
75.9.in-addr.arpa
76.9.in-addr.arpa
77.9.in-addr.arpa
78.9.in-addr.arpa
79.9.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
Address00001001.01000000.00000000.000000009.64.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00001001.01000000.00000000.000000009.64.0.0
Broadcast00001001.01111111.11111111.111111119.127.255.255
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)

9.64.0.0/10 makes 1,024 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
19.64.0.0/209.64.0.1 to 9.64.15.2549.64.15.2554,094
29.64.16.0/209.64.16.1 to 9.64.31.2549.64.31.2554,094
39.64.32.0/209.64.32.1 to 9.64.47.2549.64.47.2554,094
49.64.48.0/209.64.48.1 to 9.64.63.2549.64.63.2554,094
59.64.64.0/209.64.64.1 to 9.64.79.2549.64.79.2554,094
69.64.80.0/209.64.80.1 to 9.64.95.2549.64.95.2554,094
79.64.96.0/209.64.96.1 to 9.64.111.2549.64.111.2554,094
89.64.112.0/209.64.112.1 to 9.64.127.2549.64.127.2554,094
99.64.128.0/209.64.128.1 to 9.64.143.2549.64.143.2554,094
109.64.144.0/209.64.144.1 to 9.64.159.2549.64.159.2554,094
119.64.160.0/209.64.160.1 to 9.64.175.2549.64.175.2554,094
129.64.176.0/209.64.176.1 to 9.64.191.2549.64.191.2554,094
139.64.192.0/209.64.192.1 to 9.64.207.2549.64.207.2554,094
149.64.208.0/209.64.208.1 to 9.64.223.2549.64.223.2554,094
159.64.224.0/209.64.224.1 to 9.64.239.2549.64.239.2554,094
169.64.240.0/209.64.240.1 to 9.64.255.2549.64.255.2554,094
179.65.0.0/209.65.0.1 to 9.65.15.2549.65.15.2554,094
189.65.16.0/209.65.16.1 to 9.65.31.2549.65.31.2554,094
199.65.32.0/209.65.32.1 to 9.65.47.2549.65.47.2554,094
209.65.48.0/209.65.48.1 to 9.65.63.2549.65.63.2554,094
219.65.64.0/209.65.64.1 to 9.65.79.2549.65.79.2554,094
229.65.80.0/209.65.80.1 to 9.65.95.2549.65.95.2554,094
239.65.96.0/209.65.96.1 to 9.65.111.2549.65.111.2554,094
249.65.112.0/209.65.112.1 to 9.65.127.2549.65.127.2554,094
259.65.128.0/209.65.128.1 to 9.65.143.2549.65.143.2554,094
269.65.144.0/209.65.144.1 to 9.65.159.2549.65.159.2554,094
279.65.160.0/209.65.160.1 to 9.65.175.2549.65.175.2554,094
289.65.176.0/209.65.176.1 to 9.65.191.2549.65.191.2554,094
299.65.192.0/209.65.192.1 to 9.65.207.2549.65.207.2554,094
309.65.208.0/209.65.208.1 to 9.65.223.2549.65.223.2554,094
319.65.224.0/209.65.224.1 to 9.65.239.2549.65.239.2554,094
329.65.240.0/209.65.240.1 to 9.65.255.2549.65.255.2554,094
339.66.0.0/209.66.0.1 to 9.66.15.2549.66.15.2554,094
349.66.16.0/209.66.16.1 to 9.66.31.2549.66.31.2554,094
359.66.32.0/209.66.32.1 to 9.66.47.2549.66.47.2554,094
369.66.48.0/209.66.48.1 to 9.66.63.2549.66.63.2554,094
379.66.64.0/209.66.64.1 to 9.66.79.2549.66.79.2554,094
389.66.80.0/209.66.80.1 to 9.66.95.2549.66.95.2554,094
399.66.96.0/209.66.96.1 to 9.66.111.2549.66.111.2554,094
409.66.112.0/209.66.112.1 to 9.66.127.2549.66.127.2554,094
419.66.128.0/209.66.128.1 to 9.66.143.2549.66.143.2554,094
429.66.144.0/209.66.144.1 to 9.66.159.2549.66.159.2554,094
439.66.160.0/209.66.160.1 to 9.66.175.2549.66.175.2554,094
449.66.176.0/209.66.176.1 to 9.66.191.2549.66.191.2554,094
459.66.192.0/209.66.192.1 to 9.66.207.2549.66.207.2554,094
469.66.208.0/209.66.208.1 to 9.66.223.2549.66.223.2554,094
479.66.224.0/209.66.224.1 to 9.66.239.2549.66.239.2554,094
489.66.240.0/209.66.240.1 to 9.66.255.2549.66.255.2554,094
499.67.0.0/209.67.0.1 to 9.67.15.2549.67.15.2554,094
509.67.16.0/209.67.16.1 to 9.67.31.2549.67.31.2554,094
519.67.32.0/209.67.32.1 to 9.67.47.2549.67.47.2554,094
529.67.48.0/209.67.48.1 to 9.67.63.2549.67.63.2554,094
539.67.64.0/209.67.64.1 to 9.67.79.2549.67.79.2554,094
549.67.80.0/209.67.80.1 to 9.67.95.2549.67.95.2554,094
559.67.96.0/209.67.96.1 to 9.67.111.2549.67.111.2554,094
569.67.112.0/209.67.112.1 to 9.67.127.2549.67.127.2554,094
579.67.128.0/209.67.128.1 to 9.67.143.2549.67.143.2554,094
589.67.144.0/209.67.144.1 to 9.67.159.2549.67.159.2554,094
599.67.160.0/209.67.160.1 to 9.67.175.2549.67.175.2554,094
609.67.176.0/209.67.176.1 to 9.67.191.2549.67.191.2554,094
619.67.192.0/209.67.192.1 to 9.67.207.2549.67.207.2554,094
629.67.208.0/209.67.208.1 to 9.67.223.2549.67.223.2554,094
639.67.224.0/209.67.224.1 to 9.67.239.2549.67.239.2554,094
649.67.240.0/209.67.240.1 to 9.67.255.2549.67.255.2554,094
659.68.0.0/209.68.0.1 to 9.68.15.2549.68.15.2554,094
669.68.16.0/209.68.16.1 to 9.68.31.2549.68.31.2554,094
679.68.32.0/209.68.32.1 to 9.68.47.2549.68.47.2554,094
689.68.48.0/209.68.48.1 to 9.68.63.2549.68.63.2554,094
699.68.64.0/209.68.64.1 to 9.68.79.2549.68.79.2554,094
709.68.80.0/209.68.80.1 to 9.68.95.2549.68.95.2554,094
719.68.96.0/209.68.96.1 to 9.68.111.2549.68.111.2554,094
729.68.112.0/209.68.112.1 to 9.68.127.2549.68.127.2554,094
739.68.128.0/209.68.128.1 to 9.68.143.2549.68.143.2554,094
749.68.144.0/209.68.144.1 to 9.68.159.2549.68.159.2554,094
759.68.160.0/209.68.160.1 to 9.68.175.2549.68.175.2554,094
769.68.176.0/209.68.176.1 to 9.68.191.2549.68.191.2554,094
779.68.192.0/209.68.192.1 to 9.68.207.2549.68.207.2554,094
789.68.208.0/209.68.208.1 to 9.68.223.2549.68.223.2554,094
799.68.224.0/209.68.224.1 to 9.68.239.2549.68.239.2554,094
809.68.240.0/209.68.240.1 to 9.68.255.2549.68.255.2554,094
819.69.0.0/209.69.0.1 to 9.69.15.2549.69.15.2554,094
829.69.16.0/209.69.16.1 to 9.69.31.2549.69.31.2554,094
839.69.32.0/209.69.32.1 to 9.69.47.2549.69.47.2554,094
849.69.48.0/209.69.48.1 to 9.69.63.2549.69.63.2554,094
859.69.64.0/209.69.64.1 to 9.69.79.2549.69.79.2554,094
869.69.80.0/209.69.80.1 to 9.69.95.2549.69.95.2554,094
879.69.96.0/209.69.96.1 to 9.69.111.2549.69.111.2554,094
889.69.112.0/209.69.112.1 to 9.69.127.2549.69.127.2554,094
899.69.128.0/209.69.128.1 to 9.69.143.2549.69.143.2554,094
909.69.144.0/209.69.144.1 to 9.69.159.2549.69.159.2554,094
919.69.160.0/209.69.160.1 to 9.69.175.2549.69.175.2554,094
929.69.176.0/209.69.176.1 to 9.69.191.2549.69.191.2554,094
939.69.192.0/209.69.192.1 to 9.69.207.2549.69.207.2554,094
949.69.208.0/209.69.208.1 to 9.69.223.2549.69.223.2554,094
959.69.224.0/209.69.224.1 to 9.69.239.2549.69.239.2554,094
969.69.240.0/209.69.240.1 to 9.69.255.2549.69.255.2554,094
979.70.0.0/209.70.0.1 to 9.70.15.2549.70.15.2554,094
989.70.16.0/209.70.16.1 to 9.70.31.2549.70.31.2554,094
999.70.32.0/209.70.32.1 to 9.70.47.2549.70.47.2554,094
1009.70.48.0/209.70.48.1 to 9.70.63.2549.70.63.2554,094
1019.70.64.0/209.70.64.1 to 9.70.79.2549.70.79.2554,094
1029.70.80.0/209.70.80.1 to 9.70.95.2549.70.95.2554,094
1039.70.96.0/209.70.96.1 to 9.70.111.2549.70.111.2554,094
1049.70.112.0/209.70.112.1 to 9.70.127.2549.70.127.2554,094
1059.70.128.0/209.70.128.1 to 9.70.143.2549.70.143.2554,094
1069.70.144.0/209.70.144.1 to 9.70.159.2549.70.159.2554,094
1079.70.160.0/209.70.160.1 to 9.70.175.2549.70.175.2554,094
1089.70.176.0/209.70.176.1 to 9.70.191.2549.70.191.2554,094
1099.70.192.0/209.70.192.1 to 9.70.207.2549.70.207.2554,094
1109.70.208.0/209.70.208.1 to 9.70.223.2549.70.223.2554,094
1119.70.224.0/209.70.224.1 to 9.70.239.2549.70.239.2554,094
1129.70.240.0/209.70.240.1 to 9.70.255.2549.70.255.2554,094
1139.71.0.0/209.71.0.1 to 9.71.15.2549.71.15.2554,094
1149.71.16.0/209.71.16.1 to 9.71.31.2549.71.31.2554,094
1159.71.32.0/209.71.32.1 to 9.71.47.2549.71.47.2554,094
1169.71.48.0/209.71.48.1 to 9.71.63.2549.71.63.2554,094
1179.71.64.0/209.71.64.1 to 9.71.79.2549.71.79.2554,094
1189.71.80.0/209.71.80.1 to 9.71.95.2549.71.95.2554,094
1199.71.96.0/209.71.96.1 to 9.71.111.2549.71.111.2554,094
1209.71.112.0/209.71.112.1 to 9.71.127.2549.71.127.2554,094
1219.71.128.0/209.71.128.1 to 9.71.143.2549.71.143.2554,094
1229.71.144.0/209.71.144.1 to 9.71.159.2549.71.159.2554,094
1239.71.160.0/209.71.160.1 to 9.71.175.2549.71.175.2554,094
1249.71.176.0/209.71.176.1 to 9.71.191.2549.71.191.2554,094
1259.71.192.0/209.71.192.1 to 9.71.207.2549.71.207.2554,094
1269.71.208.0/209.71.208.1 to 9.71.223.2549.71.223.2554,094
1279.71.224.0/209.71.224.1 to 9.71.239.2549.71.239.2554,094
1289.71.240.0/209.71.240.1 to 9.71.255.2549.71.255.2554,094
1299.72.0.0/209.72.0.1 to 9.72.15.2549.72.15.2554,094
1309.72.16.0/209.72.16.1 to 9.72.31.2549.72.31.2554,094
1319.72.32.0/209.72.32.1 to 9.72.47.2549.72.47.2554,094
1329.72.48.0/209.72.48.1 to 9.72.63.2549.72.63.2554,094
1339.72.64.0/209.72.64.1 to 9.72.79.2549.72.79.2554,094
1349.72.80.0/209.72.80.1 to 9.72.95.2549.72.95.2554,094
1359.72.96.0/209.72.96.1 to 9.72.111.2549.72.111.2554,094
1369.72.112.0/209.72.112.1 to 9.72.127.2549.72.127.2554,094
1379.72.128.0/209.72.128.1 to 9.72.143.2549.72.143.2554,094
1389.72.144.0/209.72.144.1 to 9.72.159.2549.72.159.2554,094
1399.72.160.0/209.72.160.1 to 9.72.175.2549.72.175.2554,094
1409.72.176.0/209.72.176.1 to 9.72.191.2549.72.191.2554,094
1419.72.192.0/209.72.192.1 to 9.72.207.2549.72.207.2554,094
1429.72.208.0/209.72.208.1 to 9.72.223.2549.72.223.2554,094
1439.72.224.0/209.72.224.1 to 9.72.239.2549.72.239.2554,094
1449.72.240.0/209.72.240.1 to 9.72.255.2549.72.255.2554,094
1459.73.0.0/209.73.0.1 to 9.73.15.2549.73.15.2554,094
1469.73.16.0/209.73.16.1 to 9.73.31.2549.73.31.2554,094
1479.73.32.0/209.73.32.1 to 9.73.47.2549.73.47.2554,094
1489.73.48.0/209.73.48.1 to 9.73.63.2549.73.63.2554,094
1499.73.64.0/209.73.64.1 to 9.73.79.2549.73.79.2554,094
1509.73.80.0/209.73.80.1 to 9.73.95.2549.73.95.2554,094
1519.73.96.0/209.73.96.1 to 9.73.111.2549.73.111.2554,094
1529.73.112.0/209.73.112.1 to 9.73.127.2549.73.127.2554,094
1539.73.128.0/209.73.128.1 to 9.73.143.2549.73.143.2554,094
1549.73.144.0/209.73.144.1 to 9.73.159.2549.73.159.2554,094
1559.73.160.0/209.73.160.1 to 9.73.175.2549.73.175.2554,094
1569.73.176.0/209.73.176.1 to 9.73.191.2549.73.191.2554,094
1579.73.192.0/209.73.192.1 to 9.73.207.2549.73.207.2554,094
1589.73.208.0/209.73.208.1 to 9.73.223.2549.73.223.2554,094
1599.73.224.0/209.73.224.1 to 9.73.239.2549.73.239.2554,094
1609.73.240.0/209.73.240.1 to 9.73.255.2549.73.255.2554,094
1619.74.0.0/209.74.0.1 to 9.74.15.2549.74.15.2554,094
1629.74.16.0/209.74.16.1 to 9.74.31.2549.74.31.2554,094
1639.74.32.0/209.74.32.1 to 9.74.47.2549.74.47.2554,094
1649.74.48.0/209.74.48.1 to 9.74.63.2549.74.63.2554,094
1659.74.64.0/209.74.64.1 to 9.74.79.2549.74.79.2554,094
1669.74.80.0/209.74.80.1 to 9.74.95.2549.74.95.2554,094
1679.74.96.0/209.74.96.1 to 9.74.111.2549.74.111.2554,094
1689.74.112.0/209.74.112.1 to 9.74.127.2549.74.127.2554,094
1699.74.128.0/209.74.128.1 to 9.74.143.2549.74.143.2554,094
1709.74.144.0/209.74.144.1 to 9.74.159.2549.74.159.2554,094
1719.74.160.0/209.74.160.1 to 9.74.175.2549.74.175.2554,094
1729.74.176.0/209.74.176.1 to 9.74.191.2549.74.191.2554,094
1739.74.192.0/209.74.192.1 to 9.74.207.2549.74.207.2554,094
1749.74.208.0/209.74.208.1 to 9.74.223.2549.74.223.2554,094
1759.74.224.0/209.74.224.1 to 9.74.239.2549.74.239.2554,094
1769.74.240.0/209.74.240.1 to 9.74.255.2549.74.255.2554,094
1779.75.0.0/209.75.0.1 to 9.75.15.2549.75.15.2554,094
1789.75.16.0/209.75.16.1 to 9.75.31.2549.75.31.2554,094
1799.75.32.0/209.75.32.1 to 9.75.47.2549.75.47.2554,094
1809.75.48.0/209.75.48.1 to 9.75.63.2549.75.63.2554,094
1819.75.64.0/209.75.64.1 to 9.75.79.2549.75.79.2554,094
1829.75.80.0/209.75.80.1 to 9.75.95.2549.75.95.2554,094
1839.75.96.0/209.75.96.1 to 9.75.111.2549.75.111.2554,094
1849.75.112.0/209.75.112.1 to 9.75.127.2549.75.127.2554,094
1859.75.128.0/209.75.128.1 to 9.75.143.2549.75.143.2554,094
1869.75.144.0/209.75.144.1 to 9.75.159.2549.75.159.2554,094
1879.75.160.0/209.75.160.1 to 9.75.175.2549.75.175.2554,094
1889.75.176.0/209.75.176.1 to 9.75.191.2549.75.191.2554,094
1899.75.192.0/209.75.192.1 to 9.75.207.2549.75.207.2554,094
1909.75.208.0/209.75.208.1 to 9.75.223.2549.75.223.2554,094
1919.75.224.0/209.75.224.1 to 9.75.239.2549.75.239.2554,094
1929.75.240.0/209.75.240.1 to 9.75.255.2549.75.255.2554,094
1939.76.0.0/209.76.0.1 to 9.76.15.2549.76.15.2554,094
1949.76.16.0/209.76.16.1 to 9.76.31.2549.76.31.2554,094
1959.76.32.0/209.76.32.1 to 9.76.47.2549.76.47.2554,094
1969.76.48.0/209.76.48.1 to 9.76.63.2549.76.63.2554,094
1979.76.64.0/209.76.64.1 to 9.76.79.2549.76.79.2554,094
1989.76.80.0/209.76.80.1 to 9.76.95.2549.76.95.2554,094
1999.76.96.0/209.76.96.1 to 9.76.111.2549.76.111.2554,094
2009.76.112.0/209.76.112.1 to 9.76.127.2549.76.127.2554,094
2019.76.128.0/209.76.128.1 to 9.76.143.2549.76.143.2554,094
2029.76.144.0/209.76.144.1 to 9.76.159.2549.76.159.2554,094
2039.76.160.0/209.76.160.1 to 9.76.175.2549.76.175.2554,094
2049.76.176.0/209.76.176.1 to 9.76.191.2549.76.191.2554,094
2059.76.192.0/209.76.192.1 to 9.76.207.2549.76.207.2554,094
2069.76.208.0/209.76.208.1 to 9.76.223.2549.76.223.2554,094
2079.76.224.0/209.76.224.1 to 9.76.239.2549.76.239.2554,094
2089.76.240.0/209.76.240.1 to 9.76.255.2549.76.255.2554,094
2099.77.0.0/209.77.0.1 to 9.77.15.2549.77.15.2554,094
2109.77.16.0/209.77.16.1 to 9.77.31.2549.77.31.2554,094
2119.77.32.0/209.77.32.1 to 9.77.47.2549.77.47.2554,094
2129.77.48.0/209.77.48.1 to 9.77.63.2549.77.63.2554,094
2139.77.64.0/209.77.64.1 to 9.77.79.2549.77.79.2554,094
2149.77.80.0/209.77.80.1 to 9.77.95.2549.77.95.2554,094
2159.77.96.0/209.77.96.1 to 9.77.111.2549.77.111.2554,094
2169.77.112.0/209.77.112.1 to 9.77.127.2549.77.127.2554,094
2179.77.128.0/209.77.128.1 to 9.77.143.2549.77.143.2554,094
2189.77.144.0/209.77.144.1 to 9.77.159.2549.77.159.2554,094
2199.77.160.0/209.77.160.1 to 9.77.175.2549.77.175.2554,094
2209.77.176.0/209.77.176.1 to 9.77.191.2549.77.191.2554,094
2219.77.192.0/209.77.192.1 to 9.77.207.2549.77.207.2554,094
2229.77.208.0/209.77.208.1 to 9.77.223.2549.77.223.2554,094
2239.77.224.0/209.77.224.1 to 9.77.239.2549.77.239.2554,094
2249.77.240.0/209.77.240.1 to 9.77.255.2549.77.255.2554,094
2259.78.0.0/209.78.0.1 to 9.78.15.2549.78.15.2554,094
2269.78.16.0/209.78.16.1 to 9.78.31.2549.78.31.2554,094
2279.78.32.0/209.78.32.1 to 9.78.47.2549.78.47.2554,094
2289.78.48.0/209.78.48.1 to 9.78.63.2549.78.63.2554,094
2299.78.64.0/209.78.64.1 to 9.78.79.2549.78.79.2554,094
2309.78.80.0/209.78.80.1 to 9.78.95.2549.78.95.2554,094
2319.78.96.0/209.78.96.1 to 9.78.111.2549.78.111.2554,094
2329.78.112.0/209.78.112.1 to 9.78.127.2549.78.127.2554,094
2339.78.128.0/209.78.128.1 to 9.78.143.2549.78.143.2554,094
2349.78.144.0/209.78.144.1 to 9.78.159.2549.78.159.2554,094
2359.78.160.0/209.78.160.1 to 9.78.175.2549.78.175.2554,094
2369.78.176.0/209.78.176.1 to 9.78.191.2549.78.191.2554,094
2379.78.192.0/209.78.192.1 to 9.78.207.2549.78.207.2554,094
2389.78.208.0/209.78.208.1 to 9.78.223.2549.78.223.2554,094
2399.78.224.0/209.78.224.1 to 9.78.239.2549.78.239.2554,094
2409.78.240.0/209.78.240.1 to 9.78.255.2549.78.255.2554,094
2419.79.0.0/209.79.0.1 to 9.79.15.2549.79.15.2554,094
2429.79.16.0/209.79.16.1 to 9.79.31.2549.79.31.2554,094
2439.79.32.0/209.79.32.1 to 9.79.47.2549.79.47.2554,094
2449.79.48.0/209.79.48.1 to 9.79.63.2549.79.63.2554,094
2459.79.64.0/209.79.64.1 to 9.79.79.2549.79.79.2554,094
2469.79.80.0/209.79.80.1 to 9.79.95.2549.79.95.2554,094
2479.79.96.0/209.79.96.1 to 9.79.111.2549.79.111.2554,094
2489.79.112.0/209.79.112.1 to 9.79.127.2549.79.127.2554,094
2499.79.128.0/209.79.128.1 to 9.79.143.2549.79.143.2554,094
2509.79.144.0/209.79.144.1 to 9.79.159.2549.79.159.2554,094
2519.79.160.0/209.79.160.1 to 9.79.175.2549.79.175.2554,094
2529.79.176.0/209.79.176.1 to 9.79.191.2549.79.191.2554,094
2539.79.192.0/209.79.192.1 to 9.79.207.2549.79.207.2554,094
2549.79.208.0/209.79.208.1 to 9.79.223.2549.79.223.2554,094
2559.79.224.0/209.79.224.1 to 9.79.239.2549.79.239.2554,094
2569.79.240.0/209.79.240.1 to 9.79.255.2549.79.255.2554,094

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.